Refrigeration and dehumidification equipment and control method thereof

Abstract

The invention relates to the technical field of refrigeration and dehumidification, and discloses refrigeration and dehumidification equipment and a control method thereof. An exhaust port of the compressor is connected with a refrigerant inlet of the first condenser through a first pipeline, a refrigerant outlet of the first condenser is connected with a refrigerant inlet of the evaporator through a second pipeline, a refrigerant outlet of the evaporator is connected with an air return port of the compressor through an air return pipeline, and the throttling element is arranged on the second pipeline. The controller is connected with the throttling element, and the controller is configured to control the first pipeline and the second pipeline to be communicated in a low-temperature dehumidification mode, so that a refrigerant discharged from an exhaust port of the compressor sequentially flows through the first condenser and the evaporator, and control the opening degree of the throttling element, so that the evaporation temperature of the refrigerant in the evaporator is lower than the dew point temperature; therefore, moisture in the air can be condensed into a frost layer on the surface of the evaporator. The refrigeration and dehumidification equipment can adjust the temperature and the humidity, and refrigeration equipment and a dehumidifier do not need to be independently arranged.

Description

Technical Field

[0001] The present application relates to the technical field of refrigeration and dehumidification, and in particular to a refrigeration and dehumidification device and a control method thereof. Background Art

[0002] At present, germplasm resource banks, drug cold storage and other rooms require that the temperature and humidity in the cold storage or room be controlled within a range. The traditional approach is to configure a set of refrigeration equipment and a dehumidifier, which operate independently according to the temperature and humidity. When the indoor temperature exceeds the upper limit, the refrigeration equipment operates for cooling, and when the indoor temperature drops to the required lower limit, the refrigeration equipment stops. When the indoor humidity exceeds the upper limit, the dehumidifier operates for dehumidification, and when the humidity in the cold storage drops to the lower limit, the dehumidifier stops, so that the indoor temperature and humidity are controlled within the required range.

[0003] The indoor temperature and humidity are controlled by the independent operation of the refrigeration equipment and the dehumidifier. When both the temperature and humidity need to be controlled, the two sets of equipment run at the same time, which has high power and energy consumption. At the same time, the two sets of equipment need to occupy a larger space.

[0004] It should be noted that the information disclosed in the above background technology section is only used to enhance the understanding of the background of the present application, and therefore may include information that does not constitute the prior art known to ordinary technicians in the field. Summary of the invention

[0005] In order to provide a basic understanding of some aspects of the disclosed embodiments, a brief summary is given below. The summary is not an extensive review, nor is it intended to identify key / critical components or delineate the scope of protection of these embodiments, but rather serves as a prelude to the detailed description that follows.

[0006] The embodiments of the present disclosure provide a refrigeration and dehumidification device and a control method thereof to solve the problem in the related art that the temperature and humidity are controlled by the refrigeration device and the dehumidifier independently.

[0007] According to a first aspect of an embodiment of the present invention, a refrigeration and dehumidification device is provided, comprising a controller, an indoor unit, a compressor, and a throttling element; the indoor unit comprises a first condenser and an evaporator, the exhaust port of the compressor is connected to the refrigerant inlet of the first condenser through a first pipeline, the refrigerant outlet of the first condenser is connected to the refrigerant inlet of the evaporator through a second pipeline, the refrigerant outlet of the evaporator is connected to the return air port of the compressor through a return air pipeline, the throttling element is arranged on the second pipeline, the controller is connected to the throttling element, and the controller is configured to: in a low-temperature dehumidification mode, control the first pipeline and the second pipeline to be connected so that the refrigerant discharged from the exhaust port of the compressor flows through the first condenser and the evaporator in sequence, and control the opening of the throttling element so that the evaporation temperature of the refrigerant in the evaporator is lower than the dew point temperature, so that the moisture in the air can condense into a frost layer on the surface of the evaporator.

[0008] Optionally, the refrigeration and dehumidification equipment also includes: a first fan, which is arranged corresponding to the first condenser and the evaporator, and is used to drive air to flow to the first condenser through the evaporator, and the first fan is connected to the controller.

[0009] Optionally, the refrigeration and dehumidification equipment also includes: a water receiving pan, which is arranged corresponding to the evaporator, used to receive the frost layer generated by the evaporator, and the water receiving pan is provided with a drain outlet connected to the outside; a heating element, which is arranged corresponding to the water receiving pan, used to defrost the frost layer in the water receiving pan, and the heating element is connected to the controller.

[0010] Optionally, the exhaust port of the compressor is connected to the refrigerant inlet of the evaporator through a third pipeline.

[0011] According to a second aspect of an embodiment of the present invention, a control method is provided for controlling a refrigeration and dehumidification device as described in any one of the above embodiments, comprising: in a low-temperature dehumidification mode, controlling the first pipeline and the second pipeline to be connected so that the refrigerant discharged from the exhaust port of the compressor flows through the first condenser and the evaporator in sequence, and controlling the opening of the throttling element so that the evaporation temperature of the refrigerant in the evaporator is lower than the dew point temperature, so that the moisture in the air can condense into a frost layer on the surface of the evaporator.

[0012] Optionally, the control method further includes:

[0013] In low temperature dehumidification mode, the first fan is controlled to turn on.

[0014] Optionally, the control method further includes:

[0015] When the first preset condition is met, the defrost mode is executed;

[0016] In the defrost mode, the third pipeline and the return air pipeline are controlled to be connected so that the refrigerant discharged from the exhaust port of the compressor flows into the evaporator through the third pipeline and flows back to the compressor through the return air pipeline.

[0017] Optionally, the control method further includes:

[0018] In the defrost mode, when the second preset condition is met, the heating element is controlled to turn on.

[0019] Optionally, the control method further includes:

[0020] In the defrost mode, the first fan is controlled to be closed and / or the air outlet of the indoor unit is controlled to be closed.

[0021] Optionally, the refrigeration and dehumidification equipment further includes a second condenser, the exhaust port of the compressor is connected to the refrigerant inlet of the second condenser through a fourth pipeline, the refrigerant outlet of the second condenser is connected to the refrigerant inlet of the evaporator through a fifth pipeline, and the fifth pipeline is connected to the second pipeline and the connection point is located upstream of the throttling element; the control method further includes:

[0022] When the indoor temperature is higher than the preset temperature, the cooling mode is executed;

[0023] In the cooling mode, the fourth pipeline, the fifth pipeline and the return air pipeline are controlled to be connected so that the refrigerant discharged from the exhaust port of the compressor flows back to the return air port of the compressor through the fourth pipeline, the second condenser, the fifth pipeline, the evaporator and the return air pipeline;

[0024] Wherein, the opening degree of the throttling element in the low-temperature dehumidification mode is smaller than the opening degree of the throttling element in the cooling mode.

