A defrosting system, a refrigeration unit, and a defrosting control method

Abstract

The present invention discloses a defrost system, a refrigeration unit, and a defrost control method. The defrost system includes a compressor, a four-way valve, a first heat exchanger, a throttling element, and a second heat exchanger connected in sequence. The system also includes a heat storage device connected in parallel to a first pipeline, the first pipeline being a connecting pipeline between the four-way valve and the first heat exchanger. The heat storage device is used to store heat during refrigeration and release heat to heat air in an air supply device during defrosting. The air supply device is used to spray hot air toward a preset position of the second heat exchanger during defrosting. The present invention utilizes the heat storage device and the air supply device for hot gas defrosting, and utilizes the four-way valve for reversing to perform thermal fluorine defrosting. Through a defrost mode combining thermal fluorine defrosting and hot gas defrosting, the inside and outside of the second heat exchanger are heated simultaneously, thereby improving defrosting heat transfer efficiency, effectively reducing defrosting time, avoiding large fluctuations in storage temperature caused by defrosting, and preventing frost accumulation at preset positions. The defrosting is more clean and thorough, and the heat storage device recovers condensation heat during refrigeration, saving energy.

Description

Technical Field

[0001] The present invention relates to the field of defrosting technology, and in particular to a defrosting system, a refrigeration unit, and a defrosting control method. Background Art

[0002] When the air cooler used in medium and low temperature cold storage is operating normally, the fins are prone to frost. Frost or ice formation not only reduces the heat exchange area but also reduces the air output, resulting in reduced energy efficiency of the unit and inability to effectively cool.

[0003] The defrosting methods currently used include: hot fluorine defrosting with a four-way reversing valve, hot gas defrosting and electric heating defrosting.

[0004] In practice, a unit operating at a stable speed is prone to developing a thick layer of frost on the lower portion of the air cooler's evaporator. The principle of thermal fluorine defrosting is that after the compressor reverses, the high-temperature fluorine inside the evaporator gradually melts the frost on the outer surface of the copper tube. When defrosting stops and cooling begins, the bottom of the unit is not defrosted cleanly. Long-term operation leads to a buildup of ice at the bottom, which requires shoveling.

[0005] The main heat transfer method of simple hot gas defrosting and electric heating defrosting is single, with high power consumption, low heat transfer, long defrosting time, and large fluctuations in storage temperature during the defrosting process.

[0006] Currently, no effective solution has been proposed to the problems of long defrosting time, large temperature fluctuation and unclean defrosting of refrigeration units in the prior art. Summary of the Invention

[0007] The embodiments of the present invention provide a defrost system, a refrigeration unit, and a defrost control method, so as to at least solve the problems in the prior art of long defrosting time, large temperature fluctuations, and unclean defrosting of refrigeration units.

[0008] To solve the above technical problems, an embodiment of the present invention provides a defrost system, comprising a compressor, a four-way valve, a first heat exchanger, a throttling element, and a second heat exchanger connected in sequence, the defrost system further comprising:

[0009] a heat storage device connected in parallel to the first pipeline, the first pipeline being a connecting pipeline between the four-way valve and the first heat exchanger, the heat storage device being used to store heat during cooling and release heat during defrosting to heat the air in the air supply device;

[0010] The air supply device is used to spray hot air toward a preset position of the second heat exchanger during defrosting.

[0011] Optionally, the air supply device includes:

[0012] an air injection component, located at the second heat exchanger;

[0013] an air duct, wherein a first end of the air duct is used to introduce air, and a second end of the air duct is connected to the air injection component;

[0014] The heat storage device is attached to the outside of the air duct.

[0015] Optionally, a heat pipe is provided at the place where the heat storage device contacts the air duct, the evaporation section of the heat pipe is provided in the heat storage device, the condensation section of the heat pipe is provided in the air duct, and a heat pipe valve is provided between the evaporation section and the condensation section.

[0016] Optionally, the air injection component is located below or to the side of the second heat exchanger.

[0017] Optionally, when the jetting component is located below the second heat exchanger, the jetting component is a groove structure, the groove is used to receive water dripping from the second heat exchanger, and orifice plates are provided on the bosses on both sides of the groove.

[0018] Optionally, the width of the groove is greater than or equal to the width of the fin of the second heat exchanger.

[0019] Optionally, the orifice plate is inclined at a preset angle to the horizontal plane, and the holes on the orifice plate face the second heat exchanger.

[0020] Optionally, the first end of the air duct is arranged at the fan of the first heat exchanger.

[0021] Optionally, a first windshield and a second windshield are provided at the first heat exchanger, and the first windshield and the second windshield are not opened at the same time. When the first windshield is opened, the air driven by the fan flows through the first heat exchanger, and when the second windshield is opened, the air driven by the fan enters the air duct.

[0022] Optionally, a filter is provided at the first end of the air duct.

[0023] Optionally, the first port of the heat storage device is connected to the first port of the first heat exchanger and the first end of the first pipeline through a first valve, and the second port of the heat storage device is connected to the four-way valve and the second end of the first pipeline through a second valve; a first opening adjustment element is provided on the first pipeline.

[0024] Optionally, a third wind shield is provided on the air inlet side of the second heat exchanger, and a fourth wind shield is provided on the air outlet side of the second heat exchanger.

[0025] Optionally, the defrost system also includes: a cold storage device, connected in parallel with the first heat exchanger and in parallel with a second pipeline, the second pipeline is a connecting pipeline between the throttling element and the second heat exchanger, and the cold storage device is used to store cold during defrosting and release cold during refrigeration.

