Patent Application
20200284148
The invention relates to a positive displacement heat machines. More particularly the invention relates to a positive displacement heat machine for applications such as:
1. U.S. Pat. No. 4,333,424A discloses an Internal combustion engine which has a compressor which compresses air for delivery via a heat exchanger to an expander. The expander receives the compressed air and fuel and, while combustion occurs during a power stroke, the air pressure is reduced to atmosphere and the expander drives a crankshaft. The fuel is injected at a rate to maintain the air temperature at the entry temperature. The exhaust passes through the heat exchanger to heat the incoming flow of compressed air to the expander. Energy may be stored via the crankshaft or used directly (The description recites: “The compressor 40 has two stages 43, 44 with an intercooler 45 there between.”, “ . . . the compression is assumed to take place isothermally . . . ”; “ . . . . Both the large crankshaft and the large flywheel can also be eliminated by using the expander to drive a hydraulic pump which in turn drives a small hydraulic motor connected to a small crankshaft and flywheel rotating in unison at high speed . . . . This crankshaft also drives a high speed compressor as well as the load.”).
Problems of U.S. Pat. No. 4,333,424A
Thermodynamic cycle of this engine give the same large efficiency as cycle Carnot, if compressor is isothermal; efficiency no depend from compression ratio. Mentioned two stages compressor with intercooler may approximate the isothermal compression, but cause addition vortex and friction loss. If compression ratio is small, for example, kp=2, a single stage compression is near isothermal, but the small kp cause large size cylinders of compressor and expander and so large loss caused by transfer energy between compressor and expander with crankshafts or hydraulic means, Any case, this engine have a small ratio power/volume and so large weight and inertial forces, that make it very sensitive to friction loss in crankshaft bearings and to vortex loss. For this and another prior art with crankshaft, regulation to a small rotation moment (load) diminish efficiency, so as part of friction loss, caused by inertial forces, no depend from the load; regulation to a small rotation speed with gear increase friction loss, and regulation with hydraulic means cause vortex loss.
2. U.S. Pat. No. 4,369,623, discloses an engine with positive displacement piston chambers, an external combustion chamber from which combustion gases pass . . . to piston chambers, an air compressor, a heat exchanger where exhaust gases from the piston chambers preheat compressed air which then flows to the combustion chamber, and an accumulator for storing . . . compressing air from the compressor . . . . (The description recites: “
Problems in U.S. Pat. No. 4,369,623
Friction loss, caused by transfer energy with crankshaft. Regulation by compression “during about each fifth stroke” cause pulsation of pressure in the combustion chamber and so diminish efficiency. For this and another mentioned below prior art with crankshaft, regulation to a small rotation speed increase thermal loss to wall of cylinder and to piston.
3. U.S. Pat. No. 7,281,383 discloses a four stroke Brayton refrigerator or heat engine which is a thermal machine that can function as either a refrigerator or an external combustion heat engine . . . Bravton cycle . . . adiabatic compression and adiabatic expansion, take place in the same cylinder, within which a piston, driven by a crankshaft, reciprocates. The remaining two processes, each of which is a transfer of heat at constant pressure, take place in a high pressure heat exchanger and a low pressure heat exchanger. A rotary valve . . . creates passages between the cylinder and the heat exchangers, and is constructed so that compression and expansion ratios are equal.” From description: “ . . . conditioner according to a basic embodiment (Tc=16 C, Th=32 C, nitrogen refrigerant, P(low)==23 bar) gives cycle C.O.P.=8.03.”; “Th=Temperature at the outlet of heat exchanger H, . . . Tc=Temperature at the outlet of heat exchanger L”.
(“L” to cool a room air, “H” to cool compressed air. No examples for temperatures at inputs of the heat exchangers.)
Problems in U.S. Pat. No. 7,281,383 B2
For good efficiency, compression and expansion ratios must be equal; the rotary valve, constructed for it, cause a vortex loss. For engine, volume after expansion is more, than before compression, for heat pump—vice versa, so both cases, part of the cylinder volume is not used, that increase friction loss in crankshaft bearings. Part of piston stroke is used for displacing compressed gas between the cylinder and heat exchanger “H”, that increase loss in piston sealing and crankshaft bearings; near a dead point, no any useful process, but crankshaft bearings rotating under maximum pressure that cause addition friction loss. During begin output to “H” and end input from “H”, surfaces of openings are small, so velocity of gas is large that cause addition vortex loss. Large velocity current of hot gas during input increase loss of heat to surface of the cylinder. Due to parasite volume of the cylinder, part of compressed gas no make useful work. This part, mixing with a hot input gas, diminishes maximum temperature of a cycle, so diminish efficiency and power. If volumetric compression is 10 and the parasite volume is 1% of maximum volume of WC, 10% of gas no work.
A problem of any heat machine is: when Energy of Compression (EC) is close to Energy of Expansion (EE), the heat machine is very sensitive to loss during compression and expansion, so to the vortex and friction loss. Suppose, that conditioner work with open Brayton adiabatic cycle and get air from a room with Tbc=27° C.=300° K; This air is compressed to Tec=317° K, so kt=1.057, then cooled in heat exchanger “H” to Tbe=305° K, then expanded in the cylinder to Tee=Tbe/kt=289° K, then mixed with a room air. If no loss, COP=289/(305−289)=18. Compression and expansion are between the same pressures, so EC/EE=Vbc/Vee=Tbc/Tee=1.038. If EE=100 J, EC=103.8 J, no loss: MW=EC−EE=3.8 J. If efficiency of compression and expansion is 0.97: MW=103.8/0.97−100*0.97=10 J. So, really COP=18*3.8/10=6.8<<18, even with ideal heat exchanger. In the prior art with preferable closed system, C.O.P. is good due to large Pbc=“P(low)===23 bar”, so, mechanical efficiency and volumetric power of cylinder are better, then for the open system. But, the closed system have disadvantages comparing to the open system: large sizes and cost of heat exchangers; heat exchanger “L” is a source of infection, collected on a large wet surface; temperature at input of “L” is smaller, then Tee in open system, that diminish COP; temperature Tc at output of “L” is smaller, then Tbc, that diminish heat power, EC/EE is closer to 1 and the system is more sensitive to loss during compression and expansion; possible leak. The vapor compression refrigerators, that are in common use, include the same problems. Open system no have this problems, but friction loss in bearings of crankshaft and piston rings, vortex loss in the rotary valve, make the open system no practical for conditioner. So, the problems are vortex and friction loss, and in addition for closed system: possible leak, diminish COP and possible infection, larger cost and size, caused by heat exchanger “L”.
4. U.S. Pat. No. 8,360,759 Discloses a Rotary Engine Flow Conduit Apparatus and Method . . . .
It describes an Internal Combustion Engine (ICE) with vanes, moving in slots of eccentric rotor, with using slots to displace air between atmosphere and working chambers, that are between vanes, rotor and housing.
Problems in U.S. Pat. No. 8,360,759B2:
Friction loss by vanes, vortex loss inside slots, a short time for combustion—a common problem for Internal Combustion Engines. large loss of heat to surfaces of WC—a common problem for rotor engines.
5. US20070199299A1 discloses a combustion engine that has at least a plurality of power strokes during a complete cycle . . . piston—cylinder arrangement is used to compress air and deliver it to a combustion chamber . . . ” (From description: “ . . . two . . . eight or even more power strokes . . . ”; “[0021] Valve control . . . to optimize compression, combustion, expansion and exhaust during engine operation”; “Piston displacement is translated by a connecting rod linking it to a crankshaft into rotary power engine output”).
Gist: the same cylinder with several working strokes for single compression stroke; or mixing, with several cylinders, one
only for working strokes [0025]; transfer energy by crankshaft.
Problems in US20070199299A1 are the same that mentioned above for [2] U.S. Pat. No. 4,369,623.
6. DE102009049974 discloses a heat engine device for converting heat into mechanical work that has two stroke piston engines with one or multiple cylinders and crank shaft. It comprises “ . . . a two stroke piston engine with one or multiple cylinders and a crank shaft. A cool working gas is supplied into an area over a piston . . . compressed during the piston movement . . . pushed in an external heater . . . .”
Problems in DE102009049974 A1: About increased friction, vortex and thermal loss in prior art EHE during displacing compressed gas, see explain to prior art 3.
7. WO1998057038 discloses a Multi vane rotary piston engine, in which the compressed air is introduced in the combustion space through outlets on the side covers, while the exhaust gases are introduced, through outlets on the side covers, . . . .”
Problems in WO1998057038 A1: the vanes are moving inside slots under pressure force, that cause friction loss. The outlets are in side covers, so with increasing length of the rotary piston engine, increasing vortex loss. Optimal Vee/Vbc is only for a single working mode, else part of expansion energy will be lost.
8. WO2011046975 discloses a hydraulic internal combustion engine with “ . . . at least one combustion piston . . . acting on hydraulic plungers through valving to control the piston position and velocity . . . ”. It is a free piston engine with Pulse Pause Modulation (PPM).
