JP4543469B2 - Refrigeration equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a refrigeration apparatus using a working medium containing an R32 (chemical formula CH ₂ F ₂ ) refrigerant.
[0002]
[Background Art and Problems to be Solved by the Invention]
HCFC refrigerants with large ozone depletion coefficient and GWP (global warming potential) are subject to CFC regulation in heat pump refrigeration systems using refrigerants, so GWP that does not destroy the ozone layer as an alternative refrigerant R410A (R32: R125 = 50: 50) refrigerant is used as a high HFC refrigerant. In the refrigeration apparatus using the R410A refrigerant, a product that can obtain a COP (coefficient of performance) equivalent to that of R22 has been commercialized. However, since the R410A refrigerant has a low heat carrying capacity, the refrigerant charging amount must be increased in order to obtain sufficient capacity, and a large-capacity accumulator and receiver are required. Since the arrangement of the receiver and the receiver must be taken into consideration, there is a problem that the size cannot be easily reduced.
[0003]
Therefore, an object of the present invention is to provide a refrigeration apparatus that can reduce cost and size by using a working medium containing an R32 refrigerant.
[0004]
[Means for Solving the Problems]
In order to achieve the above object, the refrigeration apparatus of claim 1 comprises:
Compressor, a condenser, a pressure reducing means and the refrigerant circuit evaporator are annularly connected, a refrigeration apparatus using a refrigerant mixture of R 32 contains at least less than 70% by weight or more and 100 wt%,
The refrigerant circuit is a refrigerant circuit capable of switching between a cooling cycle and a heating cycle,
Mixed refrigerant over Symbol R32 contains at least less than 70% by weight or more and 100% by weight, a mixed refrigerant of the R32 and CO _2, high thermal carrying capacity than R410 refrigerant, and, using the above R410 refrigerant than the difference between the optimum refrigerant amount and the optimum amount of refrigerant during the heating operation during the cooling operation time, an optimal amount of refrigerant and mixed refrigerant difference is less between the optimum amount of refrigerant during the heating operation during the cooling operation,
In the refrigerant circuit having no accumulator, so that the small filling amount than the amount filled when using the R410 refrigerant, it was filled with refrigerant mixture over a Symbol R32 contains at least less than 70% by weight or more and 100 wt% It is characterized by.
[0005]
In the refrigeration apparatus using the mixed refrigerant containing at least 70% by weight and less than 100 % by weight of R 32 , the present applicant can obtain a high COP with a smaller refrigerant charge amount than that of the R410A refrigerant. It was found through experiments that the difference between the optimum refrigerant amount and the optimum refrigerant amount during heating was small.
[0006]
Therefore, according to the refrigeration apparatus of claim 1, the mixed refrigerant containing at least 70 wt% and less than 100 wt% of R 32 has a higher heat transfer capability than the R410A refrigerant, and a sufficient capacity with a small refrigerant charge amount. Since the difference between the optimum refrigerant amount during cooling and the optimum refrigerant amount during heating is small compared to the R410A refrigerant, the refrigerant amount can be reduced without adjusting the accumulator itself by adjusting the capacity of the entire system such as the capacity of the heat exchanger. Can be adjusted. As a result, the accumulator can be eliminated, and the cost can be reduced and the size can be reduced. (Here, the accumulator is not an accumulator attached to the compressor, but a low-pressure receiver type product-side accumulator for refrigerant adjustment.)
[0007]
The refrigeration apparatus according to claim 2 is:
Compressor, a condenser, a pressure reducing means and the refrigerant circuit evaporator is connected to an annular, a refrigeration apparatus using a refrigerant mixture of R 32 contains at least less than 70% by weight or more and 100 wt%,
The refrigerant circuit is a refrigerant circuit capable of switching between a cooling cycle and a heating cycle,
Mixed refrigerant over Symbol R32 contains at least less than 70% by weight or more and 100% by weight, a mixed refrigerant of the R32 and CO _2, high thermal carrying capacity than R410 refrigerant, and, using the above R410 refrigerant than the difference between the optimum refrigerant amount and the optimum amount of refrigerant during the heating operation during the cooling operation time, an optimal amount of refrigerant and mixed refrigerant difference is less between the optimum amount of refrigerant during the heating operation during the cooling operation,
In the refrigerant circuit having no receiver, so that the small filling amount than the amount filled when using the R410 refrigerant, it was filled with refrigerant mixture over a Symbol R32 contains at least less than 70% by weight or more and 100 wt% It is characterized by.
