CN101270936B - Refrigeration cycle system with heat pump defrosting - Google Patents

Abstract

The invention discloses a refrigerating cycle system using a heat pump to defrost, and aims to provide a cycle system that utilizes the energy storage of the refrigerating cycle to provide a higher ambient medium temperature when the heat pump defrosts. The refrigerant outlet of the compressor is connected to the refrigerant inlet of the sensible heat exchanger through the four-way reversing valve, and the refrigerant outlet of the sensible heat exchanger is respectively connected to the inlet of the first one-way valve and the outlet of the second one-way valve. The outlet of the first one-way valve is connected to the refrigerant inlet of the first latent heat exchanger, and the refrigerant outlet of the first latent heat exchanger is respectively connected to the inlet of the throttling device and the outlet of the third one-way valve. The outlet of the flow device is respectively connected with the inlet of the second one-way valve and the inlet of the fourth one-way valve, and the inlet of the third one-way valve and the outlet of the fourth one-way valve are respectively connected with the refrigerant inlet of the second latent heat exchanger. The refrigerant outlet of the second latent heat exchanger is connected with the refrigerant inlet of the compressor through a four-way reversing valve. The defrosting time of the system of the present invention is short.

Description

Refrigeration cycle system with heat pump defrosting

technical field

The invention relates to a refrigerating cycle system, more specifically, relates to a refrigerating cycle system using a heat pump to defrost.

Background technique

For low-temperature cold storage or low-temperature freezer, the evaporator is easy to frost during the refrigeration cycle, and the defrosting methods that are often used after the evaporator is frosted include electric heating assisted defrosting and heat pump defrosting. Heat pump defrosting has the advantages of low power consumption, fast defrosting speed, safety and reliability. When the heat pump defrosts, the system uses the four-way reversing valve to switch the functions of the original evaporator and condenser to realize the heat pump cycle. The refrigerant in the evaporator (that is, the condenser in the refrigeration cycle) in the heat pump cycle absorbs heat from the ambient medium (that is, the air), and the refrigerant pressure is increased by the compressor to reach the condenser (that is, the evaporator in the refrigeration cycle). The frost on the evaporator is melted by the condensation of the refrigerant under high pressure. When the heat pump defrosts, the evaporation temperature of the heat pump system directly affects the defrosting efficiency. The higher the evaporation temperature, the higher the heating efficiency of the heat pump and the shorter the defrosting time. Therefore, the temperature of the ambient medium directly affects the efficiency of the heat pump cycle. Especially in winter, the heat of the heat pump defrosting needs to be extracted from the lower ambient medium. Since the air temperature is low at this time, the evaporation temperature of the heat pump is also reduced accordingly, and the energy efficiency of the system The ratio is relatively small, and the defrost runs for a long time.

Contents of the invention

The purpose of the present invention is to overcome the deficiencies in the prior art, and provide a refrigeration cycle system that can utilize refrigeration cycle energy storage to provide a higher ambient medium temperature when realizing heat pump defrosting and improve heat pump defrosting efficiency.

The present invention realizes through following technical scheme:

A refrigeration cycle system using a heat pump to defrost is characterized in that it includes a compressor, a four-way reversing valve, a sensible heat exchanger, a first latent heat exchanger, a second latent heat exchanger, and a throttling device. The refrigerant outlet of the compressor is connected to the first port of the four-way reversing valve, the second port of the four-way reversing valve is connected to the refrigerant inlet of the sensible heat exchanger, and the refrigerant outlets of the sensible heat exchanger are respectively It is connected with the inlet of the first one-way valve and the outlet of the second one-way valve, the outlet of the first one-way valve is connected with the refrigerant inlet of the first latent heat exchanger, and the refrigerant outlet of the first latent heat exchanger is respectively connected with The inlet of the throttling device is connected to the outlet of the third one-way valve, the outlet of the throttling device is respectively connected to the inlet of the second one-way valve and the inlet of the fourth one-way valve, and the inlet of the third one-way valve is connected to the fourth one-way valve. The outlets of the directional valves are respectively connected to the refrigerant inlets of the second latent heat exchanger, the refrigerant outlets of the second latent heat exchanger are connected to the third port of the four-way reversing valve, and the fourth port of the four-way reversing valve is connected to the Compressor refrigerant inlet connection.

