CN114459179B - Artificial ice rink carbon dioxide direct evaporation type ice making system and application method thereof - Google Patents

Abstract

The invention discloses a direct evaporation type ice making system for carbon dioxide in an artificial ice rink and a use method thereof, wherein the direct evaporation type ice making system comprises the following steps: the system comprises a main system and at least 1 subsystem, wherein the output end of a first-stage compressor of the main system is communicated with the input end pipeline of a second gas cooler, a first pipeline and a second pipeline which are arranged in parallel are connected between the second input end of a heat regenerator and the second gas cooler, a condenser and a first control valve are arranged on the first pipeline, and a second-stage compressor, the first gas cooler and a second control valve are arranged on the second pipeline; the input end of the first-stage compressor is communicated with a first output end pipeline of the heat regenerator, the first input end of the heat regenerator is communicated with a gas output end pipeline of the gas-liquid separator, and 1 subsystem or a plurality of subsystems connected in parallel are communicated between the gas-liquid separator and a second output end of the heat regenerator; the artificial ice rink carbon dioxide direct evaporation type ice making system can realize stable and efficient operation of the system under various working conditions.

Description

Carbon dioxide direct evaporative ice-making system for artificial ice rink and its application method

technical field

The invention belongs to the technical field of ice making in artificial ice rinks, and in particular relates to a carbon dioxide direct evaporation type ice making system for artificial ice rinks and a method for using the same.

Background technique

The traditional artificial ice rink ice making system uses a liquid cooling unit with halogenated hydrocarbon refrigerants and uses ethylene glycol or brine as a refrigerant to cool the concrete floor of the artificial ice rink to complete the ice making process. However, the "Kigali Amendment to the Montreal Protocol" eliminated and restricted high-GWP halogenated hydrocarbon refrigerants, so natural working fluids such as ammonia and carbon dioxide have become the only way for ice rink refrigeration system working fluids. Ammonia refrigerant is flammable and poisonous, which poses safety hazards, and its use is generally restricted in crowded areas. Therefore, the carbon dioxide ice making system has become the best choice for artificial ice rinks.

Carbon dioxide is a natural refrigerant, non-toxic, non-flammable, with an ozone depletion potential of 0 and a global warming potential of 1, and is environmentally friendly. In the carbon dioxide direct evaporative ice-making system, carbon dioxide is directly evaporated in the ice rink coil to exchange heat and make ice, which can better ensure the temperature uniformity of the ice surface. At the same time, there is no intermediate heat exchange link, which can improve the energy efficiency of the ice making system.

The critical temperature of carbon dioxide is 31.2°C. When the external temperature is high, only a transcritical cycle can be used, and there is a large throttling loss. Therefore, ejectors are often used to recover the expansion work of the throttling process to improve energy efficiency.

Most of the existing carbon dioxide ice-making systems only consider the transcritical operation, and the ice rink needs to be refrigerated throughout the year. When the outside temperature is lower than the critical temperature, the transcritical operation of the ice-making system will cause its energy consumption to be too high. Therefore, we are looking for a Under different external temperatures, it is necessary to realize the mutual conversion between transcritical and subcritical working conditions and make the system operate efficiently under all working conditions. At the same time, although many people have proposed the use of ejectors to recover the expansion work of the refrigeration system, the adaptability of ejectors to variable working conditions is limited. How to achieve multiple working conditions (especially transcritical and subcritical working conditions) The stable and efficient operation of the down system has always been an industry problem.

Contents of the invention

Aiming at the deficiencies of the prior art, the object of the present invention is to provide a carbon dioxide direct evaporative ice-making system for an artificial ice rink, which realizes the ice-making system through the opening and closing of six control valves. It operates efficiently and stably in a variety of working conditions to meet the ice production needs of the ice rink at various times throughout the year.

The purpose of the present invention is achieved through the following technical solutions.

An artificial ice rink carbon dioxide direct evaporation ice-making system, including: a main system and at least one subsystem, wherein,

The main system includes: a first-stage compressor, a second-stage compressor, a first gas cooler, a second gas cooler, a condenser, a regenerator and a gas-liquid separator, and the output of the first-stage compressor end is communicated with the input end pipeline of the second gas cooler, and the first pipeline and the second pipeline arranged in parallel are connected between the second input end of the regenerator and the second gas cooler, so A condenser and a first control valve are installed on the first pipeline, and a second-stage compressor, a first gas cooler and a second control valve are installed on the second pipeline;

The input end of the first-stage compressor is connected to the first output end of the regenerator, and the first input end of the regenerator is connected to the gas output end of the gas-liquid separator. One subsystem or multiple parallel subsystems are communicated between the gas-liquid separator and the second output end of the regenerator;

Each of the subsystems includes: an ejector, a first expansion valve, a second expansion valve, a circulation tank and an ice field evaporation coil, the liquid output end of the gas-liquid separator is connected to the liquid input end of the circulation tank The second expansion valve is installed on the pipeline connected through the pipeline, and the third pipe connected in parallel is arranged between the gas-liquid input end of the gas-liquid separator and the second output end of the regenerator. The first expansion valve and the third control valve are installed on the third pipeline, the ejector and the fourth control valve are installed on the fourth pipeline, and the The suction port of the ejector communicates with the gas output end of the circulation tank; the liquid output end of the circulation tank communicates with the input end pipeline of the ice rink evaporation coil, and a working medium pump is installed on the pipeline between them , a fifth pipeline is communicated between the output end of the ice rink evaporation coil and the gas-liquid input end of the circulation tank, a fifth control valve is installed on the fifth pipeline, and one end of the sixth pipeline It communicates with the pipeline between the ejector and the gas-liquid separator, and the other end communicates with the fifth pipeline between the fifth control valve and the ice rink evaporation coil, and the sixth pipeline is installed with Sixth control valve.

