Constant temperature and humidity air conditioner and control method thereof

Abstract

This invention relates to the field of air conditioning technology, specifically providing a constant temperature and humidity air conditioner and its control method, aiming to solve the problem of high energy consumption in existing constant temperature and humidity air conditioners. To this end, the constant temperature and humidity air conditioner of this invention includes a main unit and an indoor unit. The indoor unit's casing forms a fresh air duct and a return air duct connected by a mixing air valve. A fresh air supply fan is installed in the fresh air duct, and a fresh air supply valve is installed at the air outlet of the fresh air duct. A heat exchange coil is installed in the return air duct, and a return air valve is installed at the return air outlet of the return air duct. This invention controls the operating load of the main unit and the cooling capacity of the heat exchange coil based on the acquired return air temperature and a preset return air temperature to avoid the main unit being constantly at full load. Furthermore, based on the acquired return air humidity and a preset return air humidity, it controls the opening and closing states of the fresh air supply fan, the fresh air supply valve, and the mixing air valve, thereby controlling the indoor temperature and humidity to a constant state by adjusting the ratio of fresh air to recirculated air supplied to the room, effectively reducing energy consumption.

Description

Technical Field

[0001] This invention relates to the field of air conditioning technology, specifically providing a constant temperature and humidity air conditioner and its control method. Background Technology

[0002] Constant temperature and humidity air conditioners are widely used in industry due to their advantage of small temperature and humidity fluctuations. However, existing constant temperature and humidity air conditioners require auxiliary heating devices to maintain constant indoor temperature and humidity, which increases energy consumption. Furthermore, existing constant temperature and humidity air conditioners involve repeated dehumidification, heating, and rehumidification processes. This repeated dehumidification and humidification increases the operating load on the air conditioner unit and consumes a large amount of water, further increasing energy consumption.

[0003] Accordingly, there is a need in the field for a new constant temperature and humidity air conditioner and its control method to solve the above-mentioned technical problems. Summary of the Invention

[0004] The present invention aims to solve the above-mentioned technical problems, namely, to solve the problem of high energy consumption of existing constant temperature and humidity air conditioners.

[0005] In a first aspect, the present invention provides a control method for a constant temperature and humidity air conditioner, the constant temperature and humidity air conditioner comprising a main unit and an indoor unit, wherein a refrigerant circulation loop is provided between the main unit and the indoor unit for heat exchange.

[0006] The indoor unit includes a casing, within which a fresh air duct and a return air duct are formed. A fresh air supply fan is installed in the fresh air duct, and a fresh air damper and a fresh air supply damper are respectively installed at the fresh air inlet and the air outlet of the fresh air duct. A heat exchange coil and a recirculating air supply fan are arranged in the return air duct along the return air flow direction. A portion of the refrigerant circulation loop is located in the heat exchange coil. A return air damper and a recirculating air supply damper are respectively installed at the return air inlet and the air inlet of the return air duct. A mixing air damper is installed between the fresh air duct and the return air duct. The fresh air inlet of the fresh air duct is connected to the outside environment, and the air outlet of the fresh air duct, the return air inlet and the air inlet of the return air duct are connected to the indoor environment. The fresh air duct and the return air duct are connected through the mixing air damper.

[0007] The control method includes:

[0008] Obtain the return air temperature at the return air inlet;

[0009] The operating load of the main unit is controlled based on the return air temperature and the preset return air temperature.

[0010] The cooling capacity of the heat exchange coil is controlled based on the return air temperature and the preset return air temperature.

[0011] Obtain the return air humidity at the return air vent;

[0012] The opening and closing states of the fresh air supply fan, the fresh air supply valve, and the mixing air valve are controlled according to the return air humidity and the preset return air humidity.

[0013] In the preferred embodiment of the above control method, the step of "controlling the operating load of the main unit according to the return air temperature and the preset return air temperature" specifically includes:

[0014] Calculate the difference between the return air temperature and the preset return air temperature, and record it as the return air temperature difference;

[0015] The operating load of the main unit is controlled based on the return air temperature difference.

[0016] In the preferred embodiment of the above control method, the step of "controlling the operating load of the main unit according to the return air temperature difference" includes:

[0017] If the return air temperature difference is greater than the first preset difference, the operating load of the host is controlled to be the product of the ratio of the return air temperature difference to the second preset difference and the full load of the host.

