Enhanced vapor injection refrigerating system

Abstract

The enhanced vapor injection refrigerating system comprises a four-way valve, the four-way valve comprises an input port end and three reversing port ends, the three reversing port ends are the end A, the end B and the end C. Refrigerant flows out of a refrigerating compressor, passes through a heat recoverer and the four-way valve, flows into an inlet of a condenser (40) from the end A of the four-way valve, flows out of an outlet of the condenser and then flows out of an outlet of the condenser. The refrigerant flows out of an outlet of the economizer and then is divided into two paths, one path is throttled through the main expansion valve, then flows into the evaporator, then flows into the end C of the four-way valve, flows out of the end B of the four-way valve and finally returns to an air suction port of the refrigeration compressor; and the other path is throttled by the auxiliary expansion valve, then flows into the economizer again, and finally flows into an air supply pipe of the refrigeration compressor. The invention effectively realizes the heat collection and recovery enhanced vapor injection refrigeration system.

Description

Technical Field

[0001] The invention relates to the technical field of refrigeration, and in particular to a jet enthalpy-increasing refrigeration system. Background Art

[0002] The existing refrigeration unit is mainly composed of a refrigeration compressor, a condenser, a filter, a liquid receiver, an expansion valve and an evaporator. Its working principle is to use a compressor to compress the refrigerant, and the compressed refrigerant circulates to the condenser to dissipate heat, and then to the liquid receiver. The liquid refrigerant then goes to the expansion valve of each cold storage for throttling refrigeration, and the cold is dissipated outward through the evaporator. The refrigerant is converted from liquid to gas and then returns to the refrigeration compressor. Driven by the operation of the refrigeration compressor, the refrigerant is transformed from gas-liquid-gas in a cycle to achieve the effect of external refrigeration.

[0003] In terms of application, because the refrigeration unit operates in spring, summer, autumn and winter, and the outdoor temperature is low in winter in the north, the refrigeration unit needs to be defrosted to ensure the normal operation of the unit. At this time, due to the low evaporation temperature of the machine, it is difficult to achieve defrosting in winter. At present, most refrigeration units use electric heating defrosting. The main problem of electric heating defrosting is that too much heat is dissipated to the refrigeration space, the warehouse temperature fluctuates greatly, and the balanced defrosting heat also causes a large amount of cold consumption. In addition, the energy utilization rate of the electric heating method itself is low, and the energy consumption is large. In addition, the heat generated by the refrigeration unit during operation is directly discharged into the atmosphere, resulting in insufficient energy utilization. Therefore, a jet enthalpy refrigeration system is provided. Summary of the invention

[0004] To achieve the above-mentioned purpose, the present invention provides the following technical solution: an injection enthalpy increase refrigeration system, comprising a four-way valve including an input port end and three reversing ports, the three reversing ports are respectively A port, B port and C port, the refrigerant flows out from the refrigeration compressor, passes through a heat recovery device and a four-way valve, flows into the inlet of a condenser (40) from the A port of the four-way valve, flows out from the outlet of the condenser, and then flows through a liquid storage device and an economizer. After the refrigerant flows out from the outlet of the economizer, it is divided into two paths, one path is throttled by a main expansion valve, then flows into an evaporator, then flows into the C port of the four-way valve, flows out from the B port of the four-way valve, and finally returns to the air intake port of the refrigeration compressor; the other path is throttled by a secondary expansion valve, then flows into the economizer again, and finally flows into the air supply pipe of the refrigeration compressor.

[0005] The invention comprises a refrigeration compressor, a heat recovery device, a four-way valve, a condenser, a liquid storage device, an economizer, a main expansion valve, an auxiliary expansion valve and an evaporator which are arranged in sequence along the flow direction of the refrigerant. The four-way valve comprises an input port and three reversing ports. The input port is connected to the output port of the heat recovery device. The three reversing ports are respectively connected to the condenser, the evaporator and the refrigeration compressor. The economizer is provided with a first flow path and a second flow path which are connected in parallel. The two ends of the first flow path are respectively connected to the liquid storage device and the main expansion valve. The two ends of the second flow path are respectively connected to the main expansion valve and the air supply pipeline of the refrigeration compressor. The auxiliary expansion valve is arranged on one end of the second flow path close to the main expansion valve.

