阅读说明：本技术 一种冰场二氧化碳制冷系统 (Carbon dioxide refrigerating system for ice rink ) 是由 马进 武晓南 李锋 王建林 冯刚 陈煜� 张川 司春强 于 2020-05-08 设计创作，主要内容包括：本发明提供了一种冰场二氧化碳制冷系统,包括：一组或多组制冷子系统,所述制冷子系统包括：第一压缩机、第二压缩机、气体冷却器、回热器组、引射器、膨胀罐、膨胀阀、第一控制阀、第二控制阀、第三控制阀和第四控制阀；所述回热器组包括多个回热器,多个所述回热器的第一通路相连通。通过本发明实施例提供的冰场二氧化碳制冷系统,利用回热器可以降低从气体冷却器出来的制冷剂温度,同时能够提高压缩机的吸气温度,提高压缩机效率,降低压缩机功耗,提高整个系统的能效比。引射器能够提高系统的运行效率和稳定性；主压缩机和并行压缩机两类压缩机同时工作,能够实现高效循环,进一步提高制冷效率。(The invention provides a carbon dioxide refrigerating system for an ice rink, which comprises: one or more sets of refrigeration subsystems, the refrigeration subsystems comprising: the system comprises a first compressor, a second compressor, a gas cooler, a heat regenerator group, an ejector, an expansion tank, an expansion valve, a first control valve, a second control valve, a third control valve and a fourth control valve; the regenerator group comprises a plurality of regenerators, and the first passages of the plurality of regenerators are communicated. According to the carbon dioxide refrigeration system for the ice rink, provided by the embodiment of the invention, the temperature of the refrigerant discharged from the gas cooler can be reduced by using the heat regenerator, meanwhile, the suction temperature of the compressor can be increased, the efficiency of the compressor is improved, the power consumption of the compressor is reduced, and the energy efficiency ratio of the whole system is improved. The ejector can improve the operation efficiency and stability of the system; the main compressor and the parallel compressor work simultaneously, so that high-efficiency circulation can be realized, and the refrigeration efficiency is further improved.)

1. An ice rink carbon dioxide refrigeration system, comprising: one or more sets of refrigeration subsystems, the refrigeration subsystems comprising: the system comprises a first compressor, a second compressor, a gas cooler, a heat regenerator group, an ejector, an expansion tank, an expansion valve, a first control valve, a second control valve, a third control valve and a fourth control valve; the heat regenerator group comprises a plurality of heat regenerators, and the input end and the output end of a first passage of the plurality of heat regenerators are respectively used as the input end and the output end of the heat regenerator group;

the output end of the first compressor and the output end of the second compressor are both connected with the input end of the gas cooler, the output end of the gas cooler is connected with the input end of the heat regenerator group, and the output end of the heat regenerator group is connected with the first input end of the ejector;

the output end of the ejector is connected with the inlet of the expansion tank, and the upper outlet of the expansion tank is connected with the second passage of the regenerator in the regenerator set and the second control valve in series and then is connected with the input end of the first compressor; the upper outlet of the expansion tank is connected with a second passage of a regenerator in the regenerator set and the third control valve in series and then is connected with the input end of the second compressor;

the lower outlet of the expansion tank is connected with the expansion valve in series and then is connected with the input end of the low-pressure circulating barrel; the low-pressure circulating barrel is used for cooling the corresponding ice rinks, the output end of the low-pressure circulating barrel is connected with the second passage of the heat regenerator in the heat regenerator set in series, the first control valve is connected with the input end of the first compressor, and the output end of the low-pressure circulating barrel is connected with the second passage of the heat regenerator in the heat regenerator set in series, the fourth control valve is connected with the input end of the second compressor.

2. The carbon dioxide refrigeration system for an ice rink of claim 1, wherein the regenerator set includes a first regenerator and a second regenerator;

the first passage of the first regenerator is communicated with the first passage of the second regenerator in series, and the input end and the output end of the communicated passage are respectively used as the input end and the output end of the regenerator group; or the first passages of the first regenerator are communicated with the first passages of the second regenerator in parallel, and the input end and the output end of each first passage are respectively used as the input end and the output end of the regenerator group;

the second passage of the first heat regenerator adopts a first connection mode, and the second passage of the second heat regenerator adopts a second connection mode;

wherein, the first connection mode is as follows: a second input end of the first heat regenerator is connected with an upper outlet of the expansion tank, a second output end of the first heat regenerator is connected with an input end of the first compressor through the second control valve, and a second output end of the first heat regenerator is connected with an input end of the second compressor through the third control valve; or a second input end of the first heat regenerator is connected with an upper outlet of the expansion tank through the second control valve, a second input end of the first heat regenerator is connected with an output end of the low-pressure circulation barrel through the first control valve, and a second output end of the first heat regenerator is connected with an input end of the first compressor;

the second connection mode is as follows: a second input end of the second heat regenerator is connected with an output end of the low-pressure circulating barrel, a second output end of the second heat regenerator is connected with an input end of the first compressor through the first control valve, and a second output end of the second heat regenerator is connected with an input end of the second compressor through the fourth control valve; or the second input end of the second regenerator is connected with the upper outlet of the expansion tank through the third control valve, the second input end of the second regenerator is connected with the output end of the low-pressure circulation barrel through the fourth control valve, and the second output end of the second regenerator is connected with the input end of the second compressor.

