CN209672629U - A kind of supercritical carbon dioxide refrigeration system of two-stage throttling - Google Patents

Abstract

The utility model discloses a two-stage throttling supercritical carbon dioxide refrigeration system. According to the utility model, the exhaust port of the low-pressure compressor and the outlet of the medium-temperature evaporator are respectively connected to the air inlet of the medium-pressure compressor, and the air outlet of the medium-pressure compressor and the air outlet of the parallel compressor are respectively connected to the hot water heater, and the hot water heater , air heat exchanger, condenser, throttle valve, air conditioner, and intercooler are connected in sequence, and the liquid outlets in the intercooler are respectively connected to the medium pressure throttle valve and the low pressure throttle valve, and the low pressure throttle valve is connected in sequence Low-temperature evaporator, low-pressure compressor inlet, medium-pressure throttling valve connected to medium-temperature evaporator for heat exchange; gas outlet in the intercooler is respectively connected to parallel compressor inlet and flash steam bypass valve, flash steam bypass The through valve is connected to the air inlet of the medium temperature compressor. The refrigeration system of the utility model adopts the CO ₂ transcritical cycle, and the CO ₂ transcritical system has a lower annual energy usage fee, which saves the operating cost of the supermarket.

Description

A two-stage throttling supercritical carbon dioxide refrigeration system

technical field

The utility model relates to the technical field of refrigeration, in particular to a comprehensive energy utilization system for supermarkets with a two-stage throttling supercritical carbon dioxide refrigeration system.

Background technique

Supermarket refrigeration refers to refrigeration applications such as cold chains, cold storage, supermarkets, display cabinets, and air coolers. _CO2 transcritical booster systems have become the standard supermarket refrigeration solution for new installations in some European countries. Due to serious environmental problems, it is stipulated in the Montreal Protocol that CFC and HCFC refrigerants will be gradually eliminated, and the research on natural working fluids such as CO ₂ has attracted people's attention again. Except for carbon dioxide, the rest of the working fluids do not have carbon dioxide. Toxicity or non-flammability, carbon dioxide heat pump is an emerging technology in recent years, using carbon dioxide as a working fluid, it has the advantages of excellent environmental performance, good chemical stability, good economy, safety, non-toxic and non-flammable, and good thermal performance. The heat pump uses carbon dioxide as the working medium. During heat recovery, the temperature of the hot water can be heated to about 90°C at one time. It does not need circulating heating or adding auxiliary heating devices. It is energy-saving and efficient. When the temperature of the heat source is low, the carbon dioxide heat pump still has High heating capacity and efficiency, can be widely used in industrial fields.

When considering the heating load and cooling load at the same time, the CO2 transcritical system has a lower annual energy usage fee. In relatively cold climate conditions, the _CO2 transcritical air-conditioning and hot water system is an effective way to meet the simultaneous cooling and heating needs of supermarkets. s solution.

Utility model content

The purpose of the utility model is to provide a comprehensive energy utilization system for supermarkets based on a two-stage throttling supercritical carbon dioxide refrigeration system in view of the low energy utilization rate in the prior art.

The technical scheme adopted for realizing the purpose of this utility model is:

A comprehensive energy utilization system for supermarkets based on a two-stage throttling supercritical carbon dioxide refrigeration system, including a low-pressure compressor, a medium-pressure compressor, and a parallel compressor;

The exhaust port of the low-pressure compressor and the outlet of the medium-temperature evaporator are respectively connected to the air inlet of the medium-pressure compressor, the air outlet of the medium-pressure compressor, and the air outlet of the parallel compressor are respectively connected to the hot water heater, the hot water heater, the air exchange The heater, condenser, throttle valve, air conditioner, and intercooler are connected in sequence, and the liquid outlets in the intercooler are respectively connected to the medium-pressure throttle valve and the low-pressure throttle valve, and the low-pressure throttle valve is connected to the low-temperature evaporator in sequence , the low-pressure compressor inlet, and the medium-pressure throttle valve are connected to the medium-temperature evaporator for heat exchange; the gas outlets in the intercooler are respectively connected to the parallel compressor inlet and the flash steam bypass valve, and the flash steam bypass valve is connected to Medium temperature compressor air intake.

