LU501502B1

LU501502B1 - Air source heat pump system and defrosting method thereof

Info

Publication number: LU501502B1
Application number: LU501502A
Authority: LU
Inventors: Huanwei Liu
Original assignee: Univ Yantai
Priority date: 2022-02-16
Filing date: 2022-02-16
Publication date: 2022-08-16

Abstract

The present disclosure discloses an air source heat pump system and defrosting method thereof. The system comprises an energy accumulator, and a pipeline assembly for communicating the energy accumulator with a compressor, an indoor unit, and an outdoor unit in the air source heat pump system; when the system works in a heating working condition, a refrigerant is discharged from the compressor, sequentially passes through the indoor unit, the energy accumulator, an expansion valve and the outdoor unit, and then returns to the compressor; and when the system works in a defrosting working condition, the refrigerant is discharged from the compressor, sequentially passes through the outdoor unit, the expansion valve and the energy accumulator, and then returns to the compressor. By additionally arranging the energy accumulator in the air source heat pump system, the energy accumulator is utilized for absorbing and storing heat of the refrigerant passing through the indoor unit, and the energy accumulator provides heat in the defrosting process, thus the consumption of indoor heat is reduced, and the fluctuation of indoor temperature in the defrosting process is reduced.

Description

AIR SOURCE HEAT PUMP SYSTEM AND DEFROSTING METHOD „501502

THEREOF TECHNICAL FIELD

[01] The present disclosure relates to the technical field of air conditioners, and in particular relates to an air source heat pump system and a defrosting method thereof.

BACKGROUND ART

[02] According to the air source heat pump air conditioning unit at present, under the heating working condition, the performance coefficient of the heat pump unit is attenuated as the environment temperature falls, and when the surface temperature of an outdoor heat exchanger is lower than 0°C, the performance coefficient of the air source heat pump air conditioning unit decreases more rapidly. The main reason is that when the air conditioning unit is operated at a low outdoor temperature with certain humidity, the outdoor air-cooled finned tube outdoor unit may generate a frost layer after operating for a period of time, the generation of the frost layer enables the spacing between fins of the air-cooled finned tube outdoor unit to be reduced, resulting in the increase of outdoor circulating air resistance and the reduction of the circulating air volume. Meanwhile, the frosting leads to the increase of the heat transfer resistance of the air-cooled finned tube outdoor unit and the decrease of the heat transfer coefficient, thus, the heat exchange temperature difference between the refrigerant and the air needs to be increased under the same working condition, which finally causes the reduction of the evaporation pressure and the evaporation temperature of the refrigerant in the air-cooled finned tube outdoor unit, further aggravates the frosting degree of the air-cooled finned tube heat exchanger, and causes the increase of shaft power of the compressor and the decrease of the performance coefficient.

SUMMARY

[03] For above problems, the present disclosure provides an air source heat pump system, which comprises an energy accumulator, and a pipeline assembly for communicating the energy accumulator with a compressor, an indoor unit, and an outdoor unit in the air source heat pump system; when the system works in a heating working condition, a refrigerant is discharged from the compressor, sequentially passes through the indoor unit, the energy accumulator, an expansion valve and the outdoor unit, and then returns to the compressor; and when the system works in a defrosting working condition, the refrigerant is discharged from the compressor, sequentially passes through the outdoor unit, the expansion valve, and the energy accumulator, and then returns to the compressor.

[04] The pipeline assembly comprises a four-way reversing valve, the four-way reversing valve is provided with pipe ports a, b, c and d, which are respectively communicated with an outlet of the compressor, the outdoor unit, an inlet of the compressor, and the energy accumulator; when the pipe ports b and c are communicated, the four-way reversing valve is in a first state, and the system works in the heating working condition at the moment; and when the pipe ports c and d are communicated, 1 the four-way reversing valve is in a second state, and the system works in the defrosting LU501502 working condition at the moment.

[05] An expansion valve is further arranged between the outdoor unit and the energy accumulator.