[0008]
According to the refrigeration apparatus of the claim 2, mixed refrigerant R 32 contains at least less than 70% by weight or more and 100% by weight, high heat-carrying ability as compared with R410A refrigerant, obtained sufficient capacity with less refrigerant charge In addition, since the difference between the optimum refrigerant amount during cooling and the optimum refrigerant amount during heating is small compared to the R410A refrigerant, the refrigerant amount can be adjusted without the receiver itself by adjusting the capacity of the entire system such as the capacity of the heat exchanger. . As a result, the receiver can be eliminated, and the cost can be reduced and the size can be reduced.
[0009]
The refrigeration apparatus according to claim 3 is:
Compressor, a condenser, a pressure reducing means and the refrigerant circuit evaporator is connected to an annular, a refrigeration system using a mixed refrigerant containing less than a R 32 at least 70% by weight or more free and 100% by weight,
The refrigerant circuit is a refrigerant circuit capable of switching between a cooling cycle and a heating cycle,
Mixed refrigerant over Symbol R32 contains at least less than 70% by weight or more and 100% by weight, a mixed refrigerant of the R32 and CO _2, high thermal carrying capacity than R410 refrigerant, and, using the above R410 refrigerant than the difference between the optimum refrigerant amount and the optimum amount of refrigerant during the heating operation at the time of the cooling operation time, an optimal amount of refrigerant and mixed refrigerant difference is less between the optimum amount of refrigerant during the heating operation at the time of the cooling operation,
In the refrigerant circuit having no accumulator and receiver filling, so that the small filling amount than the filling amount when using the R410 refrigerant, a mixed refrigerant over Symbol R32 contains at least less than 70% by weight or more and 100 wt% It is characterized in that the.
[0010]
According to the refrigeration apparatus of the third aspect, the mixed refrigerant of R 32 contains at least less than 70% by weight or more and 100% by weight, high heat-carrying ability as compared with R410A refrigerant, obtained sufficient capacity with less refrigerant charge In addition, since the difference between the optimum refrigerant amount during cooling and the optimum refrigerant amount during heating is small compared to the R410A refrigerant, the refrigerant amount can be reduced without adjusting the accumulator and receiver itself by adjusting the capacity of the entire system such as the heat exchanger capacity. Can be adjusted. As a result, it is possible to eliminate the accumulator and the receiver, and the cost can be reduced and the size can be reduced.
[0011]
A refrigeration apparatus according to a fourth aspect of the present invention is the refrigeration apparatus according to any one of the first to third aspects, wherein the refrigeration capacity is 4 kW or less.
[0012]
According to the refrigeration apparatus of the fourth aspect, if the refrigeration capacity is 4 kW or less, the accumulator and the receiver (including the modulator for adjusting the cooling / heating in the air conditioner) can be surely eliminated.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the refrigeration apparatus of the present invention will be described in detail with reference to the illustrated embodiments.
[0014]
FIG. 1 is a circuit diagram showing a schematic configuration of a heat pump type air conditioner as a refrigeration apparatus according to an embodiment of the present invention. 1 is a compressor, 2 is one end connected to the discharge side of the compressor 1 The four-way switching valve 3 is an outdoor heat exchanger having one end connected to the other end of the four-way switching valve 2, 4 is an electric expansion valve having one end connected to the other end of the outdoor heat exchanger 3, The indoor heat exchanger has one end connected to the other end of the electric expansion valve 4 and the other end connected to the suction side of the compressor 1 via the four-way switching valve 2. The air conditioner includes a temperature sensor 11 that detects a discharge pipe temperature of the compressor 1, a temperature sensor 12 that detects a refrigerant temperature of the outdoor heat exchanger 3, a temperature sensor 13 that detects an outdoor air temperature, and indoor heat exchange. A temperature sensor 14 for detecting the refrigerant temperature of the compressor 5, a temperature sensor 15 for detecting the indoor temperature, a temperature sensor 16 for detecting the refrigerant temperature on the suction side of the compressor 1, and signals from the temperature sensors 11 to 16. And a control device 7 for controlling the compressor 1, the electric expansion valve 4 and the like. In addition, a closing valve 21 is disposed between the electric expansion valve 4 and the indoor heat exchanger 5, and a closing valve 24 is disposed between the indoor heat exchanger 5 and the four-way switching valve 2. .
[0015]
The compressor 1, the four-way switching valve 2, the outdoor heat exchanger 3, the electric expansion valve 4, the control device 7, the closing valve 21, the closing valve 24, the temperature sensors 11 to 13, the temperature sensor 16, and the outdoor fan (not shown) ) Constitutes the outdoor unit 10, and the indoor unit 20 is constituted by the indoor heat exchanger 5, the temperature sensor 14, the temperature sensor 15, and an indoor fan (not shown).