[0006] The refrigeration compressor is one of a piston compressor, a rotor compressor and a scroll compressor; the main expansion valve and the auxiliary expansion valve are both electronic expansion valves.

[0007] The heat recovery device is connected with a heat exchange medium input pipe, a heat exchange medium output pipe, a delivery pump and a heat preservation box, and the heat recovery device, the heat exchange medium input pipe, the heat exchange medium output pipe, the delivery pump and the heat preservation box form a heat exchange cycle.

[0008] The heat exchange medium of the heat exchange cycle is water.

[0009] The refrigeration compressor is electrically connected to a frequency converter.

[0010] A filter is provided between the economizer and the main expansion valve.

[0011] Compared with the prior art, the present invention has the following beneficial effects:

[0012] The present invention effectively realizes a heat collection and recovery jet enthalpy increase refrigeration system. After the economizer, the refrigerant is divided into two parts. One part is further cooled by throttling and heat expansion to reduce the temperature of the other part and make it supercooled. The stabilized supercooled liquid is throttled and cooled by the main expansion valve, and then directly enters the evaporator for refrigeration. The uncooled gaseous refrigerant passes through the connecting pipe between the economizer and the refrigeration compressor, re-enters the compressor for further compression, and enters the cycle. The liquid refrigerant medium is stabilized by the above expansion refrigeration method to improve the system capacity and efficiency, which can greatly improve the energy efficiency ratio of the unit.

[0013] The present invention controls the flow path reversal of the four-way valve so that the high-temperature refrigerant flows to the evaporator first, the temperature of the evaporator is increased, and the surface of the evaporator is frosted, so that low-temperature defrosting can be achieved to ensure the normal operation of the unit.

[0014] The present invention provides a heat recovery device on the refrigeration compressor, and the heat recovery device recovers and stores the heat of the high-temperature refrigerant through the heat recovery device for reuse, thereby effectively realizing the maximum utilization of resources.

[0015] The present invention integrates the equipment of the refrigeration system into one body through reasonable layout and compact structure to form an integrated structure, which can effectively improve the installation efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a process flow diagram of a heat collection and recovery jet enthalpy increase refrigeration system of the present invention;

[0017] Figure 2 It is a schematic diagram of the process flow of hot fluorine defrosting of another heat collection and recovery multifunctional refrigeration system;

[0018] Figure 3 It is a structural schematic diagram of a heat collection and recovery jet enthalpy increase refrigeration system;

[0019] Figure 4 for Figure 3 A side view of a refrigeration unit is shown.

[0020] In the figure: 10, refrigeration compressor; 20, heat recovery device; 21, heat exchange medium input pipe; 22, heat exchange medium output pipe; 23, delivery pump; 30, four-way valve; 40, condenser; 50, liquid storage device; 60, economizer; 61, first flow path; 62, second flow path; 70, main expansion valve; 80, auxiliary expansion valve; 90, evaporator; 91, heat insulation board; 100, filter. DETAILED DESCRIPTION

[0021] Below, the present invention is further described in conjunction with the accompanying drawings and specific embodiments:

[0022] See also Figure 1 and Figure 2 , is a process flow chart of a jet enthalpy increase refrigeration system of the present invention, which integrates multiple functions such as heat recovery, frequency conversion, hot fluorine defrosting, jet enthalpy increase, etc., and can fully improve the energy efficiency ratio of the unit.