3. The carbon dioxide refrigeration system for an ice rink according to claim 1 or 2, wherein the regenerator group comprises at least three regenerators;

and the output end of the low-pressure circulating barrel is connected with the second channel of at least one heat regenerator in the heat regenerator set in series and then is connected with the second input end of the ejector.

4. The carbon dioxide refrigeration system for an ice rink of claim 3, the regenerator bank comprising a third regenerator;

and a second input end of the third heat regenerator is connected with the output end of the low-pressure circulating barrel, and a second output end of the third heat regenerator is connected with a second input end of the ejector.

5. The carbon dioxide refrigeration system for an ice rink of claim 3, wherein the refrigeration subsystem further comprises a first valve, a second valve, a third valve, a fourth valve, a fifth valve, and a sixth valve;

the upper outlet of the expansion tank is connected with the first valve in series and then is communicated with a second passage of a heat regenerator in the heat regenerator set, and the upper outlet of the expansion tank is connected with the second valve in series and then is connected with the input end of a corresponding compressor;

the output end of the low-pressure circulating barrel is connected with the second channel of another regenerator in the regenerator set after being connected with the third valve in series, and the output end of the low-pressure circulating barrel is connected with the second input end of the ejector after being connected with the fourth valve in series;

the output end of the low-pressure circulating barrel is connected with the fifth valve in series and then is communicated with the second passage of another heat regenerator in the heat regenerator group, and the output end of the low-pressure circulating barrel is connected with the sixth valve in series and then is connected with the input end of the corresponding compressor.

6. The carbon dioxide refrigeration system for an ice rink of claim 1, wherein the refrigeration subsystem further comprises a heat recovery heat exchanger;

the heat recovery heat exchanger is disposed between the first compressor and the gas cooler.

7. The carbon dioxide refrigeration system for an ice rink of claim 6, wherein the refrigeration subsystem further comprises a seventh valve and an eighth valve;

the output end of the first compressor and the output end of the second compressor are connected in series with the seventh valve and then are connected with the input end of the gas cooler;

and the heat recovery heat exchanger is connected with the eighth valve in series and then connected with the seventh valve in parallel.

8. The carbon dioxide refrigeration system for an ice rink of claim 1, wherein the number of the first compressors is one or more and the number of the second compressors is one or more.

9. The carbon dioxide refrigeration system for an ice rink of claim 1, wherein the refrigeration subsystem further comprises a low pressure recycle bin or a gas-liquid separator.

Technical Field

The invention relates to the technical field of ice rink refrigeration, in particular to a carbon dioxide refrigeration system for an ice rink.

Background

The natural refrigerant carbon dioxide is non-toxic and non-inflammable, is safe and reliable, is environment-friendly, has good thermophysical properties, is developed rapidly, and has good effects in the commercial refrigeration fields of ice and snow sports industry, supermarket refrigeration systems, cold stores, automobile air conditioners, heat pump water heaters and the like. The cycle using carbon dioxide as a refrigerant can be divided into a subcritical cycle, a transcritical cycle, and a supercritical cycle. The subcritical cycle is the same as the common vapor compression refrigeration cycle, and the heat absorption and heat release processes of the system are below the critical point; the endothermic process of the transcritical cycle is below the critical point and the exothermic process is above the critical point; the endothermic and exothermic processes of the supercritical cycle are both above the critical point.

The carbon dioxide transcritical refrigeration cycle is one member of a large family of vapor compression refrigeration cycles, and the basic cycle process is completed by an evaporator, a compressor, a gas cooler and an expansion valve. Figure 1 shows a schematic diagram of a simple carbon dioxide transcritical refrigeration cycle. Wherein, 1-2 is the process of liquid carbon dioxide gasification heat absorption refrigeration, the pressure in the evaporator is lower than the critical pressure of carbon dioxide, 2-3 is the process of carbon dioxide gas compression in the compressor, the pressure of the compressed carbon dioxide is higher than the critical pressure, 3-4 is the process of carbon dioxide gas constant pressure heat release in the supercritical state, the carbon dioxide does not generate phase change in the heat exchange process, only sensible heat is transferred, the gas cooler is realized, and 4-1 is the heat insulation throttling process, thereby forming a complete cycle process. The whole cycle process crosses the critical pressure line, so the cycle is called a transcritical refrigeration cycle.

At present, a large-scale ice rink refrigerating system mostly adopts refrigerating working media such as Freon and the like, has the problem of low efficiency, and easily causes energy waste.

Disclosure of Invention

In order to solve the above problems, embodiments of the present invention provide a carbon dioxide refrigeration system for an ice rink.

