Air source heat pump alternate defrosting system and working process thereof

Abstract

The invention relates to the field of heat pumps, in particular to an air source heat pump alternate defrosting system and a working process thereof.The air source heat pump alternate defrosting system comprises a compressor, an economizer, a water tank, a four-way reversing valve and two sets of evaporators.The four-way reversing valve is provided with a port a, a port b, a port c and a port d; the two sides of the compressor are connected with one side of the condenser and one side of the gas-liquid separator respectively, the other side of the gas-liquid separator is connected with one side of the economizer, the other three sides of the condenser are connected with one side of the hot water circulating pump, one side of the water tank and one side of the liquid storage tank respectively, and the other three sides of the economizer are connected with the other side of the liquid storage tank, the opening a and the opening d respectively. The c port is connected with the first evaporator, and the b port is connected with the second evaporator. According to the product, heat absorption and defrosting can be conducted at the same time, heat needed by defrosting comes from waste heat generated after high-temperature media do work, high-efficiency operation is achieved, and the overall operation efficiency in winter is greatly improved.

Description

Technical Field

[0001] The present invention relates to the field of heat pumps, in particular to an air source heat pump alternating defrosting system and its working process. Background Art

[0002] Air-source heat pump technology is an energy-saving and environmentally friendly heating technology based on the reverse Carnot cycle, utilizing natural energy (such as air thermal storage) to generate a low-temperature heat source. The evaporator absorbs low-temperature heat from the outside air, causing the refrigerant to evaporate and absorb heat, thereby lowering the outside air temperature and turning the refrigerant into a low-temperature, low-pressure gas. The low-temperature, low-pressure refrigerant is then drawn into the compressor and compressed into a high-temperature, high-pressure gas. It then enters the condenser, where it exchanges heat with hot water, releasing high-temperature heat and raising the water temperature. During this process, the refrigerant transforms from a gas to a liquid, releasing a significant amount of heat. Finally, the high-temperature, high-pressure refrigerant is reduced in pressure and expanded by the expansion valve before returning to the evaporator, absorbing heat and evaporating, completing the cycle. This cycle repeats, continuously absorbing heat from the low-temperature source and transferring it to the water to be heated, reaching the desired temperature.

[0003] However, the existing air source heat pump technology has the following defects: in an environment with high humidity in winter, the evaporator surface of the air source heat pump system is prone to frost, which will hinder air circulation and reduce heat exchange efficiency, requiring irregular defrosting operations to restore its heating capacity. Traditional defrosting methods generally use reverse cycle defrosting, hot gas bypass defrosting, energy storage defrosting, natural defrosting, water sprinkling defrosting, electric heating defrosting, sensible heat defrosting, high-voltage electrostatic defrosting, ultrasonic defrosting and step-by-step defrosting methods for defrosting. However, the above-mentioned defrosting methods not only consume additional energy, but also cause large fluctuations in the outlet temperature of the heated medium, affecting the continuous operation of the system and directly leading to low overall operating efficiency in winter. Summary of the Invention

[0004] To achieve the above objectives, the present invention aims to provide an air source heat pump alternating defrosting system that can solve the problems existing in the background technology. The present invention provides the following technical solutions: An air source heat pump alternating defrost system includes a compressor, an economizer, a water tank, a four-way reversing valve, and two sets of evaporators, the two sets of evaporators including a first evaporator and a second evaporator. The four-way reversing valve is provided with ports a, b, c, and d. Two sides of the compressor are respectively connected to one side of a condenser and one side of a gas-liquid separator. The other side of the gas-liquid separator is connected to one side of the economizer. The remaining three sides of the condenser are respectively connected to one side of a hot water circulation pump, a water tank, and one side of a liquid storage tank. The other side of the hot water circulation pump is respectively connected to the water tank and a cold water inlet. The water tank is provided with a hot water outlet. The remaining three sides of the economizer are respectively connected to the other side of the liquid storage tank, ports a, and d. Port c is connected to the first evaporator, and port b is connected to the second evaporator. The first and second evaporators are each connected to different filters. The filters of the first and second evaporators are connected via a throttle valve. Compared with existing products, this product has made structural improvements. The position of the four-way reversing valve in the original system is changed and the four-way reversing valve is installed on the outlet side of the liquid storage tank. An additional set of evaporators is also added.

