JPS63302268A - Air conditioner - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a heating and cooling system having a vapor compression refrigerant circuit.

<Conventional technology> In recent years, heat pump type air-conditioning equipment has improved its functionality by incorporating inverters and cycle control using microprocessors, and is also superior in safety and cleanliness, so it has gained its status as a household air-conditioning equipment. has been established.

Furthermore, future research and development will lead to even higher functionality and efficiency, and we can expect a dramatic increase in demand.

The use of non-azeotropic mixed refrigerants can be considered as one way to improve the functionality and efficiency of heat pump cycles.

Most conventional heat pump air conditioning systems use a single refrigerant, forming the following cycle.

Figure 2 shows the cycle of a conventional heat pump air conditioning system. Solid arrows indicate the flow of refrigerant during cooling, and dashed arrows indicate the flow of refrigerant during heating. During cooling operation, high temperature discharged from compressor 1,
The high-pressure refrigerant vapor enters the outdoor heat exchanger 13 via the electromagnetic four-way valve 12, radiates heat to the outdoor air, and condenses. The condensed refrigerant is depressurized by the expansion valve 14 and becomes low temperature and pressure, and is vaporized by absorbing heat from the indoor air in the indoor heat exchanger 15. The vaporized refrigerant was sucked into the compressor 11 and turned into high-temperature, high-pressure steam again, forming a cooling cycle.

On the other hand, during the heat pump heating operation, the high temperature, high pressure refrigerant vapor discharged from the compressor 2 first enters the indoor heat exchanger 15 via the electromagnetic four-way valve 12, radiates heat to the indoor air, and condenses.

The condensed refrigerant is depressurized by the expansion valve 14 to become low temperature and low pressure, and is vaporized by absorbing heat from the outdoor air in the outdoor heat exchanger 13. The vaporized refrigerant was sucked into the compressor 11 and turned into high-temperature, high-pressure steam again, forming a heating cycle.

<Problems to be Solved by the Invention> The conventional cycle described above is a cycle for a single refrigerant such as R12 or R22, and the flow of the refrigerant is reversed between cooling and heat pump heating.

In the case of a single refrigerant, at a constant pressure, the vapor and condensation processes are isothermal changes and did not pose any particular problem.

Non-azeotropic mixed refrigerants (e.g. R12-Rl3B1, R1
52a-R13Bl, R22-Rll.

In the evaporator of the refrigerant circuit using a mixture of R22-Rl3B1), the refrigerant liquid becomes refrigerant vapor while maintaining vapor-liquid equilibrium. During this time, the evaporation temperature gradually increases. In the condenser, the condensation temperature is exactly the opposite, and the condensation temperature gradually decreases. on the other hand,
In the evaporator, air loses heat and becomes lower in temperature, and in the condenser, it gains heat and becomes higher in temperature. Table 1 summarizes these temperature relationships.

This refrigerant circuit for non-azeotropic mixed refrigerants reduces heat exchange losses between the refrigerant and the cooling fluid or heating fluid by using the characteristic that the phase change temperature depends on the concentration by performing heat exchange in a countercurrent manner. and improve the coefficient of performance. Countercurrent method refers to piping in which the refrigerant inlet is located in the most leeward row and the outlet is located in the most windward row, so that the refrigerant flows sequentially from the leeward row to the upwind row. This refers to cases where The opposite case is called parallel current method.

In the conventional heat pump cycle, as mentioned above, the flow of refrigerant is completely opposite during cooling and heating, and the flow of air to the heat exchanger by the blower is always in the same direction. Therefore, a refrigerant circuit that performs countercurrent heat exchange during cooling operation uses parallel current heat exchange during heating operation, and a refrigerant circuit that performs countercurrent heat exchange during heating operation uses parallel current heat exchange during cooling operation. Since it was replaced, it was not possible to use a countercurrent system for both cooling and heating.

The present invention was devised in view of these points, and provides an air-conditioning/heating device that uses a countercurrent type evaporator and condenser for both cooling and heating.

<Means for Solving the Problem> The means for solving the problem according to the present invention, as shown in FIG. A vapor compression type refrigerant circuit X using a boiling mixed refrigerant is provided, and the refrigerant circuit The suction port of the compressor 1 is branch-connected to the refrigerant inlet B of the indoor heat exchanger 2 and the refrigerant outlet B of the outdoor heat exchanger 3 via the suction switching valve 5. The inlet E of the valve 6 is connected to the outlet B of the indoor heat exchanger 2 via a first check valve 7, and is connected to the outlet of the outdoor heat exchanger 3 via a second check valve 8. , an outlet F of the expansion valve 6 is connected to the inlet A of the indoor heat exchanger 2 via a third check valve 9, and a fourth check valve l is connected to the inlet C of the outdoor heat exchanger 3.
They are connected via O.

