Air conditioning system control method and system

Abstract

The invention discloses an air conditioning system control method and system, and relates to the technical field of refrigeration, the system comprises a central control unit, a main unit and a return air processing unit, and the method comprises the steps that fresh air temperature and humidity, return air temperature and humidity, mixed air temperature, supply air temperature and humidity, a preset temperature threshold value and a preset humidity threshold value are obtained; a system working mode is determined based on the return air temperature and the temperature threshold value, and the specific working modes of the main unit and the return air processing unit are controlled according to the system working mode, the temperature and humidity, the temperature threshold value and the humidity threshold value; by arranging the return air processing unit, outdoor low-temperature fresh air is used for cooling indoor high-temperature return air, the system energy consumption is greatly reduced, the central control unit obtains the temperature and humidity of the outdoor fresh air and the indoor return air, the temperature and humidity of mixed air and supplied air and a preset indoor temperature and humidity threshold value are combined, a proper system working mode is selected, and the system energy consumption is reduced. The main unit and the return air processing unit are intelligently controlled, and high-temperature return air is effectively and rapidly cooled on the premise that the system is low in load and energy consumption.

Description

Technical Field

[0001] The present application belongs to the field of refrigeration technology, and specifically relates to an air conditioning system control method and system thereof. Background Art

[0002] As a key equipment for power conversion, the converter valve will generate a lot of heat during operation. In order to ensure the normal operation of the converter valve hall and reduce the interference of outdoor air on the valve hall, the traditional conventional converter valve hall air handling unit usually adopts minimum fresh air operation, and the return air occupies a large part of the total air volume. The double load of fresh air and high-temperature return air leads to high energy consumption of conventional air conditioners. Summary of the invention

[0003] In order to solve at least one of the above-mentioned defects, the present invention proposes an air conditioning system control method and system thereof, which overcomes the shortcomings of the prior art.

[0004] In one aspect, the present invention provides an air conditioning system, the system comprising a central control unit, a main unit and a return air handling unit.

[0005] The host unit includes a heat exchanger electrically connected to the central control unit, and the heat exchanger is also connected to the air conditioning unit. The return air processing unit includes an air heat exchanger for heat exchange processing of indoor return air.

[0006] The method comprises:

[0007] Fresh air enters the host group through the fresh air inlet of the host group;

[0008] The heat exchanged fresh air enters the air heat exchanger, exchanges heat with the indoor return air entering the return air handling unit, and then is discharged;

[0009] The return air enters the return air processing unit through the indoor return air inlet, and after heat exchange treatment by the air heat exchanger, enters the main unit through the return air outlet;

[0010] The return air after heat exchange treatment enters the main unit and mixes with the fresh air entering the main unit to obtain mixed air;

[0011] The mixed air is subjected to heat exchange treatment by the heat exchanger to obtain supply air, and the supply air is delivered into the room through the air supply outlet of the main unit;

[0012] Obtaining the fresh air temperature and fresh air humidity, the return air temperature and return air humidity entering the return air processing unit, the mixed air temperature of the mixed air, the supply air temperature and supply air humidity of the supply air, the preset temperature threshold, and the humidity threshold;

[0013] Determining a system operating mode based on the return air temperature and the temperature threshold;

[0014] The working modes of the return air handling unit and the main unit are controlled according to the system working mode, the fresh air temperature and fresh air humidity, the return air temperature and return air humidity, the mixed air temperature, the supply air temperature and supply air humidity, and the preset temperature threshold and humidity threshold.

[0015] Preferably, determining the system operating mode based on the return air temperature and the temperature threshold specifically includes:

[0016] A first temperature difference is preset, the first temperature difference is greater than 0°C,

[0017] If the return air temperature is less than the difference between the lower limit of the temperature threshold and the first temperature difference, the central control unit control system enters a heating mode;

[0018] If the return air temperature is greater than or equal to the difference between the lower limit value of the temperature threshold and the first temperature difference, and is less than the lower limit value of the temperature threshold, the central control unit control system enters the standby mode;

[0019] If the return air temperature is greater than or equal to the lower limit of the temperature threshold, the central control unit control system enters the cooling mode.

[0020] Preferably, the main unit further comprises a first heater, a second heater and a humidifier, wherein the fresh air passes through the fresh air inlet of the main unit, first passes through the first heater and then mixes with the return air processed by the return air processing unit to obtain the mixed air; the mixed air passes through the heat exchanger, the second heater and the humidifier in sequence to reach the air supply outlet of the main unit;

[0021] The return air processing unit also includes a spray component and a fan. The spray component is used to perform heat exchange treatment on the heat exchange fresh air, and the heat exchange fresh air exchanges heat with the indoor return air after passing through the spray component; the fan is used to discharge the heat exchange fresh air after heat exchange with the indoor return air.