[06] A first passage and a second passage are provided between the outdoor unit and the energy accumulator, where the first passage is provided with first check valves at an inlet side and an outside side of the expansion valve respectively; and the second passage is provided with second check valves at the inlet side and the outlet side of the expansion valve respectively.

[07] A second solenoid valve is arranged between the indoor unit and the energy accumulator, and a first solenoid valve is arranged between the energy accumulator and the pipe port d of the four-way reversing valve.

[08] The energy accumulator comprises a box body, and a heat exchange pipe and a secondary refrigerant arranged in the box body, wherein the secondary refrigerant is an ethylene glycol solution, and the heat exchange pipe is one or more groups of copper pipes.

[09] The present disclosure further provides a defrosting method, wherein

[10] (1) during a heating working condition, a condensed refrigerant enters an energy accumulator, and the refrigerant continuously releases heat to heat a secondary refrigerant in the energy accumulator;

[11] (2) the refrigerant passing through the energy accumulator enters an outdoor unit, and then the refrigerant enters a compressor after being vaporized by absorbing the heat;

[12] 3) when defrosting is required, exhaust of the compressor enters the outdoor unit for defrosting; and

[13] (4) the refrigerant condensed by the outdoor unit enters the energy accumulator, and then enters the compressor after being vaporized by absorbing the heat in the energy accumulator.

[14] In the step (2), the refrigerant enters the outdoor unit after passing through the expansion valve; and in the step (4), the refrigerant enters the energy accumulator after passing through the expansion valve.

[15] When the refrigerant passes through the second solenoid valve in the step (2), the first solenoid valve is closed.

[16] When the refrigerant passes through the first solenoid valve in the step (4), the second solenoid valve is closed.

[17] The air source heat pump system has the beneficial effects that:

[18] 1. the energy accumulator is additionally arranged in the air source heat pump system, and is used to absorb and store the heat of the refrigerant after passing through the indoor unit, and the energy accumulator provides the heat in the defrosting process, thus the consumption of indoor heat is reduced, and the fluctuation of the indoor temperature in the defrosting process is reduced;

[19] 2. the four-way reversing valve is adopted for the switching of the heating working condition and the defrosting working condition with simple and convenient operation, and the defrosting working condition can be quickly formed to defrost a frost 2 layer of an outdoor unit, and the defrosting working condition can be quickly switched LU501502 to the heating working condition to replenish the heat to the indoor temperature in time, thus maintaining the indoor temperature, avoiding temperature loss, and further reducing the influence on the indoor temperature;

[20] 3. the first check valves and the second check valves are used to form two passages between the outdoor unit and the energy accumulator, the two passages are opposite in directions, and are provided with an expansion valve therebetween; no matter a loop in which direction, it is guaranteed that the inlet direction and the outlet direction of the expansion valve follow the flow direction of the refrigerant, thus the refrigerant can become low-temperature and low-pressure wet steam from medium-temperature and high-pressure liquid after passing through the expansion valve, thus the energy can be better replenished to the accumulator in the heating working condition, and the energy stored in the energy accumulator cane be better utilized in the defrosting working condition; and

[21] 4. the second solenoid valve is arranged between the indoor unit and the energy accumulator and the first solenoid valve is arranged between the energy accumulator and the four-way reversing valve, the on-off of the two solenoid valves is in fit with the change of the states of the four-way reversing valve, thus the refrigerant can smoothly dissipate heat in a room through the indoor unit in the heating working condition, and the refrigerant can be prevented from passing through the indoor unit in the defrosting working condition. That is, in the defrosting working condition, only the energy of the energy accumulator is utilized, and the indoor energy cannot be taken away by the indoor unit, and then the influence on the indoor temperature is reduced.

BRIEF DESCRIPTION OF THE DRAWINGS

[22] FIG. 1 is a schematic diagram of an air source heat pump system;

[23] In the drawings: 1-compressor; 2-four-way reversing valve; 3-outdoor unit; 4-indoor unit; S-energy accumulator, 6-expansion valve; 7-1-first solenoid valve; 7-2-second solenoid valve; 8-1-first check valve; 8-2-second check valve; 9-third solenoid valve.