Problems in WO2011046975 A1: Hydraulic valves, used for the PPM and another purposes, cause addition vortex loss. A short time for combustion, is a common problem for ICE, and it is very short for the free piston engine, that may cause dirty “Output products” (see GLOSSARY . . . ). Partly loss of expansion energy that is a common problem for prior art machines with the same working chamber for compression and expansion of all working fluid.
9. Peter A. J. . . . “Horsepower with brains: The design of the CHIRON Free Piston Engine” (Society of Automotive Engineers, Inc., January 2000) discloses a free piston engine with PPM, with the same problems, as for prior art 8.
Loss of efficiency at partly power. Partly loss of expansion energy. Friction loss in bearings of crankshaft, by piston rings, by vanes. Vortex loss in valves and cylinder. In ICE, short time for combustion. Loss of heat to surfaces of WC. In EHE, parasite volume of the WC, and addition (comparing to ICE) friction, vortex, and thermal loss.
Description of this problems see above and solving by this invention see below.
It is therefore an object of the present invention to provide a method of operating a Positive Displacement Heat Machine, which overcomes the drawbacks of prior art.
Other objects and advantages of this invention will become apparent as the description proceeds.
A method of operating a Positive Displacement Heat Machine (PDHM), the PDHM provided with at least a single Working Chamber (WC), arranged to change its volume during at least a part of a thermodynamic cycle and to transfer mechanical energy to/from a compressible Working Fluid (WF); the thermodynamic cycle including compression and expansion entailing Lower Pressure (LP) of the WF; the thermodynamic cycle further including Higher Pressure (HP), HP>LP; the thermodynamic cycle also including a Lowest Temperature (LT) of the WF; the thermodynamic cycle further including a High Temperature (HT), HT>LT; the PDHM is further provided with at least a single Low Pressure Chamber (LPC, 40), containing the WF with the LP; the LPC may be the atmosphere, otherwise the LPC is provided with means, arranged for thermal transfer between the LPC and an external medium; the LPC is provided with an LPC Input Part (LPCIP) for the WF and an LPC Output Part (LPCOP) for the WF with changed temperature; at least a single Low Pressure Input Mean (WCLPIM, 20) is provided between the WC and the LPCOP, and at least a single Low Pressure Output Mean (WCLPOM, 21) is provided between the WC and LPCIP, both arranged as controllable openings; the PDHM providing with at least a single High Pressure Chamber (HPC, 8), that contains the WF with the pressure HP; if the PDHM is the heat pump, the HPC 8 arranged for cooling the WF by heat transfer to external medium; at least a single High Pressure Controllable Opening (WCHPCO, 18) is provided between the WC and HPC; the thermodynamic cycle comprising:
during step 1.5, after ending compression in the WC, and when pressure in the WC is close to pressure in the HPC 8, opening the WCHPCO 18 and displacing at least a part of the WF between the WC and HPC 8, such that displacement of the part is not caused by changing the volume of the WC.
A two stroke reciprocating piston engine apparatus, comprising:
a) at least single thermally isolated High Pressure Chamber (HPC) 8 with Working Fluid (WF) compressed to High Pressure (HP), volume of the HPC 8 is sufficiency more, than end compression volume Vec;
b) at least single Cylinder 15 with two Assemblies 16, each Assembly includes:
b.1) two Crankshafts having minimal Inertial Moment, each Crankshaft is not connected to external load;
b.2) a Piston, connected to a central part of a Beam;
b.3) a Buffer 51, connected to central part of the Beam opposite to the Piston, for accumulating Energy from Expansion (EE) of WF (gas) during working stroke of the Piston, and return the EE during compression stroke as Energy for Compression (EC), while EE and EC are approximately the same, EE=EC;
b.4) two connecting rods, one side of every connecting rod connected with bearing to a tip of the Beam, and another side with another bearing connected to corresponding Crankshaft being connecting to a synchronization gear; the crankshafts are arranged to rotate to opposite directions due to the gears; at least one of the crankshafts with addition gear and synchronization Belt connected to corresponding crankshaft of another the Assembly;
c) the two Assemblies 16, are arranged such, that:
c.1) symmetrically moving each of the two Pistons inside the Cylinder 15 between High Pressure Dead Point (HPDP), that is near a central part of Cylinder 15, and a Low Pressure Dead Point(LPDP), that is near a tip of Cylinder 15, so in Cylinder 15 there are two the HPDPs and two the LPDPs;
c.2) symmetrically moving all parts, such that inertial forces are balanced;
c.3) symmetrically loading all parts by gas forces, such that there are no forces between the pistons and Cylinder 15;
c.4) volume (Vmin) between the two HPDP is equivalent or smaller than the Vec, such that the pistons are not displacing all compressed WF to the HPC 8, thereby diminishing moving pistons under the HP;
c.5) Assemblies 16 and all rotating means in it or connected to it, including the Belt, have a minimum Inertial Moment, limited only by mechanical strength, but the Reciprocating Parts in the Assemblies 16 may have a large mass, thereby diminishing dynamic load on the bearings;
d) a Working Chamber High Pressure Controllable Opening (WCHPCO) 18 in the central part of Cylinder 15, between two the HPDP, the WCHPCO 18 arranged to control a flow of WF between the Cylinder 15 and HPC 8, such that:
d.1) the flow begins after ending compression and when the pressure in Cylinder 15 is approximately equivalent to the HP;
d.2) the flow ends when volume in the Cylinder 15 is increased to Vbe, and Vbe is equivalent or more than the Vec;
e) a fuel Injector 25A between two the HPDP, remote from the WCHPCO 18; the Injector 25A arranged for combustion after end compression, such that:
e.1) after opening the WCHPCO 18, displacing at least a part of compressed WF to the HPC 8 due to heat expansion of combusted product, thereby diminishing moving of the Piston under the HP;
e.2) minimum mixing between the displacing part and the combusted product;
e.3) preferably ending combustion before expanding to the Vbe;
f) a sensor HPCIMTS 27, arranged to measure temperature T27 of the WF in the HPC 8 after the WCHPCO 18;
g) a Remote Expander 19, arranged as power output of the engine, without transferring energy from, or to, Assembling 16, with expansion from the HP to Atmospheric pressure;
h) at least a single Electrical Machine 22, mechanically connected to any of the Crankshafts, for receiving energy, for providing energy, arranged to control rotation of the Crankshafts, the power of the Machine 22 is sufficiency smaller, than the power of the Expander 19;
i) a Rotating Speed and position Sensor (RSS) 31, mechanically connected to the Electrical Machine 22 or to the Crankshaft;
j) a pressure sensor HPCPS 32, arranged to measuring differential pressure between HPC 8 and Atmosphere;
k) a Controller 29, arranged to:
k.1) control the WCHPCO 18 and Injector 25A, such that EE=EC, with using feedback from the RSS 31;
k.2) control the WCHPCO 18 and Injector 25A, such that if need fast changing of mean speed of the Crankshaft, EE>EC, or EE<EC according to desired changing;
k.3) control the Electrical Machine 22, such that kinetic energy of the Assembling 16 at position according to at least one of the HPDP or LPDP, will be desired volume, including zero, with using for this control feedback from the RSS 31;
k.4) if the speed of the Crankshaft near at least one of the HPDP or LPDP is near zero, optionally fixating the Assembling 16 during desired Fixation Time, using the Electrical Machine 22 for this fixation;
k.5) initiating moving of the Crankshaft with the Electrical Machine 22;
k.6) synchronization the mean cycle speed of Assembling 16 with throughput of the Expander 19, such that the pressure HP in the HPC 8, measured by the HPCPS 32, will be as desired;
k.7) controlling the Injector 25A and WCHPCO 18 for minimum mixing, mentioned in e.2, with using signal from the RSS 31 and HPCIMTS 27; for optimal case, T27 is not sufficiency more, than temperature at end compression Tec;
k.8) controlling the Injector 25A and WCHPCO 18, such that pressure at the end, expansion will be not substantially more than Atmospheric pressure;
l) at least a single Fuel Injector 25B, preferably inside the HPC 8, and optionally in Expander 19.
In heat machine (see explain to prior art 3) take place compression process that get energy EC, and expansion process that give energy EE. Efficiency of compressor Efc<1, expander Efe<1. For engine, EE>EC, for heat pump, EE<EC. Mechanical Work from engine or input work for heat pump is: MW=EE*Efe−EC/Efc. For heat pump MW<0.
Main principle (gist) of the present invention is to make Efc, Efe close to 1, by another words, diminishing the loss, caused by circulation energy inside heat machine.
Combination of principles, explained below, give the best result. In most embodiments used all principles.
Gist: Displacing at Least a Part of the WF Between Said WC and HPC, without Changing Volume of the WC.
The gist includes scavenging between the WC and HPC, and combustion at least a part of fuel outside the WC.
Are embodiments with combustion a part of fuel inside the WC, so pushing any part of WF to the HPC.
Gist: In the “Multi Vane Rotary Machine”, Scavenging Compressed WF Between the WC and HPC.