In the above technical solution, the input end of the condenser is used to communicate with the first control valve.

In the above technical solution, the input end of the second-stage compressor is used to communicate with the second control valve.

In the above technical solution, the fourth control valve is located on the fourth pipeline between the ejector and the regenerator.

In the above technical solution, the third control valve is located on the third pipeline between the first expansion valve and the regenerator.

In the above technical solution, the gas entering from the second input end of the regenerator releases heat in the regenerator, and then is discharged from the second output end of the regenerator; from the regenerator The gas entering the first input end of the regenerator absorbs heat in the regenerator, and then is discharged from the first output end of the regenerator.

The above method of using the carbon dioxide direct evaporative ice-making system of the artificial ice rink includes one of method 1, method 2, method 3 and method 4:

Method 1: keep the first control valve, the fourth control valve and the fifth control valve in communication, make the second control valve, the third control valve and the sixth control valve disconnect, and make the second expansion valve activate to the throttling effect;

Method 2: keep the first control valve, the third control valve and the sixth control valve in open circuit, make the second control valve, the fourth control valve and the fifth control valve disconnect, and make the first expansion valve activate To the throttling effect and the second expansion valve does not have a throttling effect for the passage;

Method 3: keep the second control valve, the fourth control valve and the fifth control valve in communication, make the first control valve, the third control valve and the sixth control valve disconnect, and make the second expansion valve activate to the throttling effect;

Mode 4: keep the second control valve, the third control valve and the sixth control valve in open circuit, make the first control valve, the fourth control valve and the fifth control valve disconnect, and make the first expansion valve activate to the throttling effect and the second expansion valve does not have a throttling effect for the passage.

In the above technical solution, when the outdoor temperature is higher than 20-25°C, the method three or four is adopted (the two methods are both transcritical cycles, and the third method is that the ejector recovers the expansion work, and the pressure difference before and after the expansion process Larger, a lot of energy is wasted during the expansion process. When the cooling condition is stable at the design condition, the cooling load of the ice making is not much different from the design load. The recovery of expansion work by the ejector in the third way can increase the carbon dioxide of the artificial ice rink The effect of the energy efficiency of the direct evaporative ice-making system; on the contrary, when the cooling conditions change drastically, such as when the carbon dioxide direct evaporative ice-making system of the artificial ice rink is turned on and off, the ice-making cooling load changes greatly, and the working condition adjustment ability of the ejector is poor. The work is unstable and it is inconvenient to control. The fourth expansion valve is used to throttle the flow to make the carbon dioxide direct evaporation ice-making system of the artificial ice rink run more stably); when the outdoor temperature is lower than 20-25°C, use the above-mentioned method 1 or method 2 (the two methods are both subcritical cycles, method 1 is the recovery of expansion work by the ejector, when the cooling condition is stable at the design condition, the cooling load of ice making is not much different from the design load, the ejector of method 1 The recovery of the expansion work of the device can achieve the effect of improving the energy efficiency of the carbon dioxide direct evaporative ice-making system in the artificial ice rink; on the contrary, when the cooling conditions change drastically, such as when the carbon dioxide direct evaporative ice-making system of the artificial ice rink is turned on and off, the ice-making cooling load changes greatly. The working condition adjustment ability of the ejector is poor, the work is unstable, and it is inconvenient to control. The second expansion valve is used to throttle the flow to make the carbon dioxide direct evaporation ice-making system of the artificial ice rink run more stably).

Considering that the ice rink needs to be refrigerated throughout the year, a subcritical cycle is used when the outdoor temperature and load are relatively low, and the heat release process is performed through the second gas cooler and condenser; In the critical cycle, heat release needs to be performed through the first and second gas coolers, which can well realize the mutual conversion and connection of transcritical and subcritical. When the ejector is used at the same time, connect the ejector to the circulation tank, inject the gas in the circulation tank to the gas-liquid separator and finally return to the first-stage compressor to complete the recovery of expansion work; at the same time, it is connected in parallel with the ejector There is a first expansion valve. During the subcritical cycle, if the outlet pressure of the first stage compressor is relatively low, the first expansion valve can be directly used to complete throttling. At the same time, the second expansion valve is installed after the gas-liquid separator to fine-tune the evaporation pressure and evaporation temperature of the ejector outlet liquid. The system can connect multiple subsystems in parallel after the gas-liquid separator to realize multiple sets of ice rink evaporation coils. Each ice rink evaporator coil can be fine-tuned through the second expansion valve, which increases the mobility of the refrigeration system and enhances the controllability of the refrigeration system.