The embodiment of the invention provides a carbon dioxide refrigerating system for an ice rink, which comprises: one or more sets of refrigeration subsystems, the refrigeration subsystems comprising: the system comprises a first compressor, a second compressor, a gas cooler, a heat regenerator group, an ejector, an expansion tank, an expansion valve, a first control valve, a second control valve, a third control valve and a fourth control valve; the heat regenerator group comprises a plurality of heat regenerators, and the input end and the output end of a first passage of the plurality of heat regenerators are respectively used as the input end and the output end of the heat regenerator group;

the output end of the first compressor and the output end of the second compressor are both connected with the input end of the gas cooler, the output end of the gas cooler is connected with the input end of the heat regenerator group, and the output end of the heat regenerator group is connected with the first input end of the ejector;

the output end of the ejector is connected with the inlet of the expansion tank, and the upper outlet of the expansion tank is connected with the second passage of the regenerator in the regenerator set and the second control valve in series and then is connected with the input end of the first compressor; the upper outlet of the expansion tank is connected with a second passage of a regenerator in the regenerator set and the third control valve in series and then is connected with the input end of the second compressor;

the lower outlet of the expansion tank is connected with the expansion valve in series and then is connected with the input end of the low-pressure circulating barrel; the low-pressure circulating barrel is used for cooling the corresponding ice rinks, the output end of the low-pressure circulating barrel is connected with the second passage of the heat regenerator in the heat regenerator set in series, the first control valve is connected with the input end of the first compressor, and the output end of the low-pressure circulating barrel is connected with the second passage of the heat regenerator in the heat regenerator set in series, the fourth control valve is connected with the input end of the second compressor.

In one possible implementation, the regenerator stack includes a first regenerator and a second regenerator;

the first passage of the first regenerator is communicated with the first passage of the second regenerator in series, and the input end and the output end of the communicated passage are respectively used as the input end and the output end of the regenerator group; or the first passages of the first regenerator are communicated with the first passages of the second regenerator in parallel, and the input end and the output end of each first passage are respectively used as the input end and the output end of the regenerator group;

the second passage of the first heat regenerator adopts a first connection mode, and the second passage of the second heat regenerator adopts a second connection mode;

wherein, the first connection mode is as follows: a second input end of the first heat regenerator is connected with an upper outlet of the expansion tank, a second output end of the first heat regenerator is connected with an input end of the first compressor through the second control valve, and a second output end of the first heat regenerator is connected with an input end of the second compressor through the third control valve; or a second input end of the first heat regenerator is connected with an upper outlet of the expansion tank through the second control valve, a second input end of the first heat regenerator is connected with an output end of the low-pressure circulation barrel through the first control valve, and a second output end of the first heat regenerator is connected with an input end of the first compressor;

the second connection mode is as follows: a second input end of the second heat regenerator is connected with an output end of the low-pressure circulating barrel, a second output end of the second heat regenerator is connected with an input end of the first compressor through the first control valve, and a second output end of the second heat regenerator is connected with an input end of the second compressor through the fourth control valve; or the second input end of the second regenerator is connected with the upper outlet of the expansion tank through the third control valve, the second input end of the second regenerator is connected with the output end of the low-pressure circulation barrel through the fourth control valve, and the second output end of the second regenerator is connected with the input end of the second compressor.

In one possible implementation, the regenerator group includes at least three regenerators;

and the output end of the low-pressure circulating barrel is connected with the second channel of at least one heat regenerator in the heat regenerator set in series and then is connected with the second input end of the ejector.

In one possible implementation, the regenerator stack includes a third regenerator;

and a second input end of the third heat regenerator is connected with the output end of the low-pressure circulating barrel, and a second output end of the third heat regenerator is connected with a second input end of the ejector.

In one possible implementation, the refrigeration subsystem further includes a first valve, a second valve, a third valve, a fourth valve, a fifth valve, and a sixth valve;

the upper outlet of the expansion tank is connected with the first valve in series and then is communicated with a second passage of a heat regenerator in the heat regenerator set, and the upper outlet of the expansion tank is connected with the second valve in series and then is connected with the input end of a corresponding compressor;

the output end of the low-pressure circulating barrel is connected with the second channel of another regenerator in the regenerator set after being connected with the third valve in series, and the output end of the low-pressure circulating barrel is connected with the second input end of the ejector after being connected with the fourth valve in series;

the output end of the low-pressure circulating barrel is connected with the fifth valve in series and then is communicated with the second passage of another heat regenerator in the heat regenerator group, and the output end of the low-pressure circulating barrel is connected with the sixth valve in series and then is connected with the input end of the corresponding compressor.

In one possible implementation, the refrigeration subsystem further includes a heat recovery heat exchanger;

the heat recovery heat exchanger is disposed between the first compressor and the gas cooler.

In one possible implementation, the refrigeration subsystem further includes a seventh valve and an eighth valve;

the output end of the first compressor and the output end of the second compressor are connected in series with the seventh valve and then are connected with the input end of the gas cooler;

and the heat recovery heat exchanger is connected with the eighth valve in series and then connected with the seventh valve in parallel.

In one possible implementation, the number of the first compressors is one or more, and the number of the second compressors is one or more.

In one possible implementation, the refrigeration subsystem further comprises a low pressure recycle drum or a gas-liquid separator.