The sensible heat exchanger is composed of a container, a heat exchanger and a heat storage medium placed in the container. The heat exchanger is a coil or plate heat exchanger.

The throttling device is any one of a capillary, a throttle valve, or an orifice.

The second latent heat exchanger is a surface heat exchanger.

The present invention has following technical effect:

In the refrigeration cycle system of the present invention, during the refrigeration cycle, the heat storage medium in the sensible heat exchanger is heated, and heat energy is stored in the heat storage medium. When realizing the defrosting of the heat pump, the refrigerant absorbs the heat energy stored in the heat storage medium of the sensible heat exchanger, which improves the defrosting efficiency and shortens the defrosting time. At the same time, due to the addition of the sensible heat exchanger, the subcooling degree of the refrigerant during the refrigeration cycle is improved, thereby improving the operating efficiency of the refrigeration system. In addition, since the first latent heat exchanger in the system (that is, the condenser in the refrigeration cycle system) does not participate in the cycle when the heat pump defrosts, the system pressure difference can be quickly established during the cycle conversion from the heat pump to refrigeration, thereby Reduced system changeover time.

Description of drawings

Fig. 1 is a schematic diagram of a refrigeration cycle system using a heat pump to defrost according to the present invention.

Detailed ways

The present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments.

Figure 1 is a schematic diagram of a refrigeration cycle system using heat pump defrosting in the present invention, including a compressor 1, a four-way reversing valve 2, a sensible heat exchanger 3, a first latent heat exchanger 4, a second latent heat exchanger 6 and Throttle device 5, the refrigerant outlet of the compressor 1 is connected to the first port 2-1 of the four-way reversing valve 2, and the second port 2-2 of the four-way reversing valve is connected to the sensible heat exchanger 3 The refrigerant inlet is connected, the refrigerant outlet of the sensible heat exchanger 3 is respectively connected with the inlet of the first one-way valve 7-1 and the outlet of the second one-way valve 7-2, and the outlet of the first one-way valve 7-1 It is connected with the refrigerant inlet of the first latent heat exchanger 4, and the refrigerant outlet of the first latent heat exchanger 4 is respectively connected with the inlet of the throttling device 5 and the outlet of the third one-way valve 7-3, and the throttling device 5 The outlet of the second one-way valve 7-2 is connected with the inlet of the fourth one-way valve 7-4 respectively, and the inlet of the third one-way valve 7-3 and the outlet of the fourth one-way valve 7-4 are respectively connected with The refrigerant inlet of the second latent heat exchanger 6 is connected, the refrigerant outlet of the second latent heat exchanger is connected with the third port 2-3 of the four-way reversing valve, and the fourth port 2-4 of the four-way reversing valve Connect to the refrigerant inlet of compressor 1. The sensible heat exchanger is composed of a container, a heat exchanger and a heat storage medium placed in the container, and the material of the container can be metal or non-metal. The heat exchanger can be a coil, plate heat exchanger, etc. The heat storage medium can be fluid, solid or phase change material, and can be organic or inorganic. Compressors can be either displacement or velocity. The first latent heat exchanger 4 is an existing technology, which is equivalent to a condenser in a refrigeration cycle system, and the form of the heat exchanger is not limited. The second latent heat exchanger 6 is a surface heat exchanger in the prior art, which is equivalent to an evaporator in a refrigeration cycle system. The throttling device 5 is the prior art, and the form is not limited, it can be a capillary, a throttle valve or an orifice plate and the like. Check valves can be spring type or gravity type.

