Air conditioner control system and method with heat recovery function

Abstract

An air conditioner control system with a heat recovery function comprises a mode detection module, a judgment module and an adjustment module. The mode detection module is used for detecting the operation mode of the air conditioning system, the judgment module is used for obtaining the surface temperature of an evaporator when an air conditioner is in a heating mode and after the air conditioner is started for a preset time, and if the surface temperature is smaller than a first temperature threshold value, an adjusting instruction is sent to the adjusting module; the adjusting module is used for receiving the adjusting instruction, obtaining the outdoor temperature, the water temperature in the heat recovery equipment and the temperature difference between the outdoor temperature and the water temperature after receiving the adjusting instruction, and judging whether the first valve needs to be opened or not according to the outdoor temperature, the water temperature in the heat recovery equipment and the temperature difference between the outdoor temperature and the water temperature. Whether the first valve needs to be opened or not is intelligently judged to adjust the flow of the water loop, after the first valve is opened, water in the heat recovery equipment can enter the winding water pipe, the temperature of the surface of the evaporator is increased through heat exchange, and therefore the defrosting effect is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of air conditioning control, and in particular to an air conditioning control system and method with heat recovery. Background Art

[0002] With the development of the times, more and more household air conditioners are equipped with heat recovery technology, which mainly collects, stores and utilizes the excess heat generated by the air conditioner during the cooling or heating process. This heat is usually wasted, but heat recovery technology can convert it into reusable energy, thereby improving energy efficiency. The recovered heat is usually used to heat water, and the heated water can be used by users.

[0003] In heat recovery technology, the heat energy of the refrigerant output by the compressor is absorbed to reduce the temperature of the refrigerant when it enters the condenser, thereby reducing the heat waste of the condenser. However, in the heating mode of the air conditioner, the evaporator of the outdoor unit will frost. This is because when heating, the outdoor unit absorbs heat and the indoor unit dissipates heat. When the outdoor temperature is low, the temperature of the evaporator body will drop below 0 degrees, and the surrounding moisture will quickly condense into frost, causing the radiator to frost. When the heat recovery equipment is not connected, the condenser can transport the waste heat to the radiator for defrosting. However, after the heat recovery equipment is installed, the waste heat temperature of the condenser is insufficient, and the radiator cannot be effectively defrosted. Therefore, how to defrost the radiator after installing the heat recovery equipment has become an urgent problem to be solved in the current air conditioner. Summary of the invention

[0004] In view of the above-mentioned defects, the object of the present invention is to provide an air-conditioning control system and method with heat recovery to solve the problem of evaporator frosting in heating mode.

[0005] To achieve this object, the present invention adopts the following technical solution: an air conditioning control system with heat recovery, comprising: a compressor, a condenser, a heat recovery device, an evaporator and an outer water pipe;

[0006] The gas output end of the compressor is connected to the gas input end of the heat recovery device, the gas output end of the heat recovery device is connected to the gas input end of the condenser, the liquid output end of the condenser is connected to the liquid input end of the evaporator, and the liquid output end of the evaporator is connected to the liquid input end of the compressor;

[0007] The outer water pipe is wound around the surface of the evaporator;

[0008] The heat recovery device is further provided with a first liquid output end and a second liquid output end, the first liquid output end of the heat recovery device is connected to the outer water pipe, so that the outer water pipe and the heat recovery device form a water loop, the second liquid output end is connected to user water, and the first liquid output end and the second liquid output end are respectively provided with a first valve and a second valve;

[0009] It also includes a mode detection module, a judgment module and an adjustment module;

[0010] The mode detection module is used to detect the operating mode of the air conditioning system, wherein the operating mode includes a cooling mode and a heating mode;

[0011] The judgment module is used to obtain the surface temperature of the evaporator after a preset time after the air conditioner is turned on when the air conditioner is in the heating mode, and send an adjustment instruction to the adjustment module if the surface temperature is less than the first temperature threshold;

[0012] The adjustment module is used to accept the adjustment instruction. After accepting the adjustment instruction, it obtains the outdoor temperature, the water temperature in the heat recovery device and the temperature difference between the two, and determines whether the first valve needs to be opened based on the outdoor temperature, the water temperature in the heat recovery device and the temperature difference between the two.