[0025] The refrigeration and dehumidification equipment and control method thereof provided in the embodiments of the present disclosure can achieve the following technical effects:

[0026] The high-temperature and high-pressure refrigerant gas discharged from the exhaust port of the compressor enters the first condenser through the first pipeline, and is cooled into a low-temperature and high-pressure refrigerant liquid after heat exchange with the low-temperature air in the room. That is, the high-temperature and high-pressure refrigerant gas in the first condenser is cooled into a low-temperature and high-pressure refrigerant liquid, and the low-temperature and high-pressure refrigerant liquid enters the evaporator through the second pipeline and the throttling element. The controller controls the opening of the throttling element so that the evaporation temperature of the refrigerant in the evaporator is lower than the dew point temperature. When the evaporation temperature of the evaporator is low enough, when the indoor humid air flows through the evaporator, the water vapor in the humid air will adhere to the surface of the evaporator fins in the form of solid frost, the absolute humidity of the indoor air will drop, and the temperature will also drop below the set temperature, so that the refrigeration and dehumidification equipment can adjust both the temperature and the humidity, and there is no need to set up a refrigeration equipment and a dehumidifier separately.

[0027] The above general description and the following description are exemplary and explanatory only and are not intended to limit the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] One or more embodiments are exemplarily described by corresponding drawings, which do not limit the embodiments. Elements with the same reference numerals in the drawings are shown as similar elements, and the drawings do not constitute a scale limitation, and wherein:

[0029] Figure 1 is a schematic diagram of the structure of a refrigeration and dehumidification device provided by an embodiment of the present disclosure, wherein the refrigeration and dehumidification device is in a low-temperature dehumidification mode, and the direction of the arrow indicates the direction of refrigerant flow;

[0030] Figure 2 is a structural schematic diagram of a refrigeration and dehumidification device provided by an embodiment of the present disclosure, wherein the refrigeration and dehumidification device is in a defrosting mode, and the direction of the arrow indicates the direction of refrigerant flow;

[0031] Figure 3 is a structural schematic diagram of a refrigeration and dehumidification device provided by an embodiment of the present disclosure, wherein the refrigeration and dehumidification device is in a refrigeration mode, and the direction of the arrow indicates the direction of refrigerant flow;

[0032] Figure 4 is a flow chart of a control method provided by an embodiment of the present disclosure;

[0033] Figure 5 is a flow chart of another control method provided by an embodiment of the present disclosure;

[0034] Figure 6 is a flow chart of another control method provided by an embodiment of the present disclosure;

[0035] Figure 7 is a structural schematic diagram of another refrigeration and dehumidification device provided by an embodiment of the present disclosure, wherein the refrigeration and dehumidification device is in a low-temperature dehumidification mode, and the direction of the arrow indicates the flow direction of the refrigerant;

[0036] Figure 8 is a structural schematic diagram of another refrigeration and dehumidification device provided by an embodiment of the present disclosure, wherein the refrigeration and dehumidification device is in a defrosting mode, and the direction of the arrow indicates the flow direction of the refrigerant;

[0037] Fig. 9 It is a structural schematic diagram of another refrigeration and dehumidification device provided in an embodiment of the present disclosure, wherein the refrigeration and dehumidification device is in a refrigeration mode, and the direction of the arrow indicates the direction of refrigerant flow.

[0038] Reference numerals:

[0039] 10. compressor; 101. exhaust port of compressor; 102. return port of compressor; 20. first condenser; 201. refrigerant inlet of first condenser; 202. refrigerant outlet of first condenser; 30. evaporator; 301. refrigerant inlet of evaporator; 302. refrigerant outlet of evaporator; 40. first fan; 50. gas-liquid separator; 60. throttling element; 70. second condenser; 80. second fan; 103. first pipeline; 104. first switch; 1041. dehumidification hot gas solenoid valve; 1042. first stop valve; 105. second pipeline; 106. second switch; 1061. first check valve; 1062. second stop valve; 107. drying filter ; 108, liquid storage tank; 109, third stop valve; 110, fourth stop valve; 111, sight glass; 112, third pipeline; 113, third switch; 114, defrost solenoid valve; 115, fifth stop valve; 116, second one-way valve; 117, fourth pipeline; 118, fourth switch; 119, refrigeration and hot air solenoid valve; 120, sixth stop valve; 121, fifth pipeline; 122, fifth switch; 123, third one-way valve; 124, pressure regulating valve; 125, return air pipeline; 126, heating element; 127, first branch; 128, second branch; 129, first thermal expansion valve; 130, second thermal expansion valve; 131, sixth switch; 132, seventh switch. DETAILED DESCRIPTION

[0040] In order to be able to understand the features and technical contents of the embodiments of the present disclosure in more detail, the implementation of the embodiments of the present disclosure is described in detail below in conjunction with the accompanying drawings. The attached drawings are for reference only and are not used to limit the embodiments of the present disclosure. In the following technical description, for the convenience of explanation, a full understanding of the disclosed embodiments is provided through multiple details. However, one or more embodiments can still be implemented without these details. In other cases, to simplify the drawings, well-known structures and devices can be simplified for display.

[0041] The terms "first", "second", etc. in the specification and claims of the embodiments of the present disclosure and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the terms used in this way can be interchanged where appropriate, so that the embodiments of the embodiments of the present disclosure described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions.

[0042] In the embodiments of the present disclosure, the terms "upper", "lower", "inside", "middle", "outside", "front", "back" and the like indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings. These terms are mainly intended to better describe the embodiments of the present disclosure and their embodiments, and are not intended to limit the indicated devices, elements or components to have a specific direction, or to be constructed and operated in a specific direction. Moreover, in addition to being used to indicate directions or positional relationships, some of the above terms may also be used to indicate other meanings. For example, the term "upper" may also be used to indicate a certain dependency or connection relationship in certain circumstances. For those of ordinary skill in the art, the specific meanings of these terms in the embodiments of the present disclosure can be understood according to specific circumstances.

[0043] In addition, the terms "disposed", "connected", and "fixed" should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral structure; it can be a mechanical connection, or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be an internal connection between two devices, elements, or components. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present disclosure can be understood according to specific circumstances.

[0044] Unless otherwise stated, the term "plurality" means two or more.

[0045] In the embodiment of the present disclosure, the character " / " indicates that the preceding and following objects are in an "or" relationship. For example, A / B indicates: A or B.

[0046] The term "and / or" is a description of the association relationship between objects, indicating that three relationships can exist. For example, A and / or B means: A or B, or, A and B.

[0047] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present disclosure may be combined with each other.

