Patent Application
20140331703
The present invention relates to an improved air-conditioning system, and more specifically to an retrofit assembly that increases the efficiency of an air-conditioning system.
The present invention relates to a cooling system that is used in conjunction with the typical split commercial or home air-conditioning units.
Historically, air-conditioning units were developed by application of the second law of thermodynamics. The second law states that there exists a useful state variable called entropy S. The change in entropy ΔS is equal to the heat transfer ΔQ divided by the temperature T.
ΔS=ΔQ/T
For a given physical process, the combined entropy of the system (S) and the environment remains a constant if the process can be reversed.
S
f
=S
i (reversible process)
An example of a reversible process is the manner in which an air-conditioning unit operates. Ideally, a fluid is forced to flow through a constricted pipe. The term “Ideal” means no boundary layer losses. As the flow moves through the constriction, the pressure, temperature and velocity change, but these variables return to their original values downstream of the constriction. The state of the fluid returns to its original conditions and the change of entropy of the system is zero. Such a process is defined as an isentropic process.
Typical air-conditioners of the type used in accordance with the present invention consist of two fundamental units: the evaporator coil and the condensing unit. These two units can be configured as a single (or package) unit, as a “split” unit, or as a “mini-split” unit. The “split” portion of the name indicates that the condenser unit is typically located outdoors, while the evaporator is typically located indoors.
The present invention is directed primarily toward the split unit, although it can be applied to the single unit with appropriate modification.
Split units typically place the louder condensing components outdoors (this is often called the “hot” side), and the quieter evaporator coil indoors (this is often called the “cold side”). The evaporator coil will either be integrated into a warm air furnace system, or into an air handler to distribute the newly cooled air around the house. Other than the fact that the hot and cold sides are split apart and the capacity is higher (making the coils and compressor larger), there is no functional difference between a split-system and a window air conditioner. Those two types of air-conditioners both operate on the same principle, in that the air-conditioner does not add cool air to an area, but instead, removes heat from the existing air, leaving the remaining air cooler.
The component parts of a typical present day air-condition system forming a closed system, consist of a compressor, a condenser, an expansion valve, an evaporator and a thermostat.
The condensing unit is the main component of a split central air conditioning system. The “condenser” comprises an outdoor housing which is a grated container having at four sides, or more, and a top as a cover or guard. The louvered slots in the grating allow air to pass freely through the outdoor housing at all times. There are multiple components located inside the outdoor housing. Included within the outdoor housing is a centrally located pump called a compressor, an electric motor to drive the compressor, condenser coils (usually made of copper) which are serpentine tubing surrounded by aluminum fins which in turn, surround the interior periphery of the housing, a fan and an electrical system.
The motorized fan positioned atop the compressor unit helps to circulate the conditioned air, while thin metal fins extending from and in contact with the tubing through which refrigerant fluid flows, allow heat to dissipate from the tubes quickly. The heaviest part of a typical air-conditioning system is often the compressor, since it must be strong enough to withstand a significant amount of pressure. The condensing coil plus the compressor, etc. encased within the outdoor housing unit are often collectively referred to in the trade as the “condenser.”
In conjunction with the compressor, air-conditioning systems use heat transfer fluids (refrigerant chemicals) that easily convert from a gas to a liquid and back again. The refrigerant fluid, as explained hereinafter, is used to transfer heat from the air inside of a home to the outside air. The compressor pressurizes and pumps the fluid which is an odorless, non-flammable refrigerant fluid (hydrofluorocarbons, or HFCs, generically referred to as Freon, a DuPont trade name) through a closed loop of copper pipe.
For the purpose of this disclosure, reference to the refrigerant fluid used in accordance with the present invention will be designated as Freon for descriptive purposes only. Scientists have determined that the ozone layer above the earth was starting to degrade, and Freon CFCs were suspected of being involved, leading to calls to ban the use and additional production of these chemicals. As a result, in The Montreal Protocol as amended and carried out in the U.S. through Title VI of the Clean Air Act, (enforced by the EPA), the use of Freon designated R-22 as a refrigerant in air-conditioning units is being phased out and a suitable substitute refrigerant, such as R-410A, a blend of hydrofluorocarbons (HFCs) that is a green HFC and which does not contribute to depletion of the ozone layer, may be used.
