Defrosting device

Abstract

The utility model relates to a defrosting device which is used for defrosting a return air heat exchanger in a dividing wall type heat extraction heat pump system, the return air heat exchanger is provided with a medium flow path, and the defrosting device is characterized by comprising a defrosting medium loop in which a defrosting medium circulates; the defrosting medium heating equipment is used for heating a defrosting medium to increase the temperature of the defrosting medium, the defrosting medium loop comprises a medium flow path, and when the defrosting medium flows through the medium flow path, the defrosting medium defrosts the return air heat exchanger, so that the temperature of the defrosting medium is reduced; the defrosting medium inlet pipeline connects a medium inlet of the medium flow path with an outlet of defrosting medium heating equipment and is used for enabling the defrosting medium with the temperature increased to flow to the return air heat exchanger; and a defrosting medium outlet pipeline which connects the medium outlet of the medium flow path with the inlet of the defrosting medium heating equipment and is used for enabling the defrosting medium with the reduced temperature to flow to the defrosting medium heating equipment.

Description

Technical Field

[0001] The utility model relates to a defrosting device which is used for a mine return air waste heat utilization system, in particular for defrosting a mine return air heat exchanger of a partition type heat extraction heat pump system. Background Art

[0002] In recent years, with the improvement of environmental awareness and increasingly stringent environmental protection requirements for coal mines, the recycling and utilization of low-temperature waste heat resources in coal mines to achieve clean heating in mining areas has attracted widespread attention from coal companies, especially the utilization of waste heat from mine return air (exhaust air). Since mine return air has a large air volume, stable wind temperature, high relative humidity and high enthalpy value, it contains a large amount of high-quality low-temperature thermal energy and is a waste heat resource with extremely high utilization value.

[0003] The mine return air waste heat utilization technology includes spray return air heat extraction system, direct steam return air heat extraction system, heat pipe air-air direct heat exchange heat extraction system and partition return air heat extraction heat pump system. Among them, the partition heat extraction heat pump system can achieve large temperature difference heat extraction of mine return air, that is, large enthalpy difference heat extraction. Extracting heat from the return air for heating buildings in the mining area, antifreeze of the shaft and bathing can replace the coal-fired boiler heating system, solve the practical problems of coal pollution and high operating costs of the heating system of coal enterprises, have good economic and social benefits, and have been widely used in coal enterprises in recent years.

[0004] Non-patent document 1 records a prior art partition type heat pump system, such as Figure 1 As shown in the figure, it is mainly composed of heat extraction device, heat pump unit, transmission and distribution pipeline and terminal equipment. The mine tunnel fan extracts the return air from the underground to the ground, and a return air heat extraction chamber is set above the mine return air shaft. The heat extraction device is set in the two side walls of the heat extraction chamber, so that the return air is forced to flow through the fin gap in the heat extraction device, and the heat of the return air is transferred to the heat medium in the heat extraction device. After the heat medium absorbs heat and changes phase, the heat energy is transferred to the evaporator end of the heat pump unit through the circulation pump. The compressor in the heat pump unit consumes a certain amount of electric energy to do work, and the low-grade heat energy is upgraded to produce high-temperature hot water for the end user side.

[0005] Prior art literature

[0006] Non-patent literature

[0007] Non-patent document 1: "Application of inter-wall heat extraction heat pump system in the recovery of waste heat from air deficiency in a coal mine", "Shaanxi Coal", 2022 (Volume 41) No. 6, Liu Jialei, Qiang Tianwei, Xu Hongjin, Chen Qianqian. Utility Model Content

[0008] Problems to be solved by the utility model

[0009] The partition-type heat pump system has a partition-type mine return air heat exchanger (hereinafter referred to as "return air heat exchanger"). The return air heat exchanger is a heat exchange device that transfers heat between the mine return air and the heat medium when the mine return air and the heat medium flow through the two sides of the heat exchanger respectively.