DETAILED DESCRIPTION OF THE EMBODIMENTS

[24] As shown in FIG. 1, the present disclosure provides an air source heat pump system, which comprises an energy accumulator 5, and a pipeline assembly for communicating the energy accumulator 5 with a compressor 1, an indoor unit 4, and an outdoor unit 3 in the air source heat pump system. It needs to be noted that the pipeline assembly comprises various connecting pipelines and necessary valves, connection and use of the pipelines and the valves are in a conventional mode, and all parts and the pipeline assembly form a circulation loop of a refrigerant. When the system works in a heating working condition, the refrigerant is discharged from the compressor 1, sequentially passes through the indoor unit 4, the energy accumulator 5, and the outdoor unit 3, and then returns to the compressor 1; and when the system works in a defrosting working condition, the refrigerant is discharged from the compressor 1, sequentially passes through the outdoor unit 3 and the energy accumulator 5, and then returns to the 3 compressor 1. To achieve switching of the heating working condition and the defrosting LU501502 working condition, the mode of dividing the outlet of the compressor 1 into two passages which are communicated with the heating working condition and the defrosting working condition respectively and is each provided with a valve such as a solenoid valve to control on-off can be adopted. Certainly, other modes can be adopted for switching the heating working condition and the defrosting working condition. In addition, it needs to be noted that the outdoor unit 3 preferably adopts an air-cooled finned tube outdoor unit, and the indoor unit 4 adopts the prior art in the field.

[25] Further, the pipeline assembly comprises a four-way reversing valve 2, two states can be formed by changing the on-off of the pipe ports of the four-way reversing valve 2, and flow directions of the states are different, thus in the field of air-conditioners, by changing a flow passage of the refrigerant, the function of switching the indoor unit and the outdoor unit of the air-conditioner system in winter and summer by changing the flow direction of the refrigerant is achieved, which is the prior art and will not be repeatedly described here. Specifically, the four-way reversing valve 2 is provided with pipe ports a, b, c and d which are respectively communicated with an outlet of the compressor 1, the outdoor unit 3, an inlet of the compressor 1, and the energy accumulator 5; when the pipe ports b and c are communicated, the four-way reversing valve 2 is in a first state, the sequence that the refrigerant successively reaches the pipe ports is a-b-c-d, and the system works in the heating working condition at the moment; when the pipe ports c and d are communicated, the four-way reversing valve 2 is in a second state, the sequence that the refrigerant successively reaches the pipe ports is a-b-d-c, and the system works in the defrosting condition at the moment.

[26] As shown in FIG. 1, an expansion valve 6 is further arranged between the outdoor unit 3 and the energy accumulator 5. Due to the fact that an inlet direction and an outlet direction of the expansion valve 6 are not interchangeable, two expansion valves 6 can be arranged between the outdoor unit 3 and the energy accumulator 5, with each corresponding to one working condition. The solenoid valve or other valve is used to control the refrigerant to pass through which expansion valve 6, thus guaranteeing a correct use direction of the expansion valve 6. Certainly, other modes may also be adopted for guaranteeing that the refrigerant enters from the inlet of the expansion valve 6 and is discharged from the outlet of the expansion valve.

[27] Further, a first passage and a second passage are provided between the outdoor unit 3 and the energy accumulator 5, wherein the first passage is provided with first check valves 8-1 at an inlet side and an outlet side of the expansion valve 6 respectively, and the second passage is provided with second check valves 8-2 at the inlet side and the outlet side of the expansion valve 6 respectively; the first check valve 8-1 and the second check valve 8-2 have the same model specification but different arrangement directions. Therefore, please referring to FIG. 1, use demands can be met only by arranging one expansion valve between the outer unit 3 and the energy accumulator 5.