In the scheme provided by the embodiment of the invention, the refrigeration subsystem is used for refrigerating the ice rink in different regions, and the method can be applied to large-scale ice rinks; the refrigeration subsystem can reduce the temperature of the refrigeration working medium when the refrigeration working medium flows through the expansion valve by utilizing the heat regenerator, and reduce throttling loss; meanwhile, the air suction temperature of the compressor can be improved, the efficiency of the compressor is improved, the power consumption of the compressor is reduced, the refrigerating capacity of the system in unit time is stably increased, and the energy efficiency ratio of the whole system is improved. The ejector plays a throttling role and can improve the operation efficiency and stability of the system; the two types of compressors work simultaneously, so that high-efficiency circulation can be realized, and the refrigeration efficiency is further improved. The heat regenerator is gated by using the valve, so that a system loop can be adjusted according to an actual scene; the heat recovery heat exchanger can provide heat for dehumidification and domestic water, and the full utilization of energy is realized; the two control valves are utilized to realize the switching of the two types of compressors, and the number of the two types of compressors can be adjusted, so that the system can adapt to different scenes and requirements.

In order to make the aforementioned and other objects, features and advantages of the present invention comprehensible, preferred embodiments accompanied with figures are described in detail below.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

FIG. 1 shows a schematic diagram of a prior art carbon dioxide refrigeration system;

FIG. 2 shows a schematic diagram of a first configuration of a carbon dioxide refrigeration system for an ice rink according to an embodiment of the present invention;

FIG. 3 is a schematic diagram illustrating a second configuration of a carbon dioxide refrigeration system for an ice rink according to an embodiment of the present invention;

FIG. 4 is a detailed schematic diagram of a carbon dioxide refrigeration system of an ice rink according to an embodiment of the invention;

FIG. 5 illustrates a portion of the legend symbols for the carbon dioxide refrigeration system of the ice rink illustrated in FIG. 4.

Icon:

c1-first compressor, C2-second compressor, Con-gas cooler, RE 1-first regenerator, RE 2-second regenerator, RE 3-third regenerator, Ej-ejector, ET-expansion tank, ExV-expansion valve, CD-low pressure circulating barrel, HE-heat recovery heat exchanger, SV 1-first valve, SV 2-second valve, SV 3-third valve, SV 4-fourth valve, SV 5-fifth valve, SV 6-sixth valve, SV 7-seventh valve, SV 8-eighth valve, CV 1-first control valve, CV 2-second control valve, CV 3-third control valve, CV 4-fourth control valve, 10-drying filter, 20-moisture indicator.

Detailed Description

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", and the like, indicate orientations and positional relationships based on those shown in the drawings, and are used only for convenience of description and simplicity of description, and do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be considered as limiting the present invention.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless specifically defined otherwise.

In the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

According to the carbon dioxide refrigeration system for the ice rink, provided by the embodiment of the invention, the refrigeration efficiency of the whole system is improved by adopting equipment facilities such as a parallel compressor unit, an ejector, a heat regenerator, an expansion tank and the like. This ice rink carbon dioxide refrigerating system includes: one or more groups of refrigeration subsystems. As shown in fig. 2, the refrigeration subsystem includes: a first compressor C1, a second compressor C2, a gas cooler Con, a regenerator group, an ejector Ej, an expansion tank ET, an expansion valve ExV, a first control valve CV1, a second control valve CV2, a third control valve CV3, and a fourth control valve CV 4; the regenerator group comprises a plurality of regenerators, and the regenerators are provided with a first passage and a second passage for heat exchange; the input end and the output end of the first passage of the plurality of heat regenerators are respectively used as the input end and the output end of the heat regenerator group.

The output end of the first compressor C1 and the output end of the second compressor C2 are both connected with the input end of a gas cooler Con, the output end of the gas cooler Con is connected with the input end of a heat regenerator group, and the output end of the heat regenerator group is connected with the first input end of an ejector Ej; the output end of the ejector Ej is connected with the inlet of an expansion tank ET, and the upper outlet of the expansion tank ET is connected with the second passage of the heat regenerator in the heat regenerator group and the input end of a first compressor C1 after being connected with a second control valve CV2 in series; the upper outlet of the expansion tank ET is connected with the second passage of the regenerator in the regenerator set and the third control valve CV3 in series and then is connected with the input end of a second compressor C2.

The lower outlet of the expansion tank ET is connected with the expansion valve ExV in series and then is connected with the input end of the low-pressure circulating barrel CD; the low-pressure circulating barrel CD is used for cooling the corresponding ice field, the output end of the low-pressure circulating barrel CD is connected with the second passage of the heat regenerator in the heat regenerator set and the input end of the first compressor C1 after being connected in series with the first control valve CV1, and the output end of the low-pressure circulating barrel CD is connected with the second passage of the heat regenerator in the heat regenerator set and the input end of the second compressor C2 after being connected in series with the fourth control valve CV 4.