[0005] As a further solution of the present invention: the first evaporator and the second evaporator are both connected to different fans, which can increase the working efficiency of the evaporators.

[0006] As a further solution of the present invention, the fan adopts an axial flow fan, which is easily available in the market and has good use effect.

[0007] As a further solution of the present invention: a throttle is installed at the outlet of the compressor to control the flow and pressure of the compressor, thereby achieving pressure buffering of the fluid and reducing impact force.

[0008] As a further solution of the present invention, the throttle valve adopts an expansion valve, which has good throttling effect, low cost and is easy to replace.

[0009] As a further solution of the present invention: the filter adopts a drying filter, and the desiccant of the drying filter is granular silica gel, which is convenient for repeated use after heating to ensure that the filter can continue to filter.

[0010] A working process of an air source heat pump alternating defrosting system includes the following steps: 1. When frost forms on the surface of the second evaporator, the high-temperature medium in the compressor enters the condenser and heats the heat exchange medium in the condenser. The heated heat exchange medium enters port a of the four-way reversing valve through the liquid storage tank and the economizer. When the four-way reversing valve is not energized, the heat exchange medium flows from port b to the second evaporator, thereby defrosting and releasing heat for the second evaporator. The heat exchange medium flowing out of the second evaporator is throttled by the filter and the throttle valve and flows to the first evaporator for evaporation and heat absorption. After evaporation and heat absorption, the heat exchange medium flows to port c of the four-way reversing valve, and then flows from port d of the four-way reversing valve through the economizer and the gas-liquid separator back to the compressor for further compression. This cycle repeats over and over again to achieve the heating purpose. 2. When frost forms on the surface of the first evaporator, the four-way reversing valve is energized and switches the flow direction of the heat exchange medium. The heat exchange medium flows from port C of the four-way reversing valve to the first evaporator, thereby defrosting and releasing heat for the first evaporator. The heat exchange medium flowing out of the first evaporator is throttled by the filter and the throttle valve and then flows to the second evaporator for evaporation and heat absorption. After evaporation and heat absorption, the heat exchange medium flows to port B of the four-way reversing valve, and then flows from port D of the four-way reversing valve through the economizer and the gas-liquid separator back to the compressor, where it can be compressed again. The cycle repeats over and over again to achieve the heating purpose.

[0011] Compared with the prior art, the present invention has the following beneficial effects: This product can continuously heat the heat exchange medium in low temperature environments in winter, ensuring the stability of the heat exchange medium outlet temperature before and after defrosting. This product uses a double set of evaporators, which can achieve heat absorption and defrosting at the same time. The heat required for defrosting comes from the waste heat after the high-temperature medium does work, achieving high-efficiency operation and greatly improving the overall operating efficiency in winter. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 This is a schematic diagram of the structure of an existing air source heat pump.

[0013] Figure 2 Schematic diagram of the structure of the air source heat pump alternating defrosting system in an embodiment of the present invention.

[0014] In the figure: 1- compressor; 2- four-way reversing valve; 3- condenser; 4- liquid storage tank; 5- filter; 6- throttle valve; 7- evaporator; 71- first evaporator; 72- second evaporator; 8- fan; 9- gas-liquid separator; 10- hot water circulation pump; 11- cold water inlet; 12- water tank; 13- hot water outlet; 14- economizer. DETAILED DESCRIPTION

[0015] The following will provide a clear and complete description of the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0016] The specific implementation of the present invention is described in detail below with reference to specific embodiments.

