JPH07269963A - Heat pump type air conditioner - Google Patents

Abstract

PURPOSE:To increase a life of a compressor without impairing cooling capacity while using a non-azeotropic refrigerant as refrigerant. CONSTITUTION:The heat pump type air conditioner comprises an indoor heat exchanger 5, an outdoor heat exchanger 9, a compressor 3, in which a non- azeotropic refrigerant having a high boiling point refrigerant and a low boiling point refrigerant is used, and a receiver tank 17 for separating the liquid refrigerant at an outlet side of the exchanger 9 which is operated as an evaporator at the time of heating. With this structure, when the liquid refrigerant is stored in the tank 17 because the atmospheric temperature is low and the outdoor exchanger cannot sufficiently absorb heat while part of the refrigerant is not evaporated and passed, and only the gas is supplied to the compressor. Accordingly, shortening of a compressor's life due to so-called wet vapor suction can be prevented. At the time of cooling, only the tank 17 is provided, and hence a pressure loss not occur, and then capacity of the cycle is not lowered.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat pump type air conditioner using a non-azeotropic mixed refrigerant composed of a high boiling point refrigerant and a low boiling point refrigerant.

[0002]

2. Description of the Related Art Generally, as shown in FIG. 2, a refrigerant circuit of a heat pump type air conditioner has a compressor 51, an indoor heat exchanger 52, a pressure reducing device 53, an indoor heat exchanger 53, and a flow path switching valve. It is composed of a four-way valve 54 and an accumulator 55. During heating operation, the refrigerant is circulated in this order as shown by the solid arrow in FIG. 2, and during cooling operation, the four-way valve is switched as shown by the dashed arrow. Refrigerant is circulated in the opposite direction to that during heating operation.

By switching the operation of such a flow path,
Cooling operation and heating operation are performed by one circuit.

On the other hand, in such a heat pump type heat exchanger, when a single refrigerant (for example, R-22) is used as the refrigerant, all the refrigerant is not evaporated in the outdoor heat exchanger during the heating operation. Outdoor heat exchanger 53 with part not evaporated
When it is derived from the above, the liquid refrigerant is prevented from entering the compressor by the accumulator 55 to protect the compressor.

[0005]

However, as the refrigerant,
When a non-azeotropic mixed refrigerant composed of a high boiling point refrigerant and a low boiling point refrigerant is used and the outside air temperature is low, the high boiling point refrigerant of the non-azeotropic mixed refrigerant enters the accumulator without being evaporated.
Therefore, the amount of the low boiling point refrigerant in the refrigerant circuit becomes large, and the ratio of the high boiling point refrigerant and the low boiling point refrigerant of the non-azeotropic mixed refrigerant fluctuates with respect to a predetermined value, and the predetermined refrigerant capacity may not be exhibited There is. In addition, there is a problem that the amount of liquid that has not been evaporated increases and causes damage to the compressor due to liquid compression.

In such a case, in order to sufficiently evaporate the high boiling point refrigerant, it is conceivable to increase the capacity of the heat exchanger or lower the evaporation pressure as compared with the conventional one. However, increasing the heat exchange capacity increases the manufacturing cost. Furthermore, when the evaporation pressure decreases, the evaporation temperature of the low-boiling-point refrigerant decreases, and even when the outside air temperature is relatively high, frost forms, the amount of heat pumped up is reduced, and the heating capacity decreases.

On the other hand, in order to avoid such inconvenience, it is conceivable to increase the capacity of the accumulator.
When the capacity of the accumulator is increased, the pressure loss in the refrigerant circuit increases, and there is a disadvantage that the cooling capacity decreases during the cooling operation.

The present invention has been made in order to solve the above problems, and uses a non-azeotropic mixed refrigerant as a refrigerant, which does not impair the refrigerating capacity and can prolong the life of the compressor. The purpose is to provide a harmony machine.

[0009]

DISCLOSURE OF THE INVENTION The present invention relates to an indoor heat exchanger that acts as an evaporator during cooling and as a condenser during heating, and an outdoor heat exchanger that acts as a condenser during cooling and as an evaporator during heating. , A heat pump type air conditioner using a non-azeotropic mixed refrigerant consisting of a high boiling point refrigerant and a low boiling point refrigerant, comprising a compressor, at the outlet side of the outdoor heat exchanger, a receiver tank for separating the liquid refrigerant is provided. ing.

The present invention also includes a compressor, an indoor heat exchanger that acts as an evaporator during cooling and a condenser during heating, and an outdoor heat exchanger that acts as a condenser during cooling and act as an evaporator during heating. , A heat pump type air conditioner using a non-azeotropic mixed refrigerant comprising a high boiling point refrigerant and a low boiling point refrigerant, comprising a flow path switching valve for switching the flow path during cooling and heating, wherein the outdoor heat exchanger and the flow A receiver tank for separating the liquid refrigerant is provided between the switching tank and the path switching valve.

