JPH09152204A - Refrigerating cycle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate the supercooling of non-azeotrope refrigerant and to attempt to improve the efficiency of the refrigerating cycle by providing means for heat exchanging the refrigerant tube of a condenser outlet side with the refrigerant tube of a compressor suction side in the cycle using the non- azeotrope refrigerant as the refrigerant. SOLUTION: In the refrigerating cycle using non-azeotrope refrigerant as the refrigerant of an air conditioner, a condenser 12, a throttle mechanism 12 and an evaporator 13 are sequentially connected to the refrigerant discharge unit of a compressor 10 via tubes to return refrigerant gas to the suction unit of a compressor 10 via a suction cup 14. In this case, a heat exchanger 15 is provided at the refrigerant tube Pa for communicating the condenser 11 with the mechanism 12 of the refrigerant tube at the outlet side of the condenser 11 and the refrigerant tube Pb for communicating the evaporator 13 with the suction unit of the compressor 0 of the refrigerant tube at the suction side of the compressor 10. Thus, the non-azeotrope refrigerant can be facilitated to be supercooled, getting large evaporating latent heat, thereby attempting to improve the efficiency of the refrigerating cycle.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a refrigeration cycle using a non-azeotropic mixed refrigerant in, for example, an air conditioner.

[0002]

2. Description of the Related Art For example, a refrigeration cycle of an air conditioner is
Conventionally, it is configured as shown in FIG. This is a so-called heat pump type refrigeration cycle circuit capable of switching between heating and cooling operations. In the figure, 1 is a compressor, 2 is a four-way valve as a switching valve, 3 is an outdoor heat exchanger, 4 is a throttling mechanism, 5
Is an indoor heat exchanger, 6 is an accumulator, and 7 is a suction cup.

During the cooling operation, the high-pressure refrigerant gas discharged from the compressor 1 is guided as shown by the solid line arrow in the figure.
That is, the order is: compressor 1-four-way valve 2-outdoor heat exchanger 3-throttle mechanism 4-indoor heat exchanger 5-four-way valve 2-accumulator 6-suction cup 7-compressor 1. The refrigerant evaporates in the indoor heat exchanger 5, and the latent heat of evaporation is taken from the air in the air-conditioned room introduced therein to lower the temperature, thereby performing a cooling function.

During heating operation, the four-way valve 2 is switched.
The high-pressure refrigerant gas discharged from the compressor 1 is guided as shown by the broken line arrow in the figure. That is, the order is compressor 1-four-way valve 2-indoor heat exchanger 5-throttle mechanism 4-outdoor heat exchanger 3-four-way valve 2-accumulator 6-suction cup 7-compressor 1. The refrigerant is condensed in the indoor heat exchanger 5, and the heat of condensation is released to the air in the air-conditioned room introduced therein to raise its temperature to perform a heating function.

[0005]

A refrigerating cycle of an air conditioner has conventionally used a refrigerant called R22. With such a single refrigerant, for example, in the indoor heat exchanger 5 during cooling operation. The evaporation temperature is almost constant (same pressure) in each part.

However, there is a case where a non-azeotropic mixed refrigerant in which, for example, R32 and R134a are mixed to form a CFC substitute. Other non-azeotropic refrigerants, R32 and R
There is also a mixture of 125 and a mixture of R134a with R32 and R125.

In any case, the non-azeotropic mixed refrigerant is composed of a combination of two or three freons, and is characteristic in that it has a temperature gradient between the refrigerant inlet and outlet of the heat exchanger. Therefore, it is necessary to design in consideration of this temperature gradient.

In the refrigeration cycle using the non-azeotropic mixed refrigerant, the temperature of the condenser as the heat exchanger decreases from the refrigerant inlet portion to the refrigerant outlet portion. That is, the difference between the outside air temperature and the refrigerant temperature becomes small at the outlet portion where the refrigerant temperature is low.