[0026] Optionally, the cold storage device includes:

[0027] a cold storage inlet, connected to the second port of the first heat exchanger via a third valve and a fourth valve in sequence;

[0028] a cold storage outlet, connected to the first port of the first heat exchanger via a fifth valve and a sixth valve in sequence;

[0029] a cooling inlet connected to the first end of the second pipeline through a seventh valve;

[0030] a cooling outlet connected to the second end of the second pipeline through an eighth valve;

[0031] The second pipeline is provided with a second opening adjustment element.

[0032] An embodiment of the present invention further provides a refrigeration unit, comprising: the defrost system described in the embodiment of the present invention.

[0033] The embodiment of the present invention further provides a defrost control method, which is applied to the defrost system described in the embodiment of the present invention. The defrost control method includes:

[0034] It is detected that the defrost entry conditions are met;

[0035] Control the reversing of the four-way valve so that the refrigerant circulation loop runs in the heating direction to perform thermal defrosting; at the same time, open the air supply device, use the heat storage device to release heat to heat the air in the air supply device, and spray hot air to the preset position of the second heat exchanger to perform hot gas defrosting.

[0036] Optionally, open the air supply device, including:

[0037] Close the first damper and open the second damper to allow air driven by the fan at the first heat exchanger to enter the air supply device;

[0038] controlling the first valve and the second valve to remain closed and opening the heat pipe valve so that the heat storage device heats the air in the air supply device;

[0039] The first port of the heat storage device is connected to the first port of the first heat exchanger through the first valve, and the second port of the heat storage device is connected to the four-way valve through the second valve.

[0040] Optionally, after detecting that the defrost entry conditions are met, it also includes: closing the third wind shield and the fourth wind shield, wherein the third wind shield is set on the air inlet side of the second heat exchanger, and the fourth wind shield is set on the air outlet side of the second heat exchanger.

[0041] Optionally, when a cold storage device is provided, after controlling the four-way valve to reverse so that the refrigerant circulation loop operates in a heating direction, the method further includes:

[0042] Control the fourth valve, the sixth valve, the seventh valve and the eighth valve to remain closed;

[0043] Controlling the third valve and the fifth valve to open so that the cold storage device can store cold;

[0044] The cold storage inlet of the cold storage device is connected to the second port of the first heat exchanger through the third valve and the fourth valve in sequence; the cold storage outlet of the cold storage device is connected to the first port of the first heat exchanger through the fifth valve and the sixth valve in sequence; the cold discharge inlet of the cold storage device is connected to the first end of the second pipeline through the seventh valve; and the cold discharge outlet of the cold storage device is connected to the second end of the second pipeline through the eighth valve.

[0045] Optionally, after performing thermal fluorine defrosting and hot gas defrosting, it also includes:

[0046] When the defrost temperature is greater than or equal to the first preset temperature, the compressor is turned off and the four-way valve is controlled to be powered off to exit the thermal fluorine defrosting;

[0047] When the defrost temperature is greater than or equal to a second preset temperature, closing the air supply device to exit hot gas defrosting;

[0048] Wherein, the second preset temperature is greater than the first preset temperature.

[0049] Optionally, after detecting that the defrost entry conditions are met, the method further includes:

[0050] If the four-way valve cannot be switched, the air supply device is opened and only hot gas defrosting is performed;

[0051] If the air supply device fails to work normally, the four-way valve is controlled to reverse so that the refrigerant circulation loop runs in the heating direction and only thermal defrosting is performed.

[0052] Optionally, when only hot gas defrosting is performed, when the defrosting temperature is greater than or equal to a third preset temperature and the defrosting time is greater than or equal to a preset time, hot gas defrosting is exited.

[0053] Optionally, in the case of performing only thermal fluorination defrosting, when the defrosting temperature is greater than or equal to the second preset temperature, the thermal fluorination defrosting is exited.

[0054] An embodiment of the present invention further provides a computer device, comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the method described in the embodiment of the present invention when executing the computer program.

[0055] An embodiment of the present invention further provides a non-volatile computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, the steps of the method described in the embodiment of the present invention are implemented.

[0056] The technical solution of the present invention is applied, and a heat storage device and an air supply device are provided. The heat storage device is connected in parallel to a first pipeline, which is a connecting pipeline between a four-way valve and a first heat exchanger. The heat storage device stores heat during cooling and releases heat to heat the air in the air supply device during defrosting. During defrosting, the air supply device sprays hot air to a preset position of the second heat exchanger to perform hot gas defrosting. The four-way valve can be switched to perform hot fluorine defrosting. In this defrosting mode, the internal high-temperature hot fluorine and the relatively high-temperature hot air outside simultaneously heat the frost layer, and the second heat exchanger is heated both inside and outside. This can improve the defrosting heat transfer efficiency, effectively reduce the defrosting time, avoid large temperature fluctuations caused by defrosting, and prevent frost accumulation at the preset position. The defrosting is more clean and thorough, ensuring uniform defrosting. In addition, the heat storage device recovers condensation heat during cooling and uses it to heat the air in the air supply device during defrosting, thereby saving energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] Figure 1 is a schematic diagram of a defrost system provided in Example 1 of the present invention;

[0058] Figure 2 Schematic diagram of the heat storage device provided in Example 1 of the present invention heating air in the air duct;