Description of drawings

Fig. 1 is the structural representation (1 subsystem) of the carbon dioxide direct evaporative ice-making system of the artificial ice rink of the present invention;

Fig. 2 is a structural schematic diagram (two subsystems) of the carbon dioxide direct evaporation ice-making system of the artificial ice rink of the present invention;

Fig. 3 is the operating first pressure-enthalpy diagram of the carbon dioxide direct evaporation ice-making system of the artificial ice rink of the present invention;

Fig. 4 is the second pressure-enthalpy diagram of the operation of the carbon dioxide direct evaporation ice-making system of the artificial ice rink of the present invention.

Among them, 1-1: first gas cooler, 1-2: second stage compressor, 1-3: second control valve, 1-4: second gas cooler, 1-5: first stage compressor , 1-6: regenerator, 1-7: gas-liquid separator, 1-8: first control valve, 1-9: condenser, 2-1: second expansion valve, 2-2: circulation tank, 2-3: fifth control valve, 2-4: working medium pump, 2-5: sixth control valve, 2-6: ice evaporator coil, 2-7: ejector, 2-8: fourth Control valve, 2-9: third control valve, 2-10: first expansion valve.

Detailed ways

The technical solutions of the present invention will be further described below in conjunction with specific embodiments.

Example 1

As shown in the figure, an artificial ice rink carbon dioxide direct evaporation ice-making system includes: a main system and at least one subsystem, wherein,

The main system includes: first-stage compressor 1-5 (C1), second-stage compressor 1-2 (C2), first gas cooler 1-1 (GC1), second gas cooler 1-4 (GC2 ), condenser 1-9 (Co), regenerator 1-6 (IHE) and gas-liquid separator 1-7 (GLS), the output of the first stage compressor 1-5 is connected with the second gas cooler 1- The input end of 4 is connected to the pipeline, and the first pipeline and the second pipeline arranged in parallel are connected between the second input end of the regenerator 1-6 and the second gas cooler 1-4, and the first pipeline is installed Condenser 1-9 and first control valve 1-8 (CV1) are arranged, and second stage compressor 1-2, first gas cooler 1-1 and second control valve 1-3 ( CV2); the input end of the condenser 1-9 is used to communicate with the first control valve 1-8, and the input end of the second stage compressor 1-2 is used to communicate with the second control valve 1-3.

The input end of the first-stage compressor 1-5 is in pipeline communication with the first output end of the regenerator 1-6, and the first input end of the regenerator 1-6 is connected with the gas output end of the gas-liquid separator 1-7 The pipeline is connected, and there is one subsystem or multiple parallel subsystems connected between the gas-liquid separator 1-7 and the second output end of the regenerator 1-6;

Each subsystem includes: ejector 2-7 (Ej), first expansion valve 2-10 (ExV1), second expansion valve 2-1 (ExV2), circulation tank 2-2 (ET) and ice evaporator Pipe 2-6(E), the liquid output end of the gas-liquid separator 1-7 communicates with the liquid input end of the circulation tank 2-2 through the pipeline and the second expansion valve 2-1 is installed on the pipeline between them, and the gas A third pipeline and a fourth pipeline connected in parallel are arranged between the gas-liquid input end of the liquid separator 1-7 and the second output end of the regenerator 1-6, and a first expansion valve is installed on the third pipeline 2-10 and the third control valve 2-9 (CV3), the ejector 2-7 and the fourth control valve 2-8 (CV4) are installed on the fourth pipeline, and the fourth control valve 2-8 is located in the ejector On the fourth pipeline between the first expansion valve 2-7 and the regenerator 1-6, the third control valve 2-9 is located on the third pipeline between the first expansion valve 2-10 and the regenerator 1-6.

The suction port of the ejector 2-7 communicates with the gas output end of the circulation tank 2-2; the liquid output end of the circulation tank 2-2 communicates with the input end pipeline of the ice evaporator coil 2-6 and the pipe between them There is a working medium pump 2-4(P) installed on the road, and a fifth pipeline is connected between the output end of the ice rink evaporation coil 2-6 and the gas-liquid input end of the circulation tank 2-2, and a fifth pipeline is installed on the fifth pipeline. There is a fifth control valve 2-3 (CV5), one end of the sixth pipeline communicates with the pipeline between the ejector 2-7 and the gas-liquid separator 1-7, and the other end communicates with the fifth control valve 2-3 and The fifth pipeline between the ice rink evaporation coils 2-6 is connected, and a sixth control valve 2-5 (CV6) is installed on the sixth pipeline.

The gas entering from the second input end of the regenerator 1-6 releases heat in the regenerator 1-6, and then is discharged from the second output end of the regenerator 1-6; from the regenerator 1-6 The gas entering the first input end absorbs heat in the regenerator 1-6, and then is discharged from the first output end of the regenerator 1-6.

The gas-liquid input ports connecting the injector and the third pipeline to the gas-liquid separator can be two different gas-liquid input ports.