[0048] Combination Figure 1-3 As shown, an embodiment of the present disclosure provides a refrigeration and dehumidification device, including a compressor 10, a first condenser 20, an evaporator 30, a throttling element 60, and a controller, wherein the controller is connected to the throttling element 60.

[0049] Among them, the exhaust port 101 of the compressor is connected to the refrigerant inlet 201 of the first condenser through the first pipeline 103, the refrigerant outlet 202 of the first condenser is connected to the refrigerant inlet 301 of the evaporator through the second pipeline 105, the refrigerant outlet 302 of the evaporator is connected to the return air port 102 of the compressor through the return air pipeline 125, and the throttling element 60 is arranged in the second pipeline 105.

[0050] In the low-temperature dehumidification mode, the first pipeline 103 and the second pipeline 105 are controlled to be connected so that the refrigerant discharged from the exhaust port 101 of the compressor flows through the first condenser 20 and the evaporator 30 in sequence, and the opening of the throttling element 60 is controlled so that the evaporation temperature of the refrigerant in the evaporator 30 is lower than the dew point temperature, so that the moisture in the air can condense into a frost layer on the surface of the evaporator 30.

[0051] The evaporator 30 and the first condenser 20 are installed in a room that needs refrigeration and dehumidification, such as a cold storage. The compressor 10 is installed outdoors.

[0052] In the low-temperature dehumidification mode, the first pipeline 103 and the second pipeline 105 are connected, and the high-temperature and high-pressure refrigerant gas discharged from the exhaust port 101 of the compressor flows into the refrigerant inlet 201 of the first condenser through the first pipeline 103, enters the first condenser 20, condenses and releases heat in the first condenser 20, and after heat exchange with the low-temperature air in the room, the refrigerant in the first condenser 20 becomes a low-temperature and high-pressure refrigerant liquid, and the refrigerant liquid flows out through the refrigerant outlet 202 of the first condenser, enters the second pipeline 105 and the throttling element 60, and then enters the evaporator. The refrigerant inlet 301 enters the evaporator 30, evaporates and absorbs heat in the evaporator 30, and the controller controls the opening of the throttling element 60 so that the evaporation temperature of the refrigerant in the evaporator 30 is low enough, for example, lower than the dew point temperature of the indoor air. When the indoor humid air flows through the evaporator 30, the water vapor in the humid air will adhere to the fin surface of the evaporator 30 in the form of solid frost, and the absolute humidity of the indoor air will drop, and the temperature will also drop below the set temperature, so that the refrigeration and dehumidification equipment can adjust both the temperature and the humidity, and there is no need to set up a separate refrigeration equipment and dehumidifier. The refrigerant then flows out through the refrigerant outlet 302 of the evaporator and flows back to the return air port 102 of the compressor through the return air pipeline 125.

[0053] The throttling element 60 may be an electronic expansion valve, a dual thermal expansion valve, a dual capillary tube, or the like.

[0054] like Figures 7 to 9 As shown, when the throttling element 60 is a double thermal expansion valve or a double capillary tube, the refrigeration and dehumidification equipment also includes a first branch 127 and a second branch 128, the first branch 127 and the second branch 128 are connected in parallel, and the first branch 127 and the second branch 128 are connected between the second pipeline 105 and the refrigerant inlet 301 of the evaporator.

[0055] The dual thermal expansion valve includes a first thermal expansion valve 129 and a second thermal expansion valve 130, wherein the first thermal expansion valve 129 is located at the first branch 127, and the second thermal expansion valve 130 is located at the second branch 128. The refrigeration and dehumidification equipment also includes a sixth switch 131 and a seventh switch 132, wherein the sixth switch 131 and the seventh switch 132 may be solenoid valves, and the sixth switch 131 and the seventh switch 132 are both connected to a controller, and the controller controls the start and stop of the sixth switch 131 and the seventh switch 132. The sixth switch 131 is provided at the first branch 127, and is used to control the on and off of the first branch 127; the seventh switch 132 is provided at the second branch 128, and is used to control the on and off of the second branch 128. Under the same conditions, the refrigerant flow rate of the first thermal expansion valve 129 is greater than the refrigerant flow rate of the second thermal expansion valve 130.

[0056] The double capillary tube includes a first capillary tube and a second capillary tube, the first capillary tube is located in the first branch 127, and the second capillary tube is located in the second branch 128. The refrigeration and dehumidification equipment also includes a sixth switch 131 and a seventh switch 132, the sixth switch 131 and the seventh switch 132 can be solenoid valves, the sixth switch 131 and the seventh switch 132 are both connected to the controller, and the controller controls the start and stop of the sixth switch 131 and the seventh switch 132. The sixth switch 131 is arranged in the first branch 127, and is used to control the on and off of the first branch 127; the seventh switch 132 is arranged in the second branch 128, and is used to control the on and off of the second branch 128. Under the same conditions, the refrigerant flow rate of the first capillary tube is greater than the refrigerant flow rate of the second capillary tube.

[0057] like Figure 7 As shown, in the low-temperature dehumidification mode, the seventh switch 132 is turned on to control the second branch 128 to be turned on, and throttling is performed through the second thermal expansion valve 130, and the sixth switch 131 is closed to control the first branch 127 to be disconnected; Figure 8 As shown, in the defrost mode, the sixth switch 131 and the seventh switch 132 are both closed, and the first branch 127 and the second branch 128 are both disconnected; Fig. 9 As shown, in the cooling mode, the sixth switch 131 is turned on to control the first branch 127 to be turned on, and throttling is performed through the first thermal expansion valve 129, and the seventh switch 132 is closed to control the second branch 128 to be disconnected.

[0058] Combination Figure 1-3 As shown, optionally, in the air flow direction, the first condenser 20 is disposed downstream of the evaporator 30 , so that the air flows toward the first condenser 20 through the evaporator 30 .

[0059] The refrigeration and dehumidification device further includes a first fan 40, which is connected to the controller. The first fan 40 is arranged corresponding to the first condenser 20 and the evaporator 30, and is used to drive air to flow to the first condenser 20 through the evaporator 30. The first fan 40 is a suction fan (suction fan), and the first fan 40, the first condenser 20 and the evaporator 30 are arranged in sequence. It can be understood that the first condenser 20, the first fan 40 and the evaporator 30 can also be arranged in sequence, or the first condenser 20, the evaporator 30 and the first fan 40 are arranged in sequence.