[0022] Preferably, the control of the working mode of the return air handling unit includes controlling the working mode of the fan, specifically including:

[0023] When the system working mode is the cooling mode, the central control unit calculates the fresh air dew point temperature based on the fresh air temperature and the fresh air humidity, and presets the second temperature difference, the second temperature difference is greater than 0°C, presets the first fan condition temperature, the second fan condition temperature and the third fan condition temperature, and presets the first fan frequency, the second fan frequency and the third fan frequency, wherein the first fan condition temperature is greater than the second fan condition temperature, the first fan frequency is greater than the second fan frequency, and the second fan frequency is greater than the third fan frequency;

[0024] If the fresh air dew point temperature is less than the difference between the return air temperature and the second temperature difference, and the return air temperature is greater than the upper limit of the temperature threshold, the central control unit turns on the fan, and the fan frequency is the first fan frequency;

[0025] If the fresh air dew point temperature is less than the difference between the return air temperature and the second temperature difference, and the return air temperature is within the temperature threshold: when the return air temperature is greater than or equal to the first fan condition temperature, the central control unit turns on the fan, and the fan frequency is the second fan frequency;

[0026] When the return air temperature is greater than or equal to the second fan condition temperature and less than the first fan condition temperature, the central control unit turns on the fan, and the fan frequency is a third fan frequency;

[0027] When the return air temperature is lower than the second fan condition temperature, the central control unit turns off the fan.

[0028] Preferably, the control of the working mode of the return air handling unit includes controlling the working mode of the spray assembly, specifically including:

[0029] Preset spray condition temperature and spray condition humidity;

[0030] When the fresh air temperature is greater than or equal to the spray condition temperature, and the fresh air humidity is less than the spray condition humidity, if the fan is turned on at this time, the central control unit turns on the spray component;

[0031] When the fresh air temperature is lower than the spray condition temperature, and / or the fresh air humidity is higher than the spray condition humidity, the central control unit turns off the spray component.

[0032] Preferably, the operating mode of the control host group includes controlling the operating mode of the first heater, specifically including:

[0033] The preset values ​​are the first heating condition temperature, the second heating condition temperature, the third heating condition temperature, the fourth heating condition temperature and the fifth heating condition temperature which increase in sequence, and the preset values ​​are the first heating power, the second heating power, the third heating power, the fourth heating power and the fifth heating power which decrease in sequence,

[0034] When the system is in heating mode,

[0035] If the mixed air temperature is lower than the first heating condition temperature, the central control unit turns on the first heater at a first heating power;

[0036] If the mixed air temperature is greater than or equal to the first heating condition temperature and less than the second heating condition temperature, the central control unit turns on the first heater with a second heating power;

[0037] If the mixed air temperature is greater than or equal to the second heating condition temperature and less than the third heating condition temperature, the central control unit turns on the first heater with a power of the third heating power;

[0038] If the mixed air temperature is greater than or equal to the third heating condition temperature and less than the fourth heating condition temperature, the central control unit turns on the first heater with a power of the fourth heating power;

[0039] If the mixed air temperature is greater than or equal to the fourth heating condition temperature and less than the fifth heating condition temperature, the central control unit turns on the first heater with a power of the fifth heating power;

[0040] If the mixed air temperature is greater than or equal to the fifth heating condition temperature, the central control unit turns off the first heater.

[0041] Preferably, the operating mode of the control host group includes controlling the operating mode of the heat exchanger, specifically including:

[0042] When the system is in cooling mode,

[0043] When the return air temperature is greater than the upper limit of the temperature threshold, the central control unit controls the heat exchanger to pass chilled water, sets the chilled water flow rate to the maximum flow rate, sets the chilled water temperature to the preset minimum temperature, and performs cooling treatment on the mixed air;

[0044] When the return air temperature drops within the temperature threshold, the working mode of the heat exchanger is further controlled according to the return air humidity, specifically including:

[0045] If the return air humidity is greater than the lower limit of the humidity threshold, the central control unit controls the heat exchanger to increase the chilled water temperature based on the current chilled water temperature and / or to reduce the chilled water flow rate based on the current chilled water flow rate.