On the other hand, the single refrigerant conventionally used has almost no problem because the actual temperature gradient is only the pressure loss, and the difference is extremely small. Therefore, in a refrigeration cycle using a non-azeotropic mixed refrigerant, it is more difficult to achieve supercooling than in a refrigeration cycle using a single refrigerant. As a result of not being able to take sufficient subcooling, there is a problem that the dryness of the refrigerant is increased after the refrigerant is expanded, the latent heat of vaporization is decreased, and the refrigeration cycle efficiency is reduced.

The present invention has been made in view of the above circumstances, and an object of the present invention is to facilitate the supercooling of a non-azeotropic mixed refrigerant in a refrigeration cycle using the non-azeotropic mixed refrigerant. It is intended to provide a refrigeration cycle capable of improving the refrigeration cycle efficiency.

[0011]

In order to satisfy the above object, the refrigeration cycle of the present invention is, as a first aspect, a refrigeration cycle in which a compressor, a condenser, a throttle mechanism and an evaporator are sequentially connected via a refrigerant pipe. A refrigeration cycle that includes a circuit and uses a non-azeotropic mixed refrigerant as a refrigerant, wherein the condenser outlet side refrigerant pipe and the compressor suction side refrigerant pipe are provided with means for exchanging heat with each other. And

As a second aspect, at least one of an accumulator and a suction cup is provided in the refrigerant pipe on the compressor suction side according to the first aspect, and the heat exchange means is at least one of the accumulator and the suction cup. One side and the refrigerant pipe on the outlet side of the condenser are heat-exchanged with each other.

As a third aspect, the refrigeration cycle circuit according to the first aspect is a heat pump type refrigeration cycle circuit capable of switching between heating and cooling operations, and the heat exchange means includes:
It is characterized in that it acts both during cooling operation and during heating operation.

According to a fourth aspect of the present invention, the refrigeration cycle circuit according to the third aspect is a heat pump type refrigeration cycle circuit capable of switching between heating and cooling operations, and the throttle mechanism is a parallel circuit for cooling operation and heating operation. And a check valve connected to these parallel circuits in series with the throttle mechanism, and the heat exchange means exchanges heat with any of the parallel circuits.

According to a fifth aspect of the present invention, the refrigeration cycle circuit according to the third aspect is a heat pump type refrigeration cycle circuit capable of switching between heating and cooling operations, and the throttling mechanism is provided at a heat exchange portion of the heat exchange means. It is characterized in that it is provided on both sides.

By providing the means for solving the invention as described above, in the invention according to the first aspect, the supercooling of the refrigerant can be made larger than before, and the dryness after the expansion of the refrigerant by the throttle mechanism is larger than before. It becomes small and has a large latent heat of vaporization. This improves evaporation performance and refrigeration cycle efficiency.

According to the second aspect of the invention, the liquid refrigerant discharged from the condenser is replaced with the refrigerant in the accumulator. At this time, if the liquid refrigerant is stored in the accumulator, supercooling can be more effectively performed.

According to the invention of claim 3 and the invention of claim 4, an efficient heat exchanging action can be achieved in any of the heating and cooling operations, and the cooling performance and the heating performance can be improved. In the invention of claim 5, when the refrigerant suction temperature becomes higher, the temperature difference becomes smaller and the amount of heat exchange decreases, which may cause superheat, but this can be set to be suppressed. Efficient heat exchange is performed with both air conditioning and heating, and cooling and heating performance can be improved.

[0019]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a refrigeration cycle circuit provided in, for example, an air conditioner. As will be described later, all the refrigeration cycle components are connected via the refrigerant pipe P.

In the figure, 10 is a compressor, and a condenser 11 is connected to this refrigerant discharge portion. The outlet side of the condenser 11 communicates with the throttle mechanism 12 and the evaporator 13, and further communicates with the suction portion of the compressor 10 via the suction cup 14. In this way, the refrigeration cycle is constructed.

A heat exchanger 15, which is a heat exchange means that is a feature of the present invention, has a refrigerant pipe Pa that connects the condenser 11 that is the refrigerant pipe on the outlet side of the condenser 11 and the throttle mechanism 12 to each other. It is provided over a refrigerant pipe Pb that connects the evaporator 13 that is the refrigerant pipe on the suction side of the compressor 10 and the suction cup 14 that is provided at the suction portion of the compressor 10.