[0059] Figure 3 is a schematic diagram of an air injection component provided in Example 1 of the present invention;

[0060] Figure 4 is another schematic diagram of the defrost system provided in Example 1 of the present invention;

[0061] Figure 5 is a flow chart of the defrost control method provided by Example 3 of the present invention;

[0062] Figure 6 This is a defrost control flow chart provided by Example 3 of the present invention;

[0063] Description of reference numerals:

[0064] Compressor 10, four-way valve 20, first heat exchanger 30, throttling element 40, second heat exchanger 50, heat storage device 60, air supply device 70, injection component 71, air duct 72, groove 73, boss 74, injection hole 75, filter 76, heat pipe 80, evaporation section 81, condensation section 82, heat pipe valve 83, cold storage device 90, first windshield 31, second windshield 32, first valve 1, second valve 2, third valve 3, fourth valve 4, fifth valve 5, sixth valve 6, seventh valve 7, eighth valve 8, first opening adjustment element 9, second opening adjustment element 11. DETAILED DESCRIPTION

[0065] To make the objectives, technical solutions, and advantages of the present invention more apparent, the present invention will be further described in detail below with reference to the accompanying drawings. It is apparent that the embodiments described are only some, not all, of the present invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort are intended to fall within the scope of protection of the present invention.

[0066] It should be noted that the terms "first", "second", etc. in the description, claims, and drawings of the present invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way are interchangeable where appropriate so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or that are inherent to these processes, methods, products, or apparatus.

[0067] It should be noted that the steps shown in the flowcharts of the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions, and that, although a logical order is shown in the flowcharts, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0068] The optional embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0069] Example 1

[0070] This embodiment provides a defrost system that can be applied to a refrigeration unit in a cold storage. Figure 1 Schematic diagram of the defrosting system provided in Example 1 of the present invention. Figure 1As shown, the defrost system includes: a compressor 10, a four-way valve 20, a first heat exchanger 30 (i.e., an outdoor heat exchanger), a throttling element 40, and a second heat exchanger 50 (i.e., an indoor heat exchanger), which are connected in sequence to form a refrigerant circulation loop. During cooling, the first heat exchanger 30 acts as a condenser and the second heat exchanger 50 acts as an evaporator. At this time, the fins of the second heat exchanger 50 are prone to frost. By reversing the four-way valve 20, the flow direction of the refrigerant can be changed, and hot fluorine defrosting can be performed. At this time, the second heat exchanger 50 acts as a condenser, and the high-temperature hot fluorine in the second heat exchanger 50 releases heat and liquefies, which can melt the frost layer outside the second heat exchanger 50.

[0071] The defrost system further includes a heat storage device 60 and an air supply device 70 .

[0072] Thermal storage device 60 is connected in parallel to the first pipeline, which connects the four-way valve 20 and the first heat exchanger 30. Thermal storage device 60 is used to store heat during cooling and release heat to heat the air in the air supply device 70 during defrosting. Thermal storage device 60 can be made of phase change material.

[0073] The air supply device 70 is used to spray hot air to a preset position of the second heat exchanger 50 during defrosting to perform hot air defrosting. The preset position refers to a position on the second heat exchanger 50 where frost is thicker, for example, the bottom of the second heat exchanger 50. The air supply device 70 supplies hot air to the second heat exchanger 50. Figure 1 In the figure, “ / / ” indicates the corresponding connected position in the air supply device 70.

[0074] This embodiment includes a heat storage device 60 and an air supply device 70. The heat storage device 60 is connected in parallel to the first pipeline, which is the connecting pipeline between the four-way valve 20 and the first heat exchanger 30. The heat storage device 60 stores heat during cooling and releases heat to heat the air in the air supply device 70 during defrosting. During defrosting, the air supply device 70 sprays hot gas to a preset position of the second heat exchanger 50 to perform hot gas defrosting. Reversing the direction of the four-way valve 20 allows for hot fluorine defrosting. This combined hot fluorine defrosting and hot gas defrosting mode allows the internal high-temperature hot fluorine and the relatively high-temperature hot gas outside to simultaneously heat the frost layer. Heat is applied to the second heat exchanger 50 both internally and externally, improving defrosting heat transfer efficiency, effectively reducing defrosting time, avoiding large temperature fluctuations caused by defrosting, and preventing frost accumulation at preset positions. This ensures clean and thorough defrosting and uniform defrosting. Furthermore, the heat storage device 60 recovers condensation heat during cooling and uses it to heat the air in the air supply device 70 during defrosting, saving energy.

[0075] The air supply device 70 includes an air jet component 71 and an air duct 72. The air jet component 71 is located at the second heat exchanger 50 to spray hot air toward a preset position of the second heat exchanger 50 during defrosting. The first end of the air duct 72 is used to introduce air, and the second end of the air duct 72 is connected to the air jet component 71. The heat storage device 60 is attached to the outside of the air duct 72. Through this arrangement, it is possible to ensure that the heat storage device 60 heats the air inside the air duct 72 and sprays hot air toward the preset position of the second heat exchanger 50. Preferably, the heat storage device 60 is attached to the bottom of the air duct 72.

[0076] The first end of the air supply device 70 is driven by a fan to introduce air. Relying on the driving force, the jet component 71 can spray hot air. Of course, a power component can also be set inside the jet component 71 to provide power for spraying hot air.

