Structure and method for reducing frosting

Abstract

The invention relates to the technical field of fin type heat exchangers, and discloses a frosting reducing structure which comprises a fin type heat exchanger, a gas collecting pipe and a liquid distributing pipe, the input end of the liquid distributing pipe is connected with the output end of an internal loop of the fin type heat exchanger, and the output end of the gas collecting pipe is connected with the input end of the internal loop of the fin type heat exchanger. The fin type heat exchanger is characterized in that when the fin type heat exchanger is used for heating, heating is carried out in a mode of downstream with a windward side in an internal loop of the middle upper part, and heating is carried out in a reverse flow mode in an internal loop of the lower part. A small part of loops at the bottom of the heat exchanger are designed into refrigeration downstream, most loops at the middle-upper part are still refrigeration countercurrent, the transformation cost is low, the superheat degree can be generated on the windward side during heating, bottom frosting is greatly reduced, defrosting is more thorough, in addition, operation of the refrigeration process is not affected, and the use effect is extremely good.

Description

Technical Field

[0001] The invention relates to the technical field of fin heat exchangers, and in particular to a structure and method for reducing frosting. Background Art

[0002] In conventional design, the outdoor condensing fin heat exchanger of the heat pump unit is usually designed to be countercurrent for cooling and concurrent for heating and evaporation.

[0003] This is because in cooling mode, the heat pump unit dissipates the heat in the refrigerant to the external environment through the outdoor condensing fin heat exchanger. At this time, the refrigerant usually flows in a countercurrent manner. The countercurrent design can improve the heat exchange efficiency, which is specifically manifested in the following aspects: Maximize temperature difference: The counterflow design maximizes the temperature difference between the refrigerant temperature at the condenser inlet and the outside air temperature. This helps to speed up the heat transfer rate, thereby improving condensation efficiency.

[0004] Uniform heat transfer: The counterflow design ensures that the refrigerant is evenly distributed along the entire length of the fin heat exchanger during the condensation process, resulting in a more uniform heat transfer effect.

[0005] In heating mode, the heat pump unit absorbs heat from the external environment through the outdoor condensing fin heat exchanger (which acts as an evaporator). At this time, the refrigerant usually flows in a co-current manner. The advantages of co-current design in heating mode are mainly reflected in the following aspects: Natural flow: Due to the pressure difference inside the evaporator, the refrigerant naturally flows from the low-pressure area to the high-pressure area, forming the basis for downstream flow.

[0006] Improve heat exchange efficiency: As the refrigerant absorbs heat in the evaporator and gradually turns into gas, its volume expands and the internal pressure increases, further promoting the formation of downstream flow. At the same time, the downstream design also helps to improve the heat exchange efficiency, allowing the heat pump unit to absorb heat from the external environment more effectively in heating mode.

[0007] However, in heating operation, the windward side of the evaporator is the strong heat absorption side for evaporation, while the air outlet side is overheated, which makes it easy for the windward side to frost. However, the air outlet side, which is not easy to frost, is inside the evaporator, especially at the bottom of the heat exchanger. The air volume is small, and the defrosting water is not easy to flow away, so it is more likely to freeze. Summary of the invention

[0008] The purpose of the present invention is to solve the problems existing in the prior art and to propose a structure and method for reducing frosting.

[0009] In order to achieve the above object, the present invention adopts the following technical solutions: A structure for reducing frosting includes a fin heat exchanger, an air collecting pipe and a liquid distributing pipe, wherein the input end of the liquid distributing pipe is connected to the output end of an internal circuit of the fin heat exchanger, and the output end of the air collecting pipe is connected to the input end of the internal circuit of the fin heat exchanger. When the fin heat exchanger is heating, the internal circuit in the middle and upper part is heated in a downstream manner with the windward surface, and the internal circuit in the lower part is heated in a countercurrent manner.

[0010] Preferably, the input end of the internal circuit of the upper part of the fin heat sink during heating is arranged on the side of the fin heat exchanger close to the windward surface, and the output end is arranged on the side of the fin heat exchanger away from the windward surface.

[0011] Preferably, the input end of the internal circuit at the lower part of the fin heat sink during heating is arranged on the side of the fin heat exchanger away from the windward surface, and the output end is arranged on the side of the fin heat exchanger close to the windward surface.

[0012] A method for reducing frosting, using a structure for reducing frosting, comprises the following steps: When heating, the medium enters the internal circuit of the fin heat exchanger through the liquid distribution pipe and exits from the gas collecting pipe; Among them, when the medium is in the internal circuit of the upper and middle part, it flows downstream with the windward surface, and when it is in the internal circuit of the lower part, it flows upstream with the windward surface.

[0013] Preferably, during refrigeration, the medium enters the internal circuit of the fin heat exchanger through the gas collecting pipe and exits from the liquid dispensing pipe; Among them, when the medium is in the internal circuit of the upper and middle part, it flows against the windward surface, and when it is in the internal circuit of the lower part, it flows along with the windward surface.

[0014] Compared with the prior art, the present invention has the following beneficial effects: In the present invention, only a small part of the circuit at the bottom of the heat exchanger is designed to be refrigeration downstream, and most of the circuits in the middle and upper parts are still refrigeration countercurrent. The modification cost is low, but the superheat can be generated on the windward side, so that the frost at the bottom is greatly reduced and the defrosting is cleaner. In addition, it does not affect the operation of the refrigeration process, and the use effect is excellent. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 A schematic diagram of a structure for reducing frosting proposed by the present invention; Figure 2 This is an enlarged schematic diagram of the countercurrent portion of the heating process of a structure for reducing frosting proposed by the present invention; Figure 3 A schematic diagram of a heating countercurrent flow process of a structure for reducing frosting proposed by the present invention; Figure 4 A schematic diagram of a heating downstream flow process of a structure for reducing frosting proposed by the present invention.