[0060] The indoor unit is provided with an air duct, an air inlet and an air outlet. The first condenser 20, the first fan 40 and the evaporator 30 are all arranged in the air duct. The air inlet end of the air duct is connected to the air inlet, and the air outlet end of the air duct is connected to the air outlet. The air inlet and the air outlet are arranged on opposite sides of the indoor unit, for example, the air inlet is arranged on the front wall surface of the indoor unit, and the air outlet is arranged on the rear wall surface of the indoor unit. In this way, in the cooling mode or the low-temperature dehumidification mode, the first fan 40 inhales air from the air inlet on the rear side, enters the air duct, exchanges heat with the first condenser 20 and / or the evaporator 30, and is cooled, and is sent out from the air outlet on the front side. During the sending process, as the gravity and the air supply power weaken, the cold air sinks and is sucked back by the indoor unit. During the sucking back process, the stored items in the room are cooled, and then enter the indoor unit to be cooled again, and this cycle repeats.

[0061] Driven by the first fan 40, the low-temperature air in the room after heat exchange with the evaporator 30 will flow through the first condenser 20 again, and exchange heat with the high-temperature and high-pressure refrigerant gas in the first condenser 20. The temperature of the indoor air rises to the set temperature range, and the relative humidity also drops to the set humidity range.

[0062] Combination Figure 1-3 As shown, optionally, the refrigeration and dehumidification equipment also includes a pressure regulating valve 124 and a gas-liquid separator 50. The pressure regulating valve 124 is arranged on the return air pipeline 125 for regulating the pressure of the refrigerant in the return air pipeline 125. The gas-liquid separator 50 is arranged on the return air pipeline 125 and is located between the pressure regulating valve 124 and the return air port 102 of the compressor.

[0063] After the low-temperature and low-pressure refrigerant gas comes out of the evaporator 30, the pressure is adjusted by the pressure regulating valve 124, and then it returns to the gas-liquid separator 50, and is then sucked into the return air port 102 of the compressor from the gas-liquid separator 50, and is compressed into high-temperature and high-pressure refrigerant gas, completing the circulation flow of the refrigerant.

[0064] Optionally, combined Figure 1-3 As shown, the refrigeration and dehumidification device further includes a first switch 104 , which is disposed in the first pipeline 103 and is used to control the on-off of the first pipeline 103 .

[0065] The first switch 104 includes one or more switch elements. When multiple switch elements are included, the multiple switch elements are connected in series on the first pipeline 103. For example, the first switch 104 includes a dehumidified hot gas solenoid valve 1041 and a first stop valve 1042. Multiple switch elements are provided to improve the reliability of the operation of the first switch 104. When the first switch 104 needs to be turned on, the multiple switch elements are all turned on to conduct the first pipeline 103; when the first switch 104 needs to be turned off, the multiple switch elements are all turned off to disconnect the first pipeline 103.

[0066] The refrigeration and dehumidification device further includes a second switch 106 . The second switch 106 is disposed in the second pipeline 105 , and is used to control the on-off of the second pipeline 105 . The second switch 106 is located upstream of the throttling element 60 .

[0067] The second switch 106 includes one or more switch elements. When multiple switch elements are included, the multiple switch elements are connected in series on the second pipeline 105. For example, the second switch 106 includes a first one-way valve 1061 and a second stop valve 1062. The conduction direction of the first one-way valve 1061 is from the refrigerant outlet 202 of the first condenser to the refrigerant inlet 301 of the evaporator. Multiple switch elements are provided to improve the reliability of the operation of the second switch 106. When the second switch 106 needs to be turned on, the multiple switch elements are all turned on to conduct the second pipeline 105; when the second switch 106 needs to be turned off, the multiple switch elements are all turned off to disconnect the second pipeline 105.

[0068] The first switch 104 and the second switch 106 are provided to control the on-off of the first pipeline 103 and the second pipeline 105 respectively, so as to control the flow direction of the refrigerant.

[0069] Optionally, combined Figure 1-3 As shown, the refrigeration and dehumidification equipment also includes a liquid reservoir 108, a drying filter 107, a sight glass 111, a third stop valve 109 and a fourth stop valve 110. The liquid reservoir 108, the drying filter 107, the sight glass 111, the third stop valve 109 and the fourth stop valve 110 are all arranged in the second pipeline 105 and are all located upstream of the throttling element 60.

[0070] Combination Figure 1-3 As shown, along the flow direction of the refrigerant, the liquid accumulator 108, the third stop valve 109, the drying filter 107, the sight glass 111 and the fourth stop valve 110, and the throttling element 60 are arranged in sequence.

[0071] The drying filter 107 is provided to absorb the moisture in the refrigerant to ensure the normal operation of the throttling element 60. The moisture content in the refrigerant is observed through the sight glass 111 to adjust the moisture content in the refrigerant in time.

[0072] Optionally, the exhaust port 101 of the compressor is connected to the refrigerant inlet 301 of the evaporator through the third pipeline 112. The refrigeration and dehumidification device further includes a third switch 113, which is arranged on the third pipeline 112 and is used to control the on-off of the third pipeline 112.

[0073] When the first preset condition is met, the controller executes the defrost mode. For example, during the low-temperature dehumidification process, when the frost layer of the evaporator 30 reaches a preset thickness, the third switch 113 is controlled to be turned on, the third pipeline 112 is turned on, and the defrost mode is entered. The high-temperature and high-pressure refrigerant gas discharged from the exhaust port 101 of the compressor enters the third pipeline 112 and enters the refrigerant inlet of the evaporator 30. In the evaporator 30, the refrigerant gas exchanges heat with the solid frost on the fins of the evaporator 30 and is cooled into a low-temperature and high-pressure refrigerant gas. At the same time, the solid frost is heated and falls off from the fins of the evaporator 30. The low-temperature and high-pressure refrigerant gas enters the return gas pipeline 125, is adjusted to a low-temperature and low-pressure refrigerant gas through the pressure regulating valve 124, and then enters the gas-liquid separator 50, and is then sucked from the gas-liquid separator 50 into the return gas port 102 of the compressor and compressed into a high-temperature and high-pressure refrigerant gas.

[0074] Optionally, combined Figure 1-3 As shown, a water receiving pan is provided at the bottom of the evaporator 30, a drain outlet connected to the water receiving pan is provided at the bottom of the water receiving pan, a drain pipe connected to the outside is provided at the drain outlet, and a heating element 126 is provided at the water receiving pan, and the heating element 126 is connected to the controller, and the controller controls the opening, closing and heating power of the heating element 126. The heating element 126 (such as a heating wire) is used to heat the water receiving pan. When the frost layer of the evaporator 30 falls off from the evaporator 30 and falls into the water receiving pan, the heating element 126 is turned on, the solid frost is heated into liquid water, and then flows out to the outside through the drain outlet and the drain pipe. As the frost is removed from the room, the working efficiency of the refrigeration and dehumidification equipment returns to normal.