[0016]
The air conditioner having the above configuration uses a working medium composed of R32 refrigerant and refrigeration oil. During the cooling operation, when the four-way switching valve 2 is switched to the solid line switching position and the compressor 1 is started, the high-pressure refrigerant discharged from the compressor 1 passes through the four-way switching valve 2 and the outdoor heat exchanger 3. to go into. The refrigerant condensed in the outdoor heat exchanger 3 is decompressed by the electric expansion valve 4 and then enters the indoor heat exchanger 5 through the communication pipe 22. The refrigerant evaporated in the indoor heat exchanger 5 returns to the suction side of the compressor 1 through the connection pipe 23 and the four-way switching valve 2. Thus, the working medium containing the R32 refrigerant circulates in the refrigerant circuit constituted by the compressor 1, the outdoor heat exchanger 3, the electric expansion valve 4, and the indoor heat exchanger 5, and the refrigeration cycle is executed. And indoor air is circulated by circulating indoor air via the indoor heat exchanger 5 with an indoor fan (not shown).
[0017]
The present applicant examined the COP with respect to the refrigerant filling amount by experiment for the R410A and R32 refrigerants. This experiment was performed under the cooling standard condition and the heating standard condition according to JISC9612. FIG. 2 shows the result of the experiment. In FIG. 2, the horizontal axis represents the refrigerant charge amount, and the vertical axis represents the COP ratio (ratio of R32 COP to R410A COP). As shown in FIG. 2, in the R410A refrigerant, the optimum refrigerant amount that maximizes the COP differs between cooling and heating, and the refrigerant charging amount during heating is small. On the other hand, with the R32 refrigerant, the optimum refrigerant amount that maximizes the COP differs between cooling and heating, the refrigerant charging amount during heating is small, and the optimum refrigerant amount is less than the R410A refrigerant, and the COP is high. . Furthermore, it was found that the R32 refrigerant has a smaller difference in the optimum refrigerant amount that maximizes the COP during cooling and heating than the R410A refrigerant.
[0018]
Moreover, the minimum volume required for the accumulator and the receiver with respect to the refrigerating capacity of the air conditioner in the R410A, R22 and R32 refrigerants was examined by experiments. As a result of the experiment, as shown in FIG. 3, the smaller the refrigeration capacity, the smaller the required refrigerant charging amount. Therefore, the R410A, R22 and R32 refrigerants all have smaller accumulator and receiver volumes, but R410A, R22. The volume of the accumulator and receiver was smaller in the R32 refrigerant than in the refrigerant. As apparent from FIG. 3, in an air conditioner using R32 refrigerant, an accumulator and a receiver are usually required for a small to medium air conditioner when the refrigerating capacity is 4 kW or more. By adjusting the capacity of the entire system, it is possible to adjust the refrigerant amount without providing an accumulator and receiver itself. That is, the air conditioner can be configured as an accumulator and receiver-less as much as possible.
[0019]
Therefore, according to the air conditioner, it is possible to eliminate the accumulator and the receiver using the R32 refrigerant, and the cost can be reduced and the size can be reduced.
[0020]
Further, if the refrigerating capacity is 4 kW or less, the accumulator and the receiver can be surely eliminated.
[0021]
In the above embodiment, the air conditioner has been described as the refrigeration apparatus. However, the present invention may be applied to other refrigeration apparatuses.
[0022]
Moreover, although the said embodiment demonstrated the air conditioner using R32 refrigerant | coolant as a freezing apparatus, the refrigerant used for a freezing apparatus is not restricted to this, The mixed refrigerant | coolant containing at least 70 weight% or more of R32 may be sufficient. For example, it is a mixed refrigerant of R32 refrigerant and CO ₂ , wherein the R32 refrigerant may be 70 wt% or more and 90 wt% or less of CO ₂ , or a mixed refrigerant of R32 refrigerant and R22 refrigerant. A mixed refrigerant in which the R32 refrigerant is 70 wt% or more and 90 wt% or less with respect to the R22 refrigerant may be used.
[0023]
【The invention's effect】
As is clear from the above, according to the refrigeration apparatus of the present invention, by using an R32 refrigerant having a high heat transfer capability or a mixed refrigerant containing at least 70% by weight or more of R32, a smaller refrigerant charging amount than the R410A refrigerant is sufficient. As compared with the R410A refrigerant, the difference between the optimum refrigerant amount during cooling and the optimum refrigerant amount during heating is small, so accumulators and receivers can be eliminated, and cost reduction and downsizing can be achieved. it can. In addition, since the amount of refrigerant charged can be reduced, the value of direct global warming can also be reduced. Therefore, there is an advantage that it is possible to easily provide a refrigeration apparatus that can cope with the global environment by reducing the GWP of R32 and saving energy.