[0011]

In the heating operation, the refrigerant is supplied to the outdoor heat exchanger through the pressure reducing device, and the refrigerant absorbs heat from the outside air and is vaporized.

However, when the outside air temperature is low, a sufficient amount of heat cannot be absorbed in the outdoor heat exchanger, so some of the refrigerant passes without being vaporized, but the refrigerant passing through the outdoor heat exchanger receives the refrigerant. Introduced into the tank. In this receiver tank, liquid and gas are separated and only gas is supplied to the compressor.

Therefore, the shortening of the life of the compressor due to the so-called liquid bag is prevented.

Further, since the high boiling point liquid refrigerant remains in the receiver tank during the heating operation, the circulation flow rate ratio of the low boiling point refrigerant in the refrigeration cycle increases. As a result, the difference between the outside air temperature and the evaporation temperature becomes large and the pumping heat amount increases,
The heating operation can be performed efficiently.

Further, in the structure having the accumulator in the refrigerant circuit, especially when the outside air temperature is low, the non-evaporated high boiling point refrigerant is retained also in the accumulator,
It is possible to reliably prevent the liquid refrigerant from entering the compressor.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 is a circuit diagram of a heat pump type air conditioner according to an embodiment of the present invention. The air conditioner according to this embodiment uses a non-azeotropic mixed refrigerant composed of a high boiling point refrigerant and a low boiling point refrigerant as the refrigerant circulating in the refrigerant circuit.

In the refrigerant circuit shown in FIG. 1, a compressor 3, an indoor heat exchanger 5, a pressure reducing device 7, an outdoor heat exchanger 9, a four-way valve 11 as a flow path switching valve, and an accumulator 13 are arranged in this order. The receiver tank 17 is arranged between the outdoor heat exchanger 9 and the four-way valve 11.

The outdoor heat exchanger 9 and the indoor heat exchanger 5 are each provided with a fan 20 so as to exchange heat with indoor air or outdoor air.

The outdoor heat exchanger 9 functions as a condenser during cooling and functions as an evaporator during heating, and the indoor heat exchanger 5 functions as an evaporator during cooling and functions as a condenser during heating. .

The four-way valve 11 is positioned so that the refrigerant flows as shown by the broken line during the cooling operation, and as shown by the solid line during the heating operation. In this way, by switching the four-way valve, the refrigerant flow paths for cooling and heating can be switched.

The receiver tank 17 is designed to operate during heating operation.
The refrigerant that has passed through the outdoor heat exchanger 9 is introduced from below by the introduction pipe 17a, and the gas above is taken out from the extraction pipe 17b.

Therefore, the liquid refrigerant of the refrigerant introduced into the receiver tank 17 is stored in the receiver tank, and only the gaseous refrigerant is drawn out and introduced into the compressor 3 through the accumulator 13. For this reason, so-called liquid back that the liquid refrigerant returns to the compressor can be prevented.

Such a liquid bag is used in the accumulator 1
Although it can be prevented by 3, even when the liquid amount is large, since the capacity is limited, when using a non-azeotropic mixed refrigerant consisting of a high boiling point refrigerant and a low boiling point refrigerant as the refrigerant,
Liquid back can be sufficiently prevented even if the amount of unvaporized liquid refrigerant increases.

The receiver tank 17 is provided on the outlet side of the outdoor heat exchanger 9 which functions as an evaporator during heating, in other words, it is arranged on the outlet side of the outdoor heat exchanger 9 during heating operation. . This is because by providing the receiver tank 17 on the outlet side of the outdoor heat exchanger 9 as described above, the pressure loss from the outdoor heat exchanger 9 to the suction of the compressor 3 is not increased. That is, before the accumulator 13,
Further, if the accumulators are arranged in series, the pressure loss will increase, but by arranging the receiver tank 17, it is possible to prevent such an increase in pressure loss. Therefore, during the cooling operation, the refrigerant cycle can be formed without any trouble.

As the refrigerant, a non-azeotropic mixed refrigerant composed of a high boiling point refrigerant and a low boiling point refrigerant is used.
A mixed refrigerant of R134a (chemical formula; CH ₂ FCF ₃ ), R125 (chemical formula; C ₂ HF ₅ ) and R32 (chemical formula; CH ₂ F ₂ ) is used.

The boiling point of R134a is generally -26 ° C.
The boiling point of R125 is −48 ° C., and the boiling point of R32 is −52 ° C.

Next, the operation of the above embodiment will be described.

During the heating operation, as shown by the solid line arrow in FIG. 1, the order of the compressor 3, the indoor heat exchanger 5, the pressure reducing device 7, the outdoor heat exchanger 9, the receiver tank 17, the four-way valve 11, and the accumulator 13 is set. The refrigerant is circulated.

