CN112714849B

CN112714849B - Refrigeration cycle device

Info

Publication number: CN112714849B
Application number: CN201880097418.5A
Authority: CN
Inventors: 梁池悟; 野本宗; 筑山亮; 石川智隆; 藤本肇; 池田隆; 佐多裕士
Original assignee: Mitsubishi Electric Corp
Current assignee: Mitsubishi Electric Corp
Priority date: 2018-09-28
Filing date: 2018-09-28
Publication date: 2022-07-08
Anticipated expiration: 2038-09-28
Also published as: JPWO2020066003A1; JP7105903B2; CN112714849A; WO2020066003A1

Abstract

A refrigeration cycle device (100) is filled in advance with a specific amount of a zeotropic refrigerant mixture containing R463A. A refrigeration cycle device (100) is provided with a compressor (1), a first heat exchanger (2), a refrigerant container (3), a pressure reducing device (4), and a second heat exchanger (5). The non-azeotropic refrigerant mixture circulates in the order of the compressor (1), the first heat exchanger (2), the refrigerant container (3), the pressure reducing device (4), and the second heat exchanger (5). The ratio of the volume of the refrigerant container (3) to the specific amount of the non-azeotropic refrigerant mixture is more than 0L/kg and not more than 11L/kg.

Description

Refrigeration cycle device

Technical Field

The present invention relates to a refrigeration cycle apparatus using a non-azeotropic refrigerant mixture.

Background

Conventionally, a refrigeration cycle apparatus using a non-azeotropic refrigerant mixture is known. For example, japanese patent application laid-open No. 7-139833 (patent document 1) discloses an air conditioner filled with a non-azeotropic refrigerant mixture containing R32 as a low boiling point refrigerant and HFC134a as a high boiling point refrigerant. In this air conditioning apparatus, a refrigerant regulator is provided between the heat source side heat exchanger and the expansion mechanism. The refrigerant regulator supplies a refrigerant amount corresponding to the amount of the liquid zeotropic refrigerant mixture accumulated to the heat source side heat exchanger during the heating operation cycle, and regulates the circulating refrigerant amount. Since a large amount of HFC134a is accumulated in the refrigerant regulator during the heating operation cycle, the proportion of R32 in the amount of circulating refrigerant increases. As a result, the capacity of the air conditioner can be improved.

Prior art documents

Patent document

Patent document 1: japanese patent laid-open publication No. 7-139833

Disclosure of Invention

The refrigerant regulator of the air conditioner disclosed in patent document 1 accumulates a surplus zeotropic refrigerant mixture during the cooling operation cycle. When the capacity of the refrigerant regulator is increased while the amount of the zeotropic refrigerant mixture charged in advance in the air conditioner is kept constant, the amount of the low boiling point refrigerant in the gas in the refrigerant regulator increases, and the amount of the low boiling point refrigerant in the circulating refrigerant amount decreases. As a result, the cooling capacity of the utilization-side heat exchanger may decrease. However, in patent document 1, the following is not considered: depending on the relationship between the capacity of the refrigerant regulator and the amount of the zeotropic mixture refrigerant to be charged in advance, the cooling capacity of the utilization-side heat exchanger may decrease and fall below the desired cooling capacity.

Problems to be solved by the invention

The present invention has been made to solve the above-described problems, and an object thereof is to ensure a desired cooling capacity of a refrigeration cycle apparatus.

Means for solving the problems

In the refrigeration cycle apparatus of the present invention, a specific amount of a zeotropic refrigerant mixture containing R463A is charged in advance. The refrigeration cycle device includes a compressor, a first heat exchanger, a refrigerant container, a pressure reducing device, and a second heat exchanger. The zeotropic refrigerant mixture circulates in this order through the compressor, the first heat exchanger, the refrigerant container, the pressure reducing device, and the second heat exchanger. The ratio of the volume of the refrigerant container to the specific amount of the non-azeotropic refrigerant mixture is more than 0L/kg and not more than 11L/kg.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the refrigeration cycle apparatus of the present invention, a desired cooling capacity can be ensured by setting the ratio of the capacity of the refrigerant container to the amount of the zeotropic refrigerant mixture filled in advance in the refrigeration cycle apparatus to more than 0L/kg and not more than 11L/kg.

Drawings

Fig. 1 is a functional block diagram showing the configuration of a refrigeration cycle apparatus according to an embodiment.