[28] Moreover, a second solenoid valve 7-2 is arranged between the indoor unit 4 and the energy accumulator 5, and a first solenoid valve 7-1 is arranged between the energy accumulator 5 and the pipe port d of the four-way reversing valve 2; in the heating working condition, the second solenoid valve 7-2 is in an open state, the 4 refrigerant can reach the energy accumulator 5 through the indoor unit 4, and the first LU501502 solenoid valve 7-1 is in a closed state at the moment; in the defrosting working condition, the first solenoid valve 7-1 is in an open state, the refrigerant can return to the compressor 1 from the energy accumulator 5 through the four-way reversing valve 2, and the second solenoid valve 7-2 is in a closed state at the moment, i.e., the refrigerant cannot pass through the indoor unit 4. It needs to be noted that the open state refers that a position of the solenoid valve is on, and the closed state refers that a position of the solenoid valve is off.

[29] The energy accumulator 5 comprises a box body, and a heat exchange pipe and a secondary refrigerant arranged in the box body, wherein the second refrigerant adopts a saline solution of sodium chloride or calcium chloride, or adopts an aqueous solution of organic compounds such as ethylene glycol or glycerol, preferably an ethylene glycol solution with a freezing point of -20 °C; a group of or multiple groups of heat exchange pipes is provided, which is generally made of steel, aluminum alloy, or copper and the like, preferably copper; the copper pipe is submerged in the ethylene glycol solution, the whole box body forms a sealing state, the inlet and the outlet of the copper pipe are exposed to the outside of the box body to facilitate connection, and a thermal insulation material can be arranged outside the box body to reduce heat dissipation into the surrounding environment. During normal working, the ethylene glycol solution absorbs and stores the heat of refrigerant liquid above 30 °C flowing through the copper pipe; and during defrosting, the refrigerant liquid flowing from the outdoor unit 3 absorbs and stores the heat stored in the ethylene glycol solution, and enters the outdoor unit 3 after recirculating to defrost a frost layer of the outdoor unit 3.

[30] As shown in FIG. 1, in one embodiment of the present disclosure, a third solenoid valve 9 is further arranged between the expansion valve 6 and the indoor unit 4; when the system is in the heating working condition and the defrosting working condition, the third solenoid valve 9 is closed, 1.e., the refrigerant cannot flow through the third solenoid valve 9; in a refrigerating working condition, the third solenoid valve 9 is opened to make the refrigerant flow through the third solenoid valve 9, and the first solenoid valve 7-1 and the second solenoid valve 7-2 are closed at the moment, thus the refrigerant cannot flow through the first solenoid valve 7-1 and the second solenoid valve 7-2.

[31] The present disclosure further provides a defrosting method.

[32] (1) during a heating working condition, a condensed refrigerant enters an energy accumulator 5, and the refrigerant continuously releases heat to heat a medium (the second refrigerant) in the energy accumulator 5;

[33] (2) the refrigerant passing through the energy accumulator 5 enters an outdoor unit 3, and then the refrigerant enters a compressor after being vaporized by absorbing heat;

[34] (3) when defrosting is required, exhaust of the compressor 1 enters the outdoor unit 3 for defrosting; and

[35] (4) the refrigerant condensed by the outdoor unit 3 enters the energy accumulator 5, and the refrigerant enters the compressor 1 after being vaporized by absorbing the heat in the energy accumulator 5.

[36] In the step (2), the refrigerant enters the outdoor unit 3 after passing through the LU501502 expansion valve 6; and in the step (4), the refrigerant enters the energy accumulator 5 after passing through the expansion valve 6.

[37] When the refrigerant passes through the second solenoid valve 7-2 in the step (2), the first solenoid valve 7-1 is closed.

[38] When the refrigerant passes through the first solenoid valve 7-1 in the step (4), the second solenoid valve 7-2 is closed.

