WO2020042768A1

WO2020042768A1 - Refrigerant circulation system

Info

Publication number: WO2020042768A1
Application number: PCT/CN2019/095404
Authority: WO
Inventors: 王蒙; 杨春
Original assignee: 艾默生环境优化技术(苏州)有限公司
Priority date: 2018-08-28
Filing date: 2019-07-10
Publication date: 2020-03-05

Abstract

The present disclosure relates to a refrigerant circulation system, comprising: a compressor, the compressor having a single compression mechanism, and the compression mechanism having a first refrigerant inlet and a second refrigerant inlet; a first evaporation device, a refrigerant having a first pressure after being subjected to heat exchange by the first evaporation device; and a second evaporation device, a refrigerant having a second pressure after being subjected to heat exchange by the second evaporation device. The refrigerant flowing out of the first evaporation device flows into the compression mechanism from the first refrigerant inlet at the first pressure; the refrigerant flowing out of the second evaporation device flows into the compression mechanism from the second refrigerant inlet at the second pressure. According to the refrigerant circulation system of the present disclosure, refrigerants having different pressures flowing out of different evaporation devices can be directly introduced in a compressor, without decompressing the refrigerants before the refrigerants enter the compressor, so that the overall energy efficiency of the refrigerant circulation system can be improved, and a dual-stage compression function can be further achieved by means of a single compressor.

Description

Refrigerant circulation system

This application claims priority from the following Chinese patent applications: Chinese patent application filed with the Chinese Patent Office on August 28, 2018 with the application number 201810986673.7 and the name of the invention as "a refrigerant circulation system"; August 28, 2018 Japanese Patent Application No. 201821397534.2 filed with the Chinese Patent Office and the name of the invention as "a refrigerant circulation system" is China. The entire contents of these patent applications are incorporated herein by reference.

Technical field

The present disclosure relates to a refrigerant cycle system, and more particularly, the present disclosure relates to a refrigerant cycle system having a plurality of evaporation devices.

Background technique

The content of this section only provides background information related to the present disclosure, which may not constitute prior art.

In the application of a refrigerant cycle system, there is often a need to provide different temperatures, and thus there is an application of a double evaporation device. For example, in freezing applications, it is often necessary to provide both moderate and low temperatures. In some domestic refrigerator applications, it may even be necessary to provide three different temperatures simultaneously. In order to control the temperature more accurately, a dual evaporation device is used in some high-end applications to independently control the temperature.

In the existing refrigerant cycle system having a double evaporation device, there are a system having a plurality of compressors and a system having a single compressor. For a system with multiple compressors and dual evaporation devices, the system as a whole is relatively large and expensive due to the use of multiple compressors, requiring a large installation space. For existing systems with a single compressor and dual evaporation devices, the refrigerant flow from the medium-temperature evaporation device needs to be reduced by the evaporation pressure regulating valve, and then the refrigerant flow from the low-temperature evaporation device flows with the refrigerant flow. They are mixed and then sucked into a compressor for compression. However, the above-mentioned depressurization process of the medium-temperature refrigerant before compression generates additional power consumption without generating any refrigeration, which reduces the energy efficiency of the system.

Therefore, it is necessary to improve the existing refrigerant circulation system with a dual evaporation device to provide accurate temperature control without significantly increasing the size and cost of the system, avoid unnecessary extra power consumption, and improve system energy efficiency. .

Summary of the Invention

The purpose of this disclosure is to solve or improve one or more of the above problems.

One aspect of the present disclosure is to provide a refrigerant cycle system including a compressor having a single compression mechanism having a first refrigerant inlet and a second refrigerant inlet; a first Evaporation device, the refrigerant has a first pressure after heat exchange through the first evaporation device, and the first evaporation device is connected to the compressor; the second evaporation device, the refrigerant has a second pressure after heat exchange through the second evaporation device, And the second evaporation device is connected to the compressor. The refrigerant flowing out of the first evaporation device flows into the compression mechanism through the first refrigerant inlet at a first pressure, and the refrigerant flowing out of the second evaporation device flows into the compression mechanism through the second refrigerant inlet at a second pressure.

With the refrigerant circulation system of the present disclosure, it is not necessary to use a pressure regulating device to reduce the pressure of the refrigerant flowing from the middle-temperature evaporation device and then introduce the refrigerant into the compressor, thereby improving the energy efficiency of the refrigerant circulation system.

In one embodiment, the first pressure is lower than the second pressure.

In one embodiment, the compression mechanism includes a first group of compression chambers and a second group of compression chambers connected in parallel, the first refrigerant inlet is a low-pressure inlet of the first group of compression chambers, and the second refrigerant inlet is a second group of compression chambers. Low-pressure inlet.

In one embodiment, the compression mechanism includes a first group of compression chambers and a second group of compression chambers connected in series, and the refrigerant flowing out of the first group of compression chambers flows into the second group of compression chambers through the low-pressure inlet of the second group of compression chambers. compression. The first refrigerant inlet is a low-pressure inlet of the first group of compression chambers, and the second refrigerant inlet is a low-pressure inlet of the second group of compression chambers.

In one embodiment, the refrigerant circulation system further includes an air-jet enthalpy branch, and the air-jet enthalpy refrigerant supplied from the air-jet enthalpy branch also flows into the second group of compression chambers through the low-pressure inlet of the second group of compression chambers.

The refrigerant flowing out of the first evaporation device directly flows into the first group of compression chambers, the refrigerant flowing out of the first group of compression chambers, the refrigerant flowing out of the second evaporation device, and the air jet enthalpy supplied by the air jet enthalpy branch The refrigerant flows into the space in the casing of the compressor and then flows into the second set of compression chambers through the low-pressure inlet of the second set of compression chambers.

In one embodiment, the compression mechanism includes a first group of compression chambers and a second group of compression chambers connected in parallel or in series. The first refrigerant inlet is a low-pressure inlet of the first group of compression chambers, and the second refrigerant inlet is a second group of compression. The low-pressure inlet of the cavity, and the medium-pressure inlet of the compression mechanism is provided at the medium-pressure cavity in the first group of compression chambers and / or the medium-pressure cavity in the second group of compression chambers. The refrigerant circulation system further includes an additional evaporation device. After the refrigerant is heat-exchanged through the additional evaporation device, the refrigerant has a third pressure higher than the first pressure and not equal to the second pressure, and the refrigerant flowing out of the additional evaporation device passes at the third pressure. The medium pressure inlet of the compression mechanism flows into the compression mechanism.