Without special requirements, the system is a traditional carbon dioxide two-stage compression refrigeration cycle. The refrigerant is discharged from the exhaust port of the low-pressure compressor, mixed with the gaseous working medium at the outlet of the medium-temperature evaporator, and enters the high-pressure compressor for further processing. The second compression, and then the refrigerant enters the intercooler sequentially through the condenser and the throttle valve, the saturated liquid in the intercooler is divided into two paths, and one path is throttled by the low pressure throttle valve After entering the low-temperature evaporator for heat exchange, it is compressed by the low-pressure compressor; the other path is throttled by the medium-pressure throttle valve, enters the medium-temperature evaporator for heat exchange, and is discharged from the exhaust port of the low-pressure compressor. Gas mixing, the gas in the intercooler is compressed by the parallel compressor and then mixed with the refrigerant discharged from the discharge port of the medium temperature compressor to complete a cycle.

When there is demand for cooling and hot water supply at the same time, the hot water heater in front of the condenser is turned on, and the refrigerant releases a part of heat in the hot water heater to meet the demand for hot water supply.

When there is demand for cooling and space heating at the same time, the air heat exchanger in front of the condenser is turned on, and the refrigerant releases heat in the air heat exchanger to meet the demand for space heating.

When there is demand for cooling and air conditioning, the air conditioner in front of the intercooler is turned on, and the refrigerant absorbs heat in the air conditioner to meet the cooling demand of the air conditioner.

When there is demand for cooling, hot water supply, and space heating at the same time, the hot water heater and the air heat exchanger in front of the condenser are turned on, and the refrigerant comes out of the high-pressure compressor to be heated by the hot water in turn Heater and the air heat exchanger release heat while meeting the demand for hot water supply and space heating.

At the same time, when there is demand for cooling, hot water supply, and air conditioning, the hot water heater in front of the condenser and the air conditioner in front of the intercooler are turned on, and the refrigerant comes out of the high-pressure compressor and passes through the air conditioners in turn. The hot water heater, the condenser, the throttle valve and the air conditioner, release part of the heat in the hot water heater, absorb part of the heat in the air conditioner, and realize hot water supply, air conditioning and refrigeration at the same time need.

Compared with the prior art, the beneficial effects of the utility model are:

1. The refrigeration system of this utility model adopts CO ₂ transcritical cycle, and the CO ₂ transcritical system has a lower annual energy usage fee, which saves the operating cost of the supermarket.

_2. The refrigeration system of the present invention uses _CO2 as a natural working medium, which has the advantages of easy preparation, excellent environmental performance, stable chemical performance, good economy, safety, non-toxicity, non-flammability, and good thermal performance. It is of great significance to promote the replacement of refrigerants, reduce the greenhouse effect and the destruction of the ozone layer.

3. The refrigeration system of this utility model provides two different evaporation temperatures, namely low temperature and medium temperature, to meet the different storage requirements of supermarkets, and integrates hot water supply, space heating and air conditioning cooling systems, making the supermarket system more compact . The integrated solution requires fewer components and less refrigerant, which helps save space resources and facilitates system maintenance and repair.

4. The refrigeration system of the present utility model can recover the heat of condensation while cooling, so as to achieve the purpose of energy saving.

5. In the refrigeration system of the present utility model, the parallel compressors are turned on when the outdoor environment is harsh and the system load is large, which enhances the safety of the system and improves the overall performance of the system.

Description of drawings

Shown in Fig. 1 is the schematic diagram of the utility model.

Detailed ways

Below in conjunction with accompanying drawing and specific example the utility model is described in further detail.

The utility model is based on the two-stage throttling supercritical carbon dioxide refrigeration system. The principle diagram of the comprehensive energy utilization system for supermarkets is shown in Figure 1. The environmental protection natural working medium CO ₂ is adopted, and the low-pressure compressor 1, the medium-pressure compressor 2, and the parallel Compressor 3, intercooler 9, flash bypass valve 14, medium pressure throttle valve 10, low pressure throttle valve 12, medium temperature evaporator 11, low temperature evaporator 13, condenser 6, air heat exchanger 5, heat exchanger A two-stage throttling supercritical carbon dioxide refrigeration system composed of water heater 4, throttle valve 7, and air conditioner 8. The exhaust port of the low-pressure compressor and the outlet of the medium-temperature evaporator are respectively connected to the inlet port of the medium-pressure compressor. The air outlet of the compressor and the air outlet of the parallel compressor are respectively connected to the hot water heater, and the hot water heater, the air heat exchanger, the condenser, the throttle valve, the air conditioner, and the intercooler are connected in sequence, and the outlet of the intercooler The liquid ports are respectively connected to the medium-pressure throttle valve and the low-pressure throttle valve, the low-pressure throttle valve is connected to the low-temperature evaporator and the air inlet of the low-pressure compressor in turn, and the medium-pressure throttle valve is connected to the medium-temperature evaporator for heat exchange; the intercooler The gas outlets of the compressors are respectively connected to the parallel compressor inlet and the flash steam bypass valve, and the flash steam bypass valve is connected to the medium temperature compressor inlet. The cooling and heating mode can be adjusted according to the cooling and heating demand in different seasons, and the energy is comprehensively utilized, which has a lower annual energy usage fee.