[0075] The third switch 113 includes one or more switch elements. When multiple switch elements are included, the multiple switch elements are connected in series on the third pipeline 112. For example, the third switch 113 includes a defrost solenoid valve 114, a fifth stop valve 115, and a second one-way valve 116. The conduction direction of the second one-way valve 116 is from the exhaust port 101 of the compressor to the refrigerant inlet 301 of the evaporator. Multiple switch elements are provided to improve the reliability of the operation of the third switch 113. When the third switch 113 needs to be turned on, the multiple switch elements are all turned on to conduct the third pipeline 112; when the third switch 113 needs to be turned off, the multiple switch elements are all turned off to disconnect the third pipeline 112.

[0076] Optionally, combined Figure 1-3As shown, the refrigeration and dehumidification equipment also includes a second condenser 70, the exhaust port 101 of the compressor is connected to the refrigerant inlet of the second condenser 70 through the fourth pipeline 117, the refrigerant outlet of the second condenser 70 is connected to the refrigerant inlet 301 of the evaporator through the fifth pipeline 121, and the fifth pipeline 121 is connected to the second pipeline 105 and the connection point is located upstream of the throttling element 60.

[0077] The second condenser 70 is located outdoors and serves as a condenser in a cooling mode. When cooling is required indoors, the cooling mode is turned on. In the cooling mode, the fourth pipe 117 and the fifth pipe 121 are controlled to be connected. The refrigerant is compressed into a high-temperature and high-pressure refrigerant gas in the compressor 10 and is discharged from the exhaust port 101 of the compressor, enters the fourth pipeline 117, passes through the second condenser 70, and is cooled into a low-temperature and high-pressure refrigerant liquid after heat exchange with the air outside the warehouse or the room. The low-temperature and high-pressure refrigerant liquid passes through the fifth pipeline 121 and the throttling element 60, and is expanded into a low-temperature and low-pressure refrigerant liquid when passing through the throttling element 60, and then enters the evaporator 30 through the refrigerant inlet 301 of the evaporator. After the evaporator 30 absorbs the heat of the indoor air, it evaporates and becomes a low-temperature and low-pressure refrigerant gas. At the same time, the indoor air is cooled and the temperature drops. After the refrigerant comes out of the refrigerant outlet 302 of the evaporator, it passes through the pressure regulating valve 124 and returns to the gas-liquid separator 50, and is then sucked from the gas-liquid separator 50 into the compressor 10 and compressed into a high-temperature and high-pressure refrigerant gas. This cycle repeats until the temperature of the indoor air drops to the set temperature range.

[0078] Optionally, combined Figure 1-3 As shown, the refrigeration and dehumidification device further includes a fourth switch 118 and / or a fifth switch 122 .

[0079] The fourth switch 118 is disposed on the fourth pipeline 117 and is used to control the on and off of the fourth pipeline 117 .

[0080] The fourth switch 118 includes one or more switch elements. When multiple switch elements are included, the multiple switch elements are connected in series on the fourth pipeline 117. For example, the fourth switch 118 includes a cooling and hot gas solenoid valve 119 and a sixth stop valve 120. Multiple switch elements are provided to improve the reliability of the operation of the fourth switch 118. When the fourth switch 118 needs to be turned on, the multiple switch elements are all turned on to connect the fourth pipeline 117; when the fourth switch 118 needs to be turned off, the multiple switch elements are all turned off to disconnect the fourth pipeline 117.

[0081] The fifth switch 122 is disposed on the fifth pipeline 121 and is used to control the on and off of the fifth pipeline 121 .

[0082] The fifth switch 122 includes one or more switch elements. When multiple switch elements are included, the multiple switch elements are connected in series on the fifth pipeline 121. For example, the fifth switch 122 includes a third one-way valve 123, and the conduction direction of the third one-way valve 123 is from the refrigerant outlet of the second condenser 70 to the refrigerant inlet 301 of the evaporator. Multiple switch elements are provided to improve the reliability of the operation of the fifth switch 122. When the fifth switch 122 needs to be turned on, the multiple switch elements are all turned on to conduct the fifth pipeline 121; when the fifth switch 122 needs to be turned off, the multiple switch elements are all turned off to disconnect the fifth pipeline 121.

[0083] Combination Figure 1-3 As shown, the refrigeration and dehumidification equipment also includes a second fan 80 , which is arranged corresponding to the second condenser 70 and is used to drive air to flow to the second condenser 70 so that the air exchanges heat with the second condenser 70 .

[0084] The controller is connected to the first switch 104, the second switch 106, the third switch 113, the fourth switch 118, and the fifth switch 122, and is used to control the switching of the first switch 104, the second switch 106, the third switch 113, the fourth switch 118, and the fifth switch 122, respectively, so as to control the on and off of the pipelines where the first switch 104, the second switch 106, the third switch 113, the fourth switch 118, and the fifth switch 122 are located.

[0085] The controller is connected to the second fan 80 and is used to control the start and stop of the second fan 80 .

[0086] The disclosed embodiment also provides a control method for controlling a refrigeration and dehumidification device as described in any one of the above embodiments.

[0087] like Figure 4 As shown, the control method includes:

[0088] Step S401, in the low-temperature dehumidification mode, the controller controls the first switch 104 to open and the second switch 106 to open, so that the first pipeline 103 and the second pipeline 105 are connected, so that the refrigerant discharged from the exhaust port 101 of the compressor flows through the first condenser 20 and the evaporator 30 in sequence, and controls the opening of the throttling element 60 so that the evaporation temperature of the refrigerant in the evaporator 30 is lower than the dew point temperature, so that the moisture in the air can condense into a frost layer on the surface of the evaporator 30.

[0089] In the low-temperature dehumidification mode, the controller controls the first pipeline 103 and the second pipeline 105 to be connected, and drives the air to flow to the first condenser 20 through the evaporator 30, and the controller controls the third pipeline 112 and the fourth pipeline 117 to be disconnected.

[0090] In the low-temperature dehumidification mode, the high-temperature and high-pressure refrigerant gas discharged from the exhaust port 101 of the compressor enters the first condenser 20 through the first pipeline 103, and is cooled into a low-temperature and high-pressure refrigerant liquid after heat exchange with the low-temperature air in the room. That is, the high-temperature and high-pressure refrigerant gas in the first condenser 20 is cooled into a low-temperature and high-pressure refrigerant liquid, and the low-temperature and high-pressure refrigerant liquid passes through the second pipeline 105 and enters the evaporator 30 through the throttling element 60. The controller controls the opening of the throttling element 60 so that the evaporation temperature of the refrigerant in the evaporator 30 is lower than the dew point temperature. When the evaporation temperature of the evaporator 30 is low enough, when the indoor humid air flows through the evaporator 30, the water vapor in the humid air will adhere to the surface of the fins of the evaporator 30 in the form of solid frost, the absolute humidity of the indoor air decreases, and the temperature also drops below the set temperature, so that the refrigeration and dehumidification equipment can adjust both the temperature and the humidity, and there is no need to set up a refrigeration equipment and a dehumidifier separately.