In one embodiment, the compression mechanism includes a single set of compression chambers, the first refrigerant inlet is a low-pressure inlet of the compression mechanism, and the second refrigerant inlet is a medium-pressure inlet of the compression mechanism.

Preferably, the medium pressure inlet is provided by a gas injection enthalpy inlet of the compression mechanism.

In one embodiment, the refrigerant flowing into the compression mechanism via the medium pressure inlet of the compression mechanism includes only the refrigerant flowing out of the additional evaporation device. Alternatively, the refrigerant flowing into the compression mechanism via the intermediate pressure inlet of the compression mechanism includes both the refrigerant flowing out of the additional evaporation device and the air-jet enthalpy refrigerant supplied by the air-jet enthalpy branch of the refrigerant cycle system.

In one embodiment, the refrigerant flowing into the compression mechanism through the medium pressure inlet of the compression mechanism includes only the refrigerant flowing out of the second evaporation device. Alternatively, the refrigerant flowing into the compression mechanism via the medium-pressure inlet of the compression mechanism includes both the refrigerant flowing out of the second evaporation device and the air-jet enthalpy-enhancing refrigerant supplied by the air-jet enthalpy-enhancing branch of the refrigerant cycle system.

The compressor is: a double-turn scroll compressor including a single double-turn scroll compression unit used as a compression mechanism; a single-turn scroll compressor including a single-turn scroll compression unit used as a compression mechanism; Rotary compressor of a compression mechanism of a single compression unit formed by a single cylinder and a single rotor and having a series of compression chambers.

The present disclosure adopts a compressor having a single compression mechanism (compression unit such as a single-turn or double-turn scroll compression unit) formed, for example, by a single movable member (such as a movable scroll) and a single fixed member (such as a fixed scroll). And the number of refrigerant inlets of the single compression mechanism is set to be the same as the number of evaporation devices (for example, in an embodiment having two evaporation devices, the single compression mechanism is provided with two refrigerant inlets, In an embodiment of the evaporation device, the single compression mechanism is provided with three refrigerant inlets), so that refrigerants having different pressures from different evaporation devices can be directly introduced into the compressor without the need for the refrigerant to enter the compressor. It was previously depressurized, so it can avoid additional power consumption compared to a compressor with two or more compression units (such as double cylinders and double rotors), and can be implemented with a simpler and more compact structure A refrigerant circulation system having multiple evaporation devices without reducing pressure is required to improve the overall energy efficiency of the refrigerant circulation system. In addition, the refrigerant circulation system according to the present disclosure also implements a two-stage compression function through a single compressor.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the present disclosure will be described below by way of example only with reference to the accompanying drawings, in which the same features or components are denoted by the same reference numerals and the drawings are not necessarily drawn to scale, and in the drawings:

FIG. 1 is a pressure-enthalpy diagram of a refrigerant cycle system having a single compressor and a dual evaporation device in a comparative example; FIG.

2 is a schematic diagram of a pipeline of a refrigerant cycle system having a single compressor and a dual evaporation device according to a first embodiment of the present disclosure;

3 is a front view of a compressor of the refrigerant cycle system in FIG. 2;

4 is a plan view of a compressor of the refrigerant cycle system in FIG. 2;

5 is a cross-sectional view taken along a section line A-A in FIG. 4;

Figure 6 is a partially enlarged view of Figure 5;

7 is a pressure enthalpy diagram of a refrigerant cycle system according to a first embodiment of the present disclosure;

8 is an energy efficiency improvement diagram of the refrigerant cycle system according to the first embodiment of the present disclosure as compared with a comparative example;

9 is a schematic diagram of a pipeline of a refrigerant cycle system having a single compressor and a dual evaporation device according to a second embodiment of the present disclosure;

10 is a schematic diagram of a pipeline of a refrigerant cycle system having a single compressor and a dual evaporation device according to a third embodiment of the present disclosure;

11 is a schematic diagram of a refrigerant flow in a compressor of a refrigerant cycle system according to a third embodiment of the present disclosure; and

FIG. 12 is a pressure-enthalpy diagram of a refrigerant cycle system according to a third embodiment of the present disclosure.

detailed description

The following description is merely exemplary in nature and is not intended to limit the present disclosure, applications, and uses. It should be understood that in all of these figures, similar reference numbers indicate the same or similar parts and features. Each drawing merely schematically illustrates the concept and principle of an embodiment of the present disclosure, and does not necessarily show the specific size and proportion of each embodiment of the present disclosure. Exaggerated Way to illustrate relevant details or structures of the embodiments of the present disclosure.

FIG. 1 shows a pressure-enthalpy diagram of a conventional refrigerant cycle system having a single compressor and a dual evaporation device as a comparative example. As shown by the line from point 1 to point 2 in FIG. 1, the refrigerant performs heat exchange in the low-temperature-level evaporation device; as shown by the line from point 4 to point 5 in FIG. 1, the refrigerant is at the intermediate-temperature evaporation device. Heat exchange. The refrigerant flowing out of the low-temperature stage evaporation device has a lower pressure P1, and the refrigerant flowing out of the medium-temperature stage evaporation device has a higher pressure P2. Before the refrigerant enters the compressor, a pressure regulating valve needs to be used to reduce the pressure P2 of the refrigerant flowing out of the medium-temperature evaporation device, so that the refrigerant flowing out of the medium-temperature evaporation device and the refrigerant flowing out of the low-temperature evaporation device are in The same pressure, that is, the pressure of the refrigerant flowing out of the middle-temperature-stage evaporation device is reduced from P2 to P1, as shown by a line from point 5 to point 2 in FIG. 1. After that, as shown by the line from point 2 to point 3 in FIG. 1, the two (that is, the depressurized refrigerant flowing out of the medium-temperature-stage evaporation device and the refrigerant flowing out of the low-temperature-stage evaporation device) are mixed, The mixed refrigerant is then sent to a compressor for compression, as shown from points 3 to 6 in FIG. 1. In the pressure-enthalpy diagram of the refrigerant cycle system of the comparative example shown in FIG. 1, the pressure of the refrigerant flowing out of the intermediate-temperature evaporation device is reduced by the pressure regulating valve during the process from point 5 to point 2. This generates additional power consumption but does not generate any refrigeration, thereby reducing the energy efficiency of the refrigerant cycle system.