Advantages:
No loss of efficiency at partly power. No loss of expansion energy. Smaller friction loss in bearings of crankshaft, by piston rings, by vanes. Smaller vortex loss in valves and cylinder. In ICE, regulated time for combustion. Smaller loss of heat to surfaces of WC. In EHE, no parasite volume of the WC, and no addition friction, vortex, and thermal loss.
“Adiabatic process” takes place when no heat transfers. Parameters of adiabatic process:
Expansion: W=(Pbe*Vbe−Pee*Vee)/(ka−1)=Pbe*Vbe/(ka−1)*(1−1/kt)>0;
Compression: W=−(Pec*Vec−Pbc*Vbc)/(ka−1)=−Pec*Vec/(ka−1)*(1−1/kt)<0;
EE=W+W(input to expander)−W(work against atmospheric pressure).
CE=W(input to compressor)−W(output from compressor)−W.
“Brayton adiabatic cycle” consist adiabatic compression and expansion and constant pressure heating and cooling. Engine efficiency: Efa=(Tec−Tbc)/Tec. Heat pump, if cooling: COP=Tee/(Tbe−Tee).
“Blower” (9) implies a separate design or set of parts, arranged to displace the WF inside the heat machine, if for this displacing need a small difference of pressure.
“Components of air” are N2, O2, CO2, H2O, etc. as they are in a normal air with appropriate concentrations.
“Clear output” implies Output products of engine with CO2 and H2O or only H2O, with concentrations of the dirty output products below than appropriate standard.
“Coefficient of Performance” (see “COP”, “Heat Pump”), this term is used for Heat Pump.
“COP”=Thermal Energy (TE)/Mechanical Work (MW). TE transferred between “cool” and “heat” objects.
“Compressor of inertial type” converts mechanical energy to pressure and kinetic energy of the WF.
“Compressor of positive displacement type” converts mechanical energy to pressure energy of the WF.
“Controllable Opening”: “Controllable” imply any type of control, including, for example, changing position of any mean relatively to the opening; piston may close and open a scavenging window, a valve driver may close or open a valve, the valve may be any type.
“Cylinder” is positive—displacement working chamber in general, not restricted to circular cross-section.
“Dirty output products” are output products of engine, except components of air.
“Efficiency” of the heat engine is Mechanical Work (MW)/Thermal Energy (TE).
“Expander of inertial type” is a Turbine, using compressible WF.
“Expander of positive displacement type”—see “Positive displacement”.
“External heating engine”, have the WC where take place near adiabatic thermodynamic processes. Heat is transferred to external volume that may be a heat exchanger or external combustion chamber.
“Heat machine” convert a part of Thermal Energy (TE) to Mechanical Work (MW) or vice versa (see “Heat pump”).
“Heat pump” uses MW to move TE opposite to spontaneous heat flow; may work as cooler or heater.
“Internal heating engine” (IHE), for example a spark ignition or Diesel type, have a working chamber (WC), for example a space bounded by a piston and a cylinder, where take place thermodynamic processes, including combustion of a fuel inside compressed air.
“Inertial Scavenging” (ISC), see “Scavenging”. Initiating moving a part of a WF from and (or) to WC and continue this moving due to kinetic energy of the WF and, in addition, due to kinetic energy of any mean, if it designed for ISC.
“Local minimum” of a velocity, V1 min, defined there according: V1>V1 min<V2, where V1, V1 min, V2 are velocity points inside any part of cycle at appropriate time points t1<t1 min<t2 with minimum detectable differences V1−V1 min and V2−V1 min. Local minimum of piston speed=0 at ‘dead points’ (crankshaft angles 0° and 180°), and it is absolute minimum as well. The crankshaft rotation speed may have a local minimum after end compression.
“Main shaft”, means the shaft which converts reciprocating piston motion into rotary motion or vice versa.
There, term “crankshaft” means the shaft which converts reciprocating piston motion into rotary motion or vice versa, but “main shaft” means the shaft which converts any motion into rotary motion or vice versa. For example, in “Vankel” engine, planetary motion converted to rotation by main shaft. So, the “main shaft” is wider definition than “crankshaft”.
“Output products” are CO2, H2O, CO, NxOy (for example, NO), etc., depended upon the fuel type and the combustion quality. After ideal combustion of good fuels, output products are CO2 and H2O, or only H2O if Hydrogen (H2) is used.
Dissociation of N2 and O2 begin approximately above 2000° K and increase concentration of NxOy in output products.
Combustion temperature in prior art ICE is more than 2000° K and is sufficiency more in local volumes if bad mixing.
After cooling, not all NxOy is decomposed to N2 and O2. So, NxOy in output may be with using every type of fuel.
“Positive displacement”, according to IPC (International Patent Classification), means the way the energy of the WF is transformed into mechanical energy, in which variations of volume created by the WF in the WC produce equivalent displacements of the mechanical member transmitting the energy, the dynamic effect of the WF current being of minor importance.
“Pump”, according to IPC, means a device for raising, forcing, compressing, or exhausting fluid by mechanical or other means. “Pump” includes fans or blowers.
“Scavenging”, according to IPC, means forcing the combustion residues from the cylinders other than by movement of the working pistons, and thus includes tuned exhaust systems. There, term “scavenging” is used not only for the combustion residues and exhaust, and imply displacing at least a part of the WF from the WC and displacing another part of the WF to the WC by any way, that cause essentially more displacing than according to changing volume of the WC during this displacing process, including a case with constant volume of the WC or even changing this volume against direction of this displacing. See above “Inertial Scavenging”, ISC.
“Sterling cycle”, in ideal, includes constant volume heat transfer in regenerator, isothermal compression and expansion, constant volume heating and cooling.
“Turbine” converts kinetic energy of the WF to mechanical energy.
“Working fluid” (WF), according to IPC, means the driven fluid in a pump and the driving fluid in an engine. The WF may be in a gaseous state, i.e., compressible, or liquid. In the former case coexistence of two states is possible. There, term “working fluid” used as well for heat pump. During working cycle in engine or heat pump, the WF may be converted from gaseous to liquid state or vice versa.
The referenced numbers are from drawings; see section “Numbers of parts for all drawings”.
Buffer (51), a mean that combine functions of Energy Receiver (ER) and Energy Source (ES), see ER, ES. Preferable a gas buffer.
ECM—Energy Conversion Means, arranging to work with at least a part of the WF, used in a thermodynamic cycle of the heat machine, with converting energy of compressed WF to mechanical work, and reverse converting, with conversion algebraic sum of compression and expansion energy to a work, named Zwork; supposing, that expansion work is positive, and compression negative, Zwork<0 is according to receiving external work, Zwork>0 is according to producing output work; all parts, that need to make the Zwork, named Zmachine.
Parameters of Heat Machines
NUMBERS OF PARTS FOR ALL DRAWINGS
Parameters are examples by computer simulations. Parts according to NUMBERS OF PARTS FOR ALL DRAWINGS.
With reference to
The counter flow heat exchanger 10 transferring heat from air with parameters Pec, Tec to water, that is with atmospheric pressure (0.1 MPa) inside tubes. Hot water may be used, or cooled by atmospheric air in external heat exchanger. Every WC formed by surfaces of neighboring vanes 3, parts of surfaces of the side walls 14, a part of surface of the body 1, and a part of surface of the rotor 2. During rotation of the rotor 2, volume (Vwc) of every WC is changing between Vmin and Vmax, kv=<Vmax/Vmin. A space, where the Vwc is diminished to Vmin, named a High Pressure Space (HPS); a space, where the Vwc is increased to theVmax, named a Low Pressure Space (LPS). Prefer a small as possible gap between tip of separator 5 and rotor 2. For example, if swing of oscillation of Separator 5 is 15 mm, may be: 0<gap<0.3 mm, even larger gap is not critical. Synchronization gear between rotor 2 and driver 6 is not shown. Shape of rotor 2 is according to oscillation of separator 5 and caused by design of driver 6.
WORKING CYCLE include scavenging by blower 9 at LPS, so output cool air with parameters LP=Pee, Tee, is displacing by room air with Pbc=LP, Tbc. During moving WC from LPS to HPS, take place compression to HP=Pec, Tec. Then scavenging in HPS between the WC and HPC 8, so air with Pec, Tec, is displacing by air with Pbe=HP, Tbe. During moving WC from HPS to LPS, take place expansion to Pee, Tee. Length of scavenging windows 11, 12 is according to length L of body 1, so L may be large (see example below). In the prior art, all windows are inside side walls, so L limited by speed of air during scavenging.
So, the main principle is: displacing the WF between WC(HPS) and HPC 8, with very small changing volume of the WC.
Scavenging across WC by a blower (Separator 5); the blower is based on the positive displacement principle.
Below Example According Computer Calculations for this Home Conditioner.