The heat exchanger 15 used as the heat exchanging means may be a heat exchanger having a normal structure, and each of the refrigerant pipes Pa, P.
The heat exchange pipe forming the heat exchanger 15 may be substituted for b.

In the refrigeration cycle thus constructed, a non-azeotropic mixed refrigerant is used as the refrigerant. Specifically, alternative CFCs that are a mixture of R32 and R134a, and R
32 and R125 mixed, R134a and R32 and R1
There are 25 mixes.

The high-pressure refrigerant gas discharged from the compressor 10 is guided to the condenser 11 and condensed to become a liquid refrigerant, which is then guided to the throttling mechanism 12 where it is decompressed. The depressurized liquid refrigerant is guided to the evaporator 13 and evaporated.

The air in the air-conditioned room is introduced into the evaporator 13 for heat exchange. That is, the cooling action is performed by removing the latent heat of evaporation from the air in the air-conditioned room to lower the temperature and returning it to the air-conditioned room again.

The refrigerant evaporated in the evaporator 13 is sucked into the compressor 10 via the suction cup 14 and circulates in the refrigeration cycle described above. On the other hand, the heat exchanger 15 provided over the refrigerant pipe Pa that communicates the condenser 11 and the throttle mechanism 12 and the refrigerant pipe Pb that communicates the evaporator 13 and the suction portion of the compressor 10 have respective refrigerant pipes. Pa, Pb
Exchanges heat with the refrigerant conducted to.

That is, a relatively high-temperature liquid refrigerant is introduced into the refrigerant pipe Pa that connects the condenser 11 and the throttle mechanism 12, and a refrigerant pipe Pb that connects the evaporator 13 and the suction portion of the compressor 10 to the refrigerant pipe Pb. , A relatively low temperature evaporative refrigerant is introduced. The heat exchanger 15 efficiently exchanges heat between the refrigerants introduced into the refrigerant pipes Pa and Pb.

The effect of providing such a heat exchanger 15 can be explained from the Mollier diagram of FIG. In the same figure, the change M shown by the solid line is the behavior due to the refrigeration cycle in which the non-azeotropic mixed refrigerant is used and the heat exchanger 15 is provided at a predetermined position as in the present invention, and the change N shown by the broken line is due to the conventional refrigeration cycle. It is a behavior.

In the change M of the solid line of the present invention, by providing the heat exchanger 15, the refrigerant can be more subcooled (point C) than in the conventional case (point c). Then, the dryness (point D) after expansion by the throttle mechanism 12 becomes smaller than that of the conventional one (point d), and the latent heat of vaporization is large.

Further, in the actual air conditioner, even when the length of the refrigerant pipe Pa from the throttle mechanism 12 to the refrigerant introduction portion of the evaporator 13 is long, the heat exchanger 15 is used to reduce the dryness of the refrigerant. As a result, the refrigerant becomes almost in the liquid phase, and the effect of reducing the pressure loss is enhanced.

FIG. 3 shows a refrigeration cycle configuration. Here, the accumulator 16 is provided in the middle of the refrigerant pipe Pb that connects the evaporator 13 and the suction cup 14 that is the suction portion of the compressor 10.

A part of the refrigerant pipe Pa that connects the condenser 11 and the throttle mechanism 12 is connected to the accumulator 16 described above.
The heat exchange section 15a is provided here. FIG. 4 shows a specific configuration of the heat exchange section 15a. FIG. 4A shows a heat exchange that is a part of the refrigerant pipe Pa from the introduction section 16a to the derivation section 16b of the accumulator 16. The portion 15a ₁ penetrates. Therefore, the heat exchange section 15a ₁ itself is efficiently heat-exchanged in the accumulator 16.

FIG. 2B shows a state in which the heat exchange portion 15a ₂ of a part of the refrigerant pipe Pa connecting the condenser 11 and the throttle mechanism 12 is wound around the peripheral surface of the accumulator 16.
Therefore, the heat exchanging portion 15a ₂ is connected to the accumulator 16
It will be cooled by itself, and efficient heat exchange will not change.