The ice rink carbon dioxide refrigeration system provided by the embodiment of the invention uses carbon dioxide (CO)₂) The refrigerant is used as a refrigerating working medium to absorb the heat of the ice surface and keep the temperature of the ice surface at about-4 ℃, thereby maintaining the proper shape of the surface of the ice rink and realizing the refrigeration of the large-scale ice rink. Meanwhile, the whole large-scale ice rink is partitioned, and each refrigeration subsystem of the carbon dioxide refrigeration system of the ice rink is used for respectively refrigerating the ice rink in the corresponding area, wherein the refrigeration subsystem in the embodiment can be in a transcritical operation state, as shown in fig. 2, and the working process is as follows:

the first compressor C1 may be a main compressor that compresses a low-temperature and low-pressure gas (carbon dioxide) sucked therein into a high-temperature and high-pressure refrigerant gas, and then discharges the high-temperature and high-pressure refrigerant gas to be input to the gas cooler Con; the gas cooler Con cools the high-temperature high-pressure refrigerant gas to generate medium-temperature high-pressure refrigerant gas, the medium-temperature high-pressure refrigerant gas enters the ejector Ej after passing through the regenerator group, and is throttled and discharged into the expansion tank ET under the action of the ejector Ej. Under the throttling action, part of the medium-temperature high-pressure refrigerant gas is converted into a liquid state, namely, a gas-liquid two-phase refrigeration working medium exists in the expansion tank ET, namely, the medium-temperature high-pressure gas working medium and the liquid working medium are included; the liquid working medium in the expansion tank ET is throttled by the expansion valve ExV to become a low-temperature low-pressure gas-liquid two-phase fluid, and enters the low-pressure circulation barrel CD, the liquid in the low-pressure circulation barrel CD can be used for ice field refrigeration, and the gas (low-temperature low-pressure gas) in the low-pressure circulation barrel CD can be discharged to the second passage of a part of regenerators (such as the second regenerator RE2 in fig. 2) in the regenerator group under the action of the first compressor C1, and then is sucked into the first compressor C1 and/or the second compressor C2, so that the first compressor C1 and/or the second compressor C2 can compress the sucked low-temperature low-pressure gas to generate high-temperature high-pressure gas, and circulation is achieved. Meanwhile, the second compressor C2 is used as a parallel compressor or a secondary compressor, the first compressor C1 and/or the second compressor C2 can suck the gas in the expansion tank ET from an upper outlet, and then the gas is sucked into the first compressor C1 and/or the second compressor C2, the first compressor C1 and/or the second compressor C2 compresses the gas to form a high-temperature and high-pressure gas, and the gas discharged from the first compressor C1 and the second compressor C2 are mixed and circulated.

In the embodiment of the invention, the refrigeration subsystem is provided with the heat regenerator for exchanging heat between the medium-temperature high-pressure gas discharged from the gas cooler Con and the recovered low-temperature gas, so that the temperature of the medium-temperature high-pressure gas discharged from the gas cooler can be reduced, the temperature of the low-temperature gas returned from the low-pressure circulating barrel can be increased, the temperature of the refrigerant flowing through the expansion valve ExV can be reduced, and the throttling loss is reduced; meanwhile, the suction temperature of the compressor (comprising the first compressor C1 and the second compressor C2) can be increased, and the efficiency of the compressor is improved; therefore, based on the heat regenerator group, the power consumption of the compressor can be reduced, the refrigerating capacity of the system in unit time can be stably increased, and the energy efficiency ratio of the whole system can be improved.

In addition, an ejector Ej in the refrigeration subsystem can improve the operation efficiency of the system; meanwhile, the ejector Ej plays a throttling role, and the stability of the system can be ensured. The refrigeration subsystem is provided with a first compressor C1 and a second compressor C2, the two compressors respectively suck refrigerated gas and gas in an expansion tank ET, high-efficiency circulation can be realized, and the refrigeration efficiency is improved; and the two types of compressors, namely the main compressor and the parallel compressor, can improve the circulating efficiency and ensure the safety of the compressors.

In the embodiment of the invention, the regenerators in the regenerator group are respectively provided with two input ends and two output ends, and one input end and one output end form one passage, namely a first passage and a second passage. Taking the first heat regenerator RE1 as an example, as shown in fig. 2, the first input terminal 1 and the first output terminal 2 form a first path, and the second input terminal 3 and the second output terminal 4 form a second path. The first passages of the plurality of heat regenerators form the input end and the output end of the heat regenerator group; specifically, as shown in fig. 2, the first passages of the multiple regenerators may be connected in series, and the input end and the output end of the connected passages are respectively used as the input end and the output end of the regenerator group; alternatively, as shown in fig. 3, the first passages of a plurality of regenerators may be connected in parallel, and the input end and the output end of each first passage are respectively used as the input end and the output end of the regenerator group.

In addition, in this embodiment, "the upper outlet of the expansion tank ET is connected in series with the second passage of the regenerator and the second control valve CV2 in the regenerator set and then connected to the input end of the first compressor C1" may be that the upper outlet of the expansion tank ET is connected in series with the second passage of the regenerator and the second control valve CV2 in sequence and then connected to the input end of the first compressor C1, as shown in fig. 2; alternatively, the upper outlet of the expansion tank ET may be connected in series with the second control valve CV2 and the second path of the regenerator in sequence, and then connected with the input end of the first compressor C1, as shown in fig. 3. Other similar descriptions are the same and are not detailed here. In the embodiment of the present invention, the return air of the return air component (including the expansion tank ET and the low-pressure circulation tank CD) can be input into the first compressor C1 and the second compressor C2, and in the embodiment, the return air pipeline is controlled by four control valves. Since the return gas line may pass through the regenerator, a control valve may be provided between the regenerator and the compressor, as shown in fig. 2; alternatively, the control valve is disposed between the return air part and the regenerator, as shown in fig. 3.