For this reason, in the refrigerant circulation system having a single compressor and a double evaporation device of the present disclosure, the refrigerant flowing out from the middle temperature stage evaporation device and the refrigerant flowing out from the low temperature stage evaporation device are directly sent to the compressor, There is no need to depressurize the refrigerant flowing out of the medium-temperature evaporation device. Therefore, in the refrigerant circulation system according to the present disclosure, there is no need to use an associated pressure regulating valve to reduce the pressure of the refrigerant, which improves the energy efficiency of the system. Hereinafter, a refrigerant cycle system according to various embodiments of the present disclosure will be described with reference to the drawings. It should be noted here that, in addition to the components shown in the drawings, the refrigerant cycle system according to the present disclosure may include many other components. In the present application, in order to clearly explain the inventive concept of the present disclosure, components related to the present disclosed concept are shown by way of example only, and other components are omitted.

FIG. 2 shows a schematic diagram of a pipeline connection of the refrigerant cycle system 100 according to the first embodiment of the present disclosure. As shown in FIG. 2, the refrigerant cycle system 100 includes a compressor 10, a first evaporation device 20, a second evaporation device 30, a condensation system 40, a liquid reservoir 50, and corresponding pipeline and valve structures. The first evaporation device 20 and the second evaporation device 30 have substantially the same structure, and include

evaporators

21, 31,

fans

22, 32,

expansion valves

23, 33,

temperature sensing bags

24, 34, and the like, respectively. The liquid refrigerant is diverted from the accumulator 50 at a branch point 70 via a diverting device (not shown), and is delivered to the first evaporation device 20 and the second evaporation device 30 through

corresponding solenoid valves

71 and 72, respectively. The first evaporation device 20 is a low-temperature-level evaporation device, and the second evaporation device 30 is a medium-temperature-level evaporation device. The liquid refrigerant becomes gaseous after being heat-exchanged in the first evaporation device 20 and is at a first pressure. The liquid refrigerant becomes gaseous after being heat-exchanged in the second evaporation device 30, and is at a second pressure, and the second pressure is higher than the first pressure.

In the present embodiment, the compressor 10 is a scroll compressor having a double-turn scroll. The compressor 10 has two air inlets, the compression mechanism of the compressor 10 has two sets of compression chambers independent of each other, and the compression mechanism has two refrigerant inlets. 3 to 6 show a front view, a top view, a cross-sectional view, and a partial enlarged view of the cross-sectional view of the compressor 10, respectively. As shown in FIG. 3, the compressor 10 includes a first air inlet 12, a second air inlet 13, and an air outlet 14 provided on a top cover. Gaseous refrigerant enters the compressor 10 from the first air inlet 12 and the second air inlet 13 respectively, and enters two independent refrigerant inlets through the first refrigerant inlet and the second refrigerant inlet of the compression mechanism of the compressor 10, respectively. The compression chambers of the group are discharged from the first exhaust hole 15 and the second exhaust hole 16 to the high-pressure space S1 above the compression mechanism after being compressed, and are discharged from the compressor 10 through the exhaust port 14 on the top cover. In this embodiment, the first refrigerant inlet of the compression mechanism is a low-pressure inlet of the first group of compression chambers in the two groups of compression chambers. The low-pressure inlet of the first group of compression chambers is the inlet (not shown) of the compression chamber of the first scroll, and communicates with the first air inlet 12, and the refrigerant flowing into the first air inlet 12 passes through the first group. The low-pressure inlet (first refrigerant inlet) of the compression chamber flows into the low-pressure chamber of the first group of compression chambers. The second refrigerant inlet of the compression mechanism is a low-pressure inlet of a second group of compression chambers in the two groups of compression chambers. The low-pressure inlet of the second set of compression chambers is the inlet (not shown) of the compression chamber of the second scroll, and communicates with the space inside the casing of the compressor 10, and flows into the casing of the compressor 10 from the second air inlet 13 The refrigerant in the body is sucked into the low-pressure chamber of the second group of compression chambers through the low-pressure inlet (second refrigerant inlet) of the second group of compression chambers.

Since the compression mechanism of the compressor 10 has two sets of compression chambers in parallel and independent of each other, and accordingly has two refrigerant inlets (a first refrigerant inlet and a second refrigerant inlet), the gaseous states at different pressures can be The refrigerant is sucked into the two compression chambers of the compressor 10 to perform compression. In the refrigerant cycle system 100, the outlet of the first evaporation device 20 is connected to the first air inlet 12 of the compressor 10, and the outlet of the second evaporation device 30 is connected to the second air inlet 13 of the compressor 10. The refrigerant flowing from the first evaporation device 20 enters the first group of compression chambers through the first air inlet 12 and the first refrigerant inlet of the compressor 10 at a first pressure and is compressed in the group of compression chambers. The first exhaust hole 15 is discharged into a high-pressure space above the compression mechanism. The refrigerant flowing out of the second evaporation device 30 enters the casing 11 of the compressor 10 through the second air inlet 13 of the compressor 10 at a second pressure and enters the second set of compression chambers through the second refrigerant inlet and is The group of compression chambers is compressed and then discharged from the second exhaust hole 16 into a high-pressure space above the compression mechanism. Thereafter, the refrigerant discharged from the first exhaust hole 15 and the refrigerant discharged from the second exhaust hole 16 are discharged from the compressor 10 through the exhaust port 14 on the top cover of the compressor 10 and are delivered to the condensation system 40 And perform heat exchange in the condensing system 40 (as shown by the lines from point 5 to point 6 in the pressure enthalpy diagram of FIG. 7 described below).