[0016] In the figure: 1. Fin heat exchanger; 2. Liquid distribution pipe; 3. Gas collecting pipe. DETAILED DESCRIPTION

[0017] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0018] Reference Figure 1 A structure for reducing frosting includes a fin heat exchanger 1, an air collecting pipe 3 and a liquid distributing pipe 2, wherein the input end of the liquid distributing pipe 2 is connected to the output end of the internal circuit of the fin heat exchanger 1, and the output end of the air collecting pipe 3 is connected to the input end of the internal circuit of the fin heat exchanger 1. When the fin heat exchanger 1 is heating, the internal circuit in the middle and upper part is heated in a downstream manner with the windward surface, and the internal circuit in the lower part is heated in a countercurrent manner.

[0019] In this embodiment, when heating, the input end of the internal circuit of the upper middle part of the fin heat sink is arranged on the side of the fin heat exchanger 1 close to the windward surface, and the output end is arranged on the side of the fin heat exchanger 1 away from the windward surface; During heating, the input end of the internal circuit at the lower part of the fin heat sink is arranged on the side of the fin heat exchanger 1 away from the windward surface, and the output end is arranged on the side of the fin heat exchanger 1 close to the windward surface.

[0020] When this structure is in use, compared with the prior art, a small part of the bottom circuit of the heat exchanger is designed to be cooling downstream, and most of the circuits in the middle and upper parts are still cooling countercurrent. The modification cost is low, but the superheat is generated on the windward side when heating, which greatly reduces the frost on the bottom and makes defrosting cleaner. In addition, it does not affect the operation of the refrigeration process, and the use effect is excellent.

[0021] A method for reducing frosting, using a structure for reducing frosting, comprises the following steps: When heating, the medium enters the internal circuit of the fin heat exchanger 1 through the liquid distribution pipe 2 and exits from the gas collecting pipe 3; Among them, when the medium is in the middle and upper internal circuit, it flows downstream with the windward surface, and when it is in the lower internal circuit, it flows upstream with the windward surface; During refrigeration, the medium enters the internal circuit of the fin heat exchanger 1 through the gas collecting pipe 3 and exits from the liquid distribution pipe 2; Among them, when the medium is in the internal circuit of the upper and middle part, it flows against the windward surface, and when it is in the internal circuit of the lower part, it flows along with the windward surface.

[0022] The method proposed in the present invention is aimed at the fact that in conventional designs, the outdoor condensing fin heat exchanger 1 of the heat pump unit is usually designed as counterflow for cooling, and the heating evaporation becomes downstream. In heating operation, the windward side of the evaporator is a strong heat absorption side for evaporation, and the air outlet side generates superheat, which makes it easy for the windward side to frost, while the air outlet side that generates superheat but is not easy to frost is inside the evaporator; especially at the bottom of the heat exchanger, the air volume is small, and the defrosting water is not easy to flow out, which is more prone to ice and frost.

[0023] In order to solve the problem that frost and ice are easy to form at the bottom of the module and it is difficult to defrost completely, the method proposed in the present invention changes the flow of the medium at the bottom of the fin heat exchanger 1 to cooling downstream and heating countercurrent, so that the superheat during heating occurs on the windward side, which greatly reduces frost at the bottom and makes defrosting cleaner.

[0024] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A structure for reducing frosting, comprising a fin heat exchanger, an air collecting pipe and a liquid distributing pipe, wherein the input end of the liquid distributing pipe is connected to the output end of the internal circuit of the fin heat exchanger, and the output end of the air collecting pipe is connected to the input end of the internal circuit of the fin heat exchanger, characterized in that: When the fin heat exchanger is heating, the internal circuit in the middle and upper part is heated in a downstream manner with the windward surface, and the internal circuit in the lower part is heated in a countercurrent manner.

2. A frosting reduction structure according to claim 1, characterized in that: During heating, the input end of the internal circuit of the upper middle part of the fin heat sink is arranged on the side of the fin heat exchanger close to the windward surface, and the output end is arranged on the side of the fin heat exchanger away from the windward surface.

3. A structure for reducing frosting according to claim 1, characterized in that: During heating, the input end of the internal circuit at the lower part of the fin radiator is arranged at the side of the fin heat exchanger away from the windward surface, and the output end is arranged at the side of the fin heat exchanger close to the windward surface.

4. A method for reducing frosting, using a frosting reducing structure according to any one of claims 1 to 3, characterized in that: The following steps are involved: When heating, the medium enters the internal circuit of the fin heat exchanger through the liquid distribution pipe and exits from the gas collecting pipe; Among them, when the medium is in the internal circuit of the upper and middle part, it flows downstream with the windward surface, and when it is in the internal circuit of the lower part, it flows upstream with the windward surface.

5. A method for reducing frosting according to claim 4, characterized in that: During refrigeration, the medium enters the internal circuit of the fin heat exchanger through the gas collecting pipe and exits from the liquid distribution pipe; Among them, when the medium is in the internal circuit of the upper and middle part, it flows against the windward surface, and when it is in the internal circuit of the lower part, it flows along with the windward surface.

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