Rotation speed Wr=63 rad/s, length of body L=1 m (this large L is practically impossible for the prior art), internal radius of body 1, Rb=72 mm, throughput V=0.045 m3/s, kv=1.358, kp=1.535, kt=1.13; Pbc=0.1 MPa, Pec=0.1535 MPa, Tbc=300° K, Tec=339° K, Tbe=3080K=35° C., Tee=273° K=0° C. COP=Tee/(Tbe-Tee)=7.8 (if no loss). Density of Air at 0° C. is 1.27 kg/m3. Power: Pcool=(Tbc-Tee)° K.*1000 J/kg/° K.*1.27 kg/m3*0.045 m3/s=1549 W; mechanical power: Pmech=Pcool/COP=199 W, it is power that need for Air compressor 7 if no loss. In assembling, that include body 1, rotor 2 and vanes 3, compression and expansion energy are the same (EC−EE=Zero); if no loss, it no send and no get mechanical energy and so named Zmachine (see GLOSSARY . . . ). It get from a room V=0.045 m3/s with Tbc (see above WORKING CYCLE) and send to the room the same V, but with Tee. To keep BALANCE OF AIR MASSE, throughput from air compressor 7 is: V7=V*Tbc/Tee−V=0.00945 m3/s. May to place it out of the room, and connect input to external air. If dT between external hot air and the room air is 5° K, ventilation by V7 add to the room heat power 54 W.
Example for Cooling Power for a Room 20 m2:
Thermal transfer coefficient x=8 W/M2/° K; surface for thermal transfer S=90 m2; mean dT between room air and walls 2.5° K; cooling power=8*90*2.5=1800 W. Calculated above Pcool=1549 W is for Wr=63 rad/s. May increase Wr to 16% and get Pcool=1800 W.
Below are Calculations for Loss (“A”−“G”), in “G”, Calculated that Increasing Wr to 16% May Diminish COP to 2%.
A. For compressor 7, with output power 199 W, suppose loss7=20 W.
B. If air speed during scavenging is 9 m/s (twice more than linear speed of rotor 2), and volume V=0.045 m3/s loss all kinetic energy 4 times during cycle, vortex loss is: loss V=9 W.
C. Sizes of Capron vane 3 is (1*8*1000) mm3. For 6 vanes and Wr=63 rad/s, inertial force on surface of body 1, is: Pw=16N. If friction coefficient kfr=0.2, sliding of vanes along surface of body 1 cause loss Pw=14.5 Watt.
D. Pressure in slot 4 is maximum between pressures from a left and right sides of vane 3, and it is Pec. According to computer simulation, mean difference of pressures that press vane to body, is: dp12 m=0.33*(Pec-Pbc)=1.8N/cm2. Suppose that dp12 m placed on ½ from vane width, so on 0.5 mm, and pressure forces on the rest part are compensated. So mean radial pressure force from all vanes is 54 N, and for mentioned kfr and Wr, it cause loss Pfr=49 W.
E_. Load from pressure force (for version at
F. Pressure force PN, normal to side surface of vane 3, cause friction force X, directed along radius. When vane 3 is moving from slot 4, force SF, pressing vane 3 to body 1, is: SF=PI−X, where PI is sum of pressure and inertial forces along radius. Must PI>X, else vane 3 cannot move from slot 4. When vane 3 is moving to slot 4, SF=PI+X. So, mean SF=PI, and force X cannot cause addition loss caused by sliding vane 3 along body 1. But, friction between vane 3 and surface of slot 4 cause loss: lossX=PN*FRN*S*Wr/6.3, where S is sliding distance, for this example S=8 mm per revolution; FRN is friction coefficient, suppose it is 0.1. So, loss caused by friction between slots and vanes: lossX=3.6 W.
G. With loss, mechanical power (see A-F) is: 199+20+9+14.5+49+2.3+3.6=297 Watt; COP_real=1549/297=5.22.
It is true for car conditioner, connected directly to engine. If compressor 7 work from electrical motor, and addition motor is connected to Zmachine to compensate loss, both motors with efficiency 0.9, COPe=5.22*0.9=4.69. For car, electrical energy produced by generator with efficiency 0.9 (the best case), so COPee=4.69*0.9=4.22. Separated HP scavenging window 12 (
If increase Wr to 16%, Pcool*1.16=1800 W (see Example for cooling power for a room 20 m2), but loss increase.
Are loss, proportional to Wr2 or to Wr3. So, 1.162=1.35, and 1.163=1.56. For this case, mechanical power for Wr*1.16, is:
199*1.16+20*1.16+9*1.35+14.5*1.56+49*1.16+2.3*1.16+3.6*1.16=353;
COPw=1800/353=5.1. So, when Wr increased to 16%, COP diminished to 2%, that mostly caused by loss from inertial force, proportional to Wr3. With reference to
With reference to
For the prior art (
According to “F”, lossX=3.6 W, but for the prior art, 3.6*3*3=32 W, so as 3 times more PN and 3 times more S. Note, that lossX calculated for friction coefficient FRN=0.1. Larger FRN is problematic for the prior art.
The rotating ring restrict version with no-load rotor 2, that is important for large power, see above explain to
The rotating ring restrict possibility for current of gas across windows in body 1, and are possible only windows in side walls 14. So length of body is very small (or must small Wr), else vortex loss is too large.
Without the rotating ring, the prior art practically cannot work so as large friction loss. With the rotating ring, must be only a small length of body or small Wr.
To keep BALANCE OF AIR MASSE (see above), relation between volumes of hot and cool gas must be according to Tbc/Tee, but Tbc and Tee are not constant. In the prior art, this relation caused by “hard” design, that cause loss of COP and sound noise if Tbc/Tee is not optimal. In the invention, this problem is solved by regulation of compressor 7. Another advantage of invention is that compressor 7 is small (V7=0.00945 m3/s). Zmachine with V=0.045 m3/s is placed in the cooling room, but compressor 7, that get main power, may be directly connected to engine of car, to wind turbine, etc.,
and placed out of room—see above example with “recommended ventilation rate . . . .”
With reference to
In the cylinder take place a thermodynamic cycle with summed compression and expansion work may be near zero (Zwork=0, see GLOSSARY . . . ), so it is Zmachine that generates compressed gas to make mechanical work by the expander. Displacing a part of the WF from the WC to HPC due to diminishing volume of the WC and due to combustion in it, with Pulse Pause Modulation (PPM) in Zmachine. Due to PPM, time for combustion is optimal and not caused by mean rotation speed, so, efficiency of the engine and quality of combustion is maximal for every working mode. Engine of a car most time is working at a partly load, and for prior art, mean efficiency may be twice smaller than optimal. Remote expanders may be connected directly to wheels. Due to PPM, throughput of Zmachine is according to demand of the expanders. For maximum power, it is possible combustion in HPC and in expanders.
The embodiment at
Assembling 16 include the piston, beam, buffer 51, connecting rods, crankshafts, bearings, and synchronization gears 17 with belt. All these parts are referenced as 16, see in addition
Working cycle include scavenging in cylinder 15 by blower 9 across at least a single valve WCLPIM 20 and WCLPOM 21, but prefer using several valves to diminish vortex and thermal loss; in addition, for this purposes, head of piston 16 have a streamlined shape. Below see more after “scavenging.” After end compression in cylinder 15, begin opening WCHPCO 18, and compressed air, during output time Tout (
Opening WCHPCO 18 begin by driver 30 when differential pressure dPx from sensor 28 is near zero. Appropriate value dPx is defining with controller 29 by feedback to avoid a fast jump of dPx. Inside interval Tout (
After closing WCHPCO 18 and end combustion, begin expansion, at this point volume of cylinder 15 is Vbe. If Vec=Vbe, and no combustion during expansion, and no loss, summed work of cycle is zero (Zwork=0), and all output work is from expander 19.
Possible mode “d”, with end combustion after closing WCHPCO 18, or mode “e”, with Vbe>Vec, or mode “f” with combination “d” and “e”, this causes Zwork>0 and may be Pec>LP. According to parameters in “Explain to Table_Z1” (see below), may calculate, that if dP=Pee−LP=0.01 MPa, it cause loss 0.4 J, while useful work is at least 635 J.
A small Zwork may compensate friction loss, may be used by electrical machine 22 and stored in electrical accumulator (no shown). According to working mode of electrical machine 22, mean speed of crankshaft 16 may be changed. At end expansion in cylinder 15, must open valves 21, then 20. As mentioned, scavenging may be initiated by blower 9. During scavenging, piston 16 may stay any controlled time (see below EXPLAIN FOR PPM), that cause a good scavenging with a small power of blower 9. If Pee>LP, may use ISC (see GLOSSARY . . . ). To begin scavenging, at end expansion stroke, with using signal from Rotating Speed and position Sensor (RSS) 31, controller 29 with one of drivers 30 (not shown) open valve 21. Due to long tube with diffuser, energy of over pressure (Pee>LP), is converted to kinetic energy of moving gas. When according to signal from sensor 33, pressure in cylinder 15 is near Atmospheric pressure, another driver 30 (not shown) open valve 20 and take place ISC. For mentioned parameters in “Explain to Table_Z1”, dP=0.01 MPa cause beginning scavenging speed: (2*dP/density)0.5=200 m/s, that is good to initiate ISC even for maximum power.