R-22 (also known as HCFC-22) has been the refrigerant of choice for residential heat pump and air-conditioning systems for more than four decades. Releases of R-22, resulting from system leaks over time to the atmosphere, contribute to ozone depletion. R-22 has been mostly phased out in new equipment sold in the United States and has been replaced by other refrigerants with lower ozone depletion potential such as (R-290), R-410A, as noted above, (an azeotropic mixture of difluoromethane and pentafluoroethane), R-507A, R-134a (1,1,1,2-tetrafluoroethane), R-409A, R-407C.
R-410A is sold under trade names as GENETRON AZ-20®, SUVA 410A®, Forane® 410A, and Puron®.
The transition away from ozone-depleting R-22 to systems that rely on replacement refrigerants like R-410A has required redesign of heat pump and air conditioning systems. New systems incorporate compressors and other components specifically designed for use with specific replacement refrigerants. For instance, if a new outdoor unit (i.e., the “condensing unit,” containing the condenser and compressor) is installed, it is likely that a new indoor unit (typically called an “evaporator”) will also be required.
The present invention does not depend upon the identity of the refrigerant used.
The Freon fluid (the refrigerant) arrives at the compressor as a cool, low-pressure gas. The compressor squeezes the fluid. This packs the molecule of the fluid closer together. The closer the molecules are together, the higher its energy and its temperature. Pressurizing and pumping Freon in the compressor inevitably raises the Freon temperature to as much as 150° F. The Freon leaves the compressor as a hot, high pressure gas and flows into the condenser, an assembly of tubes and fins that surround the compressor in the outdoor housing to cool the gas vapor. The condenser metal fins extend from the tubing surrounding the compressor help to dissipate the heat of the Freon therein by exchanging the thermal energy in the Freon with the surrounding air. The outside air, no matter how hot, is cool compared to the Freon, so as the vapor passes through the condenser tubing, it is cooled by outside air blowing through the condenser.
Freon leaves the condenser at about 100° F. degrees flowing to an expansion valve, located indoors. Within the expansion valve, a spray nozzle disperses the vapor into a wider-diameter pipe. The infinitesimal droplets have a large surface area compared to their volume, facilitating cooling, as does the expanded pipe size. Freon, which boils at about 38° F., leaves the expansion valve as a liquid having a temperature of 20° F.
Last step in the closed air-conditioning system is the evaporator, which functions like the condenser, but in reverse. A fan is connected to the evaporator that circulates the air inside the house (or business) to blow across the evaporator fins. Hot air is lighter than cold air, so the hot air in a room rises to the top of a room. There is a vent there where air is sucked into the air conditioner and goes into ducts. The hot interior air from the room in the ducts is blown across coils of chilled Freon. The Freon absorbs the heat; moisture in the air condenses on the cold coils and drips into a drain. The result is cool, dehumidified air that is blown through ductwork. The Freon, exiting the evaporator at about 50° F., returns to the compressor, and the process as described is repeated. This continues over and over and over until the room reaches the desired temperature. The thermostat senses that the temperature has reached the right setting and turns off the air conditioner. As the room warms up, the thermostat turns the air conditioner back on until the room again reaches the desired cool temperature.
In summary, refrigerated air conditioning works on the principle that when a gas (e.g., air) is compressed, the temperature of that gas is trapped, and the temperature rises higher in proportion to the pressure being exerted on it. Then when the compressed gas is directed through a cooler (condenser) the heat is lost. Then the cool-down gas, which is now a liquid, is pumped back to the evaporator and when the pressure on the cooled down liquid is released, it reverts into a gas, but much colder.
The difference in lost heat is what is felt. If the inside air temperature is, e.g., 80° F., and it is directed through an air conditioning system and 40° F. in the coolant is lost to the outdoors, then the coolant will come back inside and be distributed via a blower at 40° F.
When the working fluid leaves the condenser, its temperature is much cooler and it has changed from a gas to a liquid under high pressure. The liquid goes into the evaporator through a very tiny, narrow hole. On the other side, the liquid's pressure drops. When it does, it begins to evaporate into a gas.
As the liquid changes to gas and evaporates, it extracts heat from the air around it. The heat in the air is needed to separate the molecules of the fluid from a liquid to a gas.
By the time the working fluid leaves the evaporator, it is a cool, low pressure gas. It then returns to the compressor to begin its trip all over again.
Depending on the age of the air conditioner, its running conditions and use, there may be certain parts of the air conditioning condenser that need to be replaced from time to time. These include evaporator coils, electrical motors present in the system and the compressor.