[0017] Example 1 See Figure 1-2 , an air source heat pump alternating defrosting system, comprising a compressor 1, an economizer 14, a water tank 12, a four-way reversing valve 2 and two groups of evaporators 7, the four groups of evaporators 7 comprising a first evaporator 71 and a second evaporator 72, the four-way reversing valve 2 being provided with ports a, b, c and d, the two sides of the compressor 1 being respectively connected to one side of the condenser 3 and one side of the gas-liquid separator 9, the other side of the gas-liquid separator 9 being connected to one side of the economizer 14, the remaining three sides of the condenser 3 being respectively connected to one side of the hot water circulation pump 10, the water tank 12 and One side of the liquid storage tank 4 is connected, and the other side of the hot water circulation pump 10 is connected to the water tank 12 and the cold water inlet 11 respectively. The water tank 12 is provided with a hot water outlet 13. The remaining three sides of the economizer 14 are respectively connected to the other side of the liquid storage tank 4, port a and port d. Port c is connected to the first evaporator 71, and port b is connected to the second evaporator 72. The first evaporator 71 and the second evaporator 72 are both connected to different filters 5. The filter 5 of the first evaporator 71 and the filter 5 of the second evaporator 72 are connected by a throttle valve 6. Compared with existing products, this product has been improved in structure. The position of the four-way reversing valve 2 in the original system is changed and the four-way reversing valve 2 is installed on the outlet side of the liquid storage tank 4. A set of evaporators 7 is added, which greatly improves the overall operating efficiency in winter.

[0018] In a further solution of this embodiment, the first evaporator 71 and the second evaporator 72 are both connected to different fans 8 , which can increase the working efficiency of the evaporators 7 .

[0019] In a further solution of this embodiment, the fan 8 adopts an axial flow fan, which is easily available in the market and has good performance.

[0020] In a further solution of this embodiment, a throttle is installed at the outlet of the compressor 1 to control the flow rate and pressure of the compressor 1, thereby achieving pressure buffering of the fluid and reducing impact force.

[0021] Example 2 See Figure 1-2, an air source heat pump alternating defrosting system, comprising a compressor 1, an economizer 14, a water tank 12, a four-way reversing valve 2 and two groups of evaporators 7, the four groups of evaporators 7 comprising a first evaporator 71 and a second evaporator 72, the four-way reversing valve 2 being provided with ports a, b, c and d, the two sides of the compressor 1 being respectively connected to one side of the condenser 3 and one side of the gas-liquid separator 9, the other side of the gas-liquid separator 9 being connected to one side of the economizer 14, the remaining three sides of the condenser 3 being respectively connected to one side of the hot water circulation pump 10, the water tank 12 and One side of the liquid storage tank 4 is connected, and the other side of the hot water circulation pump 10 is respectively connected to the water tank 12 and the cold water inlet 11. The water tank 12 is provided with a hot water outlet 13. The other three sides of the economizer 14 are respectively connected to the other side of the liquid storage tank 4, port a and port d, port c is connected to the first evaporator 71, and port b is connected to the second evaporator 72. The first evaporator 71 and the second evaporator 72 are both connected to different filters 5. The filter 5 of the first evaporator 71 and the filter 5 of the second evaporator 72 are connected through a throttle valve 6.

[0022] In a further solution of this embodiment, the throttle valve 6 is an expansion valve, which has a good throttling effect, low cost and is easy to replace.

[0023] In a further solution of this embodiment, the filter 5 is a drying filter, and the desiccant of the drying filter is granular silica gel, which is convenient for repeated use after heating, thereby ensuring that the filter 5 can continue to filter.

[0024] A working process of an air source heat pump alternating defrosting system includes the following steps: 1. When frost forms on the surface of the second evaporator 72, the high-temperature medium in the compressor 1 enters the condenser 3 and heats the heat exchange medium in the condenser 3. The heated heat exchange medium enters the port a of the four-way reversing valve 2 through the liquid storage tank 4 and the economizer 14. When the four-way reversing valve 2 is not energized, the heat exchange medium flows from the port b to the second evaporator 72, thereby defrosting and releasing heat for the second evaporator 72. The heat exchange medium flowing out of the second evaporator 72 is throttled by the filter 5 and the throttle valve 6 and flows to the first evaporator 71 for evaporation and heat absorption. After evaporation and heat absorption, the heat exchange medium flows to the port c of the four-way reversing valve 2, and then flows from the port d of the four-way reversing valve 2 through the economizer 14 and the gas-liquid separator 9 back to the compressor 1 for further compression. This cycle repeats over and over again to achieve the heating purpose. 2. When frost forms on the surface of the first evaporator 71, the four-way reversing valve 2 is energized and switches the flow direction of the heat exchange medium. The heat exchange medium flows from the c port of the four-way reversing valve 2 to the first evaporator 71, thereby defrosting and releasing heat for the first evaporator 71. The heat exchange medium flowing out of the first evaporator 71 is throttled by the filter 5 and the throttle valve 6 and then flows to the second evaporator 72 for evaporation and heat absorption. After evaporation and heat absorption, the heat exchange medium flows to the b port of the four-way reversing valve 2, and then flows from the d port of the four-way reversing valve 2 through the economizer 14 and the gas-liquid separator 9 back to the compressor 1, where it can be compressed again. The cycle repeats over and over again to achieve the heating purpose.