[0018] In the preferred embodiment of the above control method, the step of "controlling the operating load of the main unit according to the return air temperature difference" further includes:

[0019] If the return air temperature difference is less than or equal to the first preset difference, the host unit is controlled not to operate.

[0020] In the preferred embodiment of the above control method, the step of "controlling the cooling capacity of the heat exchange coil according to the return air temperature and the preset return air temperature" includes:

[0021] If the return air temperature is greater than the preset return air temperature, the cooling capacity of the heat exchange coil is increased.

[0022] In the preferred embodiment of the above control method, the step of "controlling the cooling capacity of the heat exchange coil according to the return air temperature and the preset return air temperature" further includes:

[0023] If the return air temperature is less than or equal to the preset return air temperature, the cooling capacity of the heat exchange coil is reduced.

[0024] In the preferred embodiment of the above control method, the step of "controlling the opening and closing states of the fresh air supply fan, the fresh air supply valve, and the mixing air valve according to the return air humidity and the preset return air humidity" includes:

[0025] If the return air humidity is greater than the preset return air humidity, then the fresh air supply fan and the fresh air supply valve are controlled to close, and the mixing air valve is controlled to open.

[0026] In the preferred embodiment of the above control method, the step of "controlling the opening and closing states of the fresh air supply fan, the fresh air supply valve, and the mixing air valve according to the return air humidity and the preset return air humidity" further includes:

[0027] If the return air humidity is less than or equal to the preset return air humidity, then the fresh air supply fan and the fresh air supply valve are opened, and the mixing air valve is closed.

[0028] In a preferred embodiment of the above control method, the control method further includes:

[0029] When the return air humidity is greater than the preset return air humidity, the opening degree of the mixing air valve is controlled according to the return air temperature.

[0030] When the return air humidity is less than or equal to the preset return air humidity, the opening degree of the fresh air supply valve and the operating parameters of the fresh air supply fan are controlled according to the return air temperature.

[0031] In another aspect, the present invention also provides a constant temperature and humidity air conditioner, the constant temperature and humidity air conditioner including a controller, the controller being capable of executing the control method described in any of the above preferred technical solutions.

[0032] When the above technical solution is adopted, the constant temperature and humidity air conditioner of the present invention controls the operating load of the main unit and the cooling capacity of the heat exchange coil according to the obtained return air temperature and the preset return air temperature, so as to effectively avoid the main unit from running at full load and effectively reduce energy consumption. In addition, the constant temperature and humidity air conditioner of the present invention also controls the opening and closing status of the fresh air supply fan, the fresh air supply valve and the mixing air valve according to the obtained return air humidity and the preset return air humidity, so as to effectively control the indoor temperature and humidity to be constant by adjusting the ratio of fresh air and circulating air supplied to the room, without the need for an additional water source, thereby further reducing energy consumption. Attached Figure Description

[0033] The preferred embodiments of the present invention are described below with reference to the accompanying drawings, in which:

[0034] Figure 1 This is a schematic diagram of the overall structure of the constant temperature and humidity air conditioner of the present invention;

[0035] Figure 2 This is a flowchart of the main steps of the control method of the present invention;

[0036] Figure 3 This is a flowchart illustrating the specific steps of a preferred embodiment of the control method of the present invention;

[0037] Figure label:

[0038] 1. Host computer;

[0039] 2. Indoor unit; 21. Housing; 211. Fresh air duct; 2111. Fresh air supply fan; 2112. Fresh air damper; 2113. Fresh air supply damper; 212. Return air duct; 2121. Heat exchange coil; 2122. Circulating air supply fan; 2123. Drain tray; 2124. Return air damper; 2125. Circulating air supply damper; 213. Mixing air damper. Detailed Implementation

[0040] Preferred embodiments of the present invention will now be described with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of the present invention and are not intended to limit the scope of protection of the present invention. Those skilled in the art can make adjustments as needed to adapt to specific applications. For example, the control method described in this invention can be applied to cabinet-type constant temperature and humidity air conditioners, wall-mounted constant temperature and humidity air conditioners, and heat pump-type constant temperature and humidity air conditioners; these are not limiting. Those skilled in the art can define the application objects of the control method of the present invention according to actual usage requirements. Such changes in the application objects do not deviate from the basic principles of the present invention and fall within the scope of protection of the present invention.

