In researching the present invention, I discovered many patents that took advantage of waste heat to increase mechanical work and engine efficiency. Most of these patents selected water as the injected liquid. None of the other patents, however, made use of superheated injected liquids. The liquid entering a relatively low pressure cylinder when compared with the liquid's saturation pressure at the injected temperature is indeed superheated for an instant after being injected. The physical calculations of temperature and pressure show that the temperature of the injected liquid if water is the selected substance needs to be within a fairly close proximity to the critical temperature in order to increase pressure of the mixture. Water has such a high latent heat of vaporization that it can easily over cool the compressed gas and result in a decrease of pressure. No engine will be as efficient as it is without injecting water, if both temperature and pressure decrease before the power stroke begins expansion. Typically, in engine patents that I reviewed, ambient water was converted to steam using waste heat of combustion gasses. Each, typically, also used internal combustion from an Otto or Diesel cycle to generate the heat. The present invention does not use internal combustion for its heat source. A ‘carrier gas’ is heated outside the engine, via solar, a typical water heater, or exhaust recovery heat. A liquid is also pre-heated externally or by purchasing/renting an insulated, pressurized container of the hot liquid. The present invention is somewhat more like a battery powered motor than an internal combustion engine. Some combination of liquid and carrier gas should permit the use of ambient heating of the carrier gas while supplying a pressurized, stored ‘thermos’ of liquid heated to near its critical temperature as the only energy input necessary. Presently, the demonstrated RAKH Cycle Engine prefered configuration uses argon carrier gas with hot water as the injected liquid.
The engine and its thermodynamic cycle, which is described herein, will be called the RAKH CYCLE ENGINE. The said engine cycle involves a gas or mixture of gasses that are herein referred to as the ‘carrier gas’ and a superheated liquid, which vaporizes but does not burn. The purpose of the carrier gas is to bring thermal energy into a volume where compression is used to concentrate thermal energy at a higher temperature. A liquid is then injected. In an engine cycle, the liquid must be superheated above its saturation temperature corresponding to the pressure that the carrier gas attains at its maximum compression. The carrier gas must be much hotter than the injected liquid in order to force heat to be transferred into the injected liquid rapidly. Heat that is transferred from the carrier gas will cool the carrier gas resulting in a lower temperature and pressure. Transfer of the heat from the carrier gas into the liquid, on the other hand, will greatly increase the volume of the injected liquid, through converting it into a vapor. The temperature of the liquid will increase while the temperature of the carrier gas will decrease. The decrease of temperature is moderated by further compression of the carrier gas due to displacement from the vapor produced forcing the carrier gas into a smaller volume. All of the experimental results, which I have derived by calculation, have always resulted in a lower temperature from the end of event one up through to the end of mixture temperature equalization in event three. This theoretical observation may prove false in practice however, for real liquids that are injected at pressures above their critical point into a carrier gas that is also compressed to a point that is above the critical pressure of the liquid. Some real gasses and liquids exhibit an overall increase in pressure upon vaporization of the liquid in the mixture. The compression phase end temperature of the carrier gas before liquid injection decreases after temperature equalization of the mixture. The present invention may also use substances injected above their critical temperature and pressure. Those superheated substances are still considered as liquids for. The best choice of carrier gas would not condense at the peak cycle pressure. The purpose of the carrier gas is to carry heat into the cycle, which is transferred to a liquid injected at a later point in the cycle after the carrier gas is compressed. Calculations are very difficult because of changing gamma values for the liquid and carrier gas. The preferred implementation uses Argon as the carrier gas and water as the injected liquid. The gamma value for Argon is nearly constant at varying temperatures.
The first event of the RAKH CYCLE is adiabatic compression of a carrier gas to increase its temperature via input of mechanical energy similar to a diesel cycle compressing air to a temperature hot enough to ignite fuel via adiabatic compression. The purpose of this compression in the RAKH cycle, however, is to concentrate the thermal heat via an increase in temperature to force rapid transfer of energy to the liquid injected in event two.
The second event in this thermodynamic cycle is the injection of liquid into a nearly constant volume of the gas at the end of the first event. If the cycle is used in an engine, the liquid will be heated to some sufficient temperature, such that part of the liquid flashes into the gasseous phase due to the excess thermal energy of the liquid enthalpy beyond that of the liquid at its saturation temperature for the pressure in the cylinder (or turbine) arrived at by the mixture.
Event three in the cycle is equalization of temperature prior to the rapid expansion event, which follows. This third event happens very fast within the same constant volume (shown in
The fifth event, is the exhausting of the mixture. The exhaust mixture should be captured into a condenser designed to handle separation of the mixture into its separate components to increase efficiency. The RAKH Cycle, however, does not require a condenser, but does assume a continuous supply of carrier gas and liquid from some source at a constant temperature and pressure. Burning a little oxygen in a predominantly hydrogen carrier gas would provide adequate hot hydrogen carrier gas having a little superheated steam mixed in with it.
Event six is the induction of the carrier gas, which brings the cycle back to the initial conditions of event one whenever the cycle is running in a steady state. This sequence of six events will be repeated as a continuous thermodynamic cycle, which will be referred to as the RAKH CYCLE without regard for which starting point is arbitrarily picked for event 1.
Engines using this cycle are RAKH Cycle Engines. Refrigeration machines using this cycle with appropriate working substances selected for refrigeration, are referred to as RAKH refrigerators.