[0077] like Figure 2 As shown, a heat pipe 80 is provided where the thermal storage device 60 contacts the air duct 72. An evaporation section 81 of the heat pipe 80 is disposed within the thermal storage device 60, while a condensation section 82 of the heat pipe 80 is disposed within the air duct 72. Specifically, the evaporation section 81 is completely immersed in the phase change material of the thermal storage device 60, while the condensation section 82 can directly exchange heat with the air within the air duct 72. A heat pipe valve 83 is provided between the evaporation section 81 and the condensation section 82. By controlling the opening and closing of the heat pipe valve 83, it is possible to control whether the thermal storage device 60 heats the air within the air duct 72. The heat pipe valve 83 is opened during defrosting and closed during cooling. Figure 2 The arrows in FIG. 7 represent the air flow direction in the air duct 72 .

[0078] The air injection component 71 can be located below or to the side of the second heat exchanger 50, as long as it can inject hot air to a predetermined position on the second heat exchanger 50 for hot gas defrosting. Hot air is injected from the below or side of the second heat exchanger 50 to the predetermined position (the bottom or lower portion), preferentially melting the frost layer at the bottom and lower portions of the second heat exchanger 50. As the hot air rises, it exchanges heat with the middle and upper layers of frost, improving defrosting heat transfer efficiency, shortening defrost time, and preventing frost accumulation on the bottom of the fins.

[0079] In the case where the air injection component 71 is located below the second heat exchanger 50, the air injection component 71 may be a groove structure, such as Figure 3 As shown, the groove 73 is used to receive the defrost water dripping from the second heat exchanger 50 and serves as a water receiving tray. Orifice plates are provided on the bosses 74 on both sides of the groove, and the orifice plates include at least one air jet hole 75, which can be evenly arranged. Figure 3 The solid arrows in the figure represent the flow direction of the defrost water, and the dotted arrows represent the flow of hot air from the air duct 72 to the jet component 71.

[0080] The width of the groove 73 is greater than or equal to the width of the fin of the second heat exchanger 50 to prevent defrost water from falling into the air jet hole. The water receiving surface of the groove 73 can be flat or non-flat, for example, the middle is higher than the surrounding area to facilitate drainage.

[0081] The orifice plate is tilted at a preset angle relative to the horizontal plane, with the holes on the orifice plate facing the preset position of the second heat exchanger 50. The preset tilt angle ranges from 0 to 90°. The optimal tilt angle can be determined based on the actual distance between the fins of the second heat exchanger 50 and the air injection component 71 to ensure that the hot gas is smoothly injected into the preset position.

[0082] The first end of the air duct 72 may be disposed at the fan (which may be referred to as a condensing fan) of the first heat exchanger 30 , that is, the condensing fan is used to provide power to introduce air into the air duct 72 , thereby avoiding the increase in cost caused by adding an additional fan.

[0083] Furthermore, a first damper 31 and a second damper 32 are provided at the first heat exchanger 30. The first damper 31 and the second damper 32 are not opened at the same time. When the first damper 31 is opened, air driven by the fan flows through the first heat exchanger 30. When the second damper 32 is opened, air driven by the fan enters the air duct 72. During defrosting, the first damper 31 is closed and the second damper 32 is opened. During cooling, the first damper 31 is opened and the second damper 32 is closed.

[0084] A filter 76 is provided at the first end of the air duct 72 for filtering the air introduced into the air duct 72 .

[0085] The first port of the thermal storage device 60 is connected to the first port of the first heat exchanger 30 and the first end of the first pipeline via a first valve 1. The second port of the thermal storage device 60 is connected to the four-way valve 20 and the second end of the first pipeline via a second valve 2. The first and second valves 1 and 2 control whether the refrigerant flows through the thermal storage device 60 for heat storage. During cooling, the first and second valves 1 and 2 are opened to allow the thermal storage device 60 to recover exhaust heat from the compressor. When heat storage is complete, the first and second valves 1 and 2 are closed; during defrosting, the first and second valves 1 and 2 are closed. Specifically, the inlet and outlet temperature difference of the thermal storage device 60 can be detected. When this temperature difference approaches 0°C, heat storage is complete.

[0086] A first opening adjustment element 9 is provided on the first pipeline to balance the resistance of the parallel branch. This prevents the first pipeline's resistance from being too low, causing the refrigerant to flow entirely through the first pipeline and not into the branch containing the thermal storage device 60. During both cooling and defrosting operations, the first opening adjustment element 9 is open. The specific opening degree of the first opening adjustment element 9 can be adjusted based on the actual refrigerant demand.

[0087] In one embodiment, a third damper is provided on the air inlet side of the second heat exchanger 50, and a fourth damper is provided on the air outlet side of the second heat exchanger 50. Both the third damper and the fourth damper are adjustable. During defrosting, the third and fourth dampers are closed to seal the second heat exchanger 50 and prevent hot air from being ejected into the room and causing temperature fluctuations in the storage room. During cooling, the third and fourth dampers are opened.

[0088] In one embodiment, Figure 4 As shown, the defrost system may further include a cold storage device 90 connected in parallel with the first heat exchanger 30 and the second pipeline, which is a connecting pipeline between the throttling element 40 and the second heat exchanger 50. The cold storage device 90 is used to store cold during defrosting and release cold energy during cooling. The cold storage device 90 may be made of phase change material. In this embodiment, the cold storage device 90 recovers cold energy during the defrosting process and releases cold energy during cooling, thereby saving energy.