Optionally, the regenerator stack may include a first regenerator RE1 and a second regenerator RE 2; the control valve may be disposed between the regenerator and the compressor, as shown in fig. 2, an upper outlet of the expansion tank ET is connected in series with the second passage of the regenerator (e.g., the first regenerator RE1) in the regenerator set, and the second control valve CV2 and then connected to the input end of the first compressor C1, and an upper outlet of the expansion tank ET is connected in series with the second passage of the regenerator (e.g., the first regenerator RE1) in the regenerator set, and the third control valve CV3 and then connected to the input end of the second compressor C2. That is, the second input 3 of the first recuperator RE1 is connected to the upper outlet of the expansion tank ET, the second output 4 of the first recuperator RE1 is connected to the input of the first compressor C1 through the second control valve CV2, and the second output of the first recuperator RE1 is connected to the input of the second compressor C2 through the third control valve CV 3. Meanwhile, the output end of the low-pressure circulating drum CD is connected in series with the second passage of the regenerator (such as the second regenerator RE2) in the regenerator set and the first control valve CV1 in sequence and then connected with the input end of the first compressor C1, and the output end of the low-pressure circulating drum CD is connected in series with the second passage of the regenerator (such as the second regenerator RE2) in the regenerator set and the fourth control valve CV4 in sequence and then connected with the input end of the second compressor C2. That is, a second input of the second regenerator RE2 is connected to the output of the low pressure drum CD, a second output of the second regenerator RE2 is connected to the input of the first compressor C1 through a first control valve CV1, and a second output of the second regenerator RE2 is connected to the input of the second compressor C2 through a fourth control valve CV 4.

Alternatively, the control valve is disposed between the return air part and the regenerator. As shown in fig. 3, an upper outlet of the expansion tank ET is connected in series with the second control valve CV2 and a second path of a regenerator (e.g., the first regenerator RE1) in the regenerator group in sequence and then connected with an input end of the first compressor C1; the upper outlet of the expansion tank ET is connected in series with a third control valve CV3 and a second passage of another regenerator (such as a second regenerator RE2) in the regenerator set in sequence and then connected with the input end of a second compressor C2. That is, a second input of first regenerator RE1 is connected to the upper outlet of the expansion tank ET through a second control valve CV2, and a second input of second regenerator RE2 is connected to the upper outlet of the expansion tank ET through a third control valve CV 3. Meanwhile, the output end of the low-pressure circulating drum CD is sequentially connected in series with the first control valve CV1, and the second path of a regenerator (such as the first regenerator RE1) in the regenerator group and then connected with the input end of the first compressor C1, and the output end of the low-pressure circulating drum CD is sequentially connected in series with the fourth control valve CV4, and the second path of another regenerator (such as the second regenerator RE2) in the regenerator group and then connected with the input end of the second compressor C2. That is, a second input of the first recuperator RE1 is connected to the output of the low-pressure recycle bin CD through a first control valve CV1, and a second output of the first recuperator RE1 is connected to the input of the first compressor C1; a second input of second regenerator RE2 is connected to the output of low pressure drum CD through a fourth control valve CV4 and a second output of second regenerator RE2 is connected to the input of second compressor C2.

In the embodiment of the invention, the control valve can enable the first compressor C1 and the second compressor C2 to work simultaneously, and the second compressor C2 can also be used as a main compressor or the first compressor C1 can be used as a secondary compressor. Specifically, the two types of compressors (i.e., the first compressor C1 and the second compressor C2) can be switched with each other; in particular, the refrigeration subsystem may include a plurality of first compressors C1 and a plurality of second compressors C2, the number of which may be adjusted to accommodate different scene requirements by switching the compressors. For example, when the first compressor C1 is a main compressor and the second compressor C2 is a parallel compressor, the first control valve CV1 and the third control valve CV3 are turned on, and the second control valve CV2 and the fourth control valve CV4 are turned off. On the contrary, if the first compressor C1 is the parallel compressor and the second compressor C2 is the main compressor, the first control valve CV1 and the third control valve CV3 may be closed, and the second control valve CV2 and the fourth control valve CV4 may be opened. In this embodiment, each compressor is provided with two similar control valves (for example, the first compressor C1 in fig. 2 to 4 is provided with a first control valve CV1 and a second control valve CV2), and when a plurality of compressors exist, each compressor can realize function switching by controlling the on/off of the two control valves, namely, switching from the main compressor to the parallel compressor or switching from the parallel compressor to the main compressor, so as to adjust the number of the two types of compressors. For example, as described above, when the first control valve CV1 is on and the second control valve CV2 is off, the first compressor C1 is the main compressor; if the first control valve CV1 is closed and the second control valve CV2 is open, the first compressor C1 is a parallel compressor, and the switching of compressors is realized. In addition, both control valves can be opened, so that the compressor can simultaneously compress the return air of the expansion tank ET and the low-pressure circulating barrel CD; alternatively, both control valves may be closed, so that the respective compressor can be used as a backup.