[0041] It should be noted that, in the description of this preferred embodiment, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "connected" should be interpreted broadly. For example, they can refer to mechanical connections, electrical connections, direct connections, indirect connections via an intermediate medium, or connections within two components. Therefore, they should not be construed as limitations on the present invention. Those skilled in the art can understand the specific meaning of the above terms in the present invention according to the specific circumstances.

[0042] Furthermore, it should be noted that although the various steps of the control method of the present invention are described in a specific order in the description of the present invention, these orders are not restrictive. Without departing from the basic principles of the present invention, those skilled in the art can perform the steps in different orders.

[0043] First refer to Figure 1 , Figure 1 This is a schematic diagram of the overall structure of the constant temperature and humidity air conditioner of the present invention. Figure 1As shown, the constant temperature and humidity air conditioner of the present invention includes a main unit 1 and an indoor unit 2, with a refrigerant circulation loop between the main unit 1 and the indoor unit 2 for heat exchange. Specifically, the refrigerant circulation loop carries refrigerant for heat exchange between the indoor and outdoor units. The refrigerant circulation loop includes a heat exchange coil 2121, a compressor, a four-way valve, an outdoor coil, and an electronic expansion valve. The heat exchange coil is located in the indoor unit 2, and the outdoor coil is located in the main unit 1. The refrigerant continuously circulates between the heat exchange coil and the outdoor coil through the refrigerant circulation loop to achieve heat exchange. When the four-way valve reverses its direction, it controls the refrigerant to circulate in reverse within the refrigerant circulation loop, allowing the constant temperature and humidity air conditioner to switch between cooling and heating modes. It should be noted that the present invention does not impose any limitations on the specific structure of the constant temperature and humidity air conditioner; those skilled in the art can design it according to actual usage requirements.

[0044] Furthermore, the indoor unit 2 includes a housing 21, within which a fresh air duct 211 and a return air duct 212 are formed. A partition is provided between the fresh air duct 211 and the return air duct 212 to make them independent channels. A fresh air supply fan 2111 is installed in the fresh air duct 211, and a fresh air damper 2112 and a fresh air supply damper 2113 are respectively installed at the fresh air inlet and the air outlet of the fresh air duct 211. A heat exchange coil 2 is installed in the return air duct 212 along the return air flow direction. 121 and circulating air supply fan 2122, a water receiving tray 2123 is provided below the heat exchange coil 2121 to receive water dripping from the heat exchange coil 2121, a return air valve 2124 and a circulating air supply valve 2125 are respectively provided at the return air inlet and the air inlet of the return air channel 212, and a mixing air valve 213 is provided between the fresh air channel 211 and the return air channel 212. Specifically, the mixing air valve 213 is provided on the partition plate, and the fresh air channel 211 and the return air channel 212 are connected through the mixing air valve 213. The fresh air inlet of the fresh air duct 211 is connected to the outside, and the air supply outlet of the fresh air duct 211, the return air outlet of the return air duct 212, and the air inlet are connected to the indoor environment. The fresh air supply fan 2111 delivers the fresh air entering through the fresh air inlet to the room through the fresh air duct 211 and the air supply outlet. The circulating air supply fan 2122 delivers the circulating air entering through the return air outlet to the room through the return air duct and the air inlet, so as to meet the ventilation needs of the indoor environment.

[0045] It should be noted that the present invention does not impose any restrictions on the specific structure and type of the fresh air valve 2112, the fresh air supply valve 2113, the return air valve 2124, the circulating air supply valve 2125, and the mixing air valve 213, nor does it impose any restrictions on the specific structure of the fresh air supply fan 2111, the heat exchange coil 2121, the water receiving pan 2123, and the circulating air supply fan 2122. Those skilled in the art can set them according to the actual situation.

[0046] Furthermore, the constant temperature and humidity air conditioner also includes a temperature sensor and a humidity sensor (not shown in the figure). The temperature sensor is used to acquire the return air temperature, indoor temperature, and outdoor temperature at the return air vent, and the humidity sensor is used to acquire the return air humidity at the return air vent. It should be noted that the present invention does not impose any limitations on the specific structure, type, location, or number of the temperature sensor and the humidity sensor; those skilled in the art can set them according to actual conditions.