[0013] Preferably, when the water temperature in the heat recovery device is lower than the second temperature threshold, no instruction to open the first valve is issued, and after waiting for a preset time again, the judgment module is called again;

[0014] When the water temperature in the heat recovery device is higher than the second temperature threshold, it is determined whether the temperature difference between the outdoor temperature and the water in the heat recovery device is greater than the difference threshold. If it is less than, no instruction to open the first valve is issued, and after waiting for the preset time again, the judgment module is called again. If it is greater than, the opening degree of the first valve is adjusted according to the surface temperature, and an instruction to close the second valve is issued.

[0015] Preferably, the specific steps of adjusting the opening and closing degree of the first valve by the surface temperature are as follows:

[0016] When the surface temperature is lower than a fourth temperature threshold, the first valve is opened at a maximum opening degree;

[0017] When the surface temperature is greater than the fourth temperature threshold and less than the third temperature threshold, the surface temperature and the water temperature in the heat recovery device are obtained as a first difference, and the opening degree of the first valve is adjusted according to the first difference;

[0018] When the surface temperature is greater than the third temperature threshold and less than the first temperature threshold, the first valve is opened at an opening degree of 1 / 4.

[0019] Preferably, the specific steps of adjusting the opening and closing degree of the first valve according to the first difference are as follows:

[0020] The first valve is opened at an opening degree of 1 / 2, and a cycle of the water pump operation is waited for, and a change value of the first difference is obtained again, and the heat transfer coefficient of the evaporator is obtained according to the change value of the first difference;

[0021] When the heat exchange coefficient is greater than a first coefficient threshold, the opening degree of the first valve is reduced according to a preset opening degree;

[0022] When the heat exchange coefficient is less than the first coefficient threshold and greater than the second coefficient threshold, the current opening degree of the first valve is maintained;

[0023] When the heat exchange coefficient is less than the second coefficient threshold, the opening degree of the first valve is decreased or increased according to the preset opening degree.

[0024] Preferably, the heat transfer coefficient is obtained by the following formula:

[0025] Wherein ω is the empirical coefficient, ΔT1 is the change value of the first difference, S is the contact area between the outer water pipe and the evaporator, and A is the velocity coefficient corresponding to the water flow velocity in the outer water pipe.

[0026] An air conditioning control method with heat recovery is applied to the air conditioning control system with heat recovery, comprising the following steps:

[0027] Step S1: Detecting the operating mode of the air conditioning system;

[0028] Step S2: when the air conditioner is in heating mode, the surface temperature of the evaporator is obtained after a preset time after the air conditioner is turned on. If the surface temperature is less than a first temperature threshold, step S3 is executed;

[0029] Step S3: Obtain the outdoor temperature, the water temperature in the heat recovery device, and the temperature difference between the two, and determine whether the first valve needs to be opened according to the outdoor temperature, the water temperature in the heat recovery device, and the temperature difference between the two.

[0030] Preferably, the steps of determining whether the first valve needs to be opened are as follows:

[0031] When the water temperature in the heat recovery device is lower than the second temperature threshold, no instruction to open the first valve is issued, and after waiting for the preset time again, step S3 is executed again;

[0032] When the water temperature in the heat recovery device is higher than the second temperature threshold, it is determined whether the temperature difference between the two is greater than the difference threshold. If it is less than, no instruction to open the first valve is issued, and after waiting for the preset time again, step S3 is executed again. If it is greater than, the opening degree of the first valve is adjusted according to the surface temperature, and an instruction to close the second valve is issued.

[0033] Preferably, the specific steps of adjusting the opening and closing degree of the first valve according to the surface temperature are as follows:

[0034] When the surface temperature is lower than a fourth temperature threshold, the first valve is opened at a maximum opening degree;

[0035] When the surface temperature is greater than the fourth temperature threshold and less than the third temperature threshold, the surface temperature and the water temperature in the heat recovery device are obtained as a first difference, and the opening degree of the first valve is adjusted according to the first difference;

[0036] When the surface temperature is greater than the third temperature threshold and less than the first temperature threshold, the first valve is opened at an opening degree of 1 / 4.