Version “g”:
Selecting the Volumetric Compression Ratio (VCR) such that Pec<HP, then performing combustion in approximately constant volume Vec, and when the pressure in the WC increases to HP or exceeds HP, according to the dPx, opening WCHPCO 18. A small part of fuel, prefer Hydrogen, injected before end compression, and combustion may be initiated by spark (a sparker and injector not shown). Version “g” cause preheating for good and fast combustion of fuel from Injector 25A. For minimum power, used only Injector 25A.
Displacing the “Removing Part” May be, for Example, According to the Following Several Versions:
Version a.
Selecting the Vec to be approximately equivalent to Vmin, and displacing the “removing part” mostly by heat expansion of the “heating part”, whereby will be near zero moving of piston 16 under pressure HP, and so minimum friction loss. Version ‘a’ cause partly mixing between the “heating” and “removing” parts, so T27>Tec. Vmin is a construction parameter. Vec is according to begin opening WCHPCO 18 that cause regulation of VCR. Volumetric Expansion Ratio (VER) in cylinder 15, caused by Vbe, that is according to end closing WCHPCO 18 if then there is no combustion. If after closing WCHPCO 18 there no combustion, preferably Vbe will be slightly above Vec (Vbe>=Vec for example, Vbe=1.1*Vec).
Version b.
Selecting Vec>Vmin, and displacing the WF mostly by moving piston 16, performing combustion mostly when WCHPCO 18 is closed, so T27 is near Tec=Tbc*VCR(ka-1), ka=1.4. T27=Tec cause the best using of regenerator 23, minimum heat loss in HPC 8 and the widest regulation of cycle power: minimum power with temperature Tec inside HPC 8, and maximum power with using Injectors 25(B, C, D), as explained above. Version b cause more friction loss, than Version a.
Version c.
Compromises between Versions “a” and “b”, with Vec>Vmin and begin combustion before closing WCHPCO 18.
Version h.
Combination of the following three processes:
So as Table_Z1 used only to compare parameters, supposed, that no loss of heat to walls of WC and expander. If calculate this loss according to empiric formula for ICE (from many versions, selected not too optimistic and not too pessimistic), efficiency (Ef) diminish to (1.5-2.5)%. Comparing to prior art ICE, this small drop of Ef caused by mentioned smaller time for heat transfer, smaller temperature of gas, larger temperature of walls and using 2 pistons in the same cylinder—see SUMMARY OF THE INVENTION . . . This empiric formula is for large vortex, that need for better combustion, but increase thermal loss, while in this invention, vortex is smaller and so smaller thermal loss. The formula is: X=(1+1.24*pvm)*(T*P2*10−10)0.33, where X—thermal transfer coefficient, pvm—piston mean velocity.
In Table_Z1, “Ef” includes viscosity loss in regenerator, vortex and friction loss. For example, in string 6, Ef=63.0%, but without this loss, Ef=63.5%; this small distinction due to roller bearings (that is problematic for prior art, see below Regulation near HPDP) and a small moving of piston under maximum P (large moving in prior art, up to Virtual zero Volume,
Working mode is according “Version c” (see above). Zwork=0, adiabatic expansion in WC (cylinder 15), partly isothermal expansion in expander 19. kv=12, kt=2.7, Pbc=0.1 MPa, Pec=3.24 MPa, Tbc=300° K, Tec=806° K, Vbc=Vee=1090 cm3, Vec=Vbe=91 cm3, Vmin=45 cm3, Tmax=1700° K, Tee=634° K. During closing WCHPCO 18, near Vmin, begin combustion in WC with using Injector 25A. Supposed combustion with constant P=Pec, with expansion to Vbe due to appropriate work of Injector 25A. WCHPCO 18 may be open during this combustion and mistakes compensated by any small current of WF across WCHPCO 18. End combustion and closing WCHPCO 18 at Vbe=Vec, Tmax, so P=Pee=Pbc, Zwork=0. Mass of input air (in Vbc) is 1.32 g, from it 0.63 g with Pec, Tec is sent to HPC 8. Inside HPC 8, THPC=1500° K>Tec, so as before input to expander 19, take place heating in regenerator 23 (between hot and cool gas, dTr=14° K) and then combustion using Injector 25C (this combustion no need if minimum power, but Table_Z1 calculated for maximum power).
Compression energy CE=1/(ka−1)*(Pbc*Vbc−Pec*Vec)−Pbc*(Vec−Vbc)=367 J. Addition 140 J caused by output a part of compressed air dV=Vec−Vmin=46 cm3 to HPC 8, the same dV and 140 J returned by heat expansion during mentioned combustion from Injector 25A. Pair of buffers 51 must supply 367+140=507 J. Moving piston cause addition friction loss according dV=46 cm3. For “Version a” (above), dV=0. In prior art, piston push all volume Vec=91 cm3.
In Table_Z1 named: Qreg—heat, transferred in regenerator 23; Veex—part of volume of expander 19 with isothermal expansion, begin combustion after end input from HPC; J/cycle—work in cycle; Ef—efficiency.
From Table_Z1 may see that for engine without regenerator, a good efficiency, but a small power (J/cycle), may get with adiabatic expansion in expander (string 1). The same engine with partly isothermal expansion have a smaller efficiency, but power increase (string 3 is local minimum of efficiency, when regenerator only begin to work).
The best mode seems at string 7, but even a mean size regenerator with optimal dTr improve parameters of engine (string 6) and this case seems as optimal, see
A. Prefer using a “good” fuel, so as a short time for combustion in cylinder 15. At a full power mode, using<30% from fuel inside cylinder 15. Prefer using CH4 or H2.
B. Option if no used regenerator 23. So as a large time for combustion in the HPC, may use a “bad” fuel.
C. Option for over-heating after regenerator 23, or addition heating before expander 19 to avoid thermal loss in a long tube 8. A mean time for combustion, but a large temperature before combustion, so may use a “bad” fuel.
D. Heating in expander 19 if used regenerator 23. If no regenerator, Injector 25D is option for a pic power. Time for combustion in expander 19 is according to working mode.
If expander 19 directly connected to a wheel, for the wheel D=50 cm and velocity 120 km/h, need 1270 rev/min that is not a large speed for combustion.
Combustion in expander 19 begin at a temperature T4>Tec (if used regenerator or Injector 25B or 25C), that help for combustion. Output gas from expander 19 goes across regenerator 23, so is a large time to end combustion.
So, in the expander 19 no must be used a “good” fuel.
Free piston engine (prior art 8, 9) may work with PPM, when piston is fixated at Low Pressure Dead Point (LPDP). Advantage of PPM is wide regulation time for scavenging at LPDP with optimal compression, combustion and expansion time. No crankshaft; output energy used by hydraulic plunger pump and stored in accumulator. For PPM in the prior art used controllable hydraulic valve, that cause large loss. Between other problems of free piston engines, is very small time for combustion.
In the invention, speed of crankshaft 16 near LPDP and HPDP have independent regulations by controller 29, including possibility to fixate crankshaft 16. So have advantages of prior art, but without problems of it. Time for combustion is regulated, PPM not cause addition loss, the crankshaft no transfer power, small masse, small load on bearings, so used roller bearings, may use plastic or Aluminum crankshaft.
Due to PPM, possible fine synchronization between working cycle of cylinder 15 and expander 19, for example with input stroke of expander 19 when WF is pushed from cylinder 15 to HPC 8. So, may be used a small volume HPC 8 without large changing of pressure HP_in it (this changing may cause loss efficiency).
For embodiment
Near LPDP, force caused by buffer 51 is sufficiency smaller than pressure force in HPDP. Prefer, that regulation of cycles per second or fixation of crankshaft 16 take place only at LPDP, and near HPDP a large pressure force partly compensated by inertial force for every working mode. For this purpose, energy from buffer 51 must be more, then Compression Energy CE, and this over energy transferred to kinetic energy near HPDP. So moving parts of assembling 16 include functions of ER and ES (see ABBREVIATIONS OF PARTS). This compensation is not possible in prior art.
When crankshaft 16 is fixed at any DP (Dead Point), roller bearings are under static load. When crankshaft 16 is moving, roller bearings are under dynamic load. For good lifetime, permissible dynamic load must be 5-20 times smaller, than static. During moving, inertial forces are against loads from gas forces or from buffer 51, so, dynamic load diminish. It is very useful effect. With smaller dynamic loads, not only roller friction diminish, but may use light roller bearings and so diminish slide friction between rollers and separator, caused by inertial forces from reciprocating moving. To increase mentioned useful effect, may increase masse of parts with reciprocating moving, but prefer diminish inertial moment of rotating parts. For electrical machine with magnetic rotor: Me=L*D*a; I=b*L*D4 so I=C*Me*D3, where Me is moment of magnetic force; L, D, I are length, diameter, inertial moment of rotor; C=b/a=constant. “I” may be very small (with the same Me) if diminish “D”. So, summed inertial moment is mostly caused by inertial moment of crankshaft 16. Main power output is from expander 19, crankshaft 16 no send power (except a small power to or from electrical machine 22). So, rotating moment, transferred by crankshaft 16, is very small. Crankshaft 16 from Aluminum or plastic may be fast accelerated near any DP by at least a single electrical machine 22. Prefer, that every side of every crankshaft is connected to electrical machine 22. Example below explains mentioned useful effect (partly compensation of gas force).