[0046] If the return air humidity is less than the lower limit of the humidity threshold, the central control unit controls the heat exchanger to lower the chilled water temperature based on the current chilled water temperature and / or increase the chilled water flow rate based on the current chilled water flow rate.

[0047] If the return air humidity is within the humidity threshold, the temperature and flow rate of the chilled water in the heat exchanger remain unchanged;

[0048] When the system working mode is the heating mode, the central control unit controls the heat exchanger to pass hot water to perform heat exchange processing on the mixed air.

[0049] Preferably, the controlling the working mode of the host group further includes controlling the working mode of the second heater, specifically including:

[0050] A maximum supply air temperature difference is preset, and a supply air temperature difference is calculated based on the maximum supply air temperature difference.

[0051] When the system working mode is the heating mode, the central control unit turns on the second heater to heat the mixed air so that the temperature difference between the final supply air temperature and the return air temperature remains the supply air temperature difference.

[0052] Preferably, the supply air temperature difference is calculated based on the maximum supply air temperature difference and is expressed as:

[0053]

[0054] Preferably, the controlling the working mode of the host group includes controlling the working mode of the humidifier, specifically including presetting the air supply condition humidity:

[0055] When the return air humidity is less than the lower limit value of the humidity threshold, the central control unit turns on the humidifier to humidify the mixed air so that the supply air humidity is greater than the lower limit value of the humidity threshold and less than or equal to the sum of the lower limit value of the humidity threshold and the supply air condition humidity.

[0056] Compared with the prior art, the beneficial effects of the present invention include at least: by setting up a return air handling unit, the outdoor low-temperature fresh air is used to cool the indoor high-temperature return air, which greatly reduces the heat exchanger load, the cooling capacity of the main unit and the system energy consumption. In specific implementation, the central control unit obtains the temperature and humidity of the outdoor fresh air and the indoor return air, combines the temperature and humidity of the mixed air and the supply air, and the preset indoor temperature and humidity thresholds, selects the appropriate system working mode, and intelligently controls the main unit and the return air handling unit in different working modes, so as to achieve effective and rapid cooling of the high-temperature return air under the premise of low system load and low energy consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0058] Figure 1 A flow chart of an air conditioning system control method provided in the present application.

[0059] Figure 2 An architectural diagram of an air conditioning system provided in the present invention application.

[0060] The attached drawings are marked with: 1. Main unit; 2. Return air handling unit; 3. First heater; 4. Heat exchanger; 5. Second heater; 6. Humidifier; 7. Spray assembly; 8. Air heat exchanger; 9. Fan; 10. First temperature and humidity sensor element; 11. Second temperature and humidity sensor element; 12. Third temperature sensor element; 13. Fourth temperature and humidity sensor element. DETAILED DESCRIPTION

[0061] The present invention provides a temperature and humidity control air conditioning system and control method. In order to make the purpose, technical solution and effect of the present invention more clear and explicit, the present invention is further described in detail with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0062] It will be understood by those skilled in the art that, unless expressly stated, the singular forms "one", "said", and "the" used herein may also include plural forms. It should be further understood that the term "comprising" used in the specification of the present application refers to the presence of the features, integers, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or groups thereof. It should be understood that when we refer to an element as being "connected" or "coupled" to another element, it may be directly connected or coupled to the other element, or there may be an intermediate element. In addition, the "connection" or "coupling" used herein may include wireless connection or wireless coupling. The term "and / or" used herein includes all or any unit and all combinations of one or more associated listed items.

[0063] It will be understood by those skilled in the art that, unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as those generally understood by those skilled in the art to which this application belongs. It should also be understood that terms such as those defined in general dictionaries should be understood to have meanings consistent with those in the context of the prior art, and will not be interpreted with idealized or overly formal meanings unless specifically defined as here.

[0064] The application content is further explained below through the description of embodiments in conjunction with the accompanying drawings.

[0065] The drawings of the present invention are only for illustrative purposes and should not be construed as limiting the present invention. In order to better illustrate the following embodiments, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the size of the actual product; it is understandable to those skilled in the art that some well-known structures and their descriptions in the drawings may be omitted.

[0066] First, as Figure 1 As shown, an embodiment of an air conditioning system proposed in the present application, the air conditioning system comprises:

[0067] The air conditioner comprises a central control unit, a main unit 1 and a return air processing unit 2.

[0068] The host unit 1 includes a heat exchanger 4 electrically connected to the central control unit, and the heat exchanger 4 is also connected to the air conditioning unit.