FIG. 7 shows a pressure enthalpy diagram of the refrigerant cycle system 100. As shown by the line from point 1 to point 2 in FIG. 7, the refrigerant performs heat exchange in the first evaporation device 20, and then flows into the compression through the first air inlet 12 and the first refrigerant inlet at a first pressure P1. Machine 10 in a first set of compression chambers. As shown by the line from point 3 to point 4 in FIG. 7, the refrigerant performs heat exchange in the second evaporation device 30, and then enters the casing 11 of the compressor 10 through the second air inlet 13 at a second pressure P2. And enters the second set of compression chambers through the second refrigerant inlet without reducing the pressure of the refrigerant flowing out of the second evaporation device 30, and there is no pressure of the refrigerant cycle system of the comparative example shown in FIG. 1 The process from point 5 to point 2 in the enthalpy diagram. Therefore, compared with the refrigerant circulation system of the comparative example, the refrigerant circulation system 100 does not need to use a pressure regulating valve to reduce the pressure of the refrigerant flowing out of the middle-temperature-stage evaporation device. Experiments have shown that the refrigerant cycle system 100 can significantly improve system energy efficiency compared to the refrigerant cycle system of the comparative example.

FIG. 8 illustrates an energy efficiency improvement diagram generated by the refrigerant cycle system 100 according to the present disclosure compared with a refrigerant cycle system of a comparative example. The abscissa of FIG. 8 represents the mass flow rate of the refrigerant flowing into the second evaporation device 30 and the total mass flow rate of the refrigerant flowing through all the evaporation devices of the refrigerant cycle system 100 (that is, the amount of refrigerant flowing into the second evaporation device 30 The ratio of the refrigerant to the sum of the mass flow rates of the refrigerant flowing into the first evaporation device 20). The ordinate of FIG. 8 represents the percentage increase in energy efficiency. For example, in the example working condition where the temperature of the refrigerant in the first evaporation device 20 is -30.67 ° C and the temperature of the refrigerant in the second evaporation device 30 is -6.67 ° C, the energy efficiency improvement diagram shown in FIG. 8 is obtained. . As shown in FIG. 8, the larger the mass flow ratio of the refrigerant flowing into the second evaporation device 30 is, the more obvious the energy efficiency improvement effect achieved by the refrigerant cycle system 100 according to the present disclosure is. For example, when the mass flow ratio of the refrigerant flowing into the second evaporation device 30 is 0.4, compared with the comparative example, the refrigerant cycle system 100 according to the present disclosure can achieve an energy efficiency improvement of more than 15%; When the mass flow ratio of the refrigerant in the second evaporation device 30 is 0.8, the refrigerant cycle system 100 according to the present disclosure can achieve an energy efficiency improvement of approximately 40%. In addition, in particular, since a single compression mechanism (or a compression unit, for example, a scroll compression unit having a double-circle scroll) formed with a single movable member (moving scroll) and a single fixed member (fixed scroll) is employed. Compressor 10, and the compression mechanism has two refrigerant inlets, therefore, the structure can be simpler and more compact than the related scheme using a compressor having two compression units (for example, a double cylinder and a double rotor). In this case, a refrigerant circulation system with a double evaporation device without pressure reduction is realized.

It should be noted here that, although not shown in FIG. 2, the refrigerant cycle system 100 may also have an enthalpy injection (EVI) branch that injects the enthalpy injection refrigerant to the compressor 10. In the compression chamber of the compression mechanism, the EVI branch provides supercooling while providing the medium-pressure jet-enhanced refrigerant gas to the compressor (as shown by the line from point 6 to point 7 in the pressure-enthalpy diagram in FIG. 7). . In the case where the accumulator 50 is configured as a flash tank, one end of the EVI branch is connected to the accumulator 50 to introduce the gaseous refrigerant in the accumulator 50 into the EVI branch and remove the refrigerant from the The other end of the EVI branch is provided to a compression chamber (eg, a medium pressure chamber) of the compressor 10 via an EVI inlet on the compression mechanism.

FIG. 9 shows a schematic diagram of a pipeline connection of a refrigerant cycle system 200 according to a second embodiment of the present disclosure. The same parts as those of the refrigerant cycle system 100 according to the first embodiment of the present disclosure are denoted by the same reference numerals, and detailed descriptions of these parts are omitted. Hereinafter, only the differences between the refrigerant cycle system 200 according to the second embodiment of the present disclosure and the refrigerant cycle system 100 according to the first embodiment will be described in detail.

In the refrigerant cycle system 200, the compressor 10 'is a scroll compressor having a single-turn scroll. The compressor 10' has only one set of compression chambers and only one air inlet 12, but the compression of the compressor 10 ' The mechanism has two refrigerant inlets. The refrigerant flowing out of the first evaporation device 20 flows into the low-pressure cavity in the set of compression chambers of the compressor 10 'through the first refrigerant inlet, and the refrigerant flowing out of the second evaporation device 30 flows into the compressor through the second refrigerant inlet. 10 'in the set of compression chambers. The first refrigerant inlet is a low-pressure inlet of the compression mechanism of the compressor 10 ', and the second refrigerant inlet is a medium-pressure inlet of the compression mechanism of the compressor 10'.

As shown in FIG. 9, the refrigerant cycle system 200 includes an air injection enthalpy (EVI) branch 60. In the embodiment shown, a throttle valve 73 is provided on the line between the condensing system 40 and the accumulator 50, which is configured as a flash tank. One end of the EVI branch 60 is connected to the accumulator 50 to introduce the gaseous refrigerant in the accumulator 50 into the EVI branch, and the other end of the EVI branch 60 is connected through an opening 17 on the compressor casing. To compressor 10 '. The EVI branch 60 injects the enthalpy-injected refrigerant (medium-pressure gaseous refrigerant) into the medium-pressure chamber of the compressor 10 'through the EVI inlet on the compression mechanism. As shown in FIG. 9, in the refrigerant circulation system 200, the outlet of the first evaporation device 20 is connected to the air inlet 12 of the compressor 10 '. Preferably, in the embodiment shown in FIG. 9, the pressure of the gaseous gaseous enthalpy-injected refrigerant injected from the EVI branch 60 is set to be equal to the pressure of the gaseous refrigerant flowing from the second evaporation device 30, and the first The outlet of the second evaporation device 30 is connected to the EVI branch 60, and the medium pressure inlet of the compression mechanism of the compressor 10 'is provided by the EVI inlet on the compression mechanism, so that the refrigerant flowing out of the second evaporation device 30 and the EVI branch The refrigerant provided by the circuit enters the compressor 10 'through the opening 17 for the EVI branch 60 on the casing of the compressor 10' and enters the middle pressure cavity of the compression mechanism through the EVI inlet on the compression mechanism, so that the compressor The structure is simpler. The EVI branch 60 injects a medium-pressure gaseous refrigerant into an intermediate-pressure chamber of the compression mechanism of the compressor 10 ′ through an EVI inlet on the compression mechanism. The pressure of the intermediate-pressure chamber is higher than the first pressure P1, and The two pressures P2 are approximately equal. Alternatively, another opening may be provided on the casing of the compressor 10 ′ to connect the second evaporation device 30, and / or another port may be provided on the compression mechanism of the compressor 10 ′ as a medium pressure inlet to The refrigerant flowing out of the second evaporation device 30 is introduced into the intermediate pressure cavity of the compression mechanism, which can also directly introduce the refrigerant flowing out of the second evaporation device 30 into the compression mechanism of the compressor without performing the refrigerant Step down.