[0091] Optionally, the control method further includes:

[0092] In the low-temperature dehumidification mode, the controller controls the first fan 40 to turn on.

[0093] In this way, in the low-temperature dehumidification mode, the controller controls the first switch 104 to open and the second switch 106 to open, so that the first pipeline 103 and the second pipeline 105 are connected, so that the refrigerant discharged from the exhaust port 101 of the compressor flows through the first condenser 20 and the evaporator 30 in sequence, and controls the opening of the throttling element 60 so that the evaporation temperature of the refrigerant in the evaporator 30 is lower than the dew point temperature, and controls the first fan 40 to turn on.

[0094] Driven by the first fan 40, the low-temperature air in the room after heat exchange with the evaporator 30 will flow through the first condenser 20 again, and exchange heat with the high-temperature and high-pressure refrigerant gas in the first condenser 20. The temperature of the indoor air rises to the set temperature range, and the relative humidity also drops to the set humidity range.

[0095] In the low-temperature dehumidification mode, the controller controls the first fan 40 to operate at a low speed, which is lower than the operating speed of the first fan 40 in the cooling mode, so that the indoor air passes through the first condenser 20 at a low speed and fully exchanges heat with the first condenser 20.

[0096] like Figure 5 As shown, the control method also includes:

[0097] Step S501, when a first preset condition is met, the controller executes a defrost mode;

[0098] Step S502 , in the defrost mode, the controller controls the third pipeline 112 and the return pipeline 125 to be connected, so that the refrigerant discharged from the exhaust port 101 of the compressor flows into the evaporator 30 through the third pipeline 112 , and flows back to the compressor 10 through the return pipeline 125 .

[0099] The first preset condition may be that the low temperature dehumidification mode is executed once for a second preset time, or that the frost layer on the surface of the evaporator 30 reaches a preset thickness. When the first preset condition is met, the controller controls the refrigeration and dehumidification device to enter the defrosting mode.

[0100] In the defrosting mode, the controller controls the third switch 113 to open, the third pipeline 112 to conduct, and controls the return air pipeline 125 to disconnect, and controls the first pipeline 103 and the fourth pipeline 117 to disconnect. The high-temperature and high-pressure refrigerant gas discharged from the exhaust port 101 of the compressor enters the third pipeline 112 and enters the refrigerant inlet of the evaporator 30. In the evaporator 30, the refrigerant gas exchanges heat with the solid frost on the fins of the evaporator 30, and the solid frost falls off from the fins of the evaporator 30 due to the heat, thereby achieving defrosting.

[0101] The control method also includes:

[0102] In the defrost mode, when the second preset condition is met, the controller controls the heating element 126 to turn on.

[0103] The second preset condition may be that the defrosting mode is run once for a second preset time, or that the frost layer in the water receiving tray reaches a preset mass. When the second preset condition is met, the heating element 126 is controlled to be turned on, and the frost layer is melted by the heating of the heating element 126 and discharged from the drain port to restore the working efficiency of the refrigeration and dehumidification equipment.

[0104] A switch may be provided at the drain outlet to control the opening and closing of the drain outlet, or no switch may be provided, that is, the drain outlet is always in an open state. When a switch is provided at the drain outlet, the switch is turned on during the defrosting process of the heating element, so that the defrosting water can be discharged through the drain outlet.

[0105] The control method also includes:

[0106] In the defrost mode, the first fan 40 is controlled to be closed and / or the air outlet of the indoor unit is controlled to be closed.

[0107] During defrosting, the air exchanges heat with the evaporator 30 to form hot air, and the first fan 40 is controlled to be closed and / or the air outlet of the indoor unit is controlled to be closed to prevent the hot air from overflowing into the room and affecting the indoor temperature.

[0108] Optionally, the air outlet of the first fan 40 is covered with a bag air duct. When the first fan 40 stops running, the bag air duct sags due to gravity and covers the air outlet of the first fan 40 to prevent hot air from escaping.

[0109] In some embodiments, in the defrost mode, the controller controls the third pipeline 112 and the return air pipeline 125 to be connected, so that the refrigerant discharged from the exhaust port 101 of the compressor flows into the evaporator 30 through the third pipeline 112, and flows back to the compressor 10 through the return air pipeline 125, and when the second preset condition is met, the heating element 126 is controlled to be turned on, the drain port is controlled to be opened, the first fan 40 is controlled to be turned off and / or the air outlet of the indoor unit is controlled to be closed.

[0110] like Figure 6 As shown, the control method also includes:

[0111] Step S601, when the indoor temperature is greater than a preset temperature, executing a cooling mode;

[0112] Step S602, in the cooling mode, controlling the fourth pipeline 117, the fifth pipeline 121 and the return pipeline 125 to be connected, so that the refrigerant discharged from the exhaust port 101 of the compressor flows back to the return port 102 of the compressor through the fourth pipeline 117, the second condenser 70, the fifth pipeline 121, the evaporator 30, and the return pipeline 125;

[0113] The opening degree of the throttling element 60 in the low-temperature dehumidification mode is smaller than that in the cooling mode, so that the evaporation temperature of the refrigerant in the evaporator 30 is lower than the dew point temperature in the low-temperature dehumidification mode.

[0114] Taking into account the influence of factors such as the evaporation area of ​​the evaporator 30, the evaporation temperature of the refrigerant in the evaporator 30 needs to be at least 6°C lower than the dew point temperature so that the moisture in the air can condense into a frost layer on the surface of the evaporator 30 in the low-temperature dehumidification mode.

[0115] Furthermore, the rotation speed of the first fan 40 in the low-temperature dehumidification mode is lower than the rotation speed of the first fan 40 in the cooling mode.

[0116] The following takes the indoor target temperature as -18±2°C and the target humidity as 40±2.5% expressed in relative humidity as an example to illustrate the low-temperature dehumidification mode, defrost mode and refrigeration mode of the present application.

