Quick defrosting device of air source heat pump

Abstract

The utility model discloses an air source heat pump quick defrosting device which comprises an evaporator, a four-way reversing valve, a condenser and a compressor, a first outlet of the evaporator is connected to a first connector of the four-way reversing valve, and a second connector of the four-way reversing valve is connected to a first inlet of the condenser. A first outlet of the condenser is connected to a first inlet of the four-way reversing valve, a second outlet of the condenser is connected to a second inlet of the evaporator through the thermostatic expansion valve, the compressor is connected to a third connector of the four-way reversing valve, and when the surface temperature of the evaporator is lower than the set temperature, high-temperature exhaust gas generated by the compressor can enter the evaporator through the third connector and the first connector in sequence. A special defrosting flow path is adopted, and efficient defrosting can be achieved.

Description

Technical Field

[0001] The utility model relates to a defrosting device, in particular to an air source heat pump rapid defrosting device. Background Art

[0002] The air temperature T and relative air humidity ψ of the air source heat pump hot water unit are in the following ranges: -12.8℃≤T≤5.8℃, ψ≥67% will cause frost, -5.0℃≤T≤5.0℃, ψ≥67% will cause severe frost. If frost forms on the surface of the air-side heat exchanger, the heating capacity of the unit will decrease, and defrosting must be performed so that the unit can work normally. The present application aims to provide an air source heat pump fast defrosting device that can achieve a defrosting effect in a short time and ensure the normal operation and heating of the unit. Utility Model Content

[0003] The utility model aims to overcome the shortcomings of the prior art and provide an air source heat pump fast defrosting device.

[0004] The purpose of the utility model is achieved through the following technical scheme: an air source heat pump fast defrosting device, comprising an evaporator, a four-way reversing valve, a condenser and a compressor, wherein the first outlet of the evaporator 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 first inlet of the condenser, the second outlet of the condenser is connected to the second inlet of the evaporator via a thermal expansion valve, and the compressor is connected to the third interface of the four-way reversing valve, wherein when the surface temperature of the evaporator is lower than the set temperature, the high-temperature exhaust gas generated by the compressor can enter the evaporator via the third interface and the first interface in sequence.

[0005] Preferably, the evaporator is provided with a temperature sensing package for detecting the surface temperature thereof.

[0006] Preferably, the fourth interface of the four-way reversing valve is connected to the compressor via a gas-liquid separator.

[0007] Preferably, the thermal expansion valve is connected to the connecting pipeline between the fourth interface and the gas-liquid separator via a balance pipe.

[0008] Preferably, the thermal expansion valve is connected to the temperature sensing bag, and the temperature sensing bag is arranged on the connecting pipe.

[0009] Preferably, the evaporator is equipped with a fan, and the evaporator is equipped with a plurality of liquid separation capillaries, wherein the circuit with a higher surface wind speed is equipped with a shorter liquid separation capillary.

[0010] Preferably, the evaporator is a fin-tube heat exchanger, comprising a plurality of hydrophilic-coated corrugated fins, with a fin spacing of 2.2 mm to 2.5 mm.

[0011] The utility model has the following advantages:

[0012] (1) This application adopts a special defrosting flow path for efficient defrosting. The unit's own electronic control has an automatic defrosting function and adopts the most mature and reliable four-way reversing valve reversing defrosting method, that is, when the unit enters the defrosting state, the four-way reversing valve is reversed, and the high-temperature and high-pressure refrigerant gas discharged from the compressor passes through the frosted fin heat exchanger, which can quickly melt the frost on the heat exchanger. Compared with other defrosting methods, it has the characteristics of fast defrosting speed and clean defrosting.

[0013] (2) Conventional liquid separation technology uses equal-length liquid separation capillaries, and the refrigerant flow rate of each circuit is basically equal. However, since the wind speed on the surface of each heat exchanger is different, the heat exchange effect of each branch is different. Some circuits do not exchange heat sufficiently and the heat exchange area is insufficient, while some circuits exchange heat excessively and the heat exchange area cannot be fully utilized, which accelerates the formation of frost. Zhongyu heat pump units use unequal-length liquid separation control technology, using shorter liquid separation capillaries for circuits with high surface wind speeds, increasing the refrigerant flow rate of these circuits, fully utilizing the heat exchanger area, and reducing the formation of frost. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of the defrosting working principle of the air source heat pump rapid defrosting device of the utility model;

[0015] In the figure, 1-evaporator, 2-four-way reversing valve, 3-condenser, 4-compressor, 5-thermal expansion valve, 6-temperature sensing package, 7-gas-liquid separator, 8-balance pipe, 9-fan. DETAILED DESCRIPTION

[0016] The utility model is further described below in conjunction with the accompanying drawings, and the protection scope of the utility model is not limited to the following:

[0017] like Figure 1 As shown, the present application provides an air source heat pump fast defrosting device, including an evaporator 1, a four-way reversing valve 2, a condenser 3 and a compressor 4, wherein the first outlet of the evaporator 1 is connected to the first interface of the four-way reversing valve 2, the second interface of the four-way reversing valve 2 is connected to the first inlet of the condenser 3, the second outlet of the condenser 3 is connected to the second inlet of the evaporator 1 via a thermal expansion valve 5, and the compressor 4 is connected to the third interface of the four-way reversing valve 2, wherein when the surface temperature of the evaporator 1 is lower than the set temperature, the high-temperature exhaust gas generated by the compressor 4 can enter the evaporator 1 via the third interface and the first interface in sequence. The evaporator 1 is provided with a temperature sensing package 6 for detecting its surface temperature. The fourth interface of the four-way reversing valve 2 is connected to the compressor 4 via a gas-liquid separator 7. The thermal expansion valve 5 is connected to the connecting pipe between the fourth interface and the gas-liquid separator 7 via a balance pipe 8. The thermal expansion valve 5 is connected to the temperature sensing package 6, and the temperature sensing package 6 is arranged on the connecting pipe.

[0018] Preferably, the evaporator 1 is equipped with a fan 9, and the evaporator 1 is equipped with a plurality of liquid separation capillaries, wherein the circuit with a higher surface wind speed is equipped with a shorter liquid separation capillary. Conventional liquid separation technology uses equal-length liquid separation capillaries, and the refrigerant flow rate of each circuit is basically equal. However, since the surface wind speed of each heat exchanger is different, the heat exchange effect of each branch is different. Some circuits do not exchange heat sufficiently and the heat exchange area is insufficient, while some circuits exchange heat excessively and the heat exchange area cannot be fully utilized, which accelerates the formation of frost. The Zhongyu heat pump unit adopts unequal-length liquid separation control technology, and uses shorter liquid separation capillaries for circuits with high surface wind speeds, increasing the refrigerant flow rate of these circuits, making full use of the heat exchanger area, and reducing the formation of frost.

[0019] Preferably, the evaporator 1 is a fin-tube heat exchanger, comprising a plurality of hydrophilic-coated corrugated fins, with a fin spacing of 2.2 mm to 2.5 mm, so that moisture is not easily retained on the fin surface to form frost.

[0020] The defrosting working principle of the present application is: when the surface temperature of the finned tube heat exchanger (evaporator) drops to the set value t1 and exceeds the set defrosting cycle, the time relay (integrated with the temperature sensing package, the temperature detection result of the temperature sensing package triggers the operation of the time relay) starts timing and enters the defrosting mode at the same time. When entering the defrosting mode, the four-way reversing valve is actuated first, then the outdoor fan stops, and the high-temperature exhaust gas of the compressor enters the finned coil to melt the frost on the surface of the coil. When the surface temperature of the heat exchanger rises to the set value t2 or the defrosting execution time reaches the set maximum defrosting time, the defrosting stops. The unit resumes the heating condition.

[0021] Finally, it should be noted that the above description is only a preferred embodiment of the utility model and is not intended to limit the utility model. Although the utility model is described in detail with reference to the above embodiments, those skilled in the art can still modify the technical solutions recorded in the above embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the utility model shall be included in the protection scope of the utility model.

Claims

1. An air source heat pump rapid defrosting device, characterized in that: The invention comprises an evaporator (1), a four-way reversing valve (2), a condenser (3) and a compressor (4), wherein a first outlet of the evaporator (1) is connected to a first interface of the four-way reversing valve (2), a second interface of the four-way reversing valve (2) is connected to a first inlet of the condenser (3), a second outlet of the condenser (3) is connected to a second inlet of the evaporator (1) via a thermal expansion valve (5), and the compressor (4) is connected to a third interface of the four-way reversing valve (2), wherein when the surface temperature of the evaporator (1) is lower than a set temperature, high-temperature exhaust gas generated by the compressor (4) can enter the evaporator (1) via the third interface and the first interface in sequence.

2. The air source heat pump rapid defrosting device according to claim 1, characterized in that: The evaporator (1) is provided with a temperature sensing package (6) for detecting the surface temperature thereof.

3. The air source heat pump rapid defrosting device according to claim 2, characterized in that: The fourth interface of the four-way reversing valve (2) is connected to the compressor (4) via a gas-liquid separator (7).

4. The air source heat pump rapid defrosting device according to claim 3, characterized in that: The thermal expansion valve (5) is connected to the connecting pipeline between the fourth interface and the gas-liquid separator (7) via a balance pipe (8).

5. The air source heat pump rapid defrosting device according to claim 4, characterized in that: The thermal expansion valve (5) is connected to the temperature sensing package (6), and the temperature sensing package (6) is arranged on the connecting pipe.

6. The air source heat pump rapid defrosting device according to claim 1, characterized in that: The evaporator (1) is equipped with a fan (9), and the evaporator (1) is equipped with a plurality of liquid separation capillaries, wherein the circuit with a higher surface wind speed is equipped with a liquid separation capillary with a shorter length.

7. The air source heat pump rapid defrosting device according to claim 1, characterized in that: The evaporator (1) is a fin-tube heat exchanger, comprising a plurality of hydrophilic-coated corrugated fins, with a fin spacing of 2.2 mm to 2.5 mm.

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