In the refrigerant circulation system 200, the first refrigerant inlet of the compression mechanism of the compressor 10 'is the low-pressure inlet of the compression chamber of the compression mechanism, and the low-pressure inlet is the inlet of the compression chamber of the scroll of the compression mechanism, and communicates with the air intake. The port 12 communicates, and the refrigerant flowing into the air inlet 12 flows into the low-pressure chamber of the compression mechanism through the low-pressure inlet (first refrigerant inlet) of the first group of compression chambers. The second refrigerant inlet is a medium pressure inlet (preferably an EVI inlet of the compression mechanism) of the compression mechanism of the compressor 10 '. That is, the refrigerant flowing out of the second evaporation device 30 and the enthalpy-injecting refrigerant flowing into the EVI branch 60 from the accumulator 50 enter the compressor 10 ′ through the opening 17 and pass through the EVI on the compression mechanism of the compressor 10 ′. The inlet (the medium pressure inlet of the compression mechanism, that is, the second refrigerant inlet) enters the medium pressure chamber.

In the refrigerant cycle system 200 according to the second embodiment of the present disclosure, since a single compression mechanism (or compression unit) having a single movable member (moving scroll) and a single fixed member (fixed scroll) is employed, Single-scroll scroll compression unit) compressor 10 ', although the compressor 10' has only one set of compression chambers and one air inlet 12, it still has two refrigerant inlets (the first refrigerant inlet and Second refrigerant inlet), and therefore, the refrigerant flowing out from the second evaporation device 30 can still be introduced into the compressor 10 'at the second pressure P2 without using a device such as a pressure regulating valve for pressure reduction. The refrigerant cycle system 200 according to the second embodiment can achieve effects similar to those of the refrigerant cycle system 100 according to the first embodiment, and is related to the use of a compressor having two compression units (for example, two cylinders and two rotors). Compared with the scheme, a refrigerant circulation system with a double evaporation device without pressure reduction can be realized under a simpler and more compact structure, which can effectively improve system energy efficiency.

In addition, it should be noted that, although the illustrated refrigerant cycle system 200 is provided with an EVI branch 60, the gaseous gas-jet-enhanced refrigerant in the accumulator 50 is passed through the EVI branch 60 ( Medium-pressure refrigerant gas) is injected into the compression mechanism such that the refrigerant injected into the compression mechanism from the EVI inlet of the compression mechanism includes both the refrigerant flowing out of the second evaporation device 30 and the jet-enhanced refrigerant. However, the refrigerant circulation system according to the present disclosure concept may not be provided with the EVI branch 60, but only the second evaporation device 30 is connected to the opening 17 on the compressor casing, so that the injection from the EVI inlet of the compression mechanism to the compression The refrigerant in the mechanism includes only the refrigerant flowing out of the second evaporation device, and does not include the enthalpy increasing refrigerant.

FIG. 10 shows a schematic diagram of a pipeline connection of a refrigerant cycle system 300 according to a third embodiment of the present disclosure. The same parts as the refrigerant cycle system 100 and the refrigerant cycle system 200 are denoted by the same reference numerals, and detailed descriptions of these parts are omitted. Hereinafter, only the differences between the refrigerant cycle system 300 according to the third embodiment of the present disclosure, the refrigerant cycle system 100 of the first embodiment, and the refrigerant cycle system 200 of the second embodiment will be described in detail.

In the refrigerant circulation system 300, similar to the compressor 10 of the refrigerant circulation system 100, the compressor 10 "is a scroll compressor having a double-circle scroll, the compressor 10" has two air inlets, and the compressor The 10 "compression mechanism also has two sets of compression chambers and two refrigerant inlets. However, unlike compressor 10, the two sets of compression chambers of compressor 10" are not arranged in parallel with each other, but are configured in series. The compressor of the compressor 10 "is configured as a two-stage compression mechanism. As shown in Fig. 10, the first evaporation device 20 is connected to the first air inlet 12 of the compressor 10", and the second evaporation device 30 is connected to the compressor 10 " The second air inlet 13. FIG. 11 shows a schematic diagram of the refrigerant flow in the compression mechanism of the compressor 10 ". As shown by arrow A1 in FIG. 11, the refrigerant flowing out of the first evaporation device 20 enters the compressor 10 ″ from the first air inlet 12 of the compressor 10 ″ under the first pressure P1 and enters through the first refrigerant inlet. The low-pressure chamber of the first set of compression chambers is compressed in the first set of compression chambers to a second pressure P2. As shown by the dashed-dotted arrow A2 in FIG. 11, after the refrigerant is compressed by the first set of compression chambers, the refrigerant is discharged from the first exhaust hole 15 and flows into the casing 11 of the compressor 10 ”(the first exhaust can be exhausted from the first The hole 15 flows directly into the casing 11 of the compressor 10 ", or can be flowed into the casing 11 of the compressor 10" through a gas pipe not shown), and enters the second group of compression chambers for compression through the second refrigerant inlet. That is, the refrigerant first compresses through the first set of compression chambers and then enters the second set of compression chambers for compression. Therefore, the compression mechanism of the compressor 10 "is configured as a two-stage compression mechanism. In addition, as shown by an arrow A3 in FIG. 11, the refrigerant flowing out of the second evaporation device 30 enters the casing 11 of the compressor 10 ″ from the second air inlet 13 of the compressor 10 ″ at a second pressure P2 , And then enter the second set of compression chambers for compression through the second refrigerant inlet.