[0089] The cold storage device 90 includes:

[0090] The cold storage inlet is connected to the second port of the first heat exchanger 30 through the third valve 3 and the fourth valve 4 in sequence;

[0091] The cold storage outlet is connected to the first port of the first heat exchanger 30 through the fifth valve 5 and the sixth valve 6 in sequence;

[0092] The cooling inlet is connected to the first end of the second pipeline through the seventh valve 7;

[0093] The cooling outlet is connected to the second end of the second pipeline through the eighth valve 8.

[0094] The fourth valve 4 and the sixth valve 6 can control whether the first heat exchanger 30 participates in the refrigerant circulation, and the third valve 3 , the fifth valve 5 , the seventh valve 7 and the eighth valve 8 can control the cold storage device 90 to store or release cold.

[0095] Specifically, during reverse thermal defrosting, the third valve 3 and the fifth valve 5 are opened, and the fourth valve 4, the sixth valve 6, the seventh valve 7, and the eighth valve 8 are closed, so that the cold storage device 90 acts as an evaporator to store the cold energy of the low-temperature refrigerant. During cooling, the third valve 3 and the fifth valve 5 are closed, and the fourth valve 4, the sixth valve 6, the seventh valve 7, and the eighth valve 8 are opened. Some of the refrigerant flowing out of the first heat exchanger 30 enters the cold storage device 90, which releases the cold energy. When it is detected that the cold energy of the cold storage device 90 has been fully released, the seventh valve 7 and the eighth valve 8 can be closed. Specifically, the inlet and outlet temperature difference of the cold storage device 90 can be detected. When this temperature difference is close to 0°C, it indicates that the cold energy has been fully released.

[0096] The connection point between the first valve 1 and the first end of the first pipeline is located between the first valve 1 and the sixth valve 6 .

[0097] A second opening adjustment element 11 is provided on the second pipeline to balance the resistance of the parallel branch. This prevents the second pipeline's resistance from being too low, causing the refrigerant to flow entirely through the second pipeline and not into the branch containing the cold storage device 90. During both cooling and defrosting operations, the second opening adjustment element 11 is open. The specific opening of the second opening adjustment element 11 can be adjusted based on the actual refrigerant demand.

[0098] The first valve 1, second valve 2, third valve 3, fourth valve 4, fifth valve 5, sixth valve 6, seventh valve 7, and eighth valve 8 are all valves capable of automatically controlling on and off. The first opening adjustment element 9 and the second opening adjustment element 11 can be devices with adjustable opening, such as electronic expansion valves.

[0099] This embodiment provides a defrost system combining reverse hot fluorine and hot air. During the operation of the unit, whether it is cooling or defrosting, the throttling element 40, the first opening adjustment element 9 and the second opening adjustment element 11 are all opened.

[0100] by Figure 4 For example, the working process of the hot fluorine system is as follows:

[0101] During cooling operation, only the third and fifth valves 3 and 5 are closed; the remaining valves are open. The high-temperature gas discharged from compressor 10 is split into two paths: one path passes directly through first opening adjustment element 9 and enters first heat exchanger 30; the other path flows through heat storage device 60. Heat storage device 60 collects heat from compressor 10's exhaust. When heat storage device 60 detects that heat storage is complete, first valve 1 and second valve 2 close. The low-temperature, low-pressure liquid, throttled and reduced in pressure by throttling element 40, is split into two paths: one path returns to second heat exchanger 50 through second opening adjustment element 11, and the other path returns to second heat exchanger 50 through cold storage device 90. When cold storage device 90 detects that the cold capacity has been fully released, seventh valve 7 and eighth valve 8 close. The opening of throttling element 40 is automatically adjusted based on the temperature of the liquid supply main before entering second heat exchanger 50.

[0102] When entering defrost mode, only the third and fifth valves 3 and 5 are opened; all other valves are closed. The four-way valve 20 is reversed, and the refrigerant circulation loop operates in the heating direction. The high-temperature gas discharged from the compressor 10 enters the second heat exchanger 50, where the high-temperature hot fluorine in the second heat exchanger 50 releases heat and liquefies. The cold storage device 90 replaces the original first heat exchanger 30 as the evaporator to store the cold energy of the low-temperature refrigerant. The refrigerant flow direction for hot fluorine defrosting is: compressor 10 → four-way valve 20 → second heat exchanger 50 → second opening adjustment element 11 → throttling element 40 → third valve 3 → cold storage device 90 → fifth valve 5 → first opening adjustment element 9 → four-way valve 20 → compressor 10. After defrosting is completed, cooling operation is resumed, and the corresponding valves are opened or closed to enter the next cycle.

[0103] The working process of the hot gas system is as follows:

[0104] During cooling operation, the first damper 31 is opened, the second damper 32 is closed, the heat storage device 60 absorbs the exhaust heat of the compressor 10, and the heat pipe valve 83 is closed.

[0105] When entering defrost mode, the first damper 31 is closed, the second damper 32 is opened, the heat pipe valve 83 is open, and the condensing fan continues to rotate. Within the air duct 72, the filtered condensing hot air exchanges heat with the condensing section 82 of the heat pipe 80. The relatively high-temperature condensing hot gas is sprayed onto the heat exchanger coil through the air injection holes 75 below the second heat exchanger 50, achieving hot gas defrosting. Adjustable dampers are installed on both the inlet and outlet sides of the second heat exchanger 50. During defrost, these dampers are closed to ensure a tight seal on the second heat exchanger 50.