In either configuration, the accumulator 16
When the liquid refrigerant is stored inside, particularly effective supercooling can be taken. Then, the heat exchange action as described above is performed, the evaporation performance is improved, and the refrigeration cycle efficiency is improved.

The present invention can also be applied to a heat pump type refrigeration cycle. The refrigerant used here remains a non-azeotropic mixed refrigerant. FIG. 5 shows the first embodiment. In the figure, 20 is a compressor, 21 is a four-way valve as a switching valve, 22 is an outdoor heat exchanger, 23 is a parallel circuit, 24 is an indoor heat exchanger, and 25 is a suction cup provided in the suction part of the compressor 20. , Are sequentially communicated via the refrigerant pipe P.

The parallel circuit 23 is a circuit in which the cooling throttle mechanism 26 and the check valve 27 are connected in series on one side, and the heating throttle mechanism 28 and the check valve 29 are connected in series on the other side. Circuit.

Here, the heat exchanger 1 as the heat exchanging means.
5A is provided across the parallel circuit 23 and a refrigerant pipe Pc that connects the four-way valve 21 and the suction portion of the compressor 20.

During the cooling operation, the refrigerant is introduced as shown by the solid line arrow in the figure. During the heating operation, the refrigerant is guided as indicated by the broken line arrow in the figure. In the parallel circuit 23, the refrigerant is guided from the positions and directions of the check valves 27 and 28 to the throttle mechanism 26 or 29 corresponding to the operation.

In the heating operation as well as in the cooling operation, the heat exchanger 15A has a heat exchanging function, so that not only the cooling performance but also the heating performance can be improved. Similarly, when the heat pump type refrigeration cycle is provided, the second embodiment as shown in FIG. 6 may be adopted. (The configuration other than the components described later is the same as that described with reference to FIG. 5, so the same reference numerals are given and a new description will be omitted. The same applies below.) Here, instead of the parallel circuit 23 in FIG. In the refrigerant pipe Pd that connects the outdoor heat exchanger 22 and the indoor heat exchanger 24,
A pair of diaphragm mechanisms 30A and 30B having the same configuration are provided.

The heat exchanger 15A as a heat exchange means includes a refrigerant pipe Pd connecting the above-mentioned throttle mechanisms 30A and 30B,
A refrigerant pipe P that connects the four-way valve 21 and the suction portion of the compressor 20.
It is provided straddling c.

During the cooling operation, the refrigerant is introduced as shown by the solid line arrow in the figure. During the heating operation, the refrigerant is guided as indicated by the broken line arrow in the figure. Then, in both cooling and heating operations, the refrigerant is guided through the heat exchanger 15A and conducts to both throttle mechanisms 30A and 30B, thereby performing a two-stage throttle action.

FIG. 7 shows the above-described two-stage diaphragm mechanism 30A, 30.
It is a Mollier diagram of the refrigerating cycle provided with B. In any of the heating and cooling operations, the refrigerant is expanded in two steps, and heat is exchanged in the heat exchanger 15A after the first expansion.

That is, the refrigerant expanded from the point C to the point E is heat-exchanged and cooled to the point F before the second expansion. Therefore, the dryness at point D after the second expansion is
It will be smaller than before.

Further, according to the refrigeration cycle provided with such a two-stage throttle mechanism, it becomes possible to set the heat exchange amount in the heat exchanger 15A. That is, if the refrigerant suction temperature becomes too high by the heat exchanger 15A, the gas specific volume of the suction refrigerant of the compressor increases, the refrigerant circulation amount decreases, and the performance of the refrigeration cycle deteriorates. By setting the amount of heat exchange in the heat exchanger 15A to a temperature at which the refrigerant suction temperature does not become too high due to the presence of the throttle mechanism, it is possible to prevent the performance of the refrigeration cycle from deteriorating.