[0037] Preferably, the specific steps of adjusting the opening and closing degree of the first valve according to the first difference are as follows:

[0038] The first valve is opened at an opening degree of 1 / 2, and a cycle of the water pump operation is waited for, and a change value of the first difference is obtained again, and the heat transfer coefficient of the evaporator is obtained according to the change value of the first difference;

[0039] When the heat exchange coefficient is greater than a first coefficient threshold, the opening degree of the first valve is reduced according to a preset opening degree;

[0040] When the heat exchange coefficient is less than the first coefficient threshold and greater than the second coefficient threshold, the current opening degree of the first valve is maintained;

[0041] When the heat exchange coefficient is less than the second coefficient threshold, the opening degree of the first valve is decreased or increased according to the preset opening degree.

[0042] One of the above technical solutions has the following advantages or beneficial effects: the present invention additionally sets an outer water pipe, and then intelligently judges whether it is necessary to open the first valve to adjust the flow of the water circuit. When the first valve is opened, the water in the heat recovery equipment will enter the wound water pipe, and the temperature of the evaporator surface will be raised through heat exchange, thereby achieving the defrosting effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 It is a schematic diagram of the structure of an embodiment of the system of the present invention.

[0044] Figure 2is a flow chart of an embodiment of the method of the present invention.

[0045] Among them: compressor 1, evaporator 2, outer water pipe 3, first valve 4, heat recovery equipment 5, condenser 6, second valve 7. DETAILED DESCRIPTION

[0046] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals represent the same or similar elements or elements having the same or similar functions from beginning to end. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0047] In the description of the embodiments of the present invention, the terms "first" and "second" are used for descriptive purposes only and are not to be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0048] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, the meaning of "plurality" is two or more. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0049] like Figures 1-2 As shown, an air conditioning control system with heat recovery comprises: a compressor (1), a condenser (6), a heat recovery device (5), an evaporator (2) and an outer water pipe (3);

[0050] The gas output end of the compressor (1) is connected to the gas input end of the heat recovery device (5), the gas output end of the heat recovery device (5) is connected to the gas input end of the condenser (6), the liquid output end of the condenser (6) is connected to the liquid input end of the evaporator (2), and the liquid output end of the evaporator (2) is connected to the liquid input end of the compressor (1);

[0051] The outer water pipe (3) is wound around the surface of the evaporator (2);

[0052] The heat recovery device (5) is further provided with a first liquid output end and a second liquid output end. The first liquid output end of the heat recovery device (5) is connected to the outer water pipe (3), so that the outer water pipe (3) and the heat recovery device (5) form a water loop. The second liquid output end is connected to user water. The first liquid output end and the second liquid output end are respectively provided with a first valve (4) and a second valve (7);

[0053] It also includes a mode detection module, a judgment module and an adjustment module;

[0054] The mode detection module is used to detect the operating mode of the air conditioning system, wherein the operating mode includes a cooling mode and a heating mode;

[0055] The judgment module is used to obtain the surface temperature of the evaporator (2) after a preset time after the air conditioner is turned on when the air conditioner is in a heating mode, and if the surface temperature is less than a first temperature threshold, send an adjustment instruction to the adjustment module;

[0056] The regulating module is used to receive the regulating instruction, and after receiving the regulating instruction, obtains the outdoor temperature, the water temperature in the heat recovery device (5) and the temperature difference between the two, and determines whether the first valve (4) needs to be opened based on the outdoor temperature, the water temperature in the heat recovery device (5) and the temperature difference between the two.