<Operation> In the problem solving means described above, during cooling operation, the refrigerant discharged from the compressor 1 passes through the discharge switching valve 4, and then is reverse-controlled by the fourth appropriate valve IO and is transferred to the refrigerant inlet C of the outdoor heat exchanger 3. It flows into the outdoor heat exchanger 3 from there. After passing through the second check valve 8, the air does not flow into the indoor heat exchanger 2 due to the first check valve 7, but instead flows into the expansion valve 6. Next, the refrigerant flows into the indoor heat exchanger 2 from the refrigerant inlet A of the indoor heat exchanger 2 through the third check valve 9, passes through the suction switching valve 5, and then returns to compressed ml.

In addition, during heating operation, the refrigerant discharged from the compressor 1 passes through the discharge switching valve 4, and then is checked by the third check valve 9 and flows from the refrigerant inlet A of the indoor heat exchanger 2 to the indoor heat exchanger 2. flows into. Then, after passing through the first check valve 7, the second check valve 8 prevents the air from flowing into the outdoor heat exchanger 3, but flows into the expansion valve 6. Next, the refrigerant flows into the outdoor heat exchanger 3 from the refrigerant inlet C of the outdoor heat exchanger 3 via the fourth check valve IO, passes through the suction switching valve 5, and then returns to the compressor 1 again. At this time, in the indoor heat exchanger 2 and the outdoor heat exchanger 3, air flows from refrigerant outlets B and D to inlets A and C, always in a constant direction.

As described above, the flow of refrigerant in the indoor heat exchanger 2 and outdoor heat exchanger 3 is in the same direction during both cooling and heating operations.
The flow of refrigerant and air can be made countercurrent for both heating and cooling.

<Embodiment> FIG. 1 is a system diagram of a heating and cooling device showing an embodiment of the present invention. This device uses a refrigerant circuit X using a non-azeotropic mixed refrigerant.
However, compression 4111. indoor heat exchanger 2, outdoor heat exchanger 3,
Discharge switching valve 4, suction switching valve 5, expansion valve 6, first check valve 7
, a second check valve 8, a third check valve 9, and a fourth check valve 10.

A discharge port of the compressor 1 is connected to a refrigerant inlet A of the indoor heat exchanger 2 and a refrigerant inlet C of the outdoor heat exchanger 3 via a discharge switching valve 4 . The suction side of the compressor I is connected to the refrigerant outlet B of the indoor heat exchanger 2 and the refrigerant outlet of the outdoor heat exchanger 3 via the suction switching valve 5. The inlet E of the expansion valve 6 is connected to the refrigerant outlet B of the indoor heat exchanger 2 and the refrigerant outlet B of the outdoor heat exchanger 3 via a first check valve 7 and a second check valve 8, respectively. . An outlet F of the expansion valve 6 is connected to a refrigerant inlet A of the indoor heat exchanger 2 and a refrigerant inlet C of the outdoor heat exchanger 3 via a third check valve 9 and a fourth check valve IO, respectively.

Next, the operation of the air conditioning system will be explained. The wavy arrow G of the indoor heat exchanger 2 represents the flow of indoor air, and the wavy arrow H of the outdoor heat exchanger 3 represents the flow of outdoor air. This air always flows in one direction. In addition, the flow of refrigerant is shown by solid line arrows during cooling operation, and by broken line arrows during heating operation.

During the cooling operation, the discharge switching valve 4 is opened in the direction of the solid arrow ■, and the suction switching valve 5 is opened in the direction of the solid arrow J.

First, high-temperature, high-pressure refrigerant vapor discharged from the compressor 1 passes through the discharge switching valve 4, is checked by the fourth check valve 10, and flows into the outdoor heat exchanger 3 from the refrigerant inlet C. Outdoor heat exchanger 3
The heat is discharged into the outdoor air, and the refrigerant condenses and liquefies. Next, the liquid passes through the second check valve 8, is checked by the first check valve 7, and flows into the expansion valve 6, where it is depressurized and becomes a low-temperature, low-pressure gas-liquid mixed state. and check valve 9. Depending on the relationship between the direction of IO and the refrigerant pressure, the refrigerant inlet A passes through the third check valve 9 and enters the indoor heat exchanger 2.
The indoor heat exchanger 2 absorbs heat from the indoor air and performs cooling. Through this heat exchange, the refrigerant becomes a low-temperature, low-pressure vapor, which is sucked into the compressor 1 via the suction switching valve 5, and the cycle of being compressed again is repeated.

During heating operation, the discharge switching valve 4 opens in the direction of the broken line arrow, and the suction switching valve 5 opens in the direction of the broken line arrow.