FIG. 8 shows a third embodiment equipped with a heat pump type refrigeration cycle. Here, the refrigerant tube Pd that connects the outdoor heat exchanger 22 and the indoor heat exchanger 24 is provided with a pair of capillary tubes 31 and 32 as throttle mechanisms. Only one of the capillary tubes 32 constitutes a parallel circuit 34 with the check valve 33.

The heat exchanger 15A as a heat exchange means includes a refrigerant pipe Pd that connects the parallel circuit 34 of the capillary tube 31 and the capillary tube 32, and a refrigerant pipe Pc that connects the four-way valve 21 and the suction portion of the compressor 20. It is installed across and.

During the cooling operation, the refrigerant is guided as shown by the solid line arrow in the figure. During the heating operation, the refrigerant is guided as indicated by the broken line arrow in the figure. That is, only during the cooling operation, the refrigerant becomes a two-stage throttle that is guided through both capillary tubes 31 and 32 in the front and rear parts of the heat exchanger 15A.
During heating operation, it is a one-stage throttle that is guided to the heat exchanger 15A via the check valve 33 of the parallel circuit 34 and conducts one of the capillary tubes 31.

Therefore, during the cooling operation, the two-stage throttle shown in the Mollier diagram as shown in FIG. 7 is obtained, and during the heating operation, the one-stage throttle shown in the Mollier diagram as shown in FIG. 2 is obtained.

In any case, in a refrigeration cycle using a non-azeotropic mixed refrigerant, even when using capillary tubes as the expansion mechanisms 31 and 32, the performance can be improved according to each operation of cooling and heating. .

FIG. 9 shows a fourth embodiment having a heat pump type refrigeration cycle. Here, the refrigerant tube Pd that connects the outdoor heat exchanger 22 and the heat exchanger 15A is provided with a capillary tube 35 as a first throttle mechanism. Further, the refrigerant pipe Pd constitutes a parallel circuit 40 in which a circuit in which the check valves 36 and 37 and the capillary tubes 38 and 39 as a throttle mechanism are connected in series is arranged in parallel.

The heat exchanger 15A as a heat exchange means includes a refrigerant pipe Pc connecting the suction portion of the compressor 20 and the four-way valve 21.
Is provided across the refrigerant pipe Pd that connects the first capillary tube 35 and the parallel circuit 40.

During the cooling operation, the refrigerant is introduced as shown by the solid arrow in the figure. During the heating operation, the refrigerant is guided as indicated by the broken line arrow in the figure. In both of the heating and cooling operations, the refrigerant is introduced through the first capillary tube 35 and the capillary tube 38 or 39 of either one of the parallel circuits 40 in the front and rear portions of the heat exchanger 15A.

Therefore, even during the heating and cooling operation, the operation shown in FIG.
It is a two-stage diaphragm in the Mollier diagram as shown in. Then, in this refrigeration cycle, according to the respective operations of cooling and heating, the respective capillary tubes 3 are
By setting the throttling amount of 8, 39, the performance can be improved according to each operation of cooling and heating in the refrigeration cycle using the non-azeotropic mixed refrigerant.

[0054]

As described above, according to the invention of claim 1,
Since the condenser outlet side refrigerant pipe and the compressor suction side refrigerant pipe are provided with means for exchanging heat with each other, the non-azeotropic mixed refrigerant can be largely supercooled by the heat exchanging means, and after expansion by the throttling mechanism. The dryness becomes low and a large latent heat of vaporization can be obtained. Thereby, there is an effect that the refrigeration cycle efficiency can be improved.

According to the second aspect of the present invention, at least one of an accumulator and a suction cup is provided in the refrigerant pipe on the suction side of the compressor, and the heat exchange means includes either one of the accumulator and the suction cup and the refrigerant on the outlet side of the condenser. I tried to exchange heat with the pipes,
The supercooling of the non-azeotropic mixed refrigerant can be greatly increased to improve the refrigeration cycle efficiency, and it is not necessary to provide a dedicated heat exchanger, so that the increase in the number of parts can be suppressed and the space can be saved.