There are basically four types of compressors that are used in air conditioning systems. A rotary compressor is commonly used in window units and some central ac units. A reciprocating compressor is the most common in lower efficiency split air-conditioners. A scroll compressor is the most common type in higher efficiency equipment. The latest innovation is variable speed compressor. The present invention can be used with any of these compressors.
The compressor operates using the relationship among pressure (P), volume (V) and temperature (T) wherein the compression of a gas with all variables changing will result in higher pressure, higher temperature and, a decreased volume.
As noted above, the compressor operates as high temperatures and pressures for extended periods with the result that over time the integrity of the compressor is compromised and, inter alia, the suction and head pressures fall out of range.
In view of the gradual erosion of the efficiency of a compressor based upon the high pressure and high temperature at which it operates, there is a need to enhance the efficiency (e.g., lowering the pressure at which it operates, lowering the amperage used and accordingly lowering the power, and extending the life) of the compressor. The present invention specifically addresses the problems mentioned above by lowering the temperature, pressure and RLA of the compressor, thereby allowing the compressor to be more efficient and thus have a longer life.
The present invention is a retrofit assembly of constituent elements comprising a water solenoid box with a control switch, the solenoid box being connected to the electrical system of the condenser unit; water filter means to purify the water flowing into the solenoid box; a main water supply line, extending from the solenoid box to the condenser housing unit and affixed, circumferentially around the exterior periphery of the housing unit; and a plurality of distribution tubes (micro-tubing) extending downwardly from the main water supply line to terminate in a micro spray cap, the spray cap being adjustable to control spray pattern and flow rate.
Thus the present invention specifically addresses the problems inherent in the air conditioner compressor by lowering the temperature, pressure and RLA of the compressor, thereby allowing the compressor to be more efficient and thus have a longer life. The present invention achieves an improved efficiency by implementing a water supply source, which is connected to a first water supply line for providing water to the system, the first water line optionally passing through a mineral filter, a water solenoid box containing (a) electrical circuit means for controlling passage of said water in said water supply line, and for controlling the operation of said system, and (b) a solenoid for controlling passage of water from the first water supply line to a second water supply line that extends from the solenoid and encircles the perimeter of an outdoor housing unit. The first and second water supply lines are separated by the solenoid which opens upon a signal transmitted from an electrical junction box integrated as a part of the outdoor housing unit when the unit is activated (and closes when the unit is shut off) allowing the water to flow when the solenoid is open and stop when it is closed. This is the electrical connection between the outdoor housing unit and the water solenoid box. The second water supply line extending from the solenoid in the solenoid box and surrounds the upper perimeter of outdoor housing unit (containing the condenser and compressor etc.) and has suspended therefrom, a plurality of distribution tubes terminating at their respective ends in a micro spray cap. The micro spray caps are positioned to face the exterior of the outdoor housing unit.
When said system is operating, said water passes through the water supply lines, more particularly through the second water supply line that surrounds the outdoor housing unit, and is discharged through said micro spray caps resulting in a fine mist that is introduced into the interior of the outdoor housing unit thereby causing a reduction in temperature, pressure and running load amperage (RLA) of the compressor within the outdoor housing unit.
Referring to
In operation, thermostat (12) simultaneously energizes indoor blower fan (11), outside condenser fan (5), and compressor (3). Refrigerant (13) enters compressor (3) as a low temperature (LT), low pressure (LP) gas. Compressor's (3) “squeezing” action converts LT/LP gas to high temperature (HT), high pressure (HP) gas as it leaves compressor and enters condenser coil (4). Condenser fan (5) transfers heat from HP/HT gas to the outside air (14); this reduces the gas to a HP/LT liquid (6). HP/LT liquid in line (6) leaves condenser coil (4) and enters evaporator coil (10) through narrow orifice expansion valve (9). As the liquid expands after leaving the expansion valve, it loses pressure reverting to a LT/LP gas. This LT/LP gas, flowing through the evaporator coil (10), absorbs heat from the return air circulated over the evaporator coil (8) by the indoor blower (10) and returns (7) to the compressor (3) to start a new cycle.
When a compressor operates in accordance with the process detailed above for an extended period of time, the deleterious effects of heat become apparent. Such effects of heat on the unit cause a reduction in the compressor efficiency as a function of time it is operated.