Suppose, that radius of crankshaft 16 is R=5 cm, Vbc=1090 cm3 (see Explain to Table_Z1). Used 2 pistons 16 in the same cylinder 15 (
Prefer to avoid fixation near HPDP, so exist kinetic energy near HPDP (see above). To compensate Fmax=14360 N, acceleration A of reciprocating parts mast be: A=Fmax/M=2872 m/s2. Rotation speed Wr is not constant. To get A, must Wr=(A/R)0.5=240 rad/s=2290 rev/min. To get this Wr at HPDP, energy of buffer 51 (
As calculated, near HPDP, Wr=240 rad/sec. So as was fixation, Wr=0 at LPDP. What “Wr” is, for example, at angle 90° ? At this angle, near Eb/2=127 J is converted to any kinetic energy “C” and to energy of pressured gas. If was moving from LPDP, energy used for compression is small (most energy converted near HPDP). Suppose, that C=100 J, so, near angle 90°: Wr=(2*C/(mR+M)/R2)0.5=124 rad/s=1185 rev/min. It is approximately maximum mean rotation speed if fixation near LPDP was “zero” time, or, without fixation, Wr at LPDP was very small. With mentioned parameters mR=0.3 kg and M=5 kg, cannot sufficiency increase “mean” speed, so as it cause too large inertial force at HPDP. Due to fixation at LPDP, regulation to low mean speed is unlimited, but Wr at HPDP is near mentioned optimal 240 rad/s. If M=1.25 kg, instead 240 rad/s get 480 rad/s with full compensation of gas force. To calculate minimum “M”, suppose, that used two Aluminum rods (
Regulation near HPDP By OE (see “Acceleration of crankshaft”), is possible regulating a time Tout+Toin (
Expander 19 may be directly connected to wheel of a car. To regulate rotation moment, may regulate input valve of expander, combustion in expander, regulate output valve of the expander to avoid a large mistake of VER in the expander, or using more than a single expander. Controller 29 with using PPM, regulation of valve 18 and feedback from pressure sensor 32 inside HPC 8, must control frequency of cycles in cylinder 15 according to throughput of expander 19, so that pressure HP_in HPC 8 will be approximately constant.
With reference to
With reference to
With reference to
Drivers for all valves (20, 21, and 18) may include a spring with a large energy and power, to fast open and close a valve. When opened and closed, a valve fixated by electrical magnet, that can produce a large force to fixate it. This type of driver may find in prior art. If instead output valve 21 used a simple window, diminish useful part of piston stroke.
With reference to
Main distinctions from
The embodiment on
For
Working cycle include simultaneously input stroke by compressor 35 and output stroke by expander 34, kinetic energy of assembling 16S diminish that caused by friction and vortex loss; then, simultaneously compression and expansion strokes, kinetic energy of assembling 16S increase, so as expansion energy a-little more then compression energy to compensate mentioned loss. Zwork=0. Air from compressor 35 with Tec goes to HPC 8R, where heated by combustion product from isothermal expander 34 and remote isothermal expander 19, this gas with Tee=Tbe go to input part 40R and then to Atmosphere with output temperature a-little more than Tec (if ideal regeneration, with Tee). Tec is a-little more than Tbc so as kv is small and so as compressor 35 is cooled. If Tec=Tbc and no loss, efficiency is as for cycle Carnot: Ef=1−Tbc/Tee. As mentioned, isothermal expansion is due to appropriate speed of combustion, caused by injectors 25A and 25D. Work of Expander 19 is output work, produced by the engine. If the engine used for a car, prefer placing expander 19 near a wheel, and regenerator 8R, 40R near expander 19, to diminish length of tubes 24 with hot compressed gas. Zmachine (34, 35) work with PPM algorithm with synchronization to expander 19 as explained for
With reference to
With references to
With reference to
Distinction between
Input to every Compressor stage (C) and output from Expander (E) begin from 180° with force Cfi=2127N. Cfi cause acceleration and input work: wcp=213 J, so during this input, wcp is converted to kinetic energy. Return this wcp will be during compression, from 0° to 180°. Fixation of crankshaft is possible near angle 180°, where static load on bearings is minimum, it is mentioned Cfi. Maximum acceleration caused by force Efz from expander and begin from 0° with force Efz−Cfi=12774−2127=10647N. For compression used mentioned wcp, returned from kinetic energy, and expansion energy (285 J), at all 213+285=498 J. In the table, instead mentioned expansion energy, may see negative energy we (−285 J), that get compressor from expander. All expansion energy used for compression (Zwork=0).
Due to converting between expansion and compression energy, stroke from 00 to 1800 is fast, with large accelerations, and stroke from 180° to 0° is slower, with only kinetic energy, redistributed between moving masses. Moving masses and compressed gas make functions of ES (Energy Source) and ER (Energy Receiver). Note: For n=1, expansion energy is 365 J>285 J, so as near isothermal 4-stage compressor (string 4.2) is better, then adiabatic (n=1). So, for n=1, Ef=63.5, but for string 4.2, Ef=71.5%, that is closer to Carnot cycle with Ef=75%.
Pbc=0.1 MPa. After last stage: Pec=Pbe=1.22 MPa. For 4 stages: kp1=kp2=kp3=kp4=1.87; kp1*kp2*kp3*kp4=12.2. Vbc=1000 cm3, Tbc=300° K. Cooling after 1 and 2 stages to Tbcn=322° K, but after 3 stage, to TbcN=305° K=Tbc for last, 4 stage. After regenerator (8R, 40R): TH=Tbe=Tee=1200° K. For Carnot cycle: Ef=1−Tbc/TH=75%.
From Table_n see, that efficiency ‘Ef’ increase with quantity of stages n, but n>4 seems too large, so as a small increasing of ‘Ef’ may be covered by loss in valves. Loss no including in calculations.
At string 4.4 is the best efficiency (between 4.1-4.4) due to the best cooling.
For a large cost and large power engine with perfect thermal isolated and a large regenerator (8R, 40R) calculated Ef>63% is close to reality.
For n=1, we=−365 J is compression energy, and it is compensated by work of expander 34. For n>1, summed compression energy for all stages (wcp+|wc|) increase, but it partly compensated by wcp (input to compressor), so the ‘wc’ part, that give expander, diminish and Ef increase.
Disadvantage of Embodiment
Using crankshaft to get and return energy wcp need large inertial moment of crankshaft, so more load on bearings during moving with PPM, so as inertial moment of crankshaft diminish acceleration an sufficiency part of gas force is placed on bearings; the rest part of gas force accelerate piston and connected parts.
Advantage: no need a buffer.
Note: even for 1 stage compressor, may use this buffer to have a large rotation speed near HPDP, but a smaller speed (up to 0) at LPDP.
With reference to
The EHE is working according to Brayton cycle. If closed cycle, need hermetic envelope, and LP may be more than Atmospheric pressure. This cause heat from LPC 40 (long and large volume tubes, current initiated by Blower 9LP) is dissipated to Atmosphere. HPC 8 includes Sun Heater 8SH; it may be inside hermetic envelope (not shown) with low thermal conductive gas or vacuum; 8SH is separated from light source with glass that is low transparence for infra red ray. Heat transfer to and from Working Fluid (WF) is with constant pressure HP and LP correspondingly. Compression and expansion in cylinder 15 is adiabatic, with approximately the same kp=HP/LP and the same compression and expansion work (Zmachine). Volume of WF after Sun heater 8SH is more, than after compression in cylinder 15. Addition (due to heating to Tbe) volume of WF with HP=Pbe=Pec, HT=Tbe>Tec, across Thermal Isolated Tube 24 go to Remote Expander 19, where make useful work that converted to electricity by Electrical Generator 46. Remote parts are: 9LP, 19, 24, 40, 46. Other parts are small and placed from back side of Sun Heater 8SH and no dashing a Sun Concentrator (not shown).
With reference to
With reference to
Below explain, how works controller 29. When volume of cylinder 15 is near Vec according to signal from RSS 31, and dP (measured by sensor WCHPCIMDPS 28) is near zero (dP=0), by driver 30 begin opening valve WCHPCO 18. This condition (must be volume Vec when dP=0) is according to regulation, explained below in “PPM regulation”. During initiating time tini (
End expansion volume Vee detected by RSS 31, then WCLPOM 21 and WCLPIM 20 are opening by drivers 30, and due to blower 9LP, WF with parameters Pbc=LP and Tbc=LT go inside cylinder 15, while WF with Tee go to LPC 40. Instead blower 9LP, possible ISC, for example see explanation of
Version with additional Blower 9HP may be needed in case of large pressure drop across Heater 9SH, causing bad work of ISC. Blower 9HP gets addition power, but for this version may be Vec=Vmin and so diminishes friction loss. Every blower 9HP, 9LP is arranged as a rotating mean, capable to working as a turbine or as a compressor according to difference of pressure between input and output of the rotating mean. This rotating mean, when connected to electrical machine, is working as electrical generator or electrical motor and is connected to electrical accumulator across electrical Controller (29). Electrical machine of Blower 9HP is placed out of the hot zone, with appropriate sealing envelope (not shown). Obviously, appropriate control of valves (20, 21, 18, 41) may cause large energy of gas flow when scavenging begins. This energy may be accumulated by Blowers 9LP, 9HP, but this case is more practical for ICE (see explanation below about dWv to Table_Zwork).