[0106] The phase change energy storage of the heat storage device 60 can recover the condensation heat during refrigeration and use it to heat the air during defrosting. The phase change energy storage of the cold storage device 90 can recover the cold energy generated during defrosting and use it for refrigeration operation, thereby saving energy consumption and making the entire unit energy-saving.

[0107] This embodiment can simultaneously defrost by combining hot fluorine and hot air. In the case that one defrost method cannot be executed due to a malfunction, defrost can still be successfully completed by using another defrost method. This avoids the problem of poor reliability caused by the inability to defrost when the main components of the system malfunction when the unit adopts a single defrost system, thereby effectively improving the reliability of the unit's defrost.

[0108] For example, if the four-way valve 20 fails to switch after defrost entry conditions are detected, hot gas defrost is performed solely through the air supply device 70. If the air supply device 70 fails to function properly, thermal defrost is performed solely by controlling the four-way valve 20. Specifically, a temperature sensor and an air volume detection device can be installed in the air duct 72 near the air injection component 71. If the temperature sensor temperature T' ≥ T0' and the air volume Q ≥ Q0 are detected after defrost entry conditions are met, the hot gas system transition is determined to be normal and the air supply device 70 is functioning properly. T0' represents a preset reference temperature, and Q0 represents a preset air volume.

[0109] Example 2

[0110] This embodiment provides a refrigeration unit, including: the defrost system described in the above embodiment.

[0111] Example 3

[0112] This embodiment provides a defrost control method, which is applied to the defrost system described in the above embodiment. The explanations of the same or corresponding terms as in the above embodiment will not be repeated in this embodiment. Figure 5 This is a flow chart of the defrost control method provided by Example 3 of the present invention. Figure 5 As shown, the method includes the following steps:

[0113] S501: Detecting that the defrost entry conditions are met.

[0114] S502, control the reversing direction of the four-way valve so that the refrigerant circulation loop runs in the heating direction to perform hot fluorination defrosting; at the same time, open the air supply device, use the heat storage device to release heat to heat the air in the air supply device, and spray hot air to the preset position of the second heat exchanger to perform hot gas defrosting.

[0115] This embodiment does not limit the defrost entry conditions, and existing defrost entry conditions can be used. For example, when the unit is in refrigeration operation, the defrost temperature T (i.e., the surface temperature of the second heat exchanger 50) and the defrost interval Δt (i.e., the refrigeration time after the last defrost) are continuously monitored. When T ≤ T0 and Δt ≥ Δt0, the defrost entry conditions are considered to be met and defrosting is required. T0 represents the preset defrost entry temperature, and Δt0 represents the preset time interval.

[0116] Specifically, the four-way valve is controlled to be reversed so that the exhaust port of the compressor is connected to the second heat exchanger, and the intake port of the compressor is connected to the first heat exchanger, so that the refrigerant circulation loop operates in the heating direction.

[0117] In this embodiment, when the defrost entry conditions are met, reverse hot fluorine defrosting is performed by reversing the four-way valve, and hot gas defrosting is sprayed to the preset position of the second heat exchanger by using the heat storage device and the air supply device. Through the defrost mode that combines hot fluorine defrosting with hot gas defrosting, the internal high-temperature hot fluorine and the external relatively high-temperature hot gas heat the frost layer at the same time, and the second heat exchanger is heated inside and outside at the same time, which can improve the defrost heat transfer efficiency, effectively reduce the defrost time, avoid large fluctuations in storage temperature caused by defrosting, and prevent frost accumulation at the preset position. The defrost is cleaner and more thorough, ensuring the uniformity of defrosting.

[0118] In one embodiment, opening the air supply device includes: closing a first damper and opening a second damper to prevent air driven by the fan at the first heat exchanger from flowing through the first heat exchanger and entering the air supply device; controlling the first valve and the second valve to remain closed, and opening the heat pipe valve to allow the heat storage device to heat the air in the air supply device. The first port of the heat storage device is connected to the first port of the first heat exchanger via a first valve, and the second port of the heat storage device is connected to the four-way valve via a second valve. Through these control steps, the heat storage device and the air supply device can be used to spray hot air at a predetermined position on the second heat exchanger to perform hot gas defrosting.

[0119] In one embodiment, after detecting that defrost entry conditions are met, the method further includes closing a third damper and a fourth damper, wherein the third damper is provided on the air inlet side of the second heat exchanger, and the fourth damper is provided on the air outlet side of the second heat exchanger. Closing the third damper and the fourth damper during defrosting seals the second heat exchanger and prevents hot air from being ejected into the room and causing temperature fluctuations in the storage room.

[0120] In one embodiment, when a cold storage device is provided, after controlling the reversal of the four-way valve so that the refrigerant circulation loop operates in the heating direction, it also includes: controlling the fourth valve, the sixth valve, the seventh valve and the eighth valve to remain closed; and controlling the third valve and the fifth valve to open so that the cold storage device can store cold.

[0121] Among them, the cold storage inlet of the cold storage device is connected to the second port of the first heat exchanger through the third valve and the fourth valve in sequence; the cold storage outlet of the cold storage device is connected to the first port of the first heat exchanger through the fifth valve and the sixth valve in sequence; the cold discharge inlet of the cold storage device is connected to the first end of the second pipeline through the seventh valve; and the cold discharge outlet of the cold storage device is connected to the second end of the second pipeline through the eighth valve.

[0122] In this embodiment, when a cold storage device is provided, the cold storage device is used as an evaporator during defrosting through the above control, so that the cold storage device recovers the cold energy during defrosting for subsequent refrigeration, thereby saving energy consumption.