One subsystem is shown in Figure 1, and two subsystems are shown in Figure 2.

The above method of using the carbon dioxide direct evaporative ice-making system of the artificial ice rink includes one of method 1, method 2, method 3 and method 4:

Mode 1 (subcritical cycle, recovery of expansion work by the ejector), keep the first control valve 1-8, the fourth control valve 2-8 and the fifth control valve 2-3 open, and make the second control valve 1-3 , The third control valve 2-9 and the sixth control valve 2-5 are disconnected, so that the second expansion valve 2-1 plays a throttling role;

Mode 2 (subcritical cycle, unrecovered expansion work), keep the first control valve 1-8, the third control valve 2-9 and the sixth control valve 2-5 in the passage, make the second control valve 1-3, the sixth control valve The four control valves 2-8 and the fifth control valve 2-3 are disconnected, so that the first expansion valve 2-10 plays a throttling role and the second expansion valve 2-1 is a passage without throttling;

Mode 3 (transcritical cycle, recovery of expansion work by the ejector), keep the second control valve 1-3, the fourth control valve 2-8 and the fifth control valve 2-3 open, and make the first control valve 1-8 , The third control valve 2-9 and the sixth control valve 2-5 are disconnected, so that the second expansion valve 2-1 plays a throttling role;

Mode 4 (transcritical cycle, unrecovered expansion work), keep the second control valve 1-3, the third control valve 2-9 and the sixth control valve 2-5 open, make the first control valve 1-8, the sixth control valve The fourth control valve 2-8 and the fifth control valve 2-3 are disconnected, so that the first expansion valve 2-10 plays a role of throttling and the second expansion valve 2-1 is a passage and does not have a role of throttling.

When the outdoor temperature is higher than 20-25°C, adopt method 3 or method 4 (the two methods are both transcritical cycles, and method 3 is for the ejector to recover the expansion work, the pressure difference before and after the expansion process is large, and there is a large amount of The energy is wasted. When the cooling condition is stable at the design condition, the ice-making cooling load is not much different from the design load. The recovery of expansion work by the ejector in mode 3 can improve the energy efficiency of the carbon dioxide direct evaporative ice-making system in the artificial ice rink. Effect; On the contrary, when the cooling conditions change drastically, such as when the carbon dioxide direct evaporative ice-making system of the artificial ice rink is turned on and off, the ice-making cooling load changes greatly, the working condition adjustment ability of the ejector is poor, the work is unstable, and it is inconvenient to control , the first expansion valve is used to throttle the flow in mode 4, so that the direct CO2 evaporative ice-making system of the artificial ice rink operates more stably); when the outdoor temperature is lower than 20-25°C, adopt mode 1 or 2 In the subcritical cycle, the method 1 is to recover the expansion work of the ejector. When the refrigeration condition is stable at the design condition, the cooling load of ice making is not much different from the design load. The energy efficiency of the carbon dioxide direct evaporative ice-making system; on the contrary, when the cooling conditions change drastically, such as when the carbon dioxide direct evaporative ice-making system of the artificial ice rink is turned on and off, the ice-making cooling load changes greatly, and the working condition adjustment ability of the ejector is poor , the work is unstable, and it is inconvenient to control. The method 2 is adopted to throttle the flow of the first expansion valve to make the carbon dioxide direct evaporation ice-making system of the artificial ice rink run more stably).

Example 2

An artificial ice rink carbon dioxide direct evaporative ice-making system, including: a first-stage compressor (C1), a second-stage compressor (C2), a first gas cooler (GC1), and a second gas cooler (GC2) , condenser (Co), regenerator (IHE), first expansion valve (ExV1), second expansion valve (ExV2), ejector (Ej), gas-liquid separator (GLS), circulation tank (ET) , Working fluid pump (P), ice evaporator coil (E), first to sixth control valves (CV1, CV2, CV3, CV4, CV5, CV6).

The output of the first-stage compressor (C1) is connected to the input of the second gas cooler (GC2), and the input of the second-stage compressor (C2) and the input of the condenser (Co) are connected to the second gas The output of the cooler (GC2) is connected, the output of the second stage compressor (C2) is connected to the input of the first gas cooler (GC1), the output of the first gas cooler (GC1) is connected to the condenser ( The outputs of Co) are all connected to the second input of the regenerator (IHE).

The first input end of the regenerator (IHE) is connected to the gas output end of the gas-liquid separator (GLS), and the first output end of the regenerator (IHE) is connected to the input end of the first-stage compressor (C1), The second output end of the regenerator (IHE) is connected with the input end of the first expansion valve (ExV1) and the nozzle of the ejector (Ej).

The output of the ejector (Ej) is connected to the gas-liquid input of the gas-liquid separator (GLS), and the output of the first expansion valve (ExV1) is connected to the gas-liquid input of the gas-liquid separator (GLS). The liquid output of the liquid separator (GLS) is connected to the input of the second expansion valve (ExV2).