[0023] Specifically, the heat collection and recovery multifunctional refrigeration system includes a refrigeration compressor 10, a heat recovery device 20, a four-way valve 30, a condenser 40, a liquid storage device 50, an economizer 60, a main expansion valve 70, an auxiliary expansion valve 80 and an evaporator 90 which are arranged in sequence along the flow direction of the refrigerant. The four-way valve 30 includes an input port and three reversing ports. The input port is connected to the output end of the heat recovery device 20, and the three reversing ports are respectively connected to the condenser 40, the evaporator 90 and the refrigeration compressor 10. The economizer 60 is provided with a first flow path 61 and a second flow path 62 connected in parallel. The two ends of the first flow path 61 are respectively connected to the liquid storage device 50 and the main expansion valve 70, and the two ends of the second flow path 62 are respectively connected to the main expansion valve 70 and the air supply pipeline of the refrigeration compressor 10. The auxiliary expansion valve 80 is arranged on one end of the second flow path 62 close to the main expansion valve 70.

[0024] The three reversing ports are A, B and C.

[0025] like Figure 1 As shown, when the jet increases enthalpy, the refrigerant flows out of the refrigeration compressor 10, passes through the heat recovery device 20 and the four-way valve 30, flows into the inlet of the condenser 40 from the A end of the four-way valve 30, flows out from the outlet of the condenser 40, and then flows through the liquid storage tank 50 and the economizer 60. After flowing out from the outlet of the economizer 60, the refrigerant is divided into two paths. One path is throttled by the main expansion valve 70, and then flows into the evaporator 90, and then flows into the C end of the four-way valve 30, flows out from the B end of the four-way valve 30, and finally returns to the suction port of the refrigeration compressor 10; the other path is throttled by the auxiliary expansion valve 80, and then flows into the economizer 60 again, and finally flows into the air supply pipe of the refrigeration compressor 10.

[0026] In the above-mentioned jet enthalpy refrigeration system, the refrigerant flows in two parts after the economizer 60. One part is further cooled by throttling and heat expansion to reduce the temperature of the other part and make it supercooled. The stabilized supercooled liquid is throttled and cooled by the main expansion valve 70, and then directly enters the evaporator 90 for refrigeration. The uncooled gaseous refrigerant passes through the connecting pipe between the economizer 60 and the refrigeration compressor 10, re-enters the compressor for further compression, and enters the cycle. The liquid refrigerant medium is stabilized by the above expansion refrigeration method to improve the system capacity and efficiency, which can greatly improve the energy efficiency ratio of the unit.

[0027] like Figure 2 As shown, when the hot fluorine defrosts, the refrigerant flows out from the refrigeration compressor 10, passes through the heat recovery device 20 and the four-way valve 30, flows into the outlet of the evaporator 90 from the C end of the four-way valve 30, flows out from the inlet of the evaporator 90, is throttled by the main expansion valve 70, and then flows into the economizer 60 in two ways. One way flows into the liquid storage tank 50 after passing through the economizer 60, then flows into the condenser 40 and the four-way valve 30 from the A end of the four-way valve 30, then flows out from the B end of the four-way valve 30, and finally returns to the suction port of the refrigeration compressor 10; the other way is throttled by the auxiliary expansion valve 80, then flows into the economizer 60, and finally flows into the air supply pipe of the refrigeration compressor 10.

[0028] The above-mentioned hot fluorine defrost refrigeration system, when it is determined that the cold storage or the evaporator 90 is frosted enough, controls the flow reversal of the four-way valve 30 so that the high-temperature refrigerant flows to the evaporator 90 first, and the temperature of the evaporator 90 increases, so that the frost on the surface of the evaporator 90 melts, that is, the evaporator 90 is converted into a condenser 40, and low-temperature defrosting can be achieved to ensure the normal operation of the unit.

[0029] When the outdoor temperature is very low, the exchange capacity with the ambient temperature decreases, the return air volume of the normal return air port of the refrigeration compressor 10 is reduced, the power of the refrigeration compressor 10 is reduced, and the best effect cannot be achieved. However, the refrigerant gas is supplemented through another return air route of the economizer 60, thereby increasing the exhaust volume of the refrigeration compressor 10 and increasing the amount of circulating refrigerant to increase the heating capacity.