Optionally, the refrigeration subsystem may further comprise a low pressure recycle drum CD or a gas-liquid separator; after the low-temperature low-pressure gas-liquid two-phase fluid enters the low-pressure circulating barrel CD, the low-temperature low-pressure fluid is pumped into an ice field to absorb heat and vaporize, the vaporized working medium and the gas in the low-temperature low-pressure gas-liquid two-phase fluid can be sucked by the first compressor C1 together to complete circulation; and the unvaporized refrigerant liquid can be continuously and circularly pumped into an ice field for refrigeration after returning to the low-pressure circulating barrel, so that the efficient utilization is realized. The gas-liquid separator may be disposed at an input end of the compressor (including the first compressor C1 and/or the second compressor C2) to separate gas and liquid, so that the gas may be input to the compressor by pumping the liquid into the ice field for refrigeration.

According to the carbon dioxide refrigeration system for the ice rink, provided by the embodiment of the invention, the refrigeration subsystem is utilized to perform zoned refrigeration on the ice rink, and the carbon dioxide refrigeration system can be applied to large-scale ice rinks; the refrigeration subsystem can reduce the temperature of the refrigeration working medium when the refrigeration working medium flows through the expansion valve ExV by utilizing the heat regenerator, and the throttling loss is reduced; meanwhile, the air suction temperature of the compressor can be improved, the efficiency of the compressor is improved, the power consumption of the compressor is reduced, the refrigerating capacity of the system in unit time is stably increased, and the energy efficiency ratio of the whole system is improved. The ejector Ej plays a throttling role, so that the running efficiency and the stability of the system can be improved; the two types of compressors work simultaneously, so that high-efficiency circulation can be realized, and the refrigeration efficiency is further improved. The working states of the two types of compressors are adjusted by using the control valve, so that the compressor can adapt to different working conditions.

On the basis of the above embodiment, the output end of the low-pressure circulating barrel CD may be further connected to the input end (second input end) of the ejector Ej; as shown in fig. 3, the output end of the low-pressure circulating barrel CD may be directly connected to the second input end of the ejector Ej; alternatively, as shown in fig. 2 and 4, the output end of the low-pressure cycle drum CD is connected in series with the second path of at least one regenerator (e.g., a third regenerator RE3 in fig. 2) in the regenerator group and then connected to the second input end of the ejector Ej.

In this embodiment, the regenerator bank includes at least three regenerators. Specifically, as shown in fig. 2 and 4, the regenerator stack includes a first regenerator RE1, a second regenerator RE2, and a third regenerator RE 3.

In the embodiment of the present invention, the first regenerator RE1, the second regenerator RE2, and the third regenerator RE3 have similar structures, and each has two input ends and two output ends, and one input end and one output end form one passage, which is two passages in total, that is, the first passage and the second passage. The connection relationship between the first regenerator RE1 and the second regenerator RE2 can be described in detail above, and is not described herein again. In addition, a second input terminal of the third regenerator RE3 is connected to the output terminal of the low-pressure cycle drum CD, and a second output terminal of the third regenerator RE3 is connected to a second input terminal of the ejector Ej.

In this embodiment, the second passage of the third regenerator RE3 communicates the low-pressure circulation drum CD with the ejector Ej, and the ejector Ej introduces the partial gas in the low-pressure circulation drum CD into the expansion tank ET by using the expansion work generated when the high-pressure carbon dioxide at the outlet of the gas cooler Con is throttled. The ejector Ej mixes high-pressure fluid with low-pressure fluid, and the pressure of the outlet fluid is higher than the low pressure, so that the expansion valve ExV can conveniently perform secondary throttling. Specifically, when the system runs in a transcritical state, under the action of the ejector Ej, partial gas in the low-pressure circulating barrel CD is introduced into the expansion tank ET by utilizing expansion work generated when high-pressure carbon dioxide at the Con outlet of the gas cooler is throttled. The carbon dioxide flowing out of the ejector Ej enters the expansion tank ET to realize gas-liquid separation, namely, gas and liquid are in the upper part and the lower part, the gas and the liquid respectively enter different devices by utilizing the upper outlet and the lower outlet of the expansion tank ET, namely, the gas enters the compressor, and the liquid enters the low-pressure circulating barrel CD after throttling.

On the basis of the above embodiment, a valve may be provided for the regenerator to realize selective use of the regenerator. Referring to fig. 4, the refrigeration subsystem further includes a first valve SV1, a second valve SV2, a third valve SV3, a fourth valve SV4, a fifth valve SV5, and a sixth valve SV 6.

Specifically, an upper outlet of the expansion tank ET is connected in series with a first valve SV1 and then is communicated with a second passage of a regenerator (e.g., a first regenerator RE1) in the regenerator group, and an upper outlet of the expansion tank ET is connected in series with a second valve SV2 and then is connected with an input end of a corresponding compressor, for example, in fig. 4, the first compressor C1 is connected through a second control valve CV2, and the second compressor C2 is connected through a third control valve CV 3. The output end of the low-pressure circulating barrel CD is connected with a second channel of another regenerator (such as a third regenerator RE3) in the regenerator set after being connected with a third valve SV3 in series, and the output end of the low-pressure circulating barrel CD is connected with a second input end of the ejector Ej after being connected with a fourth valve SV4 in series. The output end of the low-pressure circulating barrel CD is connected with a fifth valve SV5 in series and then is also communicated with a second passage of another regenerator (such as a second regenerator RE2) in the regenerator group, and the output end of the low-pressure circulating barrel CD is connected with a sixth valve SV6 in series and then is connected with the input end of a corresponding compressor.