[0123] In one embodiment, after performing both thermal fluorine defrosting and hot gas defrosting, the process further includes: when the defrost temperature is greater than or equal to a first preset temperature, shutting down the compressor and de-energizing the four-way valve to terminate thermal fluorine defrosting; and when the defrost temperature is greater than or equal to a second preset temperature, shutting down the air supply device to terminate hot gas defrosting. The first and second preset temperatures can be set based on actual conditions. The second preset temperature is greater than the first preset temperature. After terminating hot gas defrosting, refrigeration can be restarted.

[0124] In the defrosting mode of combined hot fluorine and hot gas in this embodiment, if the conditions are met, the hot fluorine defrosting is first exited, and the hot gas defrosting continues to focus on the preset position of the second heat exchanger to ensure thorough defrosting and prevent frost accumulation at the preset position of the second heat exchanger.

[0125] In one embodiment, after detecting that the defrost entry conditions are met, it also includes: if the four-way valve cannot be reversed, the air supply device is opened and only hot gas defrosting is performed; if the air supply device cannot work normally, the four-way valve is controlled to reverse so that the refrigerant circulation loop runs in the heating direction and only hot fluorination defrosting is performed.

[0126] In this embodiment, when one defrost method cannot be executed due to a fault, defrost can still be successfully completed by using another defrost method, avoiding the problem of poor reliability caused by failure of defrost when the main components of the system fail when the unit adopts a single defrost system, thereby effectively improving the reliability of the unit's defrost.

[0127] Furthermore, when only hot gas defrosting is being performed, hot gas defrosting is terminated when the defrost temperature is greater than or equal to a third preset temperature and the defrost time is greater than or equal to a preset time. The third preset temperature is greater than the second preset temperature. This embodiment takes into account that the monitored defrost temperature may be too high due to the high temperature of the hot gas. Determining whether to terminate defrost based solely on the defrost temperature may not guarantee complete defrosting. Therefore, a combination of the defrost temperature and the defrost time is used to determine whether to terminate defrost thoroughly.

[0128] Furthermore, in the case of only performing thermal fluorination defrosting, when the defrosting temperature is greater than or equal to the second preset temperature, the thermal fluorination defrosting is terminated, thereby enabling the thermal fluorination defrosting to be terminated in a timely manner.

[0129] like Figure 6 As shown in the figure, the defrosting process includes the following steps:

[0130] S601: When the unit is in refrigeration operation, the defrost temperature and defrost interval time on the second heat exchanger of the cold storage are monitored to determine whether the defrost entry conditions are met.

[0131] S602, determine whether the four-way valve switching is normal, if so, go to S603, if not, go to S605.

[0132] S603, determine whether the hot air system conversion is normal, if so, go to S604, if not, go to S606.

[0133] S604, the unit enters defrost mode 1 (defrosting by combining hot fluorine and hot gas). When the defrost temperature T≥T1 is detected, the hot fluorine solenoid valve is closed (i.e., the four-way valve is powered off) to stop hot fluorine defrosting. When the defrost temperature T≥T2 is detected, the hot gas system is closed and defrosting is exited.

[0134] S605, the unit enters defrost mode 3 (defrosting using hot gas only), and exits defrost when the defrost temperature T≥T3 and the defrost time t≥t0 are detected.

[0135] S606, the unit enters defrost mode 2 (using only hot fluorine defrost), and exits defrost when the defrost temperature T≥T2 is detected.

[0136] T1 represents a first preset temperature, T2 represents a second preset temperature, T3 represents a third preset temperature, and t0 represents a preset time.

[0137] Example 4

[0138] This embodiment provides a computer device, including: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the method described in the above embodiment when executing the computer program.

[0139] Example 5

[0140] This embodiment provides a non-volatile computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, the steps of the method described in the above embodiment are implemented.

[0141] Through the description of the above embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus a necessary general hardware platform, or of course, by hardware. Based on this understanding, the essence of the above technical solution or the part that contributes to the existing technology can be embodied in the form of a software product. The computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a magnetic disk, an optical disk, etc., and includes a number of instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or certain parts of the embodiments.

[0142] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A defrost system comprising a compressor, a four-way valve, a first heat exchanger, a throttling element and a second heat exchanger connected in sequence, characterized in that: The defrost system also includes: a heat storage device connected in parallel to the first pipeline, the first pipeline being a connecting pipeline between the four-way valve and the first heat exchanger, the heat storage device being used to store heat during cooling and release heat during defrosting to heat the air in the air supply device; an air supply device, used for spraying hot air toward a preset position of the second heat exchanger during defrosting; The air supply device comprises: an air injection component, located at the second heat exchanger; an air duct, wherein a first end of the air duct is used to introduce air, and a second end of the air duct is connected to the air injection component; The heat storage device is attached to the outside of the air duct; a heat pipe is provided at the contact point between the heat storage device and the air duct, the evaporation section of the heat pipe is provided in the heat storage device, the condensation section of the heat pipe is provided in the air duct, and a heat pipe valve is provided between the evaporation section and the condensation section; The jet component is located below or to the side of the second heat exchanger; when the jet component is located below the second heat exchanger, the jet component is a groove structure, the groove is used to receive water dripping from the second heat exchanger, and orifice plates are provided on the bosses on both sides of the groove.

2. The defrost system according to claim 1, characterized in that: The width of the groove is greater than or equal to the width of the fin of the second heat exchanger.