The selection of the carrier gas and liquid are major variables impacting the cycle efficiencies. Ability for the combination to produce power, is a very narrow margin between operable and non-operability for a RAKH Cycle Engine. The variability of gamma for the real gasses is what allows the cycle to work below the critical point. The gamma value is the ratio of the specific heat at constant pressure to the specific heat at constant volume. For a small adiabatic change of volume, the change of pressure is dependent upon gamma in the relationship: P2=P1 times (V1/V2) raised to the gamma power where P1 is the starting pressure, V1 represents the starting volume, and V2 is the final volume. This is also frequently referred to as the compression ratio. If gamma is 2 and the compression ratio is 10 then the adiabatic final pressure will be P1 times 100 (10 squared) and not simply P1 times 10 as might have otherwise been expected. I selected carrier gasses that had a very nearly constant gamma for ease of calculation in the illustrated computer listings. Hydrogen may be the best bet for a carrier gas for efficiency in heating previously mentioned and because it is fairly easy to separate from the hydrogen-steam mixture.
Listings 1-6 are computer program listings which show power and efficiency variations and the thermodynamic conditions of the RAKH Cycle Engine Run at uniform incremental points of the cycle under variations of compression ratio, initial carrier gas induction temperatures, and liquid injection quantities for water injected near the critical temperature at 704 degrees F.
Exhaust pressure of the binary mixture is 63.6814 psia at 820.8011 degrees F.
Work done is 947.6757 ft-lbs;
Estimated W-9 Horsepower @ 3600 RPM = 9.644 hp
Estimated heat for Argon = 55.3475 BTU/sec and for liquid = 20.51642 BTU/sec
Theoretical Efficiency = 8.983552%
Exhaust pressure of the binary mixture is 63.75652 psia at 938.801 degrees F.
Work done is 953.8967 ft-lbs;
Estimated W-9 Horsepower @ 3600 RPM = 12.697 hp
Estimated heat for Argon = 60.37178 BTU/sec and for liquid = 20.51642 BTU/sec
Theoretical Efficiency = 11.09368%
Exhaust pressure of the binary mixture is 40.2295 psia at 749.0366 degrees F.
Work done is 778.1189 ft-lbs,
Estimated W-9 Horsepower @ 3600 RPM = 9.551 hp
Estimated heat for Argon = 36.6385 BTU/sec and for liquid = 17.0970 BTU/sec
Theoretical Efficiency = 12.5612%
Exhaust pressure of the binary mixture is 40.2651 psia at 851.0366 degrees F.
Work done is 783.384 ft-lbs;
Estimated W-9 Horsepower @ 3600 RPM = 12.1361 hp
Estimated heat for Argon = 39.96441 BTU/sec and for liquid = 17.0970 BTU/sec
Theoretical Efficiency = 15.03015%
Exhaust pressure of the binary mixture is 29.1875 psia at 758.4092 degrees F.
Work done is 666.9431 ft-lbs;
Estimated W-9 Horsepower @ 3600 RPM = 9.0370 hp
Estimated heat for Argon = 26.50443 BTU/sec
Estimated heat for injected liquid = 11.96791 BTU/sec
Theoretical Efficiency = 16.59994%
Exhaust pressure of the binary mixture is 29.2010 psia at 864.4092 degrees F.
Work done is 671.0901 ft-lbs,
Estimated W-9 Horsepower @ 3600 RPM = 11.073 hp
Estimated heat for Argon = 28.9104 BTU/sec and for liquid = 11.9679 BTU/sec
Theoretical Efficiency = 19.14237%
The RAKH Cycle Engine utilizes a novel thermodynamic cycle, which is described here in detail.
Eventually the liquid at the bottom of the condenser would overflow so a float controller (F) sends a signal to open drain line valve (E) draining to a low pressure air vented overflow tank, not shown on the drawing. Steam trapped between the ceramic disks continually heats tank (B) and preheats the carrier gas a little bit after the spray injection (I) has cooled it for a slight added efficiency bonus in capturing and recycling the carrier gas with a closed cycle.
Listings 1 and 2 computer printouts are for an 8 to 1 compression ratio RAKH Cycle Engine with 0.06 grams of water injected at 704 degrees F.
Listings 3 and 4 computer printouts are for a 10 to 1 compression ratio RAKH Cycle Engine with 0.05 grams of water injected at 704 degrees F.
Listings 5 and 6 computer printouts are for a 12 to 1 compression ratio RAKH Cycle Engine with 0.035 grams of water injected at 704 degrees F.
Listing 1 has 1200 degree F. initial Argon carrier gas temperature and 71 psia intake pressure.
Listing 2 has 1400 degree F. initial Argon carrier gas temperature and 71 psia intake pressure.
Listing 3 has 1200 degree F. initial Argon carrier gas temperature and 47 psia intake pressure.
Listing 4 has 1400 degree F. initial Argon carrier gas temperature and 47 psia intake pressure.
Listing 5 has 1200 degree F. initial Argon carrier gas temperature and 34 psia intake pressure.
Listing 6 has 1400 degree F. initial Argon carrier gas temperature and 34 psia intake pressure.
At TDC for each of these listings, the maximum pressure is close to 3000 psia
Number | Date | Country | |
---|---|---|---|
Parent | 10090433 | Mar 2002 | US |
Child | 10979087 | Oct 2004 | US |