The efficiency of an air-conditioning system is improved in accordance with the present invention by the use of application of a coolant to the exterior of the grated outdoor housing unit of the split air-conditioning system. The coolant, preferably water, is supplied in the form of a fine mist which is drawn into the interior of the outdoor housing by virtue of the low pressure created within the outdoor unit as a result of the air movement from the condenser fan which thereby cools the heat generated by the compressor and lowers the pressure at which the refrigerant leaves the compressor.
Filter 51 is included in the elements included in the present invention because it is necessary to eliminate dissolved minerals such as calcium and magnesium in water which would leave hard scale deposits on the outdoor unit when the water dries. In areas where the water is hard or very hard, the local water utility may soften the water to about 5 or 6 gpg. This figure is still considered moderately hard, and in order to operate the present invention effectively, it will be necessary to soften the water further using a filter. An actual in-line filter may not be necessary if the source of water used in accordance with the present invention has been pretreated using an ion exchange water softening treatment in the home to result in “soft” water.
Water solenoid box 52 is controlled by an on/off switch 53 which allows the unit to be shut down when desired, for example, during periods of the year when the air-conditioning unit is not necessary.
Within water solenoid box 52 is an electrically activated solenoid (not shown) which operates when the air conditioning unit is activated. Line 10 is a twenty-four volt line that connects junction box 501 integrated into outdoor housing unit 55 to a junction box (not shown) within water solenoid box 52. When activated, water from line 54′ enters the solenoid valve through an inlet port and flows through an orifice before continuing into an outlet port (see
At a plurality of locations around the upper perimeter of the outdoor housing unit, attached in-line to water supply line 54, there are a number of T-fittings 56, 57, 58, 59, 60, 61. To each of these T-fittings is connected a distribution tube (micro tube) 560, 570, 580. 590, 600 and 610 each of which terminates at its end in a micro spray cap 62, 63, 64, 65, 66, 67 respectively, referred to herein as “spray heads.” It has been found convenient in this embodiment to insert a mid-portion of the distribution tubes within the interior of the grid from water supply line 54 (as indicated by the dashed lines) and position the micro spray caps back out through the louvered spaces so that they are positioned outside the exterior surface of outdoor housing unit 55.
Within water solenoid box 62 is an electrical junction box 600 which contains terminals 601, 602 that secure at one end thereof, the 24 volt circuit connecting wire (collectively comprising hot wire 620 and neutral wire 621) extending from terminals 601 and 602 to terminals 603 and 604 respectively, positioned on terminal block 605 in electrical junction box 606 within the outdoor housing unit 69.
When the operation of compressor, condenser, etc. within outdoor unit 69 is activated, the plunger and solenoid coil (not shown) in solenoid 608 positioned atop valve body 607 is concurrently activated via current sent to it through the 24 volt connection (i.e., hot wire 620 and neutral wire 621). When activated, the plunger is lifted to allow water to flow though line 60 around the periphery of outdoor housing unit 69 through T-fittings 6001, 6002, 6003, 6004 and from said T-fittings into micro-tubes 610, 611, 612, 613 and thence spray heads 614, 615, 616 and 617 respectively. The solenoid system used in accordance with the present invention is more specifically described hereinafter.
On/off switch 609 to control the operation of the system of the present invention is positioned at any convenient location on water solenoid box.
The micro-tubes connected at the T-fittings are threaded downwardly within the interior of outdoor unit 40 before emerging at the exterior sides of outdoor housing unit 40 at the location depicted and terminating at spray heads 4100, 4200, 4300, 4500, 4600 and 4700.
In
The standard outdoor housing unit comprises a top and four sides all louvered. As depicted in
As noted, when the outdoor unit is activated, the solenoid is concurrently activated by an electric current flowing via electrical connector 89 to solenoid coil windings 85 creating an electromagnetic field which in turn pulls plunger 86 upward against the downward tension of spring 87 allowing water to flow through orifice 88. When the solenoid is not activated, plunger 86 is firmly seated over orifice 89 thereby blocking the water in inlet port 82 from flowing.
Solenoid valve 80 requires a constant flow of electrical current in order to remain open because once the current is stopped, the electromagnetic field disperses and the valve returns to its original closed position.
It has been demonstrated that the assembly of the present invention reduces the stress and strain experienced by the compressor and ultimately by the rest of the air conditioning system. When the compressor and the condenser fan motor are operating, the suction resulting from the rotating fan causing a low pressure area, causes the water mist supplied by the 12 spray heads to be drawn into the interior of the outdoor housing through the condenser coil. Results have shown that the application of mist in the manner described takes 30 to 50 lbs/in2 off the compressor while running. The lowering of pressure also reduces the amperage used, thereby lowering electricity costs.