[0047] More preferably, the constant temperature and humidity air conditioner further includes a controller (not shown in the figure). The controller can acquire the return air temperature and humidity at the return air vent, as well as the indoor temperature and the outdoor temperature. It can also control the operating status of the constant temperature and humidity air conditioner, such as controlling the operating load of the main unit 1, the cooling capacity of the heat exchange coil 2121, and the opening and closing status of the mixing valve 213. These are not limiting factors. Those skilled in the art will understand that the present invention does not impose any limitations on the specific structure and model of the controller. The controller can be either the original controller of the constant temperature and humidity air conditioner or a controller specifically designed to execute the control method of the present invention. Those skilled in the art can customize the structure and model of the controller according to actual usage requirements.

[0048] See next Figure 2 , Figure 2 This is a flowchart of the main steps of the control method of the present invention. Figure 2 As shown, based on the constant temperature and humidity air conditioner described in the above embodiments, the control method of the present invention mainly includes the following steps:

[0049] S1: Obtain the return air temperature at the return air vent;

[0050] S2: Control the operating load of the main unit based on the return air temperature and the preset return air temperature;

[0051] S3: Control the cooling capacity of the heat exchange coil based on the return air temperature and the preset return air temperature;

[0052] S4: Obtain the humidity of the return air at the return air vent;

[0053] S5: Control the opening and closing status of the fresh air supply fan, fresh air supply valve and mixing air valve according to the return air humidity and the preset return air humidity.

[0054] First, in step S1, the controller acquires the return air temperature at the return air vent detected by the temperature sensor. It should be noted that this invention does not impose any restrictions on the specific method or timing of acquiring the return air temperature; the controller can acquire it in real time or at regular intervals, neither of which is limiting. Preferably, the controller acquires the return air temperature in real time to adjust the operating status of the constant temperature and humidity air conditioner in a timely manner, thereby effectively reducing energy consumption.

[0055] Next, in step S2, the controller controls the operating load of the main unit 1 based on the return air temperature and the preset return air temperature. Further, in step S3, the controller controls the cooling capacity of the heat exchange coil 2121 based on the return air temperature and the preset return air temperature, thereby effectively reducing the operating energy consumption of the constant temperature and humidity air conditioner.

[0056] It should be noted that the present invention does not impose any restrictions on the specific control logic of steps S2 and S3. The controller can compare the return air temperature with the preset return air temperature, and then control the operating load of the main unit 1 and the cooling capacity of the heat exchange coil 2121 according to the comparison result. Of course, this is not restrictive, as long as it can reduce the energy consumption of the constant temperature and humidity air conditioner. In addition, it should also be noted that the present invention does not impose any restrictions on the specific execution order of steps S2 and S3. They can be executed simultaneously or in any order, and those skilled in the art can set it themselves.

[0057] Further, in step S4, the controller acquires the return air humidity detected by the humidity sensor at the return air vent. It should be noted that the present invention does not impose any restrictions on the specific method or timing of acquiring the return air humidity; the controller can acquire it in real time or at certain intervals, and these are not limiting factors.

[0058] Next, in step S5, the controller controls the opening and closing states of the fresh air supply fan 2111, the fresh air supply valve 2113, and the mixing air valve 213 according to the return air humidity and the preset return air humidity, so as to effectively control the constant indoor temperature and indoor humidity by adjusting the ratio of fresh air and circulating air supplied to the room, thereby further reducing energy consumption.

[0059] It should be noted that the present invention does not impose any restrictions on the specific control logic of step S5. The controller can compare the return air humidity with the preset return air humidity and control the opening and closing states of the fresh air supply fan 2111, the fresh air supply valve 2113 and the mixing air valve 213 according to the comparison result. This is not a limitation.

[0060] It should also be noted that the present invention does not impose any restrictions on the specific setting values ​​of the preset return air temperature and the preset return air humidity. The controller can be set according to the actual operation of the constant temperature and humidity air conditioner, or according to the actual usage needs of the user.

[0061] Furthermore, it should be noted that the present invention does not impose any restrictions on the specific execution order of steps S1 and S4. They can be executed simultaneously or in any order, and those skilled in the art can set the order themselves.