In addition, as shown in FIG. 10, the refrigerant cycle system 300 includes an air injection enthalpy (EVI) branch 60 '. In the present embodiment, a throttle valve 73 is provided upstream of the reservoir 50, and the reservoir 50 is configured as a flash tank. One end of the EVI branch 60 'is connected to the accumulator 50 to introduce gaseous medium-pressure refrigerant into the EVI branch 60', and the other end of the EVI branch 60 'is connected to the compressor 10 via an opening 17 ". The The EVI branch 60 ′ is further provided with a pressure regulating valve 74 to inject a gaseous refrigerant having a pressure approximately equal to the second pressure P2 into the compressor 10 ″. Different from the EVI branch 60 of the refrigerant circulation system 200 according to the second embodiment, the EVI branch 60 ′ of the refrigerant circulation system 300 does not directly inject the refrigerant into the compression chamber of the compression mechanism, but is compressed. The opening 17 in the casing 11 of the compressor 10 "injects refrigerant into the casing 11 of the compressor 10", as shown by arrow A4 in FIG. 11. Then, the refrigerant in the casing 11 enters the second set of compression chambers through the second refrigerant inlet. In the refrigerant circulation system 300, the first refrigerant inlet is the low-pressure inlet of the first group of compression chambers of the compressor 10 ", and the low-pressure inlet of the first group of compression chambers is the inlet of the first-round scroll compression chamber (not shown) Out), and communicates with the first air inlet 12, and the refrigerant flowing into the first air inlet 12 flows into the low-pressure cavity of the first group of compression chambers through the low-pressure inlet (first refrigerant inlet) of the first group of compression chambers. The second refrigerant inlet is the low-pressure inlet of the second group of compression chambers of the compressor 10 ″, and the low-pressure inlet of the second group of compression chambers is the inlet of the compression chamber of the second scroll (not shown), and communicates with the compressor 10 The space in the casing 11 communicates, and the refrigerant flowing from the second air inlet 13 into the casing 11 of the compressor 10 is sucked into the second group through the low-pressure inlet (second refrigerant inlet) of the second group of compression chambers. Low-pressure chamber of the compression chamber.

In this exemplary embodiment, the gaseous refrigerant flowing out of the first evaporation device 20 is compressed in the first set of compression chambers to a second pressure P2, is discharged from the first exhaust hole 15 and flows into the casing of the compressor. The gaseous refrigerant flowing from the second evaporation device 30 flows into the casing of the compressor at the second pressure P2 through the second air inlet 13, and the EVI branch 60 ′ also injects the gaseous refrigerant at a medium pressure to the compression Machine case. Therefore, the pressure in the casing 11 of the compressor 10 "is these three (i.e., the gaseous refrigerant flowing out of the first exhaust hole 15 after being compressed by the first set of compression chambers and flowing into the casing of the compressor, The gaseous refrigerant flowing into the casing of the compressor from the second air inlet 13 and the gaseous refrigerant injected into the casing of the compressor from the EVI branch 60 ') are mixed at a mixing pressure P3. The mixing pressure P3 is between Between the air pressure (the first pressure P1) and the exhaust pressure. Therefore, the motor is neither under the intake pressure nor the exhaust pressure, but between the exhaust pressure and the intake pressure Under intermediate pressure. Therefore, the compressor 10 "of this configuration is not a high-pressure side scroll compressor or a low-pressure side scroll compressor in the traditional sense. The gaseous refrigerant flowing out of the first evaporation device 20 is compressed to a second pressure P2 in the first set of compression chambers. Preferably, the pressure of the gaseous refrigerant sprayed from the EVI branch 60 'is set equal to the second pressure P2, In this case, the mixing pressure P3 is approximately equal to the second pressure P2. After that, the refrigerant in the casing 11 is sucked into the second group of compression chambers for compression through the second refrigerant inlet, and is discharged from the second exhaust hole 16 into the high-pressure space above the compression mechanism after compression, as shown in FIG. 11 The arrow A5 is shown. Then, the refrigerant discharged from the second exhaust hole 16 flows out from the exhaust port 14 provided on the top cover, enters the condensation system 40, and performs heat exchange in the condensation system 40 (as shown in the pressure enthalpy of FIG. 12 described below) (Points 5 to 6 in the figure).

FIG. 12 illustrates a pressure enthalpy diagram of a refrigerant cycle system 300 according to a third embodiment of the present disclosure. As shown by the arrowed line from point 1 to point 2 in the pressure-enthalpy diagram of FIG. 12, the refrigerant performs heat exchange in the first evaporation device 20, and then passes through the first air inlet 12 and the first at the first pressure P1. A refrigerant inlet enters the first set of compression chambers of the compressor 10 "and is compressed to a second pressure P2. As shown by the line from point 3 to point 4 in the enthalpy diagram of Fig. 12, the refrigerant evaporates on the second Heat exchange is performed in the device 30, and then enters the casing of the compressor 10 "through the second air inlet 13 at the second pressure P2, and is drawn into the second group of compression chambers of the compressor 10" through the second refrigerant inlet. Compression. In addition, the refrigerant flowing out of the first evaporation device 20 is compressed in the first set of compression chambers of the compressor 10 ″ and flows into the casing 11 after being compressed, and then flows into the compressor from the second air inlet 13. The refrigerant in the 10 "casing 11 and the refrigerant injected from the EVI branch 60 'through the opening 17 in the casing 11 into the casing 11 enter the second group of the compressor 10" through the second refrigerant inlet. Compression is performed in the compression chamber, as shown by the line from point 8 to point 5 in the enthalpy diagram of FIG. 12.

Compared with the refrigerant cycle system of the comparative example, the refrigerant cycle system 300 according to the third embodiment of the present disclosure adopts a unit having a single movable member (moving scroll) and a single fixed member (fixed scroll). Compressor 10 "of a compression mechanism (or compression unit, for example, a scroll compression unit with a double-turn scroll), and the compression mechanism has two refrigerant inlets, and does not require the use of a device such as a pressure regulating valve to evaporate from the second The refrigerant flowing out of the device 30 is first depressurized and then introduced into the compressor. There is no process from point 5 to point 2 in the pressure-enthalpy diagram of the refrigerant cycle system of the comparative example shown in FIG. Achieving similar technical effects to the above-mentioned refrigerant cycle system 100 and refrigerant cycle system 200, compared with the related scheme using a compressor having two compression units (for example, two cylinders and two rotors), the structure can be simpler and the In a compact case, a refrigerant circulation system with a dual evaporation device without pressure reduction is realized, and the energy efficiency of the system is improved.