[0057] In order to solve the problem that when the outdoor evaporator (2) is operating in the winter heating mode, the air flow is affected due to the freezing of the outdoor evaporator (2), which ultimately leads to a poor heating effect. In the present invention, an outer water pipe (3) is provided, which is wound around the outer surface of the evaporator (2). If the surface temperature is lower than the preset first temperature threshold (2-4°C), it means that the evaporator (2) may face the risk of freezing. At this time, the judgment module will send an adjustment instruction to the adjustment module. After receiving the instruction, the adjustment module will intelligently determine whether it is necessary to open the first valve (4) to adjust the flow of the water circuit according to the outdoor temperature, the water temperature in the heat recovery device (5) and the temperature difference between the two. When the first valve (4) is opened, the water in the heat recovery device (5) will enter the winding water pipe, and the temperature of the surface of the evaporator (2) will be raised through heat exchange, thereby achieving the defrosting effect.

[0058] Preferably, when the water temperature in the heat recovery device (5) is lower than the second temperature threshold, no instruction to open the first valve (4) is issued, and after waiting for a preset time again, the judgment module is called again;

[0059] When the water temperature in the heat recovery device (5) is higher than the second temperature threshold, it is determined whether the temperature difference between the outdoor temperature and the water temperature in the heat recovery device (5) is greater than the difference threshold. If it is less than the difference threshold, no instruction to open the first valve (4) is issued, and after waiting for a preset time again, the judgment module is called again. If it is greater than the difference threshold, the opening degree of the first valve (4) is adjusted according to the surface temperature, and an instruction to close the second valve (7) is issued.

[0060] Of course, when the air conditioner runs for a preset time, the heat energy produced may not be able to raise the water temperature to a temperature that can be used for defrosting. Therefore, when the water temperature in the heat recovery device (5) is lower than the second temperature threshold, the instruction to open the first valve (4) is not issued, and the heat recovery device (5) continues to be heated to reduce unnecessary heat energy loss. After waiting for the preset time (1 hour) again, the judgment module is called again;

[0061] When the water temperature in the heat recovery device (5) is higher than the second temperature threshold, the external environment may change after a period of operation, resulting in an increase in temperature. Therefore, it is also necessary to determine whether the temperature difference between the outdoor temperature and the water in the heat recovery device (5) is greater than the difference threshold. If it is greater, it means that the outdoor temperature has not increased over time, resulting in the temperature of the water in the heat recovery device (5) becoming increasingly higher, so defrosting is required. At this time, in order to ensure that the water temperature is sufficient for defrosting, the second valve (7) needs to be closed. Because when the user uses hot water, new cold water will be added to the heat recovery device (5), causing the temperature of the water in the heat recovery device (5) to drop, and the quality of defrosting cannot be ensured.

[0062] Preferably, the specific steps of adjusting the opening and closing degree of the first valve (4) by the surface temperature are as follows:

[0063] When the surface temperature is lower than a fourth temperature threshold, the first valve (4) is opened at a maximum opening degree;

[0064] When the surface temperature is greater than a fourth temperature threshold and less than a third temperature threshold, the surface temperature and the water temperature in the heat recovery device (5) are obtained as a first difference, and the opening degree of the first valve (4) is adjusted according to the first difference;

[0065] When the surface temperature is greater than the third temperature threshold and less than the first temperature threshold, the first valve (4) is opened at an opening degree of 1 / 4.

[0066] The fourth temperature threshold is -5°C. When the surface temperature is less than the fourth temperature threshold, it means that the temperature of the outer surface of the evaporator (2) is very low, and hot water needs to be supplied to the outer water pipe (3) at the maximum flow rate for heat exchange, thereby achieving defrosting. The third temperature threshold is 0 to 1 degree Celsius. When the surface temperature is greater than the fourth temperature threshold and less than the third temperature threshold, the frosting temperature is just reached. At this time, the opening and closing degree of the valve is adjusted by calculating the difference (first difference) between the surface temperature and the water temperature in the heat recovery device (5). This intelligent adjustment can dynamically adjust the heat recovery amount according to actual conditions to avoid unnecessary energy waste. When the surface temperature is greater than the third temperature threshold and less than the first temperature threshold, it is the temperature ready for frosting. Only a certain amount of hot water needs to be input for heat exchange to avoid frosting and reduce unnecessary heat energy loss.