According to the third aspect of the invention, in the heat pump type refrigeration cycle circuit, the heat exchanging means operates both during the cooling operation and the heating operation, and in the invention of the fourth aspect, the heat pump type. In the refrigeration cycle circuit, the throttle mechanism is provided with parallel circuits for cooling operation and heating operation, and a check valve is connected to these parallel circuits in series with the throttle mechanism. Since heat is exchanged with each other, the heat exchanging action is achieved not only during cooling but also during heating, so that cooling and heating performance can be improved.

According to the fifth aspect of the present invention, in the heat pump type refrigeration cycle circuit that can be switched, the throttling mechanism is provided on both sides of the heat exchanging portion of the heat exchanging means, so that heat is generated not only during cooling but also during heating. It can be exchanged, improving cooling and heating performance. Then, by adjusting the throttle amount of the throttle mechanism on both sides of the heat exchanging part, it becomes possible to set the heat exchanging amount in the heat exchanging part, keep the refrigerant circulation amount properly, and prevent the performance deterioration of the refrigeration cycle. it can.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a refrigeration cycle circuit showing an embodiment of the present invention.

FIG. 2 is a Mollier diagram of the same embodiment.

FIG. 3 is a configuration diagram of a refrigeration cycle circuit according to another embodiment.

4A is a vertical cross-sectional view of an accumulator in the refrigeration cycle circuit of FIG. (B) is a vertical cross-sectional view of a different accumulator.

FIG. 5 is a configuration diagram of a refrigeration cycle circuit according to still another embodiment.

FIG. 6 is a configuration diagram of a refrigeration cycle circuit according to still another embodiment.

7 is a Mollier diagram of the refrigeration cycle of FIG.

FIG. 8 is a configuration diagram of a refrigeration cycle circuit according to still another embodiment.

FIG. 9 is a configuration diagram of a refrigeration cycle circuit according to still another embodiment.

FIG. 10 is a configuration diagram of a refrigeration cycle circuit in a conventional form.

[Explanation of Codes] 10, 20 ... Compressor, 11 ... Condenser, 12 ... Throttling mechanism,
13 ... Evaporator, P ... Refrigerant tube, 15, 15A ... Heat exchanger,
22 ... Outdoor heat exchanger, 24 ... Indoor heat exchanger, 16 ... Accumulator, 23 ... Parallel circuit, 30A, 30B ... Throttle mechanism, 31, 32 ... Throttle mechanism, 35 ... Throttle mechanism, 40 ...
Parallel circuit.

Claims (5)

[Claims] 1. A refrigeration cycle circuit for sequentially connecting a compressor, a condenser, a throttle mechanism and an evaporator via a refrigerant pipe,
A refrigeration cycle using a non-azeotropic mixed refrigerant as a refrigerant, characterized in that the condenser outlet side refrigerant pipe, and the compressor suction side refrigerant pipe, a refrigeration cycle comprising means for exchanging heat with each other. . 2. A refrigerant pipe on the suction side of the compressor is provided with at least one of an accumulator and a suction cup, and the heat exchange means is provided with at least one of the accumulator and a suction cup and the outlet side of the condenser. The refrigeration cycle according to claim 1, wherein heat exchange is performed between the refrigerant pipe and the refrigerant pipe. 3. The refrigeration cycle circuit is a heat pump type refrigeration cycle circuit capable of switching between heating and cooling operations, and the heat exchange means operates both during cooling operation and during heating operation. The refrigeration cycle according to claim 1. 4. The refrigeration cycle circuit is a heat pump type refrigeration cycle circuit capable of switching between heating and cooling operations, and the throttling mechanism includes cooling operation and heating operation as parallel circuits, and these parallel circuits are connected to each other. The refrigeration cycle according to claim 3, wherein a check valve is connected in series with the throttle mechanism, and the heat exchange means exchanges heat with any of the parallel circuits. 5. The refrigeration cycle circuit is a heat pump type refrigeration cycle circuit capable of switching between heating and cooling operations, and the throttle mechanism is provided on both sides of a heat exchange portion by the heat exchange means. The refrigeration cycle according to claim 3.