3. The defrost system according to claim 1, characterized in that: The orifice plate is inclined at a preset angle to a horizontal plane, and the holes on the orifice plate face the second heat exchanger.

4. The defrost system according to claim 1, characterized in that: The first end of the air duct is arranged at the fan of the first heat exchanger.

5. The defrost system according to claim 4, characterized in that: The first heat exchanger is provided with a first windshield and a second windshield, and the first windshield and the second windshield are not opened at the same time. When the first windshield is opened, the air driven by the fan flows through the first heat exchanger, and when the second windshield is opened, the air driven by the fan enters the air duct.

6. The defrost system according to claim 1, characterized in that: A filter is provided at the first end of the air duct.

7. The defrost system according to claim 1, characterized in that: The first port of the heat storage device is connected to the first port of the first heat exchanger and the first end of the first pipeline through a first valve, and the second port of the heat storage device is connected to the four-way valve and the second end of the first pipeline through a second valve; The first pipeline is provided with a first opening adjustment element.

8. The defrost system according to any one of claims 1 to 7, characterized in that: A third windshield is provided on the air inlet side of the second heat exchanger, and a fourth windshield is provided on the air outlet side of the second heat exchanger.

9. The defrost system according to any one of claims 1 to 7, characterized in that: The defrost system also includes: A cold storage device is connected in parallel with the first heat exchanger and the second pipeline, the second pipeline is a connecting pipeline between the throttling element and the second heat exchanger, and the cold storage device is used to store cold during defrosting and release cold during refrigeration.

10. The defrost system according to claim 9, characterized in that: The cold storage device comprises: a cold storage inlet, connected to the second port of the first heat exchanger via a third valve and a fourth valve in sequence; a cold storage outlet, connected to the first port of the first heat exchanger via a fifth valve and a sixth valve in sequence; a cooling inlet connected to the first end of the second pipeline through a seventh valve; a cooling outlet connected to the second end of the second pipeline through an eighth valve; The second pipeline is provided with a second opening adjustment element.

11. A refrigeration unit, characterized in that: include: The defrost system according to any one of claims 1 to 10.

12. A defrost control method, applied to the defrost system according to any one of claims 1 to 10, characterized in that: The defrost control method comprises: It is detected that the defrost entry conditions are met; Control the reversing of the four-way valve so that the refrigerant circulation loop runs in the heating direction to perform thermal defrosting; at the same time, open the air supply device, use the heat storage device to release heat to heat the air in the air supply device, and spray hot air to the preset position of the second heat exchanger to perform hot gas defrosting.

13. The method according to claim 12, characterized in that Turn on the air supply, including: Close the first damper and open the second damper to allow air driven by the fan at the first heat exchanger to enter the air supply device; controlling the first valve and the second valve to remain closed and opening the heat pipe valve so that the heat storage device heats the air in the air supply device; The first port of the heat storage device is connected to the first port of the first heat exchanger through the first valve, and the second port of the heat storage device is connected to the four-way valve through the second valve.

14. The method according to claim 12, characterized in that After it is detected that the defrost entry conditions are met, the following also applies: Close the third windshield and the fourth windshield, wherein the third windshield is arranged on the air inlet side of the second heat exchanger, and the fourth windshield is arranged on the air outlet side of the second heat exchanger.

15. The method according to claim 12, characterized in that In the case of a cold storage device, after controlling the four-way valve to reverse and make the refrigerant circulation loop run in the heating direction, the following steps are also included: Control the fourth valve, the sixth valve, the seventh valve and the eighth valve to remain closed; Controlling the third valve and the fifth valve to open so that the cold storage device can store cold; The cold storage inlet of the cold storage device is connected to the second port of the first heat exchanger through the third valve and the fourth valve in sequence; the cold storage outlet of the cold storage device is connected to the first port of the first heat exchanger through the fifth valve and the sixth valve in sequence; the cold discharge inlet of the cold storage device is connected to the first end of the second pipeline through the seventh valve; and the cold discharge outlet of the cold storage device is connected to the second end of the second pipeline through the eighth valve.

16. The method according to claim 12, characterized in that After hot fluorine defrosting and hot gas defrosting, it also includes: When the defrost temperature is greater than or equal to the first preset temperature, the compressor is turned off and the four-way valve is controlled to be powered off to exit the thermal fluorine defrosting; When the defrost temperature is greater than or equal to a second preset temperature, closing the air supply device to exit hot gas defrosting; Wherein, the second preset temperature is greater than the first preset temperature.

17. The method according to any one of claims 12 to 16, characterized in that After it is detected that the defrost entry conditions are met, the following also applies: If the four-way valve cannot be switched, the air supply device is opened and only hot gas defrosting is performed; If the air supply device fails to work normally, the four-way valve is controlled to reverse so that the refrigerant circulation loop runs in the heating direction and only thermal defrosting is performed.

18. The method according to claim 17, characterized in that In the case of performing hot gas defrosting only, when the defrosting temperature is greater than or equal to the third preset temperature and the defrosting time is greater than or equal to the preset time, the hot gas defrosting is exited.

19. The method according to claim 17, wherein In the case of performing only thermal fluorination defrosting, when the defrosting temperature is greater than or equal to the second preset temperature, the thermal fluorination defrosting is exited.

20. A computer device comprising: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the method according to any one of claims 12 to 19 when executing the computer program.

21. A non-volatile computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 12 to 19 are implemented.

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