The liquid input end of the circulation tank (ET) is connected with the output end of the second expansion valve (ExV2), the gas output end of the circulation tank (ET) is connected with the suction port of the ejector (Ej), and the liquid in the circulation tank (ET) The output end is connected to the input end of the working fluid pump (P), the working fluid pump (P) is connected to the input end of the evaporating coil (E) of the ice rink, and the output end of the evaporating coil (E) of the ice rink is connected to the circulation tank (ET ) is connected to the gas-liquid input end of the gas-liquid separator (GLS).

The output end of the second gas cooler (GC2) is connected to one end of the first control valve (CV1), and the other end of the first control valve (CV1) is connected to the input end of the condenser (Co); the second gas cooler (GC2) The output end of the second control valve (CV2) is connected to one end of the second control valve (CV2), and the other end of the second control valve (CV2) is connected to the input end of the second stage compressor (C2), while the second control valve (CV2) is connected to the first control valve (CV1) in parallel; the second output end of the regenerator (IHE) is connected to one end of the third control valve (CV3), and the other end of the third control valve (CV3) is connected to the input end of the first expansion valve (ExV1); The second output end of the regenerator (IHE) is connected to one end of the fourth control valve (CV4), and the other end of the fourth control valve (CV4) is connected to the nozzle of the ejector (Ej), and the fourth control valve (CV4) It is connected in parallel with the third control valve (CV3); the output end of the ice rink evaporation coil (E) is connected to one end of the fifth control valve (CV5), and the other end of the fifth control valve (CV5) is connected to the gas-liquid of the circulation tank (ET) The input end is connected; the output end of the ice evaporator coil (E) is connected to one end of the sixth control valve (CV6), and the other end of the sixth control valve (CV6) is connected to the gas-liquid input end of the gas-liquid separator (GLS), At the same time, the sixth control valve (CV6) is connected in parallel with the fifth control valve (CV5).

The carbon dioxide direct evaporative ice-making system of the above-mentioned artificial ice rink uses carbon dioxide as the refrigerant, and realizes the ice-making process through the ice rink evaporator coil (E), and this process is in direct contact with the ice surface without making ice through a medium, making the process higher energy efficiency. The above artificial ice rink carbon dioxide direct evaporative ice-making system can be in the subcritical cycle (ejector recovers expansion work) operating state, as shown in Figure 1 and pressure enthalpy lgP-h Figure 3, and its working process is as follows:

The first control valve (CV1), the fourth control valve (CV4) and the fifth control valve (CV5) maintain the open circuit, and the second control valve (CV2), the third control valve (CV3) and the sixth control valve (CV6) are disconnected . The first-stage compressor (C1) sucks low-temperature and low-pressure carbon dioxide [state point 1'], compresses it into high-temperature and high-pressure refrigerant gas [state point 2], and then discharges high-temperature and high-pressure refrigerant gas, which is sent to the second gas cooler (GC2), cooled in the second gas cooler (GC2), discharged after cooling to saturated gas state [state point 3], sent to condenser (Co), continued cooling in condenser (Co) and discharged [state Point 4], sent to the heat recuperator (IHE), so that the refrigerant is subcooled at this time [state point 4'], and then sent to the nozzle of the ejector (Ej), and in the ejector (Ej) The decompression is accelerated under the effect [state point 5], and it is mixed with the CO ₂ working fluid [state point 9] at the gas output end of the circulation tank [state point 6], and the mixed working fluid is pressurized through the diffuser [state point 7 ], and then sent to the gas-liquid separator (GLS), under the action of the depressurization acceleration of the ejector (Ej), part of the refrigerant gas is converted into liquid, and some of the refrigerant gas is not converted. At this time, the gas-liquid separator ( GLS) exists in gas-liquid two-phase flow. Then the liquid refrigerant in the gas-liquid separator (GLS) [state point 7L] passes through the throttling effect of the second expansion valve (ExV2), becomes a low-temperature and low-pressure gas-liquid two-phase fluid [state point 8], and then enters the circulation tank (ET), the fluid in the circulation tank (ET) directly enters the ice rink evaporation coil (E) through the working fluid pump (P) to directly evaporate and absorb heat to make ice. It is possible that the liquid at the outlet of the ice rink evaporator coil (E) cannot be completely converted into low-pressure gas, and the gas-liquid two-phase flow is sent out from the ice rink evaporator coil (E) and then discharged into the circulation tank (ET), and the liquid continues to pass through the working The mass pump (P) circulates, and the low-pressure gas [status point 9] is ejected, through the suction port of the ejector (Ej), sucked into the interior of the ejector (Ej), and finally the low-pressure gas is ejected to the gas-liquid separator (GLS) [state point 7], while the gas in the gas-liquid separator (GLS) [state point 7G or state point 1] is discharged through the gas output port and sent to the regenerator (IHE), making the low-pressure gas superheated Afterwards, it is discharged through the first output end of the regenerator (IHE) [status point 1'] and enters the input end of the first stage compressor (C1) to complete the cycle.