[0010] When using the partition heat pump system to heat the waste heat of the mine return air, the mine return air temperature is high and the humidity is high before heat extraction. After heat extraction, the temperature is generally below 0℃. In severe cold and cold areas, it can usually reach -10℃ or even lower, causing frost on the return air heat exchanger. If defrosting is not performed, a thick layer of ice will form on the surface of the return air heat exchanger. As a result, it not only affects the appearance, but also reduces the heat exchange capacity of the return air heat exchanger. At the same time, it will also increase the wind resistance of the mine return air heat exchanger. If it affects the ventilation of the mine, it will affect the safety of the coal mine.

[0011] The utility model is completed in view of the above actual situation, and its main purpose is to provide a defrosting device, which can defrost the return air heat exchanger when the mine return air is heated by the partition-type heat pump system.

[0012] Solutions for solving problems

[0013] A defrost device is used to defrost a return air heat exchanger in a partition-type heat extraction heat pump system, the return air heat exchanger having a medium flow path, and the defrost device is characterized in that it comprises: a defrost medium circuit in which a defrost medium circulates; and a defrost medium heating device for heating the defrost medium to increase the temperature of the defrost medium, wherein the defrost medium circuit comprises: the medium flow path, the defrost medium defrosts the return air heat exchanger when flowing through the medium flow path, thereby reducing the temperature of the defrost medium; a defrost medium inlet pipeline, which connects the medium inlet of the medium flow path with the outlet of the defrost medium heating device, and is used to allow the defrost medium with an increased temperature to flow to the return air heat exchanger; and a defrost medium outlet pipeline, which connects the medium outlet of the medium flow path with the inlet of the defrost medium heating device, and is used to allow the defrost medium with a reduced temperature to flow to the defrost medium heating device.

[0014] The defrost device is characterized in that the partition-type heat-taking heat pump system comprises: a heat medium circuit in which the heat medium circulates; and a heat pump unit having an evaporator, in which the heat medium exchanges heat with the heat pump working fluid, thereby reducing the temperature of the heat medium, wherein the heat medium circuit comprises: the medium flow path, through which the heat medium exchanges heat with the mine return air when flowing through the medium flow path, thereby increasing the temperature of the heat medium; a heat medium inlet pipeline, which connects the inlet of the medium flow path with the outlet of the evaporator, and is used to allow the heat medium with a reduced temperature to flow to the return air heat exchanger; and a heat medium outlet pipeline, which connects the outlet of the medium flow path with the inlet of the evaporator, and is used to allow the heat medium with a raised temperature to flow to the evaporator, the defrost medium inlet pipeline is branched from the middle of the heat medium inlet pipeline, and the defrost medium outlet pipeline is branched from the middle of the heat medium outlet pipeline.

[0015] The defrost device is characterized in that a three-way pipe is provided at each branch position, and control valves are respectively provided at the heat medium inlet pipeline, the defrost medium inlet pipeline, the heat medium outlet pipeline, and the defrost medium outlet pipeline, and each control valve is controlled so that the heat medium flows through the medium flow path in the heat extraction mode and the defrost medium flows through the medium flow path in the defrost mode.

[0016] The defrosting device is characterized in that a three-way valve is respectively provided at each branch position, and each three-way valve is adjusted so that the heat extraction medium flows through the medium flow path in the heat extraction mode and the defrosting medium flows through the medium flow path in the defrosting mode.

[0017] The defrost device is characterized in that, in the heat extraction mode, the heat extraction medium flows through the heat extraction medium circuit and the defrost medium circuit is cut off; and in the defrost mode, the defrost medium flows through the defrost medium circuit and the heat extraction medium circuit is cut off.

[0018] The defrost device is characterized in that the defrost mode and the heat extraction mode can be performed alternately, and the time of the defrost mode does not exceed 20% of the operation cycle.

[0019] Effect of utility model

[0020] According to the defrosting device, the number of pipelines and valves can be reduced, and on-site installation and maintenance are easy, thereby reducing material costs and labor costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram showing the structure of a partition-type heat extraction heat pump system in the prior art.

[0022] Figure 2 1 is a schematic structural diagram showing a defrosting device according to a first embodiment.

[0023] Figure 3 2 is a schematic structural diagram showing a defrosting device according to a second embodiment. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical solutions and advantages of the present invention more clear, the embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0025] It should be clear that the described embodiments are part of the embodiments of the utility model, not all of them. Based on the embodiments in the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the embodiments of the utility model.