Another benefit of the present invention is if the fan motor fails, the mist on the condenser will be continuously applied, which will keep the hot gas cool enough to run until maintenance can cure the defect.
The following Examples provide data to establish a difference in kind by use of the present invention as opposed to a difference merely in degree.
To demonstrate the efficiency of the system of the present invention, the following comparative test was run.
The elements comprising the system as depicted in
A water-line as shown as element 54 extending from solenoid box 52 was placed around to encircle the upper perimeter of the Goodman unit with eight separate micro-tubes each having a spray head at each terminal end thereof and each being placed equidistant from each other around the perimeter of the Goodman unit.
To establish a base line for comparison of the present invention with the prior art, the Goodman air conditioning unit was operated for two hours without implementing the spray system of the present invention, and then measurements were taken. The readings were taken in the month of August in Phoenix, Ariz. The ambient temperature at the time was 105° F. and the temperature at the exterior surface of the Goodman unit was 142° F.
As noted previously above, the compressor is the engine that keeps coolant circulating through an air conditioning system. The compressor accomplishes this task by creating high and low pressure areas with the use of a moving piston in a sealed chamber. The high and low sides on a home air-conditioning compressor are also known as its high pressure discharge line (See
Pressure readings were taken at the back of the Goodman unit at the suction line on the Goodman unit, which was the line connected to the compressor from the top or higher position on the back of the unit. It was cold to the touch and was wrapped with insulation since this location is where Freon enters the compressor as a gas. The suction pressure reading taken at the end of the two hour air-conditioner run time was 75 psi.
Pressure readings were then taken at the high pressure side, or discharge line, which was the line connected to the compressor from the bottom or lower position. It was not wrapped in insulation and was warm to the touch since this is where Freon exits the compressor as a liquid. The high pressure reading at this location was 275 psi.
A reading of the compressor (depicted in
After taking the base readings as described above, the spray system of the present invention was activated by turning on the water which flowed through the supply line and out the spray heads. The fine mist emitted from the eight spray heads formed spheres of micro droplets which were drawn into the interior of the grated housing unit. After the Goodman unit had operated for 45 minutes and experiencing the fine water droplet mist emanating from the micro caps which mist was drawn into the interior of the outdoor housing unit all in accordance with the system of the present invention, readings were again taken. The temperature at the exterior surface of the Goodman unit was found to be 97° F. Pressure readings were taken at the suction pressure input line which read 58 psi and at the discharge (high pressure) line which read 217 psi. The RLA reading was 21.2 amps.
Table I presented below summarizes the data obtained as a result of the protocol detailed above.
Table I provides the test data obtained from the air-conditioning unit described before and after undergoing the comparative testing in accordance with the present invention.
Note that after the spray treatment of the present invention the suction pressure was lowered by 23%, the discharge high pressure was lowered by 21% and the RLA was lowered by 11%. Further, the exterior temperature of the Goodman unit was lowered 45° F. or 32%. The results of the comparative testing establish a substantial efficiency improvement over the prior art.
A test following the identical sequence of steps as set forth above on a Goodman air-conditioning unit that uses R-410 refrigerant, provides the following results.
Table II set forth above provides the experimental test data from the air conditioning unit described before and after undergoing the comparative testing in accordance with the present invention.
It is noted that when the R-410 refrigerant is used, the compressor pressures are significantly higher, (almost twice as high) than when the R-22 refrigerant is used. This doubling of pressure on the compressor puts a severe strain on it which ultimately lowers its useful life expectancy. Note that after the spray treatment of the present invention, the suction pressure is lowered by 12%, the discharge high pressure is lowered by 14% and the RLA is lowered by 12%. Further, the exterior temperature of the Goodman unit is lowered 50° F. or 32%. The results of the comparative testing establish a substantial efficiency improvement over the prior art.
While all of the fundamental characteristics and features of the present apparatus of the disclosed invention have been described herein, with reference to particular embodiments thereof, a latitude of modification, various changes and substitutions are intended in the foregoing disclosure and it will be apparent that in some instance, some features of the invention will be employed without a corresponding use of other features without departing from the scope of the invention as set forth. It should be understood that any such substitutions, modifications, and variations may be made by those skilled in the art without departing from the spirit or scope of the invention. Consequently, all such modifications and variations are included within the scope of the invention as defined by the following claims.