[39] A working process of the air source heat pump system is as follows:

[40] During the heating working condition, the exhaust of the compressor 1 enters the indoor unit 4 through the four-way reversing valve 2, the condensed refrigerant enters the energy accumulator 5 through the second solenoid valve 7-2, the refrigerant continuously releases heat to heat the secondary refrigerant-ethylene alcohol solution in the energy accumulator 5, and the refrigerant is supercooled at the moment; afterwards, the refrigerant enters the expansion valve 6 through the first check valve 8-1, then enters the outdoor unit 3 after passing through another first check valve 8-1, and the refrigerant enters the compressor 1 through the four-way reversing valve 2 after being vaporized by absorbing the heat. At the moment, the first solenoid valve 7-1 is in a closed state, 1.e., an off state.

[41] During the defrosting working condition, when the outdoor unit 3 needs defrosting, the exhaust of the compressor 1 enters the outdoor unit 3 through the four-way reversing valve 2 to conduct defrosting on the outdoor unit. The condensed refrigerant liquid enters the expansion valve 6 through the second check valve 8-2, and then enters the energy accumulator 5 after passing through another second check valve 8-2, and the refrigerant enters the four-way reversing valve 2 through the first solenoid valve 7-1 and then enters the compressor 1 after being vaporized by absorbing heat. At the moment, the second solenoid valve 7-2 is in a closed state, i.e., an off state.

[42] During the cooling working condition, the exhaust of the compressor 1 enters the outdoor unit 3 through the four-way reversing valve 2, the condensed refrigerant enters the expansion valve 6 through the second check valve 8-2, the refrigerant passes through another second check valve 8-2 after being throttled and depressurized, and then enters the indoor unit 4 through the third solenoid valve 9; and the refrigerant enters the compressor 1 through the four-way reversing valve 2 after being vaporized by absorbing the heat, thus achieving the effect of indoor refrigerating. At the moment, the first solenoid valve 7-1 and the second solenoid valve 7-2 are both in a closed state, i.e, an off state.

6

Claims

WHAT IS CLAIMED IS: LUS01502

1. An air source heat pump system, comprising an energy accumulator and a pipeline assembly for communicating the energy accumulator with a compressor, an indoor unit, and an outdoor unit in the air source heat pump system, wherein when the system works in a heating working condition, a refrigerant is discharged from the compressor, sequentially passes through the indoor unit, the energy accumulator and the outdoor unit, and then returns to the compressor; an expansion valve is further arranged between the outdoor unit and the energy accumulator; and when the system works in a defrosting working condition, the refrigerant is discharged from the compressor, sequentially passes through the outdoor unit and the energy accumulator, and then returns to the compressor.

2. The air source heat pump system according to claim 1, wherein the pipeline assembly comprises a four-way reversing valve, the four-way reversing valve is provided with pipe ports a, b, c and d, which are respectively communicated with an outlet of the compressor, the outdoor unit, an inlet of the compressor, and the energy accumulator; when the pipe ports b and c are communicated, the four-way reversing valve is in a first state, and the system works in the heating working condition at the moment; and when the pipe ports c and d are communicated, the four-way reversing valve is in a second state, and the system works in the defrosting working condition at the moment.

3. The air source heat pump system according to claim 1, wherein a first passage and a second passage are provided between the outdoor unit and the energy accumulator, where the first passage 1s provided with first check valves at an inlet side and an outside side of the expansion valve respectively; and the second passage is provided with second check valves at the inlet side and the outlet side of the expansion valve respectively.

4. A defrosting method applying the air source heat pump system according to any one of claims 1-3, wherein (1) during heating, a condensed refrigerant enters an energy accumulator, and then the refrigerant continuously releases heat to heat a secondary refrigerant in the energy accumulator; (2) the refrigerant passing through the energy accumulator enters an outdoor unit through an expansion valve, and then the refrigerant enters a compressor after being vaporized by absorbing the heat; (3) during defrosting, exhaust of the compressor enters the outdoor unit for defrosting; and (4) the refrigerant condensed by the outdoor unit enters the energy accumulator through the expansion valve, and the refrigerant enters the compressor after being vaporized by absorbing the heat in the energy accumulator.

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