[0026] <First Embodiment>

[0027] In this embodiment, the return air heat exchanger 1 of the partition-type heat extraction heat pump system has a medium flow path (not shown), which can be used as a heat extraction medium flow path and a defrosting medium flow path. Figure 2 As shown, a medium outlet 101 and a medium inlet 102 are provided on one side of the return air heat exchanger 1 .

[0028] The medium outlet 101 is connected to the medium inlet of the evaporator in the heat pump unit (not shown) via the heat medium outlet pipeline 11. In the heat medium outlet pipeline 11, a medium outlet stop valve 111, a heat medium outlet control valve 113, and an evaporator medium inlet stop valve 115 are sequentially arranged from the medium outlet 101 side of the return air heat exchanger 1. Between the medium outlet stop valve 111 and the heat medium outlet control valve 113, a defrost medium outlet pipeline 14 is branched from the heat medium outlet pipeline 11. A defrost medium outlet control valve 124 and a heating device inlet stop valve 126 are arranged in the defrost medium outlet pipeline 14. Preferably, a three-way pipe is arranged at the branching position.

[0029] On the other hand, the medium inlet 102 is connected to the medium outlet of the evaporator in the heat pump unit (not shown) via the heat medium inlet pipeline 12. In the heat medium inlet pipeline 12, a medium inlet stop valve 112, a heat medium inlet control valve 114, and an evaporator medium outlet stop valve 116 are sequentially arranged from the medium inlet 102 side of the return air heat exchanger 1. Between the medium inlet stop valve 112 and the heat medium inlet control valve 114, a defrost medium inlet pipeline 13 is branched from the heat medium inlet pipeline 12. A defrost medium inlet control valve 123 and a heating device outlet stop valve 125 are arranged in the defrost medium inlet pipeline 13. Preferably, a three-way pipe is arranged at the branching position.

[0030] In this embodiment, the medium outlet 101 can be used as a defrosting medium outlet and a heat extraction medium outlet, and the medium inlet 102 can be used as a defrosting medium inlet and a heat extraction medium inlet. Specifically, as described below.

[0031] In the heat extraction mode, the medium outlet stop valve 111, the evaporator medium inlet stop valve 115, the medium inlet stop valve 112, and the evaporator medium outlet stop valve 116 are all kept in a flow state, the heat extraction medium outlet control valve 113 and the heat extraction medium inlet control valve 114 control the flow of the heat extraction medium HTM, and the defrost medium inlet control valve 123 and the defrost medium outlet control valve 124 control the flow of the defrost medium DM to 0 (off state). In the heat extraction mode, the heating device outlet stop valve 125 and the heating device inlet stop valve 126 can be in a flow state or in a cut-off state.

[0032] In the heat extraction mode, the heat medium HTM exchanges heat with the mine return air CMA in the return air heat exchanger 1, thereby increasing the temperature of the heat medium HTM. The heat medium HTM with increased temperature flows out from the medium outlet 101 of the return air heat exchanger 1, flows to the evaporator in the heat pump unit through the heat medium outlet pipeline 11, and exchanges heat with the heat pump working fluid in the evaporator, thereby reducing the temperature of the heat medium HTM. The heat medium HTM with reduced temperature flows from the evaporator to the return air heat exchanger 1 through the heat medium inlet pipeline 12, and flows into the return air heat exchanger 1 from the medium inlet 102.

[0033] Thus, the heat medium HTM circulates in the heat medium loop composed of the medium flow path in the return air heat exchanger 1, the heat medium outlet pipeline 11, the evaporator, and the heat medium inlet pipeline 12, so as to extract the waste heat of the mine return air CMS and transfer the heat to the heat pump working fluid in the heat pump unit.

[0034] On the other hand, in the defrost mode, the medium outlet stop valve 111, the heating device inlet stop valve 126, the medium inlet stop valve 112, and the heating device outlet stop valve 125 all maintain a flow state, the defrost medium inlet control valve 123 and the defrost medium outlet control valve 124 control the flow of the defrost medium DM, and the heat medium outlet control valve 113 and the heat medium inlet control valve 114 control the flow of the heat medium HTM to 0 (cut-off state). In the defrost mode, the evaporator medium inlet stop valve 115 and the evaporator medium outlet stop valve 116 can be in a flow state or a cut-off state.