[0067] It is worth mentioning that during the adjustment process, when the surface temperature is greater than the first temperature threshold, the first valve (4) needs to be closed, so that the second valve (7) can be opened, so that the user can use the hot water in the heat recovery device (5) normally. Before the adjustment, if the user is using the hot water in the heat recovery device (5) (i.e., the second valve (7) is open), it is necessary to wait until the user stops using the hot water, and then call the judgment module again to re-judge the temperature condition.

[0068] Preferably, the specific steps of adjusting the opening and closing degree of the first valve (4) according to the first difference are as follows:

[0069] The first valve (4) is opened at a 1 / 2 opening degree, and a cycle of the water pump operation is waited for, and a change value of the first difference is obtained again, and the heat transfer coefficient of the evaporator (2) is obtained according to the change value of the first difference;

[0070] When the heat exchange coefficient is greater than a first coefficient threshold, the opening degree of the first valve (4) is reduced according to a preset opening degree;

[0071] When the heat exchange coefficient is less than a first coefficient threshold value and greater than a second coefficient threshold value, the current opening degree of the first valve (4) is maintained;

[0072] When the heat exchange coefficient is less than the second coefficient threshold, the opening degree of the first valve (4) is decreased or increased according to a preset opening degree.

[0073] First, the first valve (4) is opened at a 1 / 2 opening degree. Such a setting can ensure a certain amount of heat recovery and avoid energy waste or overheating of the evaporator (2) due to excessive opening. Then, after another cycle, the first difference is obtained again, and the heat exchange coefficient can be obtained based on the change in the first difference. The heat exchange coefficient can be used to more accurately evaluate the current heat exchange status, providing reliable data support for subsequent control strategies.

[0074] When the heat exchange coefficient is greater than the first coefficient threshold, it indicates that the current heat exchange efficiency is high, but there may be overheating waste. Therefore, the system will reduce the opening degree of the first valve (4) according to the preset opening degree to reduce the heat recovery amount and prevent heat energy waste.

[0075] When the heat transfer coefficient is between the first coefficient threshold and the second coefficient threshold, it indicates that the current heat exchange efficiency is moderate, which almost meets the defrosting requirements and does not consume excessive heat energy. Therefore, the system will maintain the current opening and closing degree of the first valve (4) unchanged to ensure stable operation of the system.

[0076] When the heat transfer coefficient is less than the second coefficient threshold, it indicates that the current heat exchange efficiency is low and cannot effectively increase the surface temperature of the evaporator (2) to meet the defrosting requirement. At this time, the system will increase the opening degree of the first valve (4) according to the preset opening degree to increase the supply of hot water and improve the heat exchange efficiency to meet the defrosting requirement.

[0077] Preferably, the heat transfer coefficient is obtained by the following formula:

[0078] Wherein ω is an empirical coefficient, ΔT1 is a change value of the first difference, S is an area of ​​contact between the outer water pipe (3) and the evaporator (2), and A is a velocity coefficient corresponding to the water flow velocity in the outer water pipe (3).

[0079] An air conditioning control method with heat recovery is applied to the air conditioning control system with heat recovery, comprising the following steps:

[0080] Step S1: Detecting the operating mode of the air conditioning system;

[0081] Step S2: when the air conditioner is in heating mode, the surface temperature of the evaporator (2) is obtained after a preset time after the air conditioner is turned on. If the surface temperature is less than a first temperature threshold, step S3 is executed;

[0082] Step S3: Obtain the outdoor temperature, the water temperature in the heat recovery device (5) and the temperature difference between the two, and determine whether the first valve (4) needs to be opened based on the outdoor temperature, the water temperature in the heat recovery device (5) and the temperature difference between the two.

[0083] Preferably, the steps of determining whether the first valve (4) needs to be opened are as follows:

[0084] When the water temperature in the heat recovery device (5) is lower than the second temperature threshold, no instruction to open the first valve (4) is issued, and after waiting for a preset time again, step S3 is executed again;

[0085] When the water temperature in the heat recovery device (5) is higher than the second temperature threshold, it is determined whether the temperature difference between the two is greater than the difference threshold. If it is less than, no instruction to open the first valve (4) is issued, and after waiting for a preset time again, step S3 is executed again. If it is greater than, the opening degree of the first valve (4) is adjusted according to the surface temperature, and an instruction to close the second valve (7) is issued.