[0062] See next Figure 3 , Figure 3 This is a flowchart illustrating the specific steps of a preferred embodiment of the control method of the present invention. Figure 3 As shown, based on the constant temperature and humidity air conditioner described in the above embodiments, the control method of the preferred embodiment of the present invention includes the following steps:

[0063] S101: Obtain the return air temperature at the return air vent;

[0064] S102: Calculate the difference between the return air temperature and the preset return air temperature, and record it as the return air temperature difference;

[0065] S103: If the return air temperature difference is greater than the first preset difference, the operating load of the control unit is the product of the ratio of the return air temperature difference to the second preset difference and the full load of the control unit.

[0066] S104: If the return air temperature difference is less than or equal to the first preset difference, the main control unit will not operate;

[0067] S105: If the return air temperature is greater than the preset return air temperature, the cooling capacity of the heat exchange coil will be increased.

[0068] S106: If the return air temperature is less than or equal to the preset return air temperature, the cooling capacity of the heat exchange coil will be reduced.

[0069] S107: Obtain the humidity of the return air at the return air vent;

[0070] S108: If the return air humidity is greater than the preset return air humidity, control the fresh air supply fan and fresh air supply damper to close, and control the mixing air damper to open.

[0071] S109: If the return air humidity is less than or equal to the preset return air humidity, control the fresh air supply fan and fresh air supply damper to open, and control the mixing air damper to close.

[0072] S110: When the return air humidity is greater than the preset return air humidity, control the opening of the mixing air valve according to the return air temperature.

[0073] S111: When the return air humidity is less than or equal to the preset return air humidity, control the opening degree of the fresh air supply damper and the operating parameters of the fresh air supply fan according to the return air temperature.

[0074] First, in step S101, the controller acquires the return air temperature at the return air vent detected by the temperature sensor. It should be noted that the present invention does not impose any restrictions on the specific method or timing of acquiring the return air temperature; the controller can acquire it in real time or at regular intervals, neither of which is limiting. Preferably, the controller acquires the return air temperature in real time to adjust the operating status of the constant temperature and humidity air conditioner in a timely manner, thereby effectively reducing energy consumption.

[0075] Next, the controller controls the operating load of the main unit 1 based on the return air temperature and the preset return air temperature. It should be noted that this invention does not impose any restrictions on the specific control logic of the controller regarding the operating load of the main unit 1. The controller can compare the return air temperature and the preset return air temperature, and then control the operating load of the main unit 1 based on the comparison result; these are not limiting factors.

[0076] Preferably, in step S102, the controller calculates the difference between the return air temperature and the preset return air temperature, and records it as the return air temperature difference.

[0077] Then, the controller controls the operating load of the main unit 1 based on the return air temperature difference. Of course, the present invention does not impose any restrictions on the specific control logic of the controller controlling the operating load of the main unit 1 based on the return air temperature difference. For example, the controller can compare the return air temperature difference with a preset return air temperature difference, and then control the operating load of the main unit 1 based on the comparison result.

[0078] In this preferred embodiment, in step S103, if the return air temperature difference is greater than the first preset difference, the operating load of the main unit 1 is the product of the ratio of the return air temperature difference to the second preset difference and the full load of the main unit 1. That is, the smaller the value of the return air temperature difference, the smaller the difference between the return air temperature and the preset return air temperature, and the smaller the operating load of the main unit 1, so as to effectively meet the indoor heat exchange demand and effectively reduce the operating energy consumption.

[0079] Furthermore, in step S104, if the return air temperature difference is less than or equal to the first preset difference, the main unit 1 will not operate, that is, the operating load of the main unit 1 is 0, so as to further reduce the operating energy consumption of the constant temperature and humidity air conditioner.

[0080] It should be noted that the present invention does not impose any restrictions on the specific setting values ​​of the preset return air temperature, the first preset difference, and the second preset difference. The controller can be set according to the actual operation of the constant temperature and humidity air conditioner, or according to the actual usage needs of the user. In this specific embodiment, the first preset difference is preferably 0, and the second preset difference is preferably 10, so as to effectively ensure that the constant temperature and humidity air conditioner can keep the indoor temperature constant; of course, this is not limiting, and those skilled in the art can set it according to the actual situation.