[0035] In the defrost mode, the defrost medium DM defrosts the return air heat exchanger 1, so that the temperature of the defrost medium DM decreases. The defrost medium DM with a decreased temperature flows out from the medium outlet 101 of the return air heat exchanger 1, and flows to the defrost medium heating device via a portion of the heat medium outlet pipe 11 and the defrost medium outlet pipe 14. The defrost medium DM is heated in the defrost medium heating device, so that the temperature increases. The defrost medium DM with a increased temperature flows from the defrost medium heating device via the defrost medium inlet pipe 13 and a portion of the heat medium inlet pipe 12 to the return air heat exchanger 1, and flows into the return air heat exchanger 1 from the medium inlet 102.

[0036] Thus, the defrost medium DM circulates in the defrost medium circuit composed of the medium flow path in the return air heat exchanger 1, a part of the heat medium outlet pipeline 11, the defrost medium outlet pipeline 14, the defrost medium heating equipment, the defrost medium inlet pipeline 13, and a part of the heat medium inlet pipeline 12, thereby achieving defrosting of the return air heat exchanger 1.

[0037] According to such a defrosting device, the structure of the return air heat exchanger 1 can be simplified and easy to manufacture. In addition, the number of pipelines and valves can be reduced, and on-site installation and maintenance can be facilitated, thereby reducing material costs and labor costs.

[0038] <Second Embodiment>

[0039] In this embodiment, the return air heat exchanger 1 of the partition-type heat extraction heat pump system is the same as that of the second embodiment, and has a medium flow path (not shown), which can be used as a heat extraction medium flow path and a defrosting medium flow path. Figure 3As shown, the difference between the structure of the third embodiment and the structure of the second embodiment is that: in the heat medium outlet pipeline 11', a medium outlet stop valve 111', a medium outlet three-way valve 117, and an evaporator medium inlet stop valve 115 are sequentially arranged from the medium outlet 101' side of the return air heat exchanger 1, and a defrost medium outlet pipeline 14' is branched from the heat medium outlet pipeline 11' at the medium outlet three-way valve 117; in the heat medium inlet pipeline 12', a medium inlet stop valve 112', a medium inlet three-way valve 118, and an evaporator medium outlet stop valve 116 are sequentially arranged from the medium inlet 102' side of the return air heat exchanger 1, and a defrost medium inlet pipeline 13' is branched from the heat medium inlet pipeline 12' at the medium inlet three-way valve 118.

[0040] In this embodiment, the medium outlet 101' can be used as a defrosting medium outlet and a heat extraction medium outlet, and the medium inlet 102' can be used as a defrosting medium inlet and a heat extraction medium inlet. Specifically, as described below.

[0041] In the heat extraction mode, the medium outlet stop valve 111', the evaporator medium inlet stop valve 115, the medium inlet stop valve 112', and the evaporator medium outlet stop valve 116 are all kept in a flow state, and the medium outlet three-way valve 117 and the medium inlet three-way valve 118 adjust the flow of the heat extraction medium HTM and the defrosting medium DM. Preferably, the medium outlet three-way valve 117 and the medium inlet three-way valve 118 adjust the flow of the defrosting medium DM to 0 (off state). In the heat extraction mode, the heating device outlet stop valve 125 and the heating device inlet stop valve 126 can be in a flow state or a cut-off state.

[0042] On the other hand, in the defrost mode, the medium outlet stop valve 111', the heating device inlet stop valve 126, the medium inlet stop valve 112', and the heating device outlet stop valve 125 are all kept in a flow state, and the medium outlet three-way valve 117 and the medium inlet three-way valve 118 adjust the flow of the heat medium HTM and the defrost medium DM. Preferably, the medium outlet three-way valve 117 and the medium inlet three-way valve 118 adjust the flow of the heat medium HTM to 0 (off state). In the defrost mode, the evaporator medium inlet stop valve 115 and the evaporator medium outlet stop valve 116 can be in a flow state or a cut-off state.