[0030] In one embodiment, an inlet temperature detector and an outlet temperature detector (not shown) are installed on the evaporator 90, and the severity of frosting of the evaporator 90 is judged by the temperature difference between the inlet temperature detector and the outlet temperature detector. Method for judging frosting of the evaporator 90: set a measured value of the warehouse temperature, when the difference between the absolute value of the measured value of the warehouse temperature and the absolute value of the outlet temperature of the evaporator 90 is ≤5-10°C, the evaporator 90 is not frosted; when the difference between the absolute value of the warehouse temperature control threshold and the absolute value of the outlet temperature of the evaporator 90 is greater than 11-20°C, and the difference between the absolute value of the outlet temperature of the evaporator 90 and the absolute value of the inlet temperature is in the range of 5-10°C, the evaporator 90 is partially frosted; when the difference between the absolute value of the measured value of the warehouse temperature and the absolute value of the outlet temperature of the evaporator 90 is greater than 21-30°C, and the difference between the absolute value of the outlet temperature of the evaporator 90 and the absolute value of the inlet temperature is in the range of 10-20°C, the evaporator 90 is seriously frosted. When the evaporator 90 is severely frosted, the hot fluorine defrosting refrigeration system is started to perform defrosting.

[0031] Optionally, the refrigeration compressor 10 is but not limited to one of a piston compressor, a rotor compressor, and a scroll compressor; the main expansion valve 70 and the auxiliary expansion valve 80 are but not limited to electronic expansion valves; the refrigerant is but not limited to R404a; the refrigeration compressor 10 is electrically connected to a frequency converter, and the output power of the refrigeration compressor 10 is controlled by the frequency converter. The control method of the frequency conversion of the refrigeration compressor 10 is: setting an operating temperature target value, when the actual measured value of the cold storage temperature is greater than the operating temperature target value + 3°C, the output power of the refrigeration compressor 10 is increased by the frequency converter, so that the refrigeration compressor 10 outputs at a high frequency; when the actual measured value of the cold storage temperature is less than or equal to the operating temperature target value, the output power of the refrigeration compressor 10 is reduced by the frequency converter, so that the refrigeration compressor 10 outputs at a low frequency, thereby greatly reducing the operating energy consumption of the entire system.

[0032] In one embodiment, the heat recovery device 20 is but not limited to a plate heat exchanger, a heat pipe heat exchanger, or a seesaw heat exchanger; the condenser 40 is but not limited to an air-cooled condenser with forced air flow, which is composed of one or more groups of coils with fins and a fan. The high-temperature refrigerant enters the coils from the upper inner header, and the fan is used to enhance the heat exchange on the air side and compensate for the defect of too low heat transfer coefficient on the air surface. After heat exchange, the low-temperature refrigerant flows out from the upper outer header. In order to improve the utilization rate of the heat exchange area, the number of tube rows of the condenser 40 along the air flow direction is 4-6 rows. The evaporator 90 is but not limited to a horizontal evaporator 90, which is composed of a row pipe and a cold air blower. The row pipe is but not limited to a cooling row pipe, a coil-type row pipe, or a U-shaped row pipe. The heat recovery device 20 is connected with a heat exchange medium input pipe 21, a heat exchange medium output pipe 22, a delivery pump 23 and an insulation box (not shown). The heat recovery device 20, the heat exchange medium input pipe 21, the heat exchange medium output pipe 22, the delivery pump 23 and the insulation box form a heat exchange cycle. The heat is stored and utilized by the insulation box. The heat exchange medium of the heat exchange cycle is water. The insulation box can be installed separately later, or the heat exchange medium input pipe 21 is directly connected to the tap water pipe, and the heat exchange medium output pipe 22 is connected to the faucet for direct use.

[0033] In another embodiment, the heat collection and recovery multifunctional refrigeration system further includes a filter 100 disposed between the economizer 60 and the main expansion valve 70 to filter impurities in the liquid refrigerant to avoid clogging the evaporator 90. In this embodiment, the filter 100 is located before the input port of the auxiliary expansion valve 80.

