Quick cooling air conditioning system

A quick cooling air conditioning system that uses a pressurized reservoir to preserve refrigerant in liquid form after the shutdown of air conditioning compressor. The quick air cooling is achieved by the vaporization of liquid refrigerant, supplied by refrigerant reservoir, at the startup of the conditioning system.

FIELD OF THE INVENTION 
The present invention relates to refrigeration systems. More particularly, 
the present invention describes a means to provide a quick cooling effect. 
BACKGROUND OF THE INVENTION 
An air conditioning system cannot pump heat when the refrigerant is in the 
non-operating equilibrium. Assuming that all other factors remain the 
same, the closer the refrigerant in the system is to the operating 
equilibrium, the more efficient the heat pumping action. When the 
refrigerant in the system is at a non-operating equilibrium, the 
efficiency is zero, even though the compressor may be running. Heat 
pumping efficiency of the air conditioning system increases from zero as 
the refrigerant in the system reaches the operating equilibrium. 
Conventional systems allow the refrigerant to return to a non-operating 
equilibrium when the compressor is turned off. As a result, the air 
conditioning system has no heat pumping action the instant it is turned 
on. As stated above, once the compressor is turned on the efficiency of 
the air conditioning system starts to increase from zero as the 
refrigerant in the system reaches the operating equilibrium. This causes 
the delay from the time the system starts using energy to the time the 
system begins to cool. 
Other attempts to provide quick cooling of an automobile's interior have 
been attempted. One such product that can quickly cool down the internal 
temperature of an automobile, is a pressurized spray can. Apparently the 
cooling effect is achieved by the depressurisation and evaporation of the 
chemical in the spray can. The major disadvantage of the product is that 
it is not reusable and has possible environmental impacts. 
Therefore the primary purpose of the present invention is to provide 
cooling action and to increase the heat pumping efficiency to a positive 
number the instant when the compressor of an air conditioning system is 
turned on. 
SUMMARY OF THE INVENTION 
According to this invention, the time to cool the interior of an automobile 
during the startup can be shortened by the vaporization of liquid 
refrigerant. The liquid refrigerant is supplied by a refrigerant 
reservoir, where the reservoir is an addition to the conventional air 
conditioning system. A scheme has been proposed by this invention to 
integrate the refrigerant reservoir with the conventional air conditioning 
system to make this quick air cooling possible.