Fig. 2 is a graph showing a relationship between a ratio of a volume of the accumulator to a specific amount of R463A (accumulator volume ratio) previously filled in the refrigeration cycle apparatus and a cycle composition ratio.

Fig. 3 is a graph showing a relationship between the accumulator volume ratio and the cooling capacity ratio of the refrigeration cycle device.

Fig. 4 is a graph showing a relationship between the accumulator volume ratio and the weight composition ratio of the micro-ignition refrigerant to the non-combustible refrigerant.

Detailed Description

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Note that the same or corresponding portions in the drawings are given the same reference numerals, and description thereof will not be repeated in principle.

Fig. 1 is a functional block diagram showing the configuration of a refrigeration cycle apparatus 100 according to an embodiment. As shown in fig. 1, the refrigeration cycle apparatus 100 includes a compressor 1, a condenser 2 (first heat exchanger), an accumulator 3 (refrigerant container), an expansion valve 4 (pressure reducing device), an evaporator 5 (second heat exchanger), and a control device 6.

The refrigeration cycle apparatus 100 is previously filled with a specific amount of R463A specified by the specifications of the refrigeration cycle apparatus 100. R463A as a zeotropic refrigerant mixture circulates in the order of compressor 1, condenser 2, receiver 3, expansion valve 4, and evaporator 5.

The pipe 7 connects the condenser 2 and the accumulator 3. The end 71 of the pipe 7 is disposed in the reservoir 3. R463A flows from end 71 into reservoir 3. The pipe 8 connects the liquid reservoir 3 and the expansion valve 4. The end 81 of the pipe 8 is disposed in the reservoir 3. R463A in the reservoir 3 flows out from the end 81. The reservoir 3 has a cylindrical structure formed by welding both ends of a flat plate, for example.

The control device 6 controls the driving frequency fc of the compressor 1, thereby controlling the amount of the zeotropic mixture refrigerant discharged per unit time from the compressor 1. The control device 6 includes a storage unit 11. The storage unit 11 stores, for example, physical property values of R463A, the volume of the accumulator 3, and control target values of specific parameters (for example, evaporation temperature or condensation temperature).

R463A in which liquid is accumulated in the accumulator 3, and a refrigerant having a lower boiling point (low-boiling-point refrigerant) than other refrigerants in the refrigerants included in the R463A are vaporized. As R463A circulates through the refrigeration cycle apparatus 100, the amount of refrigerant (gas refrigerant) contained in the accumulator 3 increases. Since the amount of the low-boiling-point refrigerant contained in the R463A circulating through the refrigeration cycle apparatus 100 decreases, the composition ratio (cycle composition ratio) of the R463A circulating through the refrigeration cycle apparatus 100 changes.

R463A is substituted with 36: 30: 14: 14: weight percent (wt%) (pure composition ratio) of 6 contained R32, R125, R1234yf, R134a and CO 2. To ensure refrigerant pressure, CO2 is contained in R463A. The boiling points at 1 atmosphere of R32, R125, R1234yf, R134a and CO2 were-51.7 ℃, -48.1 ℃, -29.4 ℃, -26.1 ℃ and-78.5 ℃ respectively. Among the refrigerants contained in R463A, the boiling point of CO2 is lowest, and the boiling point of R32 is lower than that of CO 2. The low boiling point refrigerant of R463A contains R32 and CO 2.

Fig. 2 is a graph showing a relationship between a ratio of a volume of the accumulator 3 to a specific amount of R463A previously filled in the refrigeration cycle apparatus 100 (accumulator volume ratio) and a cycle composition ratio. As the accumulator volume ratio increases, the proportion of the volume of the liquid refrigerant accumulated in the accumulator 3 occupied in the volume of the accumulator 3 decreases. Therefore, the proportion of the volume of the gas refrigerant occupied in the volume of the accumulator 3 increases. As a result, as shown in fig. 2, the proportion of the low boiling point refrigerant in R463A circulating in the refrigeration cycle apparatus 100 decreases as the accumulator volume ratio increases. As a result, the cooling capacity of the refrigeration cycle device 100 may drop and fall below the desired cooling capacity.

In general, the cooling capacity ratio of the refrigeration cycle device is generally designed to have a margin of about 20%. In this case, the desired cooling capacity of the refrigeration cycle device is a cooling capacity ratio of 80% or more.