[0069] Optionally, the host group 1 may further include a first heater 3, a second heater 5, and a humidifier 6;

[0070] A first heater 3, a heat exchanger 4, a second heater 5 and a humidifier 6 electrically connected to the central control unit are sequentially arranged between the fresh air inlet and the air supply outlet of the host group 1;

[0071] In an optional solution, the first heater 3 and the second heater 5 may be electric heaters to heat the outdoor fresh air or mixed air to increase the supply air temperature.

[0072] The heat exchanger 4 can be a surface cooling heat exchanger, which can cool or heat the mixed air according to the working mode of the system;

[0073] Optionally, the return air processing unit 2 includes a spray assembly 7, an air heat exchanger 8 and a fan 9;

[0074] A spray assembly 7, an air heat exchanger 8 and a fan 9 electrically connected to the central control unit are arranged in sequence between the fresh air inlet and the fresh air outlet of the return air handling unit 2; the return air inlet of the return air handling unit 2 is connected to the indoor room, and the return air outlet is connected to the main unit 1. During specific implementation, the outdoor low-temperature heat exchange fresh air enters the return air handling unit, and after being cooled by the spray assembly 7, it enters the air heat exchanger, and heat exchange treatment is performed on the indoor return air entering the return air handling unit, and the heat exchange fresh air after heat exchange treatment is discharged to the outdoors.

[0075] In a preferred embodiment, fresh air enters the main unit 1 through the fresh air inlet of the main unit 1, is mixed with the return air processed by the return air processing unit 2 in the main unit 1, and obtains mixed air. After the mixed air is heat exchanged by the heat exchanger 4, supply air is obtained, and the supply air is delivered into the room through the supply air outlet of the main unit 1.

[0076] Preferably, the return air handling unit 2 may also include a first temperature and humidity sensing element 10 and a second temperature and humidity sensing element 12. The first temperature and humidity sensing element 10 is arranged at the fresh air inlet of the return air handling unit 2, and is used to obtain the fresh air temperature T1 and fresh air humidity RH1 entering the return air handling unit; the second temperature and humidity sensing element 11 is arranged at the return air inlet of the return air handling unit 2, and is used to obtain the return air temperature T2 and return air humidity RH2 entering the return air handling unit 2.

[0077] Preferably, the main unit group 1 may also include a second temperature sensing element 12 and a fourth temperature and humidity sensing element 13, the third temperature sensing element 13 being arranged between the mixed air space 7 and the heat exchanger 4 for obtaining the mixed air temperature T3; the fourth temperature and humidity sensing element 13 being arranged at the air supply outlet of the main unit group 1 for obtaining the supply air temperature T4 and the supply air humidity RH4.

[0078] The first temperature and humidity sensing element 10 , the second temperature and humidity sensing element 11 , the third temperature sensing element 12 and the fourth temperature and humidity sensing element 13 are electrically connected to the central control unit respectively, and send the monitored temperature and humidity data to the central control unit.

[0079] In an optional embodiment, a filtering device is arranged between the fresh air inlet of the main unit group 1 and the first heater 3, and / or a filtering device is arranged at the heat exchanger 4, and / or a filtering device is arranged at the air supply outlet of the main unit group 1, for filtering the fresh air, mixed air or supply air to improve the indoor air quality.

[0080] A fan device may also be provided in the main unit 1 to control the speed and flow rate of air entering the room and maintain a stable indoor air pressure.

[0081] Second, as Figure 2 As shown, an implementation scheme of a control method of an air-conditioning system proposed in the present application corresponds to an air-conditioning system described in the first aspect, and the method includes:

[0082] S1, the return air enters the return air handling unit 2 through the indoor return air inlet, and after the heat exchange treatment of the return air handling unit 2, enters the main unit 1 through the return air outlet;

[0083] S2, fresh air enters the host group 1 through the fresh air inlet of the host group 1;

[0084] S3, the heat exchanged fresh air enters the return air handling unit 2, exchanges heat with the indoor return air entering the return air handling unit 2, and is then discharged;

[0085] S4, the return air after heat exchange by the return air processing unit 2 enters the main unit 1 and is mixed with the fresh air entering the main unit 1 to obtain mixed air;

[0086] S5, the mixed air is subjected to heat exchange treatment by the heat exchanger to obtain supply air, and the supply air is delivered into the room through the supply air outlet of the main unit 1;

[0087] S6, obtaining the fresh air temperature and fresh air humidity, the return air temperature and return air humidity entering the return air processing unit 2, the mixed air temperature of the mixed air, the supply air temperature and supply air humidity of the supply air, the preset temperature threshold, and the humidity threshold;