[0117] like Figure 1 As shown, low temperature dehumidification mode:

[0118] After the cooling mode, the indoor cold air temperature is in the range of -18±2℃. If the relative humidity is ≥42.5% at this time, dehumidification is required and the low-temperature dehumidification mode must be entered. At this time, the indoor air temperature is -20°C, and the dew point temperature is the lowest when the relative humidity is 42.5%, and the dew point temperature is found to be -28.6°C. By pre-setting the opening degree of the throttling element 60, the opening degree of the throttling element 60 is reduced, reducing the flow rate of the liquid refrigerant, thereby reducing the evaporation temperature of the refrigerant in the evaporator 30 to -35°C. In this way, when the indoor air flows through the evaporator 30, because the evaporation temperature of the refrigerant in the evaporator 30 is lower than the dew point temperature of the indoor air, the water vapor in the indoor air directly condenses into solid frost, the absolute moisture content of the indoor air is reduced, and the temperature also drops below the target temperature. Then, the indoor low-temperature air will continue to flow through the first condenser 20 to exchange heat with the high-temperature and high-pressure refrigerant gas in the first condenser 20. At the same time, the speed of the first fan 40 is reduced, and the time for the indoor low-temperature air to flow through the first condenser 20 becomes longer, and the heat exchange with the first condenser 20 is more sufficient. In this way, the temperature of the indoor air slowly rises to the set temperature range, and the relative humidity drops to the set humidity range.

[0119] When the indoor air needs to be dehumidified, the controller controls the refrigeration and dehumidification equipment to enter the low-temperature dehumidification mode. The dehumidification hot gas solenoid valve 1041 is opened, the refrigeration hot gas solenoid valve 119 and the defrost solenoid valve 114 are closed, and the low-temperature and low-pressure refrigerant gas in the refrigeration pipeline is sucked into the compressor 10, and is compressed into high-temperature and high-pressure refrigerant gas in the compressor 10 and discharged through the exhaust port 101 of the compressor, and then enters the first condenser 20 after passing through the dehumidification hot gas solenoid valve 1041 and the first stop valve 1042, and is cooled into a low-temperature and high-pressure refrigerant liquid after heat exchange with the low-temperature air in the room. The high-temperature and high-pressure refrigerant gas in the first condenser 20 is cooled into a low-temperature and high-pressure refrigerant liquid, and the low-temperature and high-pressure refrigerant liquid passes through the first one-way valve 1061 and the second stop valve 1062 and enters the liquid reservoir 108, and then flows out from the liquid reservoir 108, and passes through the third stop valve 109, the drying filter in turn. The device 107, the sight glass 111, the fourth stop valve 110, and the throttling element 60 enter the evaporator 30. At this time, the opening of the throttling element 60 is reduced, so that the flow rate of the low-humidity and low-pressure refrigerant liquid passing through the evaporator 30 is reduced, and the evaporation temperature of the refrigerant in the evaporator 30 gradually decreases. When the evaporation temperature is lower than the dew point temperature, when the indoor humid air flows through the evaporator 30, the water vapor in the humid air will adhere to the surface of the fins of the evaporator 30 in the form of solid frost, the absolute humidity of the indoor air will decrease, and the temperature will also drop below the set temperature. Then, under the action of the first fan 40, the indoor low-temperature air will flow through the first condenser 20 again, and exchange heat with the high-temperature and high-pressure refrigerant gas in the first condenser 20. The temperature of the indoor air rises to the set temperature range, and the relative humidity will also drop to the set humidity range. After coming out of the evaporator 30, the low-temperature and low-pressure refrigerant gas returns to the gas-liquid separator 50 through the pressure regulating valve 1247, and is then sucked into the compressor 10 from the gas-liquid separator 50 to be compressed into high-temperature and high-pressure refrigerant gas. This cycle repeats itself, the absolute humidity of the indoor air decreases, the relative humidity drops to the set humidity range, and the temperature remains in the set temperature range.

[0120] In this way, after running the low-temperature dehumidification mode, the water vapor in the indoor air condenses into solid frost, the absolute moisture content decreases, the relative humidity drops to the range of 40±2.5%, and the indoor temperature remains in the range of -18±2℃.

[0121] After the air flows to the first condenser 20 through the evaporator 30, the temperature of the air increases. The parameters of the evaporator 30 and the first condenser 20 can be pre-designed so that the temperature of the air reaches the target temperature after passing through the first condenser 20. The refrigerant flowing out of the exhaust port 101 of the compressor can also be divided into two parts, one part enters the fourth pipeline 117 (at this time, the fourth pipeline 117 and the fifth pipeline 121 are connected), and the other part enters the first pipeline 103. Through the distribution of the refrigerant, the temperature of the air reaches the target temperature after passing through the first condenser 20.

[0122] like Figure 2 As shown, defrost mode:

[0123] During the low-temperature dehumidification process, since the evaporation temperature of the refrigerant in the evaporator 30 is about -35°C, the water vapor in the air directly adheres to the fin surface of the evaporator 30 in the form of solid frost when flowing through the evaporator 30. When the frost layer of the evaporator 30 reaches a preset thickness, the defrosting mode is entered. At this time, the defrosting solenoid valve 114 is opened, the cooling hot gas solenoid valve 119, the dehumidification hot gas solenoid valve 1041 and the throttling element 60 are closed, the first fan 40 stops running, and the air outlet of the first fan 40 is closed to prevent hot air from escaping from the indoor unit during hot gas defrosting and causing indoor temperature fluctuations. The low-temperature and low-pressure gas in the refrigeration pipe is sucked into the compressor 10, compressed into high-temperature and high-pressure refrigerant gas in the compressor 10 and discharged, and then enters the evaporator 30 after passing through the defrost solenoid valve 114, the fifth stop valve 115 and the second one-way valve 116, and exchanges heat with the solid frost on the fins of the evaporator 30, and is cooled into a low-temperature and high-pressure refrigerant gas. At the same time, the solid frost falls off the fins due to the heat and falls into the water receiving tray. The heating element 126 is turned on, and the solid frost is heated into liquid water, and then flows out to the outside through the drainage pipe to restore the working efficiency of the refrigeration and dehumidification equipment. The low-temperature and high-pressure gas is regulated into low-temperature and low-pressure refrigerant gas through the pressure regulating valve 124 and then enters the gas-liquid separator 50, and is then sucked into the compressor 10 from the gas-liquid separator 50 to be compressed into high-temperature and high-pressure refrigerant gas. After the defrost mode exit mechanism is triggered, the defrost mode is exited and the low-temperature dehumidification mode, shutdown state or refrigeration mode is entered. This cycle is repeated, the absolute humidity of the indoor air decreases, the relative humidity drops to the set range, the temperature is maintained in the set temperature range, and the refrigeration and dehumidification equipment also maintains normal working efficiency.