When in use, charge refrigerant in the refrigeration cycle system. During the refrigeration cycle, the refrigerant vapor enters the sensible heat exchanger 3 through the first interface 2-1 and the second interface 2-2 of the four-way reversing valve 2 after being boosted by the refrigeration compressor 1, and exchanges heat with the sensible heat. The heat storage medium in the device 3 dissipates heat, then passes through the first one-way valve 7-1, reaches the first latent heat exchanger 4 and condenses into a high-pressure liquid, and then is depressurized by the throttling device 5, and then passes through the fourth one-way valve 7-1. -4 enters the second latent heat exchanger 6, evaporates and absorbs heat in the second latent heat exchanger 6 to become a low-pressure steam, due to the phase change of the refrigerant, a refrigeration phenomenon occurs, and the low-pressure steam of the refrigerant passes through the four-way reversing valve 2 The third interface 2-3 and the fourth interface 2-4 go back to the compressor. During the defrosting cycle of the heat pump, each channel in the four-way reversing valve 2 is switched, and the refrigerant vapor enters through the first port 2-1 and the third port 2-3 of the four-way reversing valve 2 after the pressure is raised by the refrigeration compressor 1. In the second latent heat exchanger 6, heat is condensed in the second latent heat exchanger 6, and the released condensation heat melts the frost condensed on the surface of the second latent heat exchanger 6 during the refrigeration cycle, and condenses into a high-pressure liquid After passing through the third one-way valve 7-3, the refrigerant is decompressed by the throttling device 5, and then enters the sensible heat exchanger 3 through the second one-way valve 7-2, and the refrigerant absorbs the sensible heat in the heat exchanger 3 The heat stored in the middle heat storage medium evaporates and returns to the compressor 1 through the second port 2-2 and the fourth port 2-4 of the four-way reversing valve 2 to complete the heat pump defrosting cycle. Since the heat is stored in the sensible heat exchanger 3 during the refrigeration cycle, when the heat pump defrosting cycle is performed, the evaporation temperature of the system is increased, thereby improving the system efficiency during defrosting, speeding up the defrosting speed, and shortening the defrosting cycle. defrost time.

When the heat pump defrosting system is running, due to the addition of the sensible heat exchanger 3, the high pressure in the first latent heat exchanger 4 is ensured, and the first latent heat exchanger 4 is not allowed to participate in the heat pump cycle. In this way, when the system is converted from the heat pump cycle to the refrigeration cycle, the high pressure in the first latent heat exchanger 4 is utilized, and the refrigeration system will quickly establish a high and low pressure difference, thereby improving the conversion efficiency and shortening the conversion time .

Although the disclosed refrigeration cycle system involving a heat pump for defrosting has been specifically described with reference to the embodiments, the above-described embodiments are illustrative rather than restrictive, without departing from the spirit and scope of the present invention Below, all changes and modifications are within the scope of the present invention.

Claims (4)

1. A refrigeration cycle system that adopts heat pump defrosting, is characterized in that, comprises compressor, four-way reversing valve, sensible heat exchanger, the first latent heat exchanger, the second latent heat exchanger and throttling device , the refrigerant outlet of the compressor is connected to the first interface of the four-way reversing valve, the second interface of the four-way reversing valve is connected to the refrigerant inlet of the sensible heat exchanger, and the refrigerant of the sensible heat exchanger The outlets are respectively connected to the inlet of the first one-way valve and the outlet of the second one-way valve, the outlet of the first one-way valve is connected to the refrigerant inlet of the first latent heat exchanger, and the refrigerant outlet of the first latent heat exchanger They are respectively connected to the inlet of the throttling device and the outlet of the third one-way valve, the outlet of the throttling device is respectively connected to the inlet of the second one-way valve and the inlet of the fourth one-way valve, and the inlet of the third one-way valve is connected to the outlet of the third one-way valve. The outlets of the four one-way valves are respectively connected to the refrigerant inlets of the second latent heat exchanger, the refrigerant outlets of the second latent heat exchanger are connected to the third interface of the four-way reversing valve, and the fourth port of the four-way reversing valve The interface is connected with the refrigerant inlet of the compressor. 2. The refrigeration cycle system using heat pump defrosting according to claim 1, wherein the sensible heat exchanger is composed of a container, a heat exchanger and a heat storage medium placed in the container. 3 . The refrigeration cycle system using heat pump defrosting according to claim 1 , wherein the throttling device is any one of a capillary tube, a throttle valve, or an orifice plate. 4 . 4. The refrigeration cycle system using heat pump defrosting according to claim 1, wherein the second latent heat exchanger is a surface heat exchanger.

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