Fig. 3 is a graph showing a relationship between the accumulator volume ratio and the cooling capacity ratio of the refrigeration cycle device 100. In fig. 3, the cooling capacity on the vertical axis is set to 100% as compared with the cooling capacity when the circulation composition ratio of R463A is the pure composition ratio. As shown in fig. 3, the cooling capacity ratio decreases as the accumulator volume ratio increases, and the cooling capacity ratio becomes 80% when the accumulator volume ratio is 11. In the case where the accumulator volume ratio is larger than 11, the cooling capacity ratio is lower than 80%.

Therefore, in the refrigeration cycle apparatus 100, the receiver volume ratio is set to be greater than 0L/kg and 11L/kg or less. By limiting the range of the accumulator volume ratio to this range, a cooling capacity ratio of 80% or more can be ensured.

Next, the combustibility of R463A will be described. For example, according to the classification of ASHRAE (American Society of Heating, reforming and Air-Conditioning Engineers), R32 and R1234yf among refrigerants included in R463A are classified as micro-burning refrigerants, and R125, R134a and CO2 are classified as non-burning refrigerants. In the pure composition ratio of R463A, the composition ratio by weight of the slightly-flammable refrigerant to the noncombustible refrigerant is 1. In order to suppress combustibility of the refrigerant that leaks from the refrigeration cycle apparatus 100 due to slow leakage or the like of R463A, the weight composition ratio of the slightly flammable refrigerant to the non-flammable refrigerant is preferably 1 or less. Since the welded portion is a portion that is relatively low in strength and easily damaged, the welded portion of the cylindrical accumulator 3 can be used as the leakage portion of the refrigerant, for example.

Fig. 4 is a graph showing a relationship between the accumulator volume ratio and the weight composition ratio of the micro-ignition refrigerant to the non-combustible refrigerant. As shown in fig. 4, when the receiver volume ratio of the slightly-burned refrigerant to the non-burned refrigerant is greater than 0L/kg and 2.4L/kg or less or 9.8L/kg or more, the weight composition ratio of the slightly-burned refrigerant to the non-burned refrigerant is 1 or less. Therefore, in the refrigeration cycle apparatus 100, the receiver volume ratio is set to be greater than 0L/kg and 2.4L/kg or less, or set to be 9.8L/kg or more and 11L/kg or less. By limiting the accumulator volume ratio to this range, it is possible to suppress combustibility of the refrigerant leaking from the refrigeration cycle apparatus 100 while ensuring a desired cooling capacity.

As described above, according to the refrigeration cycle apparatus of the embodiment, a desired cooling capacity can be ensured. In addition, according to the refrigeration cycle apparatus of the embodiment, the combustibility of the leaked refrigerant can be suppressed.

The presently disclosed embodiments are to be considered in all respects as illustrative and not restrictive. The scope of the present invention is defined by the claims, not by the above description, and all modifications within the meaning and scope equivalent to the claims are intended to be included.

Description of reference numerals

1 compressor, 2 condenser, 3 accumulator, 4 expansion valve, 5 evaporator, 6 control device, 7, 8 piping, 11 storage part, 100 refrigeration cycle device.

Claims

1. A refrigeration cycle device which is filled with a specific amount of a non-azeotropic refrigerant mixture as R463A in advance, wherein,

the refrigeration cycle device is provided with:

a compressor;

a first heat exchanger;

a refrigerant container;

a pressure reducing device; and

a second heat exchanger for the heat-exchange medium,

the zeotropic mixed refrigerant circulates in the order of the compressor, the first heat exchanger, the refrigerant container, the pressure reducing device, and the second heat exchanger,

the non-azeotropic refrigerant mixture is stored in the refrigerant container, and a refrigerant having a lower boiling point than other refrigerants in the refrigerants included in the non-azeotropic refrigerant mixture is vaporized,

the ratio of the volume of the refrigerant container to the specific amount of the non-azeotropic refrigerant mixture is more than 0L/kg and not more than 11L/kg.

2. The refrigeration cycle apparatus according to claim 1,

the ratio is greater than 0L/kg and 2.4L/kg or less, or 9.8L/kg or more and 11L/kg or less.

3. The refrigeration cycle device according to claim 1 or 2, wherein,

an end portion on one side of a first pipe that connects the first heat exchanger and the refrigerant container is disposed in the refrigerant container,

an end portion of one side of a second pipe that connects the refrigerant container and the pressure reducing device is disposed in the refrigerant container.

4. The refrigeration cycle device according to claim 1 or 2, wherein,

the refrigerant container has a cylindrical structure formed by welding both ends of a flat plate.