[0043] According to such a defrosting device, the number of pipelines and valves can be further reduced, and on-site installation and maintenance are easier, thereby further reducing material costs and labor costs.

[0044] The above are only embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the scope of the claims of the present invention.

[0045] In the embodiment, the heat medium HTM and the defrost medium DM are the same medium. Preferably, the medium has large specific heat, low density, good thermal conductivity, high safety and is environmentally friendly. In particular, ethylene glycol solution is preferred. Preferably, the defrost mode is started when the heat extraction temperature is lower than 4°C. Preferably, the defrost mode time does not exceed 20% of the operation cycle, and ensure that the ventilation resistance of the heat exchange device is not higher than 200Pa.

[0046] Each stop valve in the embodiment can be used for on-site installation and equipment maintenance, but can be omitted if installation and maintenance are not considered. Although not shown, other components such as pumps, thermometers, pressure gauges, flow meters, etc. can also be provided in each medium circuit.

Claims

1. A defrosting device for defrosting a return air heat exchanger in a partition-type heat pump system, wherein the return air heat exchanger has a medium flow path, and is characterized in that: have: a defrost medium circuit in which a defrost medium circulates; and a defrost medium heating device, which is used to heat the defrost medium to increase the temperature of the defrost medium, Wherein, the defrost medium circuit comprises: the medium flow path, the defrosting medium defrosts the return air heat exchanger when flowing through the medium flow path, so that the temperature of the defrosting medium is reduced; a defrost medium inlet pipeline, which connects the medium inlet of the medium flow path with the outlet of the defrost medium heating device, and is used to allow the defrost medium with increased temperature to flow to the return air heat exchanger; and A defrost medium outlet pipeline connects the medium outlet of the medium flow path with the inlet of the defrost medium heating device, and is used to allow the defrost medium with a reduced temperature to flow to the defrost medium heating device.

2. The defrosting device according to claim 1, characterized in that: The partition wall heat pump system comprises: a heat extraction medium circuit in which a heat extraction medium circulates; and The heat pump unit has an evaporator, in which the heat medium exchanges heat with the heat pump working medium, so that the temperature of the heat medium decreases. Wherein, the heat medium circuit comprises: The medium flow path, when the heat medium flows through the medium flow path, heat is exchanged with the mine return air, so that the temperature of the heat medium increases; a heat medium inlet pipeline, which connects the inlet of the medium flow path with the outlet of the evaporator, and is used to allow the heat medium with a reduced temperature to flow to the return air heat exchanger; and a heat medium outlet pipeline, which connects the outlet of the medium flow path with the inlet of the evaporator, and is used to allow the heat medium with increased temperature to flow to the evaporator, The defrost medium inlet pipeline is branched from the middle of the heat medium inlet pipeline, and the defrost medium outlet pipeline is branched from the middle of the heat medium outlet pipeline.

3. The defrosting device according to claim 2, characterized in that: A tee pipe is provided at each branch position, and a control valve is provided at the heat medium inlet pipeline, the defrost medium inlet pipeline, the heat medium outlet pipeline, and the defrost medium outlet pipeline, respectively. Each of the control valves performs control so that the heat extraction medium flows through the medium flow path in a heat extraction mode and the defrost medium flows through the medium flow path in a defrost mode.

4. The defrosting device according to claim 2, characterized in that: A three-way valve is provided at each branch. Each of the three-way valves is adjusted so that the heat extraction medium flows through the medium flow path in the heat extraction mode and the defrost medium flows through the medium flow path in the defrost mode.

5. The defrosting device according to claim 3 or 4, characterized in that: In the heat extraction mode, the heat extraction medium flows through the heat extraction medium circuit, and the defrosting medium circuit is cut off. In the defrost mode, the defrost medium flows through the defrost medium circuit, and the heat extraction medium circuit is cut off.

6. The defrosting device according to claim 5, characterized in that: The defrost mode and the heat extraction mode can be performed alternately, and the time of the defrost mode does not exceed 20% of the operation cycle.

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