In the embodiment of the invention, two valves are arranged on the second passage of each heat regenerator, so that gating of the second passage is realized. Taking the first regenerator RE1 as an example, when the gas in the expansion tank ET needs to pass through the first regenerator RE1 for heat exchange, the first valve SV1 is turned on, and the second valve SV2 is closed, at this time, the gas in the expansion tank ET can reach the second passage of the first regenerator RE1, and further be sucked by the first compressor C1 and the like. When the gas in the expansion tank ET does not need to be subjected to heat exchange, the first valve SV1 is closed, the second valve SV2 is opened, and the gas in the gas return line can be directly sucked into the first compressor C1 and the like, so that circulation is realized. Similarly, the second pass of the third regenerator RE3 can be gated by the third valve SV3 and the fourth valve SV4, and the second pass of the second regenerator RE2 can be gated by the fifth valve SV5 and the sixth valve SV6, which have the same principle as gating the first regenerator RE1 and are not described herein. The first valve SV1, the second valve SV2, the third valve SV3, the fourth valve SV4, the fifth valve SV5 and the sixth valve SV6 can be electromagnetic valves, so that automatic control is realized.

On the basis of the above embodiment, referring to fig. 3 or fig. 4, the refrigeration subsystem further includes a heat recovery heat exchanger HE; the heat recovery heat exchanger HE is disposed between the first compressor C1 and the gas cooler Con.

In the embodiment of the invention, the ice rink can be provided with a heat recovery system; a heat recovery heat exchanger HE is arranged between the compressor and the gas cooler Con, so that heat exchange between high-temperature and high-pressure gas discharged by the compressor and equipment in the ice rink heat recovery system can be realized, and heat supply to the equipment is realized. In the embodiment, the heat recovery heat exchanger HE is used for single-section heat exchange at the high-pressure side and a heat-carrying heat recovery system is used for ensuring that the heat recovery system does not influence the reliability and stability of the unit; meanwhile, the heat recovery system provides heat of dehumidification and domestic water at the same time, and full utilization of energy is achieved. The working principle of the heat recovery heat exchanger HE is substantially similar to that of the regenerator, and will not be described in detail herein.

Optionally, referring to FIG. 4, the refrigeration subsystem further includes a seventh valve SV7 and an eighth valve SV 8. The output end of the first compressor C1 and the output end of the second compressor C2 are connected in series with a seventh valve SV7 and then connected with the input end of the gas cooler Con; the heat recovery heat exchanger HE is connected with an eighth valve SV8 in series and then is connected with a seventh valve SV7 in parallel.

In the embodiment of the invention, the seventh valve SV7 and the eighth valve SV8 are utilized to realize the gating of the heat recovery heat exchanger HE; the principle of the gate heat recovery heat exchanger HE is the same as that of the gate first heat recovery heat exchanger RE1, and for example, the heat recovery heat exchanger HE is turned off when the seventh valve SV7 is turned on and the eighth valve SV8 is turned off, and the heat recovery heat exchanger HE operates when the seventh valve SV7 is turned off and the eighth valve SV8 is turned on, so that heat can be supplied to the heat recovery system.

In this embodiment, the legend symbols of the partial devices in fig. 4 are shown in fig. 5; in fig. 4, D108, D89, D25, and D133 denote line symbols, D108 denotes a high-temperature high-pressure gas flow line, D89 denotes a medium-temperature high-pressure gas flow line cooled by the gas cooler Con, D25 denotes a return gas line, and D133 denotes a low-temperature low-pressure gas flow line discharged from the low-pressure drum CD. In fig. 4, 10 denotes a drying filter, 20 denotes a moisture indicator, and the liquid discharged from the lower outlet of the expansion tank ET is dried (moisture is removed), detected, and the like.

According to the carbon dioxide refrigeration system for the ice rink, provided by the embodiment of the invention, the refrigeration subsystem is utilized to perform zoned refrigeration on the ice rink, and the carbon dioxide refrigeration system can be applied to large-scale ice rinks; the refrigeration subsystem can reduce the temperature of the refrigeration working medium when the refrigeration working medium flows through the expansion valve ExV by utilizing the heat regenerator, and the throttling loss is reduced; meanwhile, the air suction temperature of the compressor can be improved, the efficiency of the compressor is improved, the power consumption of the compressor is reduced, the refrigerating capacity of the system in unit time is stably increased, and the energy efficiency ratio of the whole system is improved. The ejector Ej plays a throttling role, so that the running efficiency and the stability of the system can be improved; the two types of compressors work simultaneously, so that high-efficiency circulation can be realized, and the refrigeration efficiency is further improved. The heat regenerator is gated by using the valve, so that a system loop can be adjusted according to an actual scene; the heat recovery heat exchanger HE is arranged, so that heat of dehumidification and domestic water can be provided, and energy can be fully utilized; the control valve is utilized to realize the switching of the two types of compressors, and the number of the two types of compressors can be adjusted, so that the system can adapt to different scenes and requirements.

The above description is only for the specific embodiments of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily conceive of the modifications or alternative embodiments within the technical scope of the present invention, and shall be covered by the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the appended claims.