[0081] Furthermore, the controller also controls the cooling capacity of the heat exchange coil 2121 based on the return air temperature and the preset return air temperature. It should be noted that this invention does not impose any restrictions on the specific control logic of the controller regarding the cooling capacity of the heat exchange coil 2121. The controller can compare the return air temperature and the preset return air temperature, and then control the cooling capacity of the heat exchange coil 2121 based on the comparison result; these are not limiting factors.

[0082] Preferably, in step S105, if the return air temperature is greater than the preset return air temperature, the controller controls the cooling capacity of the heat exchange coil 2121 to increase. Further, in step S106, if the return air temperature is less than or equal to the preset return air temperature, the controller controls the cooling capacity of the heat exchange coil 2121 to decrease, so as to promptly and effectively ensure a constant indoor temperature and effectively meet the user's needs.

[0083] It should be noted that the present invention does not impose any restrictions on the extent to which the cooling capacity of the heat exchange coil 2121 increases or decreases. The controller can be set according to the actual operating conditions of the constant temperature and humidity air conditioner, or according to the actual usage needs of the user. These are not restrictive.

[0084] Furthermore, it should be noted that the present invention does not impose any restrictions on the specific execution order of steps S102 and S105 or S106. They can be executed simultaneously or in any order. Those skilled in the art can set the order themselves.

[0085] Furthermore, in this preferred embodiment, in step S107, the controller acquires the return air humidity detected by the humidity sensor at the return air vent. It should be noted that the present invention does not impose any restrictions on the specific method or timing of acquiring the return air humidity; the controller can acquire it in real time or at regular intervals, which are not limiting.

[0086] Next, the controller controls the opening and closing states of the fresh air supply fan 2111, the fresh air supply valve 2113, and the mixing valve 213 based on the return air humidity and the preset return air humidity. This effectively controls the indoor temperature and humidity by adjusting the ratio of fresh air to recirculated air supplied to the room, thereby further reducing energy consumption. It should be noted that this invention does not impose any limitations on the specific control logic of the above steps; those skilled in the art can set it according to actual conditions.

[0087] Preferably, in step S108, if the return air humidity is greater than the preset return air humidity, the controller controls the fresh air supply fan 2111 and the fresh air supply valve 2113 to close, and controls the mixing valve 213 to open, so that the air entering from the fresh air inlet enters the return air channel 212 through the mixing valve 213 and mixes with the circulating air entering from the return air inlet of the return air channel 212. Then, after being dehumidified by the heat exchange coil 2121, it enters the room through the air inlet of the return air channel 212 to effectively control the indoor humidity. Further, in step S109, if the return air humidity is less than or equal to the preset return air humidity, the controller controls the fresh air supply fan 2111 and the fresh air supply valve 2113 to open, and controls the mixing valve 213 to close, so that the fresh air with a higher moisture content enters the room directly through the fresh air channel 211 without being dehumidified by the heat exchange coil 2121, and without the need for an additional water source, thus effectively controlling the indoor humidity.

[0088] It should be noted that the present invention does not impose any restrictions on the specific setting value of the preset return air humidity. The controller can be set according to the actual operation of the constant temperature and humidity air conditioner, or according to the actual usage needs of the user. In addition, it should also be noted that the present invention does not impose any restrictions on the specific execution order of steps S101 and S107. They can be executed simultaneously or in any order. Those skilled in the art can set it themselves.

[0089] Furthermore, in this preferred embodiment, in step S110, when the return air humidity is greater than the preset return air humidity, the controller also controls the opening degree of the mixing air valve 213 according to the return air temperature; specifically, in an environment with the same temperature, the higher the return air humidity, the higher the perceived temperature. In this preferred embodiment, the opening degree of the mixing air valve 213 is proportional to the return air temperature in order to effectively improve the user's experience.

[0090] Furthermore, in step S111, when the return air humidity is less than or equal to the preset return air humidity, the controller also controls the opening degree of the fresh air supply valve 2113 and the operating parameters of the fresh air supply fan 2111 according to the return air temperature.

[0091] It should be noted that the present invention does not impose any restrictions on the specific control methods of the controller on the opening degree of the fresh air supply valve 2113 and the operating parameters of the fresh air supply fan 2111; for example, the opening degree of the fresh air supply valve 2113 and the operating speed of the fresh air supply fan 2111 are proportional to the return air temperature, so as to further improve the user experience; of course, the present invention does not impose any restrictions on the specific opening degree of the fresh air supply valve 2113 and the specific operating speed of the fresh air supply fan 2111, and those skilled in the art can set them according to the actual situation.