The refrigerant introduced from the decompression device 7 into the outdoor heat exchanger 9 is operated by the outdoor heat exchanger 9 as an evaporator, and the refrigerant is vaporized to pump up heat from the outside air, but when the outside air temperature is low. In the mixed refrigerant, the high-boiling point refrigerant has a large amount of non-evaporated and passes through the outdoor heat exchanger 9 in a liquid state.
However, the refrigerant that has passed through the outdoor heat exchanger 9 is conveyed to the receiver tank 17, where it is separated into gas and liquid, and only gas is supplied to the compressor 3 via the accumulator 13.

Therefore, when the outside air temperature is low, the liquid refrigerant is separated and retained in the receiver tank 17 and only the gas is supplied to the accumulator 13 even if the amount of non-evaporated refrigerant increases, so that the liquid refrigerant accumulates in the accumulator. Thirteen
It is possible to prevent exceeding the limit amount of.

As described above, since the so-called liquid back, in which the accumulator 13 exceeds the limit amount and liquid enters the compressor 3, it is possible to prevent the life of the compressor 3 from being shortened due to the liquid back.

Further, during the heating operation, since the high boiling point liquid refrigerant remains in the accumulator 13, the circulation flow rate ratio of the low boiling point refrigerant in the refrigeration cycle increases. As a result, the difference between the outside air temperature and the evaporation temperature becomes large, and the heating operation can be efficiently performed. During the cooling operation, the refrigerant flows in the opposite direction to the heating operation. That is, the refrigerant is circulated in the order of the compressor 3, the receiver tank 17, the outdoor heat exchanger 9, the pressure reducing device 7, and the indoor heat exchanger 5.

In such a cooling operation, it is possible to obtain the same capacity as a normal cooling cycle. That is, when the capacity of the accumulator is increased, the pressure loss increases in proportion to the increase of the capacity of the refrigeration cycle, but since the capacity of the accumulator is not increased in the present embodiment,
Such a reduction in ability does not occur.

[0035]

According to the present invention, since the outside air temperature is low during heating operation using a non-azeotropic mixed refrigerant composed of a high boiling point refrigerant and a low boiling point refrigerant as the refrigerant, sufficient heat is generated in the outdoor heat exchanger. Is not absorbed and a part of the refrigerant passes without being vaporized, the liquid refrigerant is retained in the receiver tank, and only the gas is supplied to the compressor. Therefore, the shortening of the life of the compressor due to the so-called liquid bag is prevented.

Further, during the heating operation, the high-boiling-point liquid refrigerant among the high-boiling-point refrigerant and the low-boiling-point refrigerant remains as a liquid in the receiver tank, so that the circulation flow ratio of the low-boiling point refrigerant in the refrigeration cycle increases. As a result, the difference between the outside air temperature and the evaporation temperature becomes large, and the heating operation can be efficiently performed.

Since only the receiver tank is provided during the cooling operation, there is no particular pressure loss and the refrigeration cycle capacity is not reduced.

Further, in the structure having the accumulator in the refrigerant circuit, especially when the outside air temperature is low, the non-evaporated high boiling point refrigerant is retained also in the accumulator,
It is possible to reliably prevent the liquid refrigerant from entering the compressor.

[Brief description of drawings]

FIG. 1 is a refrigerant circuit diagram showing an embodiment of a heat pump type air conditioner of the present invention.

FIG. 2 is a refrigerant circuit diagram of a conventional heat pump type air conditioner.

[Explanation of symbols]

 3 Compressor 5 Indoor heat exchanger 9 Outdoor heat exchanger 11 Four-way valve (flow path switching valve) 17 Receiver tank

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Naoto Sakamoto 2-5-5 Keihan Hondori, Moriguchi City, Osaka Sanyo Electric Co., Ltd.

Claims (2)

[Claims] 1. An indoor heat exchanger that functions as an evaporator during cooling and a condenser during heating, an outdoor heat exchanger that functions as a condenser during cooling, and an evaporator during heating, and a compressor, respectively. In a heat pump type air conditioner using a non-azeotropic mixed refrigerant consisting of a boiling point refrigerant and a low boiling point refrigerant, the outlet side of the outdoor heat exchanger, a heat pump type characterized by providing a receiver tank for separating the liquid refrigerant Air conditioner. 2. A compressor, an indoor heat exchanger that acts as an evaporator during cooling and a condenser during heating, an outdoor heat exchanger that acts as a condenser during cooling, and an evaporator during heating, respectively, and during cooling. A heat pump type air conditioner that includes a flow path switching valve that switches the flow path during heating, and uses a non-azeotropic mixed refrigerant composed of a high boiling point refrigerant and a low boiling point refrigerant, wherein the outdoor heat exchanger and the flow path switching valve A heat pump type air conditioner characterized in that a receiver tank for separating the liquid refrigerant is provided between the two.