In addition, in the application of the existing two-stage compression system, multiple compressors are often used to achieve two-stage compression. And the refrigerant circulation system 300 according to the third embodiment of the present disclosure achieves the effect of two-stage compression by a single compressor 10 ", making the construction of the entire refrigerant circulation system simpler, and reducing the existing two-stage compression system. the cost of.

In the embodiment shown above, each of the refrigerant cycle systems includes two evaporation devices (the first evaporation device 20 and the second evaporation device 30). Also, since a single compression mechanism (or compression unit) having, for example, a single movable member (for example, a movable scroll) and a single fixed member (for example, a fixed scroll) is used, for example, a single-turn scroll or a double-turn scroll Scroll scroll compression unit) compressor (for example, compressor 10, compressor 10 ', compressor 10 "), and the compressor's compression mechanism has two refrigerant inlets. Compared with related solutions of compressors (for example, dual cylinders and dual rotors), a refrigerant circulation system having a dual evaporation device without pressure reduction can be realized under a simpler and more compact structure.

But this disclosure is not limited to this. In other possible embodiments of the present disclosure, the concept of the present disclosure may also be applied to a refrigerant cycle system having three or more evaporation devices. For example, the refrigerant circulation system may include a first evaporation device, a second evaporation device, and an additional evaporation device (a third evaporation device). These three evaporation devices may provide different refrigerating temperatures from each other to achieve a more accurate temperature as required. It is controlled that the refrigerant flowing from the three evaporation devices has different pressures. In such a refrigerant circulation system, a scroll compressor having a single scroll compression mechanism with double-circle scrolls can be used. The compression mechanism of the compressor has two sets of compression chambers connected in parallel or in series independently of each other and having separate Two air inlets for these two sets of compression chambers, and the compression mechanism has three refrigerant inlets. In addition, the refrigerant cycle system is also provided with an air injection enthalpy (EVI) branch, and an opening for the EVI branch is also provided on the casing of the compressor. The EVI branch injects gaseous medium-pressure refrigerant through the opening for the EVI branch on the compressor casing to the EVI branch on the compression mechanism of the compressor and sends the refrigerant through the EVI inlet on the compression mechanism. A medium pressure chamber of a group of compression chambers injected into the two compression chambers of the compression mechanism. In the above-mentioned refrigerant circulation system having three evaporation devices, the first refrigerant inlet is the low-pressure inlet of the first group of compression chambers, and the low-pressure inlet of the first group of compression chambers is the compression chamber of the first coil of the compression mechanism. The inlet is in communication with the first air inlet, and the refrigerant flowing into the first air inlet flows into the low-pressure cavity in the first group of compression cavity through the low-pressure inlet of the first group of compression cavity. The second refrigerant inlet is the low-pressure inlet of the second group of compression chambers, and the low-pressure inlet of the second group of compression chambers is the inlet of the compression chamber of the second-round scroll of the compression mechanism, and communicates with the second air inlet. The refrigerant flowing from the air inlet into the casing of the compressor flows into the low-pressure cavity of the second group of compression cavity through the second refrigerant inlet. The third refrigerant inlet is a medium-pressure inlet of the compression mechanism. In an embodiment where the accumulator 50 is configured as a flash tank, one end of the EVI branch is connected to the accumulator 50 to introduce a gaseous medium-pressure refrigerant into the EVI branch, and the other end of the EVI branch Connected to the compressor. The EVI branch injects the refrigerant through the EVI inlet on the compression mechanism to the intermediate pressure chamber of one of the first set of compression chambers and the second set of compression chambers of the compression mechanism. The first evaporation device and the second evaporation device are connected to a first air inlet and a second air inlet of the compressor, respectively. In addition, similar to the refrigerant cycle system 200 of the second embodiment shown above, it is preferable that a third evaporation device is connected to the EVI branch of the refrigerant cycle system, and the intermediate pressure inlet of the compression mechanism is preferably composed of The EVI inlet in the compression mechanism is provided so that the refrigerant flowing out of the third evaporation device and the refrigerant provided by the EVI branch both enter the compressor through the opening for the EVI branch in the compressor casing and pass through the compression. The EVI inlet on the mechanism enters the medium pressure cavity of the compression mechanism, making the structure of the compressor simpler. The EVI branch injects a medium-pressure gaseous refrigerant into a medium-pressure chamber of the compression mechanism through an EVI inlet on the compression mechanism, and the pressure of the medium-pressure chamber is substantially equal to the pressure of the refrigerant flowing out of the third evaporation device. Alternatively, another opening may be provided on the casing of the compressor to connect to the third evaporation device, and / or another port may be provided on the compression mechanism of the compressor as a medium pressure inlet to evaporate from the third The refrigerant flowing out of the device is introduced into the intermediate pressure cavity of the compression mechanism, which can also directly introduce the refrigerant flowing out of the third evaporation device into the compression mechanism of the compressor without reducing the pressure of the refrigerant.

In the refrigerant cycle system having three evaporation devices according to the present disclosure concept, since a single compression mechanism (or compression unit) having a single movable member (moving scroll) and a single fixed member (fixed scroll) is employed, For example, a compressor with a double-screw scroll compression unit), and the compression mechanism has three refrigerant inlets, and the refrigerant flowing out of the three evaporation devices can be directly introduced into the compressor without being used. The compressor is introduced after the pressure is adjusted by a pressure regulating valve or the like, so that the effects similar to the refrigerant cycle system 100, the refrigerant cycle system 200, and the refrigerant cycle system 300 of the above embodiment can be achieved, and the structure can be simpler and more compact. The realization of a refrigerant circulation system with multiple evaporation devices without pressure reduction can improve the energy efficiency of the system.

In addition, it should be noted that the above-mentioned refrigerant cycle system having three evaporation devices is provided with an EVI branch, and a gaseous jet enthalpy refrigerant (medium-pressure refrigerant gas) is injected through the EVI branch to In the compression mechanism, the refrigerant injected from the EVI inlet of the compression mechanism into the compression mechanism includes both the refrigerant flowing out of the third evaporation device and the jet-enhanced refrigerant. However, the refrigerant circulation system having three evaporation devices according to the present disclosure concept may not be provided with the EVI branch, but only the second evaporation device 30 is connected to the opening for the EVI branch on the compressor housing, The refrigerant injected from the EVI inlet of the compression mechanism into the compression mechanism includes only the refrigerant flowing out from the third evaporation device, and does not include the enthalpy-enhancing refrigerant.