[0124] like Figure 3 As shown, cooling mode:

[0125] When the indoor air temperature is greater than -16°C and needs to be cooled, the cooling and hot gas solenoid valve 119 is opened, the dehumidification and hot gas solenoid valve 1041 and the defrost solenoid valve 114 are closed, and the low-temperature and low-pressure refrigerant gas in the refrigeration pipeline is sucked into the compressor 10, and is compressed into high-temperature and high-pressure refrigerant gas in the compressor 10 and discharged, and then enters the second condenser 70 after passing through the cooling and hot gas solenoid valve 119 and the sixth stop valve 120, and is cooled into a low-temperature and high-pressure refrigerant liquid after heat exchange with the outdoor air. The low-temperature and high-pressure refrigerant liquid passes through the third one-way valve 123 and the second stop valve 1062 and enters the liquid storage tank 108. , and then flows out from the liquid storage tank 108, passes through the third stop valve 109, the filter drier 107, the sight glass 111, the fourth stop valve 110, and the throttling element 60 in sequence. The throttling element 60 adjusts the opening degree according to the preset superheat degree, and the low-temperature and high-pressure refrigerant liquid is expanded into a low-temperature and low-pressure refrigerant liquid. The refrigerant then enters the evaporator 30, and after absorbing the heat of the indoor air in the evaporator 30, it evaporates and becomes a low-temperature and low-pressure refrigerant gas. At the same time, the indoor air is cooled and the temperature drops. After the indoor cold air exchanges heat with the stored items, it is re-inhaled into the air inlet by the first fan 40, flows through the evaporator 30 and is cooled again. After coming out of the evaporator 30, it passes through the pressure regulating valve 124 and returns to the gas-liquid separator 50, and then is sucked from the gas-liquid separator 50 into the compressor 10 and compressed into a high-temperature and high-pressure refrigerant gas. This cycle repeats, and the evaporation temperature drops to about -28°C, and the temperature of the air in the cold storage drops to the range of -18±2°C.

[0126] In summary, the present invention has the following advantages: 1. Low initial investment; 2. Low energy consumption, one set of equipment is in operation with low energy consumption; 3. Low maintenance cost, only routine maintenance of refrigeration and dehumidification equipment is required; 4. Wide application range, as long as the refrigeration and dehumidification equipment can be operated, normal refrigeration and dehumidification can be performed; 5. High thermal energy utilization efficiency, dehumidification is accompanied by refrigeration mode, and then when the indoor temperature reaches the preset temperature and the humidity does not meet the standard, the low-temperature dehumidification mode is operated to condense water vapor in the air into frost, and then the liquid water is discharged after the hot air defrosts, the defrosting time is short, the drainage speed is fast, and the room temperature fluctuation is small.

[0127] The above description and the accompanying drawings sufficiently illustrate the embodiments of the present disclosure to enable those skilled in the art to practice them. Other embodiments may include structural and other changes. The embodiments represent only possible variations. Unless explicitly required, individual components and functions are optional, and the order of operations may vary. Portions and features of some embodiments may be included in or replace portions and features of other embodiments. The embodiments of the present disclosure are not limited to the structures described above and shown in the accompanying drawings, and various modifications and changes may be made without departing from the scope thereof. The scope of the present disclosure is limited only by the appended claims.

Claims

1. A refrigeration and dehumidification device, characterized in that: The invention comprises a controller, an indoor unit, a compressor, and a throttling element; the indoor unit comprises a first condenser and an evaporator, the exhaust port of the compressor is connected to the refrigerant inlet of the first condenser through a first pipeline, the refrigerant outlet of the first condenser is connected to the refrigerant inlet of the evaporator through a second pipeline, the refrigerant outlet of the evaporator is connected to the return air port of the compressor through a return air pipeline, the throttling element is arranged on the second pipeline, the controller is connected to the throttling element, and the controller is configured as follows: In the low-temperature dehumidification mode, the first pipeline and the second pipeline are controlled to be connected so that the refrigerant discharged from the exhaust port of the compressor flows through the first condenser and the evaporator in sequence, and the opening of the throttling element is controlled so that the evaporation temperature of the refrigerant in the evaporator is lower than the dew point temperature, so that the moisture in the air can condense into a frost layer on the surface of the evaporator.

2. The refrigeration and dehumidification equipment according to claim 1, characterized in that: Also includes: The first fan is arranged corresponding to the first condenser and the evaporator, and is used for driving air to flow to the first condenser through the evaporator, and the first fan is connected to the controller.

3. The refrigeration and dehumidification equipment according to claim 1 or 2, characterized in that: Also includes: A water receiving tray is provided corresponding to the evaporator, used to receive the frost layer produced by the evaporator and the water receiving tray is provided with a drain port connected to the outside; The heating element is arranged corresponding to the water receiving tray and is used for defrosting the frost layer in the water receiving tray. The heating element is connected to the controller.

4. The refrigeration and dehumidification equipment according to claim 1 or 2, characterized in that: The exhaust port of the compressor is connected to the refrigerant inlet of the evaporator through a third pipeline.

5. A control method for controlling the refrigeration and dehumidification equipment according to any one of claims 1 to 4, characterized in that: include: In the low-temperature dehumidification mode, the first pipeline and the second pipeline are controlled to be connected so that the refrigerant discharged from the exhaust port of the compressor flows through the first condenser and the evaporator in sequence, and the opening of the throttling element is controlled so that the evaporation temperature of the refrigerant in the evaporator is lower than the dew point temperature, so that the moisture in the air can condense into a frost layer on the surface of the evaporator.

6. The control method according to claim 5, characterized in that: Also includes: In low temperature dehumidification mode, the first fan is controlled to turn on.

7. The control method according to claim 5 or 6, characterized in that: Also includes: When the first preset condition is met, the defrost mode is executed; In the defrost mode, the third pipeline and the return air pipeline are controlled to be connected so that the refrigerant discharged from the exhaust port of the compressor flows into the evaporator through the third pipeline and flows back to the compressor through the return air pipeline.

8. The control method according to claim 7, characterized in that: Also includes: In the defrost mode, when the second preset condition is met, the heating element is controlled to turn on.

9. The control method according to claim 7, characterized in that: Also includes: In the defrost mode, the first fan is controlled to be turned off and / or the air outlet of the indoor unit is controlled to be closed.

10. The control method according to claim 5 or 6, characterized in that: The refrigeration and dehumidification equipment also includes a second condenser, the exhaust port of the compressor is connected to the refrigerant inlet of the second condenser through a fourth pipeline, the refrigerant outlet of the second condenser is connected to the refrigerant inlet of the evaporator through a fifth pipeline, and the fifth pipeline is connected to the second pipeline and the connection point is located upstream of the throttling element; the control method also includes: When the indoor temperature is higher than the preset temperature, the cooling mode is executed; In the cooling mode, the fourth pipeline, the fifth pipeline and the return air pipeline are controlled to be connected so that the refrigerant discharged from the exhaust port of the compressor flows back to the return air port of the compressor through the fourth pipeline, the second condenser, the fifth pipeline, the evaporator and the return air pipeline; Wherein, the opening degree of the throttling element in the low-temperature dehumidification mode is smaller than the opening degree of the throttling element in the cooling mode.

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