[0088] S7. determining a system operating mode based on the return air temperature and the temperature threshold;

[0089] S8, controlling the working modes of the return air handling unit 2 and the main unit 1 according to the system working mode, the fresh air temperature and fresh air humidity, the return air temperature and return air humidity, the mixed air temperature, the supply air temperature and supply air humidity, and the preset temperature threshold and humidity threshold;

[0090] In an optional embodiment, corresponding temperature thresholds and humidity thresholds are preset according to different requirements of different spaces. For example, the temperature threshold of the converter valve hall can be set at 10°C-35°C or 10°C to 26°C, the upper limit value Tmax of the temperature threshold of the conventional working mode is 35°C, and the lower limit value Tmin is 10°C, the upper limit value of the temperature threshold of the maintenance working mode is 26°C, and the lower limit value is 10°C, and the humidity threshold can be set at 10%-50%.

[0091] In a preferred embodiment, based on the return air temperature T2 and the temperature threshold, determining the system operating mode specifically includes:

[0092] A first temperature difference ΔT1 is preset, and the first temperature difference ΔT1 is greater than 0°C.

[0093] If T2<Tmin-ΔT1, the central control unit control system enters the heating mode;

[0094] If Tmin-ΔT1≤T2<Tmin, the central control unit control system enters the standby mode;

[0095] If T2>Tmin, the central control unit control system enters the cooling mode.

[0096] During specific implementation, according to different temperature requirements, ΔT1 can be set to a required temperature value. For example, in this embodiment, ΔT1 is set to 0.5°C.

[0097] In a preferred embodiment, the central control unit controls the working mode of the host group 1, including controlling the working mode of the fan 9, specifically including:

[0098] The central control unit obtains the fresh air temperature T1 and the fresh air humidity RH1 obtained by the first temperature and humidity sensor unit 11, calculates the fresh air dew point temperature LD1, and presets the second temperature difference ΔT2, the second temperature difference ΔT2 is greater than 0°C, presets the first fan condition temperature, the second fan condition temperature and the third fan condition temperature, presets the first fan frequency, the second fan frequency and the third fan frequency, wherein the first fan condition temperature is greater than the second fan condition temperature, the first fan frequency is greater than the second fan frequency, and the second fan frequency is greater than the third fan frequency,

[0099] If LD1<T2-ΔT2, and T2>Tmax, the central control unit turns on the fan 9, and the fan frequency is the first fan frequency;

[0100] If LD1<T2-ΔT2, and Tmin≤T2≤Tmax,

[0101] When T2 ≥ the first fan condition temperature, the central control unit turns on the fan 9, and the fan frequency is the second fan frequency;

[0102] When the second fan condition temperature ≤ T2 < the first fan condition temperature, the central control unit turns on the fan 9, and the fan frequency is the third fan frequency;

[0103] When T2 is less than the second fan condition temperature, the central control unit turns off the fan 9 .

[0104] For example, in this embodiment, the second temperature difference ΔT2 is set to 2°C, the first fan condition temperature is set to 0.6*(Tmin+Tmax), the second fan condition temperature is set to 0.5*(Tmin+Tmax), the first fan frequency is set to 100%, and the second fan frequency is set to The third fan frequency is set to 30%, wherein Tmax is the upper limit value of the temperature threshold, and Tmax is the lower limit value of the temperature threshold.

[0105] In a preferred embodiment, the control of the working mode of the return air handling unit includes controlling the working mode of the spray assembly 7, specifically including presetting the spray condition temperature Ts and the spray condition humidity RHs,

[0106] When T1>Ts and RH1<RHs, if the fan 9 is turned on at this time, the central control unit turns on the spray assembly 7;

[0107] When T1<Ts and / or RH1>RHs, the central control unit turns off the spray assembly 7 .

[0108] Exemplarily, in this embodiment, the temperature of the spraying condition is preset to 10° C., and the humidity of the spraying condition is preset to 80%.

[0109] In an optional preferred implementation, when the working mode is the heating mode, the central control unit further controls the working mode of the first heater 3 according to the mixed air temperature T3, specifically including:

[0110] A first heating condition temperature Th1, a second heating condition temperature Th2, a third heating condition temperature Th3, a fourth heating condition temperature Th4, and a fifth heating condition temperature Th5 are preset, and a first heating power W1, a second heating power W2, a third heating power W3, a fourth heating power W4, and a fifth heating power W5 are preset, wherein Th1>Th2>Th3>Th4>Th5, W1<W2<W3<W4<W5,

[0111] If T