Without special requirements, the system is a traditional carbon dioxide two-stage compression refrigeration cycle, the refrigerant is discharged from the exhaust port of the low-pressure compressor 1, mixed with the gaseous working medium at the outlet of the medium-temperature evaporator 11, and enters the high-pressure compressor 2 The second compression is carried out, and then the refrigerant enters the intercooler 9 through the condenser 6 and the throttle valve 7 in sequence, and the saturated liquid in the intercooler 9 is divided into two paths, and one path passes through the low-pressure The throttling valve 12 enters the low-temperature evaporator 13 for heat exchange and is compressed by the low-pressure compressor 1; the other path passes through the medium-pressure throttle valve 10 and enters the medium-temperature evaporator 11 for heat exchange. It is mixed with the gas discharged from the discharge port of the low-pressure compressor A, and the gas in the intercooler 9 is compressed by the parallel compressor 3 and then mixed with the refrigerant discharged from the discharge port of the medium-temperature compressor 2 to complete a cycle.

When there is demand for cooling and hot water supply at the same time, the hot water heater 4 in front of the condenser 6 is turned on, and the refrigerant releases a part of heat in the hot water heater 4 to meet the demand for hot water supply.

When there is demand for cooling and space heating at the same time, the air heat exchanger 5 in front of the condenser F is turned on, and the refrigerant releases heat in the air heat exchanger 5 to meet the space heating demand.

When there is demand for cooling and air conditioning, the air conditioner 8 in front of the intercooler 9 is turned on, and the refrigerant absorbs heat in the air conditioner 8 to meet the cooling demand of the air conditioner.

When there is demand for cooling, hot water supply, and space heating at the same time, the hot water heater 4 and the air heat exchanger 5 in front of the condenser 6 are turned on, and the refrigerant comes out of the high-pressure compressor 2 and passes through the The hot water heater 4 and the air heat exchanger 5 dissipate heat while meeting the demands of hot water supply and space heating.

When there is demand for cooling, hot water supply, and air-conditioning refrigeration at the same time, the hot water heater 4 in front of the condenser 6 and the air conditioner 8 in front of the intercooler 9 are turned on, and the refrigerant is compressed from the high pressure Machine B comes out and passes through the hot water heater 4, the condenser 6, the throttle valve 7 and the air conditioner 8 in sequence, and releases a part of heat in the hot water heater 4, and in the air conditioner 8 Absorb part of the heat, and at the same time meet the needs of hot water supply and air conditioning cooling.

The above is only a preferred embodiment of the utility model, it should be pointed out that for those of ordinary skill in the art, without departing from the principle of the utility model, some improvements and modifications can also be made, these Improvement and retouching should also be regarded as the protection scope of the present utility model.

Claims (1)

1. a kind of supercritical carbon dioxide refrigeration system of two-stage throttling, which is characterized in that compressed including low pressure compressor, middle pressure Machine and compressors in parallel；

The low pressure compressor exhaust outlet, medium temperature evaporator outlet are connect with intermediate pressure compressor air inlet respectively, intermediate pressure compressor Gas outlet, compressors in parallel gas outlet are separately connected hot-water heater, hot-water heater, air heat exchanger, condenser, throttling Valve, air-conditioning, intercooler are sequentially connected, and the liquid outlet in the intercooler is separately connected middle pressure throttle valve and low pressure section Valve is flowed, low pressure throttle valve is sequentially connected cryogenic vaporizer, low pressure compressor air inlet, and middle pressure throttle valve connection medium temperature evaporator changes Heat；Gas outlet in the intercooler is separately connected compressors in parallel air inlet and flash steam by-passing valve, flash steam bypass Valve connects medium temperature compressor inlet.