The above artificial ice rink carbon dioxide direct evaporative ice-making system can be in the subcritical cycle (expansion work is not recovered) operating state, see Figure 1 and pressure enthalpy lgP-h Figure 3, and its working process is as follows:

The first control valve (CV1), the third control valve (CV3) and the sixth control valve (CV6) maintain the open circuit, and the second control valve (CV2), the fourth control valve (CV4) and the fifth control valve (CV5) are disconnected . The first-stage compressor (C1) inhales low-temperature and low-pressure carbon dioxide [state point 9'], compresses it into high-temperature and high-pressure refrigerant gas [state point 2'], and then discharges high-temperature and high-pressure refrigerant gas and sends it into the second gas for cooling Cooled in the second gas cooler (GC2), cooled to a saturated gas state [state point 3] and then discharged, sent to the condenser (Co), continued to cool in the condenser (Co) and then discharged [ State point 4], sent to the heat recuperator (IHE), so that the refrigerant is subcooled at this time [state point 4'], then sent to the first expansion valve (ExV1), and in the first expansion valve (ExV1) Throttle under the action of [state point 5'], and sent to the gas-liquid separator (GLS), under the action of the first expansion valve (ExV1) throttling, part of the refrigerant gas is converted into liquid, and part of the refrigerant gas Not converted, at this time there is a gas-liquid two-phase flow in the gas-liquid separator (GLS). Then the liquid refrigerant in the gas-liquid separator (GLS) enters the circulation tank (ET) (at this time, the second expansion valve (ExV2) is a passage without throttling), and the fluid in the circulation tank (ET) directly passes through The working fluid pump (P) enters the ice rink evaporation coil (E) to directly evaporate and absorb heat to make ice. It may be that the liquid at the outlet of the ice rink evaporator coil (E) cannot be completely converted into low-pressure gas, and the gas-liquid two-phase flow is sent out from the ice rink evaporator coil (E) and then discharged into the gas-liquid separator (GLS), and the liquid continues to pass through The circulation tank (ET) circulates through the working fluid pump (P), and the low-pressure gas in the gas-liquid separator (GLS) [status point 9] is discharged through the gas output of the gas-liquid separator (GLS) and sent to the recuperator In the regenerator (IHE), the low-pressure gas is overheated [status point 9'] and then discharged through the first output end of the regenerator (IHE) into the input end of the first-stage compressor (C1) to complete the cycle.

The above artificial ice rink carbon dioxide direct evaporative ice-making system can be in the operating state of transcritical cycle (ejector recovers expansion work), as shown in Figure 1 and pressure enthalpy lgP-h Figure 4, and its working process is as follows:

The second control valve (CV2), the fourth control valve (CV4) and the fifth control valve (CV5) maintain the open circuit, and the first control valve (CV1), the third control valve (CV3) and the sixth control valve (CV6) are disconnected . The first-stage compressor (C1) sucks low-temperature and low-pressure carbon dioxide [state point 1'], compresses it into high-temperature and high-pressure refrigerant gas [state point 2], and then discharges high-temperature and high-pressure refrigerant gas, which is sent to the second gas cooler (GC2), cooled in the second gas cooler (GC2), cooled to a saturated gas state [state point 3], then discharged, sent to the second stage compressor (C2), and compressed into a supercritical fluid again [state point 4 ], the supercritical fluid is discharged from the output end of the second-stage compressor (C2) and sent to the first gas cooler (GC1), and the cooled refrigerant fluid [state point 5] is sent to the recuperator (IHE), The refrigerant is further cooled [status point 5'], and then sent to the nozzle of the ejector (Ej), and decompressed and accelerated under the action of the ejector (Ej) [status point 6], and is combined with the gas in the circulation tank The CO ₂ working fluid at the output end [status point 10] is mixed [status point 7]. Under the action of accelerating the decompression of the ejector (Ej), part of the refrigerant gas is converted into liquid, and part of it is not converted. At this time, there is a gas-liquid two-phase flow in the gas-liquid separator (GLS). Then the liquid refrigerant in the gas-liquid separator (GLS) [status point 8L] passes through the throttling effect of the second expansion valve (ExV2), becomes a low-temperature and low-pressure gas-liquid two-phase fluid [status point 9], and then enters the circulation tank (ET), the fluid in the circulation tank (ET) directly enters the ice rink evaporation coil (E) through the working fluid pump (P) to directly evaporate and absorb heat to make ice. It is possible that the liquid at the outlet of the ice rink evaporator coil (E) cannot be completely converted into low-pressure gas, and the gas-liquid two-phase flow is sent out from the ice rink evaporator coil (E) and then discharged into the circulation tank (ET), and the liquid continues to pass through the working medium The pump (P) circulates, and the low-pressure gas [status point 10] is ejected, through the suction port of the ejector (Ej), sucked into the interior of the ejector (Ej), and finally the low-pressure gas is ejected to the gas-liquid separator ( GLS) [state point 8], while the gas in the gas-liquid separator (GLS) [state point 8G or state point 1] is discharged through the gas output of the gas-liquid separator (GLS) and sent to the regenerator (IHE) In the process, the low-pressure gas is superheated and discharged through the first output end of the regenerator (IHE) [status point 1'] and enters the input end of the first-stage compressor (C1) to complete the cycle.