First, high-temperature, high-pressure refrigerant vapor discharged from the compressor 1 passes through the discharge switching valve 4, is checked by the third check valve 9, and flows into the indoor heat exchanger 2 from the refrigerant inlet A. Heating is performed by transferring heat to the indoor air. Through this heat exchange, the refrigerant condenses and liquefies, then passes through the first check valve 7, is checked by the second check valve 8, and flows into the expansion valve 6, where it is depressurized and becomes a low-temperature, low-pressure gas-liquid mixed state. Become. and check valve 9.
Depending on the relationship between the direction of lO and the refrigerant pressure, the refrigerant flows into the outdoor heat exchanger 3 from the refrigerant inlet C via the fourth check valve 10, collects heat from the outdoor air in the outdoor heat exchanger 3, becomes low temperature and low pressure steam, and is switched to suction. It is sucked into the compression It via the valve 5, and the cycle of being compressed again is repeated.

As shown above, in both cooling and heating operations, the refrigerant in the indoor heat exchanger 2 flows from the refrigerant inlet A to the refrigerant outlet B, performing countercurrent heat exchange with the indoor air.

Further, in the outdoor heat exchanger 3, the refrigerant flows from the refrigerant inlet C to the refrigerant outlet, and performs countercurrent heat exchange with the outdoor air.

Note that fin-tube heat exchangers are generally used for refrigerant-air heat exchangers in air conditioning equipment, and in a single-row heat exchanger, the refrigerant and air flow in cross flow, and cannot flow in countercurrent or parallel flow. . When there are two or more rows of fin-tube heat exchangers, the refrigerant inlet is located in the most leeward row, the outlet is located in the most windward row, and the refrigerant is sequentially distributed upwind from the leeward row. Countercurrent flow occurs when piping is arranged so that the flow flows in rows. The opposite case is parallel flow. In reality, the refrigerant and air flow in a cross flow in each row, so strictly speaking, it is a mixture of cross flow and countercurrent flow, but this will be referred to as countercurrent flow here. Therefore, in a fin-tube heat exchanger, the larger the number of rows, the greater the effect of counterflow.

<Effects of the Invention> As is clear from the above explanation, non-azeotropic mixed refrigerants are used in evaporators (indoor heat exchangers during cooling, outdoor heat exchangers during heating).
The temperature of the refrigerant increases as heat is exchanged. on the other hand,
In a condenser (an outdoor heat exchanger during cooling, an indoor heat exchanger during heating), the temperature of the refrigerant decreases as heat is exchanged. In the heating and cooling apparatus according to the present invention, heat exchange is performed in a countercurrent manner between the refrigerant and air, so that heat exchange loss in the indoor heat exchanger or the outdoor heat exchanger can be reduced.

Furthermore, due to the reduction in heat exchange loss in the evaporator, the temperature of the refrigerant sucked into the compressor increases, and the suction pressure increases. This increases the density of the refrigerant, increases the refrigerant mass flow rate of the compressor, and improves the capacity.

In addition, due to the decrease in heat exchange loss in the condenser, the temperature of the refrigerant discharged from the compressor decreases and the discharge pressure decreases, but due to the above-mentioned increase in suction pressure and decrease in discharge pressure, the compression ratio of the compressor decreases. , the coefficient of performance can be improved.

[Brief explanation of the drawing]

FIG. 1 is a system diagram of a heating and cooling device showing an embodiment of the present invention, and FIG. 2 is a system diagram of a conventional heating and cooling device. 1: Compressor, 2: Indoor heat exchanger, 3; Outdoor heat exchanger, 4
: Discharge switching valve, 5: Suction switching valve, 6: Expansion valve, 7: First check valve, 8: Second check valve, 9: Third check valve, lO: Fourth check valve, ll: Compressor, 12: Solenoid four-way valve, 13 Two outdoor heat exchangers, 14: Expansion valve, 15. Indoor heat exchanger, X: Refrigerant circuit.

Claims (1)

[Claims] A refrigerant circuit is provided that includes a compressor, an indoor heat exchanger, an outdoor heat exchanger, and an expansion valve and uses a non-azeotropic mixed refrigerant. connected to a refrigerant inlet of the heat exchanger and a refrigerant inlet of the outdoor heat exchanger, and a suction port of the compressor is connected to a refrigerant outlet of the indoor heat exchanger and a refrigerant outlet of the outdoor heat exchanger via a suction switching valve;
The inlet of the expansion valve is connected to the outlet of the indoor heat exchanger via a first check valve and the outlet of the outdoor heat exchanger via a second check valve, and the outlet of the expansion valve is connected to the outlet of the indoor heat exchanger via a first check valve. An air-conditioning/heating device, characterized in that it is connected to the inlet of the indoor heat exchanger via a third check valve, and is connected to the inlet of the outdoor heat exchanger via a fourth check valve.