[0092] The technical solution of the present invention has been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after such changes or substitutions will all fall within the scope of protection of the present invention.

Claims

1. A control method of a constant temperature and humidity air conditioner, characterized by, The constant temperature and humidity air conditioner includes a main unit and an indoor unit, with a refrigerant circulation loop between the main unit and the indoor unit for heat exchange. The indoor unit includes a casing, within which a fresh air duct and a return air duct are formed. A fresh air supply fan is installed in the fresh air duct, and a fresh air damper and a fresh air supply damper are respectively installed at the fresh air inlet and the air outlet of the fresh air duct. A heat exchange coil and a recirculating air supply fan are installed in the return air duct along the return air flow direction. A portion of the refrigerant circulation loop is located in the heat exchange coil. A return air damper and a recirculating air supply damper are respectively installed at the return air inlet and the air inlet of the return air duct. The fresh air inlet of the fresh air duct is connected to the outside environment, while the air outlet of the fresh air duct, the return air inlet of the return air duct, and the air inlet of the return air duct are connected to the indoor environment. A mixing air damper is installed between the fresh air duct and the return air duct, and the fresh air duct and the return air duct are connected through the mixing air damper. The control method includes: Obtain the return air temperature at the return air inlet; The operating load of the main unit is controlled based on the return air temperature and the preset return air temperature. The cooling capacity of the heat exchange coil is controlled based on the return air temperature and the preset return air temperature. Obtain the return air humidity at the return air vent; Based on the return air humidity and the preset return air humidity, the opening and closing states of the fresh air supply fan, the fresh air supply damper, and the mixing damper are controlled, the steps of which include: If the return air humidity is less than or equal to the preset return air humidity, then the fresh air supply fan and the fresh air supply valve are opened, and the mixing air valve is closed.

2. The control method according to claim 1, characterized by, The step of "controlling the operating load of the main unit based on the return air temperature and the preset return air temperature" specifically includes: Calculate the difference between the return air temperature and the preset return air temperature, and record it as the return air temperature difference; The operating load of the main unit is controlled based on the return air temperature difference.

3. The control method according to claim 2, characterized by, The step of "controlling the operating load of the main unit based on the return air temperature difference" includes: If the return air temperature difference is greater than the first preset difference, the operating load of the host is controlled to be the product of the ratio of the return air temperature difference to the second preset difference and the full load of the host.

4. The control method according to claim 3, characterized by The step of "controlling the operating load of the main unit based on the return air temperature difference" further includes: If the return air temperature difference is less than or equal to the first preset difference, the host unit is controlled not to operate.

5. The control method according to claim 1, characterized by, The step of "controlling the cooling capacity of the heat exchange coil based on the return air temperature and the preset return air temperature" includes: If the return air temperature is greater than the preset return air temperature, the cooling capacity of the heat exchange coil is increased.

6. The control method according to claim 5, characterized in that, The step of "controlling the cooling capacity of the heat exchange coil based on the return air temperature and the preset return air temperature" further includes: If the return air temperature is less than or equal to the preset return air temperature, the cooling capacity of the heat exchange coil is reduced.

7. The control method according to any one of claims 1 to 6, characterized in that, The step of "controlling the opening and closing states of the fresh air supply fan, the fresh air supply valve, and the mixing valve according to the return air humidity and the preset return air humidity" includes: If the return air humidity is greater than the preset return air humidity, then the fresh air supply fan and the fresh air supply valve are controlled to close, and the mixing air valve is controlled to open.

8. The control method according to claim 7, characterized in that, The control method further includes: When the return air humidity is greater than the preset return air humidity, the opening degree of the mixing air valve is controlled according to the return air temperature. When the return air humidity is less than or equal to the preset return air humidity, the opening degree of the fresh air supply valve and the operating parameters of the fresh air supply fan are controlled according to the return air temperature.

9. A constant temperature and humidity air conditioner, characterized in that, The constant temperature and humidity air conditioner includes a controller, which is capable of executing the control method according to any one of claims 1 to 8.

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