The above artificial ice rink carbon dioxide direct evaporative ice-making system can be in the operating state of transcritical cycle (without recovery of expansion work), as shown in Figure 1 and pressure enthalpy lgP-h in Figure 4, and its working process is as follows:

The second control valve (CV2), the third control valve (CV3) and the sixth control valve (CV6) maintain the open circuit, and the first control valve (CV1), the fourth control valve (CV4) and the fifth control valve (CV5) are disconnected . The first-stage compressor (C1) inhales low-temperature and low-pressure carbon dioxide [state point 10'], compresses it into high-temperature and high-pressure refrigerant gas [state point 2'], and then discharges high-temperature and high-pressure refrigerant gas and sends it into the second gas for cooling (GC2), cooled in the second gas cooler (GC2), cooled to saturated gas state [state point 3], then discharged, sent to the input end of the second stage compressor (C2), and compressed into a supercritical fluid again [State point 4], the supercritical fluid is discharged from the output end of the second-stage compressor (C2) and sent to the first gas cooler (GC1), and the cooled refrigerant fluid [state point 5] is sent to the regenerator (IHE), so that the refrigerant is further cooled [state point 5'], then sent to the first expansion valve (ExV1), and throttled under the action of the first expansion valve (ExV1) [state point 6'], and It is sent into the gas-liquid separator (GLS), and under the throttling effect of the first expansion valve (ExV1), part of the refrigerant gas is converted into liquid, and some of the refrigerant gas is not converted. At this time, the refrigerant gas in the gas-liquid separator (GLS) There is a gas-liquid two-phase flow. Then the liquid refrigerant in the gas-liquid separator (GLS) enters the circulation tank (ET) (at this time, the second expansion valve (ExV2) is a passage without throttling), and the fluid in the circulation tank (ET) directly passes through The working fluid pump (P) enters the ice rink evaporation coil (E) to directly evaporate and absorb heat to make ice. It may be that the liquid at the outlet of the ice rink evaporator coil (E) cannot be completely converted into low-pressure gas, and the gas-liquid two-phase flow is sent out from the ice rink evaporator coil (E) and then discharged into the gas-liquid separator (GLS), and the liquid continues to pass through The circulation tank (ET) circulates through the working medium pump (P), and the low-pressure gas [status point 10] in the gas-liquid separator (GLS) is discharged through the gas output end of the gas-liquid separator (GLS) and sent to the return In the heater (IHE), the low-pressure gas is overheated [state point 10'] and then discharged through the first output of the regenerator (IHE) into the input of the first-stage compressor (C1) to complete the cycle.

The carbon dioxide direct evaporative ice-making system of the artificial ice rink of the present invention uses carbon dioxide as the refrigerant, and two compressors in series (the first-stage compressor and the second-stage compressor) are arranged. Considering that the ice rink needs year-round refrigeration, the outdoor Subcritical cycle with exothermic process through second gas cooler and condenser at relatively low temperatures and loads; dual-stage compression (first compressor and second compressor) at higher outdoor temperatures and loads To realize the transcritical cycle, at this time, the first and second gas coolers need to be used for heat release, which can well realize the mutual conversion and connection between the transcritical and subcritical; at the same time, an ejector is set to connect the ejector and The circulation tank is connected to reduce the throttling loss, complete the recovery of expansion work, and can also increase the suction temperature at the inlet of the first-stage compressor and improve the efficiency of the first-stage compressor; at the same time, there is a first expansion valve connected in parallel with the ejector , in the subcritical cycle process, if the outlet pressure of the first-stage compressor is relatively low, the first expansion valve can be directly used to complete throttling; The evaporation pressure and evaporation temperature of the liquid at the outlet of the device can be fine-tuned. The system can connect multiple sub-systems in parallel after the gas-liquid separator to realize the ice production of multiple sets of ice rink evaporator coils. Each set of ice rink evaporator coils can pass through the second expansion valve. Fine-tuning increases the mobility of the direct evaporative ice-making system of carbon dioxide in the artificial ice rink; meanwhile, the direct evaporative ice-making system of carbon dioxide in the artificial ice rink is equipped with a regenerator, which cools by lowering the outlet of the first gas cooler (or condenser) Increase the temperature of the agent and increase the inlet temperature of the first-stage compressor to improve the energy efficiency of the compressor. Enhanced the controllability of the carbon dioxide direct evaporative ice-making system and the energy efficiency of the air conditioner in the artificial ice rink.

Example 3

An artificial ice rink carbon dioxide direct evaporative ice-making system is the same as Embodiment 2, except that the number of subsystems in the artificial ice rink carbon dioxide direct evaporative ice-making system in this embodiment is two.

Its working process is consistent with embodiment 2.

The present invention has been described as an example above, and it should be noted that, without departing from the core of the present invention, any simple deformation, modification or other equivalent replacements that can be made by those skilled in the art without creative labor all fall within the scope of this invention. protection scope of the invention.