[0024]
Further, by setting the refrigeration capacity to 4 kW or less, the accumulator and the receiver can be surely eliminated.
[Brief description of the drawings]
FIG. 1 is a circuit diagram showing a schematic configuration of an air conditioner as a refrigeration apparatus according to an embodiment of the present invention.
FIG. 2 is a diagram showing COP with respect to the refrigerant charge amount during cooling and heating for R410A refrigerant and R32 refrigerant.
FIG. 3 is a diagram showing the volume of the accumulator and receiver with respect to the refrigerating capacity of R410A, R22 refrigerant and R32 refrigerant.
[Explanation of symbols]
1 ... compressor, 2 ... four-way switching valve,
3 ... outdoor heat exchanger, 4 ... electric expansion valve,
5 ... outdoor heat exchanger, 7 ... control device,
10: outdoor unit, 20: indoor unit.

Claims (4)

Compressor (1), a condenser (3), the pressure reducing means (4) and an evaporator (5) is a refrigerant circuit connected to the annular, the mixed refrigerant of R 32 contains at least less than 70% by weight or more and 100 wt% A refrigeration unit used,
The refrigerant circuit is a refrigerant circuit capable of switching between a cooling cycle and a heating cycle,
Mixed refrigerant over Symbol R32 contains at least less than 70% by weight or more and 100% by weight, a mixed refrigerant of the R32 and CO _2, high thermal carrying capacity than R410 refrigerant, and, using the above R410 refrigerant than the difference between the optimum refrigerant amount and the optimum amount of refrigerant during the heating operation during the cooling operation time, an optimal amount of refrigerant and mixed refrigerant difference is less between the optimum amount of refrigerant during the heating operation during the cooling operation,
In the refrigerant circuit having no accumulator, so that the small filling amount than the amount filled when using the R410 refrigerant, it was filled with refrigerant mixture over a Symbol R32 we contain at least less than 70% by weight or more and 100 wt% A refrigeration apparatus characterized by. Compressor (1), a condenser (3), the pressure reducing means (4) and an evaporator (5) is a refrigerant circuit connected to the annular, the mixed refrigerant of R 32 contains at least less than 70% by weight or more and 100 wt% A refrigeration unit used,
The refrigerant circuit is a refrigerant circuit capable of switching between a cooling cycle and a heating cycle,
Mixed refrigerant over Symbol R32 contains at least less than 70% by weight or more and 100% by weight, a mixed refrigerant of the R32 and CO _2, high thermal carrying capacity than R410 refrigerant, and, using the above R410 refrigerant than the difference between the optimum refrigerant amount and the optimum amount of refrigerant during the heating operation during the cooling operation time, an optimal amount of refrigerant and mixed refrigerant difference is less between the optimum amount of refrigerant during the heating operation during the cooling operation,
In the refrigerant circuit having no receiver, so that the small filling amount than the amount filled when using the R410 refrigerant, it was filled with refrigerant mixture over a Symbol R32 contains at least less than 70% by weight or more and 100 wt% A refrigeration apparatus characterized by. Compressor (1), a condenser (3), decompression means (4) and an evaporator (5) is a refrigerant circuit connected to the annular, mixed refrigerant containing less than a R 32 at least 70% by weight or more free and 100% by weight A refrigeration apparatus using
The refrigerant circuit is a refrigerant circuit capable of switching between a cooling cycle and a heating cycle,
Mixed refrigerant over Symbol R32 contains at least less than 70% by weight or more and 100% by weight, a mixed refrigerant of the R32 and CO _2, high thermal carrying capacity than R410 refrigerant, and, using the above R410 refrigerant than the difference between the optimum refrigerant amount and the optimum amount of refrigerant during the heating operation during the cooling operation time, an optimal amount of refrigerant and mixed refrigerant difference is less between the optimum amount of refrigerant during the heating operation during the cooling operation,
In the refrigerant circuit having no accumulator and receiver filling, so that the small filling amount than the filling amount when using the R410 refrigerant, a mixed refrigerant over Symbol R32 contains at least less than 70% by weight or more and 100 wt% A refrigeration apparatus characterized by that. The refrigeration apparatus according to any one of claims 1 to 3,
A refrigeration apparatus having a refrigeration capacity of 4 kW or less.

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