[0086] Preferably, the specific steps of adjusting the opening and closing degree of the first valve (4) according to the surface temperature are as follows:

[0087] When the surface temperature is lower than a fourth temperature threshold, the first valve (4) is opened at a maximum opening degree;

[0088] When the surface temperature is greater than a fourth temperature threshold and less than a third temperature threshold, the surface temperature and the water temperature in the heat recovery device (5) are obtained as a first difference, and the opening degree of the first valve (4) is adjusted according to the first difference;

[0089] When the surface temperature is greater than the third temperature threshold and less than the first temperature threshold, the first valve (4) is opened at an opening degree of 1 / 4.

[0090] Preferably, the specific steps of adjusting the opening and closing degree of the first valve (4) according to the first difference are as follows:

[0091] The first valve (4) is opened at a 1 / 2 opening degree, and a cycle of the water pump operation is waited for, and a change value of the first difference is obtained again, and the heat transfer coefficient of the evaporator (2) is obtained according to the change value of the first difference;

[0092] When the heat exchange coefficient is greater than a first coefficient threshold, the opening degree of the first valve (4) is reduced according to a preset opening degree;

[0093] When the heat exchange coefficient is less than a first coefficient threshold value and greater than a second coefficient threshold value, the current opening degree of the first valve (4) is maintained;

[0094] When the heat exchange coefficient is less than the second coefficient threshold, the opening degree of the first valve (4) is decreased or increased according to a preset opening degree.

[0095] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0096] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. An air conditioning control system with heat recovery, characterized in that: include: Compressor, condenser, heat recovery equipment, evaporator and external water pipe; The gas output end of the compressor is connected to the gas input end of the heat recovery device, the gas output end of the heat recovery device is connected to the gas input end of the condenser, the liquid output end of the condenser is connected to the liquid input end of the evaporator, and the liquid output end of the evaporator is connected to the liquid input end of the compressor; The outer water pipe is wound around the surface of the evaporator; The heat recovery device is further provided with a first liquid output end and a second liquid output end, the first liquid output end of the heat recovery device is connected to the outer water pipe, so that the outer water pipe and the heat recovery device form a water loop, the second liquid output end is connected to user water, and the first liquid output end and the second liquid output end are respectively provided with a first valve and a second valve; It also includes a mode detection module, a judgment module and an adjustment module; The mode detection module is used to detect the operating mode of the air conditioning system, wherein the operating mode includes a cooling mode and a heating mode; The judgment module is used to obtain the surface temperature of the evaporator after a preset time after the air conditioner is turned on when the air conditioner is in the heating mode, and send an adjustment instruction to the adjustment module if the surface temperature is less than the first temperature threshold; The adjustment module is used to accept the adjustment instruction. After accepting the adjustment instruction, it obtains the outdoor temperature, the water temperature in the heat recovery device and the temperature difference between the two, and determines whether the first valve needs to be opened based on the outdoor temperature, the water temperature in the heat recovery device and the temperature difference between the two.

2. The air conditioning control system with heat recovery according to claim 1, characterized in that: When the water temperature in the heat recovery device is lower than the second temperature threshold, no instruction to open the first valve is issued, and after waiting for the preset time again, the judgment module is called again; When the water temperature in the heat recovery device is higher than the second temperature threshold, it is determined whether the temperature difference between the outdoor temperature and the water in the heat recovery device is greater than the difference threshold. If it is less than, no instruction to open the first valve is issued, and after waiting for the preset time again, the judgment module is called again. If it is greater than, the opening degree of the first valve is adjusted according to the surface temperature, and an instruction to close the second valve is issued.

3. The air conditioning control system with heat recovery according to claim 2, characterized in that: The specific steps of adjusting the opening and closing degree of the first valve by the surface temperature are as follows: When the surface temperature is lower than a fourth temperature threshold, the first valve is opened at a maximum opening degree; When the surface temperature is greater than the fourth temperature threshold and less than the third temperature threshold, the surface temperature and the water temperature in the heat recovery device are obtained as a first difference, and the opening degree of the first valve is adjusted according to the first difference; When the surface temperature is greater than the third temperature threshold and less than the first temperature threshold, the first valve is opened at an opening degree of 1 / 4.