Optimal Tbe selected as a compromise between infrared loss from 8SH when Tbe is high, and small Ef, when Tbe is small; Tbe measured by TSSH 48. A throughput of Remote Expander 19 is regulated to keep pressure HP, measured by HPCPS 32, near optimal. If HP is too small, must diminish throughput of expander 19, and vice versa. When HP is optimal, mentioned condition “Vec when dp=0” is true. For example, may regulate throughput of expander 19 by regulating input and output valves of expander 19. Note, that for car, power of expander 19 is according to load, but for Sun Power Plant—vice versa: power of electrical generator 46 and, so, expander 19, must be according to Sun Heater.
If used Electrical Generator 46 synchronous type, this regulation cause changing rotating moment of Electrical Generator 46 and so changing electrical current and power, that must be according to power of Sun Heater 8SH. Receiving surface of 8SH is sufficiency more than a surface normal to concentrated Sun rays. Most ray energy, that go across this normal surface, is absorbed by the receiving surface of 8SH, but infra-red loss is equivalent to loss from the “virtual” normal surface, heated to TH+dt, where dt may be, for example, 20° C. and need for thermal transfer from 8SH to WF.
Example from Computer Calculation.
HT=750° K=477° C., LP=7 atm, HP=56 atm, Ef=42% with calculated thermal and friction loss in cylinder 15. For ideal Brayton cycle: Ef=44.6%; for Carnot cycle: Ef=(HT−LT)/HT=60%. Diameter of cylinder 15 is 45 mm, stroke 2×40 mm, cycle work=81 J, so power is 4 kW for 3000 cycles/min. If common efficiency (including loss in Sun concentrator, heater 8SH, expander 19, generator 46) is 25%, and power of Sun radiation is 1 kW/m2, need Sun concentrator surface 16 m2. Calculated for this EHE, good Ef=42% caused by scavenging between Cylinder 15 and HPC 8, by PPM regulation and due to using large, but low cost, high efficiency remote expander 19 and generator 46, that impossible for prior art. To increase Ef, must increase HT, that is possible with using special glass (available today), transparent for Sun Spector, but no transparent for infra red loss from heating surface of heater 8SH.
With reference to
HPC 8 include Sun Heater 8SH, and HPC 8 separated by valve HPSDV 47 to an input part HPCIP and an output part HPCOP (80P). HPSDV 47 may be directly controlled by dP between two sides of it, or from a driver (not shown), activated by sensor of this dP (not shown), this case dP may be near zero due to high sensitivity of this sensor.
By combustion in the HPCOP, initiating scavenging between WC (cylinder 15) and HPC, that includes parts 8SH, 26, and 44. Is used PPM. LPC is Atmosphere, WF is air, open cycle, but Versions “P” and “47P” are without combustion (so may be LP>0.1 MPa, closing cycle). Scavenging between WC and LPC is initiated by blower 9.
With reference to
After end compression in Cylinder 15 (at volume Vec), begin opening of WCHPCO 18, WCHPIM 41, and begin combustion in the HPCOP, caused by Injector 25A. Combusted product from previously cycle pushed to cylinder 15, so as HPSDV 47 is closed and Injector 25A is placed near HPSDV 47. Simultaneously, compressed air pushed to the HPCIP. So, heat expansion of WF in HPCOP initiates scavenging between Cylinder 15 and HPC 8; scavenging continue when HPSDV 47 is open. When volume of cylinder 15 return Vbe=Vec, end closing of valves WCHPCO 18, WCHPIM 41. So as scavenging caused by combustion in HPCOP, possible Vec=Vmin. So as combustion may continue during scavenging, this scavenging may be fast. May end combustion before than valves 18, 41 are closed, this causes ISC to begin. Scavenging time, when valves 18, 41 are opened, adjusted by controller 29 with feedback from temperature T27, measured by sensor 27, placed in HPCIP. About optimal T27 see explain to
Version “P”.
This case does not need combustion. Main principle: Scavenging between WC and HPC proceeds by changing volume in Expander 19, and then using ISC. By PPM, end compression in Cylinder 15 is synchronistic to at least a part of input stroke of Expander 19, that cause diminishing pressure in part of HPC named HPCIP, while HPSDV 47 is closed. Signals from WCHPCIMDPS 28 and WCHPCOMDPS 43, initiate opening WCHPCO 18 and WCHPIM 41 by controller 29 with appropriate drivers 30, so begin scavenging. Then, due to kinetic energy of WF, pressure in HPCOP and HPCOM 44 diminish, that cause opening HPSDV 47 and scavenging continue with ISC. After scavenging time tsc (see above), valves 18 and 41 are closed.
Version 47P.
Instead HPSDV 47, HPSDV 47P is used. Scavenging between Cylinder 15 and HPC 8 proceeds by combination of two factors: increasing pressure in part 8SH due to heating from Sun light, and then ISC. HPC 8 is separated to two parts 8HS and HPCIP with valve HPSDV 47P. When valves HPSDV 47, WCHPIM 41, and WCHPCO 18 are closed, part 8SH is (temporarily) hermetically sealed by WCHPIM 41 and WCHPCO 18, and heating by Sun light causes changing ratio between pressures in parts 8SH and HPCIP. Opening WCHPIM 41 and WCHPCO 18, initiates flow of the WF between the two parts across Cylinder 15; when ratio between pressures in parts 8HS and HPCIP is close to 1, opening the HPSDV 47, thereby proceeding with ISC, with control valves WCHPIM 41, WCHPCO 18 and time tsc as explained. During scavenging, input valve (not shown) of Expander 19 is closed.
Comparing Between Versions
With reference to
The embodiment comprising parts: 7, 8B, 8C, 8H, 9LP, 9HP, 10, 15-22, 24, 26-33, 40, 41, 43, 44-46, 49, 50, 52-56, 58 and optionally 47.
On View A-A may see items 26 and 44, designed to improve inertial scavenging. Valve drivers 30 are not shown.
The Heat pump working according to open reverse Brayton cycle, LPC 40 is atmosphere.
Output of Compressor 7 across Distributor 50 connected to Cool part 8C of HPC and to thermal isolated Buffer Volume 8B, that across on/off valve 54 connected to Expander 19, mechanically connected to Electrical Generator 46.
At cooling mode, the LPC is a cooling room, and the HPC cooled by external air.
At heating mode, the LPC is atmosphere, and the HPC cooled by a room air.
Blowers (turbines) 9LP, 9HP, 9E are working during all cycle from any small power source.
Working Algorithm Includes:
Closing WCHPIM 41 and WCHPCO 18, thereby separating the HPC 8 to two parts (8C, 8H); changing a ratio between pressures of WF in these parts, using blower 9HP; opening the WCHPIM 41 and WCHPCO 18, and so initiating flow of the WF between parts 8C and 8H across Cylinder 15, then using ISC; closing the WCHPIM 41 and WCHPCO 18 to end ISC. So, after compression in Cylinder 15, scavenging is initiated by Blower 9HP.
After expansion in Cylinder 15, scavenging initiated by Blower 9LP.
Air current across heating section of Heat exchanger 10 initiated by Blower 9E.
Input air from room—Valve 52cIR—compression in Cylinder 15—sink heat to Atmosphere in Heat Exchanger 10 with heating section connected by valve 52cEA—expansion—Valve 52cOR—to room.
Input air from Atmosphere—Valve 52HIA—compression in Cylinder 15—sink heat to room in Heat Exchanger 10 with heating section connected by valve 52HER—expansion—Valve 52HOA—to Atmosphere.
All sections of Valve 52 may be connected together mechanically.
Piston assembling 16 is shown at HPDP (Dead Point when end compression), so volume of Cylinder 15 (WC) is Vmin. Due to scavenging after end compression, Vmin is large and so surfaces of valves WCHPCO 18 and WCHPIM 41 may be large, vortex loss and time for scavenging is small.
HP scavenging from volume 8C across cylinder 15 to volume 8H is initiated by blower 9HP when valves WCHPCO 18 and WCHPIM 41 are open. Power of blower 9HP is regulated by controller 29 for optimal HP scavenging. It is optimal when temperature after output from cylinder 15, T27, measured by HPCIMTS 27, is a-little smaller than Tec; Tec=Tbc*kv(ka-1), Tbc measured by TSBC 45, kv may be regulated by valves 20 and 21. T27<Tec due to partly mixing in cylinder 15 with input air with Tbe, measured by TSBE 55. In case of over scavenging, a large part of input air with Tbe goes to output from Cylinder 15, so T27 sufficiency smaller then Tec. Over scavenging cause increasing of vortex loss.