[0025] It should be noted that, in the present invention, unless otherwise expressly specified or limited, the terms "fixed" and "disposed" should be understood in a broad sense. For example, they can refer to welded connections, bolted connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; internal communication between two elements or interaction between two elements, unless otherwise expressly specified. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0026] In addition, it should be understood that although this specification is described in terms of implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

Claims

1. An air source heat pump alternating defrosting system, comprising a compressor, an economizer, a water tank, a four-way reversing valve and two sets of evaporators, characterized in that: The two groups of evaporators include a first evaporator and a second evaporator. The four-way reversing valve is provided with port a, port b, port c and port d. The two sides of the compressor are respectively connected to one side of the condenser and one side of the gas-liquid separator, and the other side of the gas-liquid separator is connected to one side of the economizer. The remaining three sides of the condenser are respectively connected to one side of the hot water circulation pump, the water tank and one side of the liquid storage tank. The other side of the hot water circulation pump is respectively connected to the water tank and the cold water inlet. A hot water outlet is provided on the water tank. The remaining three sides of the economizer are respectively connected to the other side of the liquid storage tank, port a and port d. Port c is connected to the first evaporator, and port b is connected to the second evaporator. The first evaporator and the second evaporator are both connected to different filters. The filter of the first evaporator and the filter of the second evaporator are connected through a throttle valve.

2. The air source heat pump alternating defrosting system according to claim 1, characterized in that: The first evaporator and the second evaporator are both connected to different fans.

3. The air source heat pump alternating defrosting system according to claim 2, characterized in that: The fan is an axial flow fan.

4. The air source heat pump alternating defrosting system according to claim 1, characterized in that: A throttle is installed at the outlet of the compressor.

5. The air source heat pump alternating defrosting system according to claim 1 or 4, characterized in that: The throttle valve is an expansion valve.

6. The air source heat pump alternating defrosting system according to claim 1, characterized in that: The filter adopts a drying filter, and the desiccant of the drying filter is granular silica gel.

7. A working process of an air source heat pump alternating defrosting system, characterized in that: The following steps are involved: (1) When the surface of the second evaporator is frosted, the high-temperature medium in the compressor enters the condenser and heats the heat exchange medium in the condenser. The heated heat exchange medium enters port a of the four-way reversing valve through the liquid storage tank and the economizer. When the four-way reversing valve is not energized, the heat exchange medium flows from port b to the second evaporator. The heat exchange medium flowing out of the second evaporator is throttled by the filter and the throttle valve and flows to the first evaporator for evaporation and heat absorption. After evaporation and heat absorption, the heat exchange medium flows to port c of the four-way reversing valve, and then flows from port d of the four-way reversing valve through the economizer and the gas-liquid separator back to the compressor. (2) When frost forms on the surface of the first evaporator, the four-way reversing valve is energized and switches the flow direction of the heat exchange medium. The heat exchange medium flows from the c port of the four-way reversing valve to the first evaporator. The heat exchange medium flowing out of the first evaporator is throttled by the filter and the throttle valve and then flows to the second evaporator for evaporation and heat absorption. After evaporation and heat absorption, the heat exchange medium flows to the b port of the four-way reversing valve, and then flows from the d port of the four-way reversing valve through the economizer and the gas-liquid separator back to the compressor.

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