4. The air conditioning control system with heat recovery according to claim 3, characterized in that: The specific steps of adjusting the opening and closing degree of the first valve according to the first difference are as follows: The first valve is opened at an opening degree of 1 / 2, and a cycle of the water pump operation is waited for, and a change value of the first difference is obtained again, and the heat transfer coefficient of the evaporator is obtained according to the change value of the first difference; When the heat exchange coefficient is greater than a first coefficient threshold, the opening degree of the first valve is reduced according to a preset opening degree; When the heat exchange coefficient is less than the first coefficient threshold and greater than the second coefficient threshold, the current opening degree of the first valve is maintained; When the heat exchange coefficient is less than the second coefficient threshold, the opening degree of the first valve is decreased or increased according to the preset opening degree.

5. The air conditioning control system with heat recovery according to claim 4, characterized in that: The formula for obtaining the heat transfer coefficient is as follows: Wherein ω is the empirical coefficient, ΔT1 is the change value of the first difference, S is the contact area between the outer water pipe and the evaporator, and A is the velocity coefficient corresponding to the water flow velocity in the outer water pipe.

6. An air conditioning control method with heat recovery, applied to an air conditioning control system with heat recovery as claimed in any one of claims 1 to 5, characterized in that: The steps include: Step S1: Detecting the operating mode of the air conditioning system; Step S2: when the air conditioner is in heating mode, the surface temperature of the evaporator is obtained after a preset time after the air conditioner is turned on. If the surface temperature is less than a first temperature threshold, step S3 is executed; Step S3: Obtain the outdoor temperature, the water temperature in the heat recovery device, and the temperature difference between the two, and determine whether the first valve needs to be opened according to the outdoor temperature, the water temperature in the heat recovery device, and the temperature difference between the two.

7. The air conditioning control method with heat recovery according to claim 6, characterized in that: The steps for determining whether the first valve needs to be opened are as follows: When the water temperature in the heat recovery device is lower than the second temperature threshold, no instruction to open the first valve is issued, and after waiting for the preset time again, step S3 is executed again; When the water temperature in the heat recovery device is higher than the second temperature threshold, it is determined whether the temperature difference between the two is greater than the difference threshold. If it is less than, no instruction to open the first valve is issued, and after waiting for the preset time again, step S3 is executed again. If it is greater than, the opening degree of the first valve is adjusted according to the surface temperature, and an instruction to close the second valve is issued.

8. The air conditioning control method with heat recovery according to claim 7, characterized in that: The specific steps of adjusting the opening and closing degree of the first valve according to the surface temperature are as follows: When the surface temperature is lower than a fourth temperature threshold, the first valve is opened at a maximum opening degree; When the surface temperature is greater than the fourth temperature threshold and less than the third temperature threshold, the surface temperature and the water temperature in the heat recovery device are obtained as a first difference, and the opening degree of the first valve is adjusted according to the first difference; When the surface temperature is greater than the third temperature threshold and less than the first temperature threshold, the first valve is opened at an opening degree of 1 / 4.

9. The air conditioning control method with heat recovery according to claim 7, characterized in that: The specific steps of adjusting the opening and closing degree of the first valve according to the first difference are as follows: The first valve is opened at an opening degree of 1 / 2, and a cycle of the water pump operation is waited for, and a change value of the first difference is obtained again, and the heat transfer coefficient of the evaporator is obtained according to the change value of the first difference; When the heat exchange coefficient is greater than a first coefficient threshold, the opening degree of the first valve is reduced according to a preset opening degree; When the heat exchange coefficient is less than the first coefficient threshold and greater than the second coefficient threshold, the current opening degree of the first valve is maintained; When the heat exchange coefficient is less than the second coefficient threshold, the opening degree of the first valve is decreased or increased according to the preset opening degree.

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