DETAILED DESCRIPTION OF THE INVENTION 
A conventional air conditioning system is depicted in FIG. 1. The 
accumulator 105 is shown in two possible places; its placement is not 
important to the present invention. There are generally two equilibrium 
states that the system may be in. The first equilibrium state is referred 
as the non-operating equilibrium. After a system has not been in operation 
for while, the refrigerant will have the same pressure, phase, and 
temperature throughout the system. The second equilibrium state is 
referred to as the operating equilibrium. Referring to FIG. 1, when the 
system is operating in operation equilibrium the following is a list of 
phase and pressure of the refrigerant in the system: 
A) Between compressor 101 and condenser 102: high pressure, has phase, high 
temperature. 
B) Between condenser 102 and expansion valve 103: high pressure, liquid 
phase, a medium temperature 
C) Between expansion valve 103 and evaporator 104: low pressure, gas phase, 
low temperature 
D) Between evaporator 104 and compressor 101: low pressure, gas phase, 
medium temperature. 
It would be apparent to one skilled in the art that for a non-operating 
equilibrium system, when the compressor is first energized, no heat 
pumping action is accomplished. Furthermore, maximum heat pumping action 
is not achieved until the system reaches the operating equilibrium. 
To reduce this inefficiency, the air conditioning system may be used to 
give out cool air immediately if liquid refrigerant is available between 
the condenser 102 and the expansion 103 valve at the beginning of the 
operation of the air conditioning system. 
The preferred embodiment is a modification of the conventional air 
conditioning system. The modification as conceptually shown on FIG. 2, 
consists of the addition of three valves (206-208) and a pressurized 
reservoir for liquid refrigerant 205. Refrigerant accumulator, which is 
normally in the air conditioning system, is not shown in FIG. 2 for 
clarification. However, it may be put in various locations as shown in 
FIG. 1 (105). Physically the accumulator and the reservoir may be combined 
into one unit depending on the actual design. Opening and closing of the 
valves shall be synchronized with the operation of the compressor as 
indicated by the lines. 
Referring to FIG. 2, the present invention consists of a compressor 201, 
condenser 202, expansion valve or similar devices 203, evaporator 204, 
refrigerant reservoir 205, upstream valve 206, downstream valve 207, and 
by-pass valve 208. Note that valve 208 allows the system to return to a 
non-operating equilibrium state when the system is shut off. 
In operation, compressor 201 is running, valves 206 and 207 are open, valve 
208 is closed, and the other parts of the system will operate as in the 
conventional system. As the refrigerant is compressed by the compressor 
201, it changes into a liquid at the condenser 202. As with the 
conventional system, the liquid refrigerant vaporizes at the evaporator 
204 through expansion 203 valve before returning to the compressor. The 
air cooling is achieved by the heat absorption due to the vaporization of 
liquid refrigerant at the evaporator. 
When the compressor 201 is turned off, the valves 206 and 207 are closed, 
and valve 208 is opened. Thus, liquid refrigerant is trapped in the 
reservoir and stays in the liquid phase under ambient temperatures. 
Refrigerant in the rest of the system reaches the non-operating 
equilibrium state. 
When the compressor 201 is turned on again, valves 206 and 207 are opened, 
and valve 208 is closed. Liquid refrigerant in the reservoir 205 will flow 
through expansion valve 203 (or similar devices) to evaporator 204 to 
provide quick cooling at the instant when the air conditioner is turned 
on. The time for the refrigerant in the preferred embodiment to achieve 
the operating equilibrium after turned on is greatly reduced compared to 
the time required for the conventional air conditioning system. Thus, the 
preferred embodiment has a positive heat pumping efficiency at start up 
while the conventional air conditioning system has zero efficiency at 
start up. 
It may be necessary to delay the switching of valves 206-208 to allow the 
compressor to come up to speed first thereby reducing startup stress on 
compressor 201. Another possible solution, valve 206 could remain closed 
while valve 208 is closed and 207 is opened. This will keep the liquid 
refrigerant from back flowing into the compressor 201. 
The preferred embodiment provides several advantages to other quick cooling 
solutions. The preferred embodiment can be added to existing 
air-conditioning systems with minimal modification to the original air 
conditioning system. Reservoir 205 and valves 206-208 could all be 
manufactured into to a single component. Assuming that the accumulator 
(105 in FIG. 1) is between the condenser 102 and expansion valve 103, the 
single component can simply replace the accumulator. 
This quick cooling system requires a relatively simple control system. 
Basically, the system must only open valves 206 and 207, close valve 208, 
when compressor 201 is turned on; close valves 206 and 207, open valve 
208, when compressor 201 is turned off. 
Another advantage of the preferred embodiment is the minimal use of 
mechanical moving parts, hence high reliability. The three additional 
valves (206-208) will not reduce the overall reliability of the system by 
a significant amount. Generally, leaks and faulty compressors are the 
primary source of system failures. An increased failure rate for the 
compressor could be caused by allowing the high pressure liquid in the 
reservoir to back flow into the compress during start-up of the 
compressor. This can be reduced by proper sequencing of the new valves as 
discussed above. 
Several modifications are possible to the preferred embodiment. This 
includes: 
1. Valve 208 could be a check valve or a small diameter tube like a 
capillary tube. 
2. Valve 206 may be moved to a location between compressor 201 and 
condenser 202. Valve 208 has to be moved accordingly to provide the safety 
mechanism and allow the system to return to a non-operating equilibrium 
state during shutoff. 
3. Other control mechanism for the valves is possible. For example, open 
valves 206 and 207, and closing valve 208, when the compressor 201 is 
turned on. Then, close valves 206 and 207, and open valve 208, when 
pressure at the reservoir reaches at certain pressure. To reduce start-up 
demand on the compressor, during the start-up period of the compressor, 
valve 206 could remain closed while valve 208 is closed and 207 is opened. 
The same principle can also be used for other refrigeration system to 
reduce the time required to achieve refrigeration temperature. The 
principle can also be adapted to non-conventional air 
conditioning/refrigeration system so long as their cooling rate can be 
improved by the release of stored working medium during startup period. 
In short, the present invention stores the liquid refrigerant produced by 
the system in operation in a reservoir. Thereby keeping the stored 
refrigerant under pressure and in a liquid phase when the compressor is 
turned off. To achieve quick cooling, the stored refrigerant is released 
to the evaporator through the expansion valve when the compressor is 
turned on (at startup). 
Although the preferred embodiment of the invention has been illustrated, 
and that form described, it is readily apparent to those skilled in the 
art that various modifications may be made therein without departing from 
the spirit of the invention or from the scope of the appended claims.