In other possible alternative embodiments of the above-mentioned refrigerant cycle system having three evaporation devices according to the present disclosure concept, the third evaporation device may be connected to the first set of compression chambers via the EVI branch, and is connected with the third The embodiment is similar, so that the refrigerant flowing out from the exhaust holes of the first group of compression chambers flows into the casing of the compressor, and is sucked into the second group of compression chambers to be compressed again, thereby achieving two-stage compression.

Herein, the exemplary embodiments of the present disclosure have been described in detail, but it should be understood that the present disclosure is not limited to the specific embodiments described and illustrated in detail above. Those skilled in the art can make various modifications and variations to the present disclosure without departing from the spirit and scope of the present disclosure. All of these variations and modifications fall within the scope of the disclosure. Moreover, all components described herein may be replaced by other technically equivalent components.

Claims

A refrigerant cycle system (100, 200, 300), the refrigerant cycle system includes:

A compressor (10, 10 ', 10 "), said compressor having a single compression mechanism, said compression mechanism having a first refrigerant inlet and a second refrigerant inlet;

A first evaporation device (20), the refrigerant having a first pressure after heat exchange through the first evaporation device, and the first evaporation device is connected to the compressor;

A second evaporation device (30), the refrigerant having a second pressure after heat exchange through the second evaporation device, and the second evaporation device is connected to the compressor,

Wherein, the refrigerant flowing out of the first evaporation device flows into the compression mechanism through the first refrigerant inlet at the first pressure, and the refrigerant flowing out of the second evaporation device uses the first pressure Two pressures flow into the compression mechanism through the second refrigerant inlet.
The refrigerant cycle system (100, 200, 300) according to claim 1, wherein the first pressure is lower than the second pressure.
The refrigerant cycle system (100) according to claim 1 or 2, wherein the compression mechanism includes a first group of compression chambers and a second group of compression chambers in parallel, and the first refrigerant inlet is the first The low-pressure inlet of the group of compression chambers, and the second refrigerant inlet is the low-pressure inlet of the second group of compression chambers.
The refrigerant cycle system (300) according to claim 1 or 2, wherein:

The compression mechanism includes a first group of compression chambers and a second group of compression chambers connected in series, and the refrigerant flowing out of the first group of compression chambers flows into the second group of compression chambers through a low-pressure inlet of the second group of compression chambers. Further compression; and

The first refrigerant inlet is a low-pressure inlet of the first group of compression chambers, and the second refrigerant inlet is a low-pressure inlet of the second group of compression chambers.
The refrigerant cycle system (300) according to claim 4, wherein:

The refrigerant cycle system further includes an air jet enthalpy increasing branch, and the air jet enthalpy increasing refrigerant supplied from the air jet increasing enthalpy branch also flows into the second group of compression chambers through a low-pressure inlet of the second group of compression chambers. .
The refrigerant cycle system (300) according to claim 5, wherein the refrigerant flowing out of the first evaporation device directly flows into the first group of compression chambers, and the refrigerant flowing out of the first group of compression chambers The refrigerant, the refrigerant flowing out of the second evaporation device, and the enthalpy-enriched refrigerant supplied from the enthalpy-enhanced branch flow into the space in the casing of the compressor and then pass through the second set of compression chambers. The low-pressure inlet flows into the second set of compression chambers.
The refrigerant cycle system (100, 300) according to claim 1, wherein:

The compression mechanism includes a first group of compression chambers and a second group of compression chambers connected in parallel or in series, the first refrigerant inlet is a low-pressure inlet of the first group of compression chambers, and the second refrigerant inlet is the A low-pressure inlet of a second group of compression chambers, and a medium-pressure inlet of the compression mechanism is provided at the medium-pressure chamber in the first group of compression chambers and / or the medium-pressure chamber in the second group of compression chambers; as well as

The refrigerant cycle system further includes an additional evaporation device, and the refrigerant has a third pressure higher than the first pressure and not equal to the second pressure after heat exchange through the additional evaporation device, and evaporates from the additional evaporation. The refrigerant flowing out of the device flows into the compression mechanism at the third pressure through the intermediate pressure inlet of the compression mechanism.
The refrigerant cycle system (200) according to claim 1, wherein the compression mechanism includes a single set of compression chambers, the first refrigerant inlet is a low-pressure inlet of the compression mechanism, and the second refrigerant inlet It is the medium pressure inlet of the compression mechanism.
The refrigerant cycle system (100, 200, 300) according to claim 7, wherein the intermediate pressure inlet is provided by a gas injection enthalpy inlet of the compression mechanism.
The refrigerant cycle system (100, 200, 300) according to claim 9, wherein the refrigerant flowing into the compression mechanism via a medium-pressure inlet of the compression mechanism includes only the refrigerant flowing out of the additional evaporation device Or, the refrigerant flowing into the compression mechanism through the medium pressure inlet of the compression mechanism includes the refrigerant flowing out of the additional evaporation device and the gas injection enthalpy supplied by the gas injection enthalpy branch of the refrigerant circulation system. Refrigerant both.
The refrigerant cycle system (100, 200, 300) according to claim 8, wherein the intermediate pressure inlet is provided by a gas injection enthalpy inlet of the compression mechanism.
The refrigerant cycle system (100, 200, 300) according to claim 11, wherein the refrigerant flowing into the compression mechanism via a medium pressure inlet of the compression mechanism includes only the refrigerant flowing out of the second evaporation device Or, the refrigerant flowing into the compression mechanism through the intermediate pressure inlet of the compression mechanism includes the refrigerant flowing out of the second evaporation device and the air jet supplied from the air enthalpy increasing branch of the refrigerant circulation system. Enthalpy-enhancing refrigerants both.
The refrigerant cycle system (100, 200, 300) according to claim 1 or 2, wherein the compressor is a double-circle scroll compression including a single double-circle scroll compression unit serving as the compression mechanism. A single-turn scroll compressor including a single single-turn scroll compression unit used as the compression mechanism; or a single-turn scroll compressor including a single cylinder and a single rotor and having a series of compression chambers used as the compression mechanism Rotor compressor for compression unit.