During HP scavenging, air with begin parameters HP, T27, is pushed across Heat Exchanger 10 by Blower 9HP and is cooled. Air across heating section of Heat Exchanger 10, is pushed by Blower 9E.
If the Heat pump working with cooling mode, heat from compressed air (T27, HP) is sinking to Atmosphere; with heating mode, this heat sinking to a room; reconnection between Atmosphere and the room by Valves 52cEA, 52HER.
After end expansion in cylinder 15, WCLPIM 20 and WCLPOM 21 must be open, and cooled (due to adiabatic expansion) air across 52cOR go to the room; at heating mode, this cooled air go to Atmosphere across 52HOA.
Optimal LP scavenging is controlled by: sensor TSBC 45, measuring Tbc, that is as well temperature of scavenging air in input of cylinder 15; by sensor TSILPC 58, measuring mean temperature after output from cylinder 15, it is T58; by TSBE 55, measuring Tbe. For optimal LP scavenging, T58 is a-little more than Tee, Tee=Tbe/kv(ka-1). If over scavenging, T58 is too large, that caused by mixing with air with Tbc. If scavenging is not good (for example, a small time for scavenging), T58 is close to Tee and throughput of cool air diminish, “pumping” of heat energy diminish, while mechanical loss is approximately the same and so efficiency of the heat pump diminish.
Over scavenging not diminish “pumping” of heat energy, but increase vortex loss. For air conditioner, over scavenging is not critical (in any case, output air is mixed with hot air in the room), but prefer avoid over scavenging if the heat pump used for refrigerator.
Throughput of the Heat Pump Controlled by PPM.
If HP, measured by HPCPS 32, increase over desired level, part of throughput of Remote Compressor 7 must be directed to buffer 8B across Distributor 50 and thermal isolated tube 24.
Buffer 8B is large volume, thermal isolated and used as energy source for Remote Expander 19, connected to Electrical Generator 46. Pressure inside Buffer 8B is measured by HPCBPS 56. If this pressure is smaller then desired minimum, must close valve 54, and vice versa.
If throughput of Remote Compressor 7 is too small, may using an addition compressor (not shown) from any energy source, for example from Remote Expander 19, reconnecting it to the addition compressor.
One of advantages of Heat Pump (
Version with Valve HPSDV 47 may work without Blower 9HP, but preferably with using for heat pump only mentioned addition compressor (below named “compressor”). This method for the heat pump, with scavenging at least by changing of an external volume (in this case, the volume in a compressor of positive displacement type). For this version, providing phase difference sensors (not shown), arranged to detect difference between cycle phases of Cylinder 15 and the compressor. Controller 29 provides synchronization between cycles of Cylinder 15 and the compressor, using signals from HPCPS 32 and the phase difference sensors, so that pressure in HPC 8 will be approximately as desired, and after end compression in Cylinder 15, take place at least a part of an output stroke of the compressor. So, when HPSDV 47 is closed, initiating ISC. Adjusting the optimal scavenging duration, for optimal T27, as explained above.
Synchronization with Compressor 7, working from wind energy (and so with wide swing of rotation speed) may be problematic, so this version is practical only with mentioned “additional compressor”.
With reference to
The embodiment (
Calculations are for adiabatic process. Above in “Explain to Table_Z1” mentioned, that heat loss may diminish Ef to 1.5-2.5%. Mass of fuel is smaller than 5% from mass of air. Volume of HPC is 1500 cm3; Vbc=1000 cm3, Tbc=300° K, Pbc=0.1 MPa, Pec=3.975 MPa, Tec=859° K; Tbe=Tmax=2000° K; Pee=0.1043 MPa, Tee=697° K. Virtual work, workv=0.06 J, may be caused by expansion from Pee, Tee, Vee=Vbc, to virtual: Pbc, 688° K, 1030 cm3. This work named “virtual”, so as it may be used (for example, by turbine), but often it is not used even in prior art, where workv is large. There, workv is small and may be used for ISC. Used heat=826 J. Tbe/Tee=Tec/Tbc=2.87.
Work: 0.06 (workv)+20.5 (Zwork)+510 (expander)=530 J; Ef.=530/826=64%, if no loss of heat to walls of WC and expander. Temperature in HPC, THPCes=1246° K, calculated supposing a full mixing inside cylinder 15 during output to HPC, caused by combustion. In Table_Zwork (below) may see, that THPCes caused by Vbe. Really, THPCes is smaller, and without mentioned mixing, THPCes=Tec. To get a full power, must addition combustion in HPC 8 or in expander 19, and combustion in cylinder 15 to Tmax. Combustion in HPC 8 or expander 19 is better than in WC (cylinder 15) so as more time, more temperature at begin combustion, better mixing. So, for the same fuel, output from expander is clearer than output from WC. So, for clearer output, prefer to diminish output from WC. Below, mass of combusted product, that go from WC to atmosphere, named Moutwc, and all output named Mout (for a full power). Both Moutwc and Mout caused by the same proportion coefficient “k” (according to combustion energy of fuel, that is near 47e6 J/kg; mass air/fuel, is 15-20 for a full power).
From mass of air in cycle, Mbc=1161 mg, and mass, displaced from WC to HPC, mtoHPC=639 mg, may calculate Moutwc/Mout. So, Moutwc=(Mbc−mtoHPC)*(Tmax−Tec)*k; Mout=Mbc*(Tmax−Tec)*k; Moutwc/Mout=X=(Mbc−mtoHPC)/Mbc=522/1161=0.45. Calculating X by another way: X=300/688*1030/1000=0.45.
Due to PPM, combustion inside WC may be optimal, so as possible regulation a time for combustion (see explain of PPM for
Zwork used by the Hydraulic pump 16G, that include electrical controlled input valve 16V and automatic Output Valves 16O. As example, mean velocity of piston and plunger (assembling 16P) is 8 m/s and it is velocity of oil mass 5G; kinetic energy of oil is lost and for 2 pumps and 2 strokes is 0.3 J (for
For oil velocity 4 m/s across valve 16V, dP=0.8N/cm2. Surface of valve 16V is 2 cm2, so an electrical magnet must make 1.6N (in this case, the magnetic gap>0) to compensate this dP. If acceleration of valve 16V is 1 mm during 1 ms, and mass 5 g, mean acceleration force from spring is 10 N, pic force is 20 N. So, the electrical magnet must make>21.6N when magnetic gap is zero. Electrical magnet at
Calculated above small loss (0.3 J=0.05% from the cycle work) in valve 16V is due to fixation of assembling 16G by crankshaft, but not by any valve. For prior art [9], fixation caused by closing a valve (named in the Prior Art a FREQUENCY CONTROL VALVE), and driver of it must compensate force, for this example: 2000 N/2 cm2*2 cm2=4000 N, so construction of this valve must be another and loss in it is more. From prior art [9]: “ . . . the frequency control valve of 50 bar would for example result in an energy loss of 31 J. Compared to a total pump work of 410 J, this would be a loss of 7.7% . . . . This then sets the requirements for the frequency control valve: a rather large valve with an extremely fast opening response time. An opening time of a few milliseconds is acceptable since the valve can start to open at the end of the previous stroke . . . ”.
Compare loss 7.7% in valve of prior art [9], with loss 0.05% in valve according to
Zwork (Zw)=EWz−CWz, where EWz is expansion, and CWz is compression works in Zmachine; if Zw>>0, it used by the hydraulic pump. Main output (EW) is from Expander. dWv=virtual work for expansion from Pee, Vee=1000 cm3, to 1 atm up to virtual volume Vwcv,cm3; work=Zw+dWv+EW, Ef=work/heat (if no loss). Vwcv no exist in reality in this embodiment; it included to “work”, so as it may be used by any addition volume (Vwcv−Vee), but it is not practical. CWz=376 J, Pec39.7 atm, Tec859K, Tmax in WC=1900° K; gas with THPCes from HPC go to expander; Vec=72, Vmin=67 cm3. Changing of parameters caused by begin expansion volume Vbe.
From TableZwork may see, that Zw (Zwork) may be a sufficiency part of the full output work (530 J); for prior art, Zw is a full work of engine and so dWv, that practically not used (to use it, must expansion from Vee=1000 cm3 to Vwcv, that for prior art is sufficiency more, than in Table_Zwork), cause a loss of efficiency. In embodiment
Below example about friction loss in bearings and rings (
From the last string may see, that if after end compression at Vec=72 cm3, piston continue moving to Vmin=46.5 cm3 with pushing compressed gas to HPC, friction loss is maximum: 5.13+3.8=8.93 J, that caused by moving piston and crankshaft against Pec. Then displacing compressed gas continues by any of methods explained above. For Prior Art [3] with proportional sizes, Vmin=0, all gas pushed by piston, and loss is sufficiency more than for Vmin=46.5 cm3.
Optimal is Vmin=71.5 cm2: due to near zero moving piston after end compression, friction loss is minimum (4.4 J). dWv=0.07 J used for inertial scavenging, that help to Blower 9.
| Number | Date | Country | Kind |
|---|---|---|---|
| 255807 | Nov 2017 | IL | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/IL2018/051251 | 11/20/2018 | WO | 00 |