[0034] Please refer again Figure 2 and Figure 3 , is a structural schematic diagram of an integrated refrigeration unit of the present invention, the integrated refrigeration unit includes the above-mentioned heat collection and recovery multifunctional refrigeration system, the heat collection and recovery multifunctional refrigeration system includes a refrigeration compressor 10, a heat recovery device 20, a four-way valve 30, a condenser 40, a liquid storage device 50, an economizer 60, a main expansion valve 70, an auxiliary expansion valve 80 and an evaporator 90 arranged in sequence along the flow direction of the refrigerant, the refrigeration compressor 10, the heat recovery device 20, the four-way valve 30, the condenser 40, the liquid storage device 50, the economizer 60, the main expansion valve 70, and the auxiliary expansion valve 80 are all installed on the top of the evaporator 90, the condenser 40 is located on one side of the top of the evaporator 90 and the heat dissipation air outlet of the condenser 40 is arranged outward.

[0035] A heat insulation board 91 is provided on the top of the evaporator 90. The heat insulation board 91 is used to separate the evaporator 90 from other devices, so as to prevent the heat emitted by other devices from exchanging heat with the evaporator 90 and affecting the refrigeration efficiency.

[0036] The heat insulation board 91 includes the following components in parts by weight: 25-40 parts of polystyrene foam particles, 10-15 parts of linear low-density polyethylene, 5-8 parts of aluminum hydroxide, 5-8 parts of ceramic fiber, 5-8 parts of graphene oxide, 1-3 parts of maleic anhydride grafted POE, and 1-3 parts of silane coupling agent. The heat insulation board 91 is added with graphene oxide, which can more effectively block heat transfer. At high temperatures, the carbon layer formed by graphene oxide is dense and continuous, which will block the surface and prevent oxygen from entering the depth of the material. The formed carbon layer has good wrapping properties for polystyrene foam particles, making the material have good fire resistance; in addition, graphene oxide also has a very high surface area, which can absorb flammable organic volatiles and toxic gases, and prevent their release and diffusion during the combustion process. Ceramic fiber is also added. Ceramic fiber not only has a flame retardant effect, but also has the characteristics of light weight and high temperature resistance, as its main components are aluminum oxide and zirconium oxide.

Claims

1. A jet enthalpy refrigeration system, It is characterized in that The four-way valve (30) includes an input port and three reversing ports, wherein the three reversing ports are respectively an A port, a B port and a C port. The refrigerant flows out of the refrigeration compressor (10), passes through a heat recovery device (20) and a four-way valve (30), flows into the inlet of the condenser (40) from the A port of the four-way valve (30), flows out from the outlet of the condenser (40), and then flows through a liquid storage device (50) and an economizer (60). After the refrigerant flows out from the outlet of the economizer (60), it is divided into two paths. One path is throttled by a main expansion valve (70), then flows into an evaporator (90), then flows into the C port of the four-way valve (30), flows out from the B port of the four-way valve (30), and finally returns to the air intake port of the refrigeration compressor (10); the other path is throttled by an auxiliary expansion valve (80), then flows into the economizer (60) again, and finally flows into the air supply pipe of the refrigeration compressor (10).

2. The jet enthalpy refrigeration system according to claim 1, It is characterized in that The refrigeration compressor is one of a piston compressor, a rotor compressor and a scroll compressor; the main expansion valve and the auxiliary expansion valve are both electronic expansion valves.

3. The jet enthalpy refrigeration system according to claim 2, It is characterized in that The heat recovery device is connected with a heat exchange medium input pipe, a heat exchange medium output pipe, a delivery pump and a heat preservation box, and the heat recovery device, the heat exchange medium input pipe, the heat exchange medium output pipe, the delivery pump and the heat preservation box form a heat exchange cycle.

4. The jet enthalpy refrigeration system according to claim 3, It is characterized in that The heat exchange medium of the heat exchange cycle is water.

5. The jet enthalpy refrigeration system according to claim 1, It is characterized in that The refrigeration compressor is electrically connected to a frequency converter.

6. The jet enthalpy refrigeration system according to claim 1, It is characterized in that A filter is provided between the economizer and the main expansion valve.

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