Claims (7)

1. A method for using a carbon dioxide direct evaporative ice-making system in an artificial ice rink, characterized in that the artificial ice rink carbon dioxide direct evaporative ice-making system includes: a main system and at least one subsystem, wherein, The main system includes: a first-stage compressor (1-5), a second-stage compressor (1-2), a first gas cooler (1-1), a second gas cooler (1-4), Condenser (1-9), regenerator (1-6) and gas-liquid separator (1-7), the output end of the first stage compressor (1-5) is connected with the second gas cooler ( 1-4), the input end of the regenerator (1-6) is connected to the pipeline, and the first pipeline and the second gas cooler (1-4) connected in parallel are connected between the second input end of the regenerator (1-6). Two pipelines, a condenser (1-9) and a first control valve (1-8) are installed on the first pipeline, and a second-stage compressor (1-2) and a second-stage compressor (1-2) are installed on the second pipeline. A gas cooler (1-1) and a second control valve (1-3); The input end of the first-stage compressor (1-5) is in pipeline communication with the first output end of the regenerator (1-6), and the first input end of the regenerator (1-6) Connected with the gas output end pipeline of the gas-liquid separator (1-7), between the gas-liquid separator (1-7) and the second output end of the regenerator (1-6) There is one said subsystem or a plurality of said subsystems connected in parallel; Each of the subsystems includes: an ejector (2-7), a first expansion valve (2-10), a second expansion valve (2-1), a circulation tank (2-2) and an ice rink evaporation coil (2-6), the liquid output end of the gas-liquid separator (1-7) is connected with the liquid input end of the circulation tank (2-2) through a pipeline, and the first Two expansion valves (2-1), a third pipe connected in parallel between the gas-liquid input end of the gas-liquid separator (1-7) and the second output end of the regenerator (1-6) The first expansion valve (2-10) and the third control valve (2-9) are installed on the third pipeline, and the pilot valve is installed on the fourth pipeline. ejector (2-7) and the fourth control valve (2-8), the suction port of the ejector (2-7) communicates with the gas outlet of the circulation tank (2-2); the circulation The liquid output end of the tank (2-2) is in communication with the input end pipeline of the ice rink evaporation coil (2-6), and a working medium pump (2-4) is installed on the pipeline between them, and the ice rink A fifth pipeline is communicated between the output end of the evaporation coil (2-6) and the gas-liquid input end of the circulation tank (2-2), and a fifth control valve (2 -3), one end of the sixth pipeline communicates with the pipeline between the ejector (2-7) and the gas-liquid separator (1-7), and the other end communicates with the fifth control valve (2-3 ) communicates with the fifth pipeline between the ice rink evaporation coil (2-6), and the sixth control valve (2-5) is installed on the sixth pipeline; The method of using the carbon dioxide direct evaporative ice-making system of the artificial ice rink includes one of mode 1, mode 2, mode 3 and mode 4: Method 1: keep the first control valve (1-8), the fourth control valve (2-8) and the fifth control valve (2-3) open, and make the second control valve (1-3) , The third control valve (2-9) and the sixth control valve (2-5) are disconnected, so that the second expansion valve (2-1) plays a throttling role; Method 2: keep the first control valve (1-8), the third control valve (2-9) and the sixth control valve (2-5) in a passage, and make the second control valve (1-3) , the fourth control valve (2-8) and the fifth control valve (2-3) are disconnected, so that the first expansion valve (2-10) plays a throttling role and the second expansion valve (2-1) is The passage does not function as a throttling; Mode 3: keep the second control valve (1-3), the fourth control valve (2-8) and the fifth control valve (2-3) open, and make the first control valve (1-8) , The third control valve (2-9) and the sixth control valve (2-5) are disconnected, so that the second expansion valve (2-1) plays a throttling role; Mode 4: keep the second control valve (1-3), the third control valve (2-9) and the sixth control valve (2-5) open, and make the first control valve (1-8) , the fourth control valve (2-8) and the fifth control valve (2-3) are disconnected, so that the first expansion valve (2-10) plays a throttling role and the second expansion valve (2-1) is Passages are not throttling. 2. The use method according to claim 1, characterized in that the input end of the condenser (1-9) is used to communicate with the first control valve (1-8). 3. The use method according to claim 1, characterized in that the input end of the second-stage compressor (1-2) is used to communicate with the second control valve (1-3). 4. The use method according to claim 1, characterized in that, the fourth control valve (2-8) is located between the ejector (2-7) and the regenerator (1-6) on the fourth line. 5. The use method according to claim 1, characterized in that, the third control valve (2-9) is located at the first expansion valve (2-10) and the regenerator (1-6). Three pipes. 6. The use method according to claim 1, characterized in that the gas entering from the second input end of the regenerator (1-6) releases heat in the regenerator (1-6) , and then discharged from the second output end of the regenerator (1-6); the gas entering from the first input end of the regenerator (1-6) is discharged in the regenerator (1-6) The heat is absorbed inside, and then discharged from the first output end of the regenerator (1-6). 7. The method of use according to claim 1, characterized in that, when the outdoor temperature is higher than 20-25°C, the method three or four is adopted; when the outdoor temperature is lower than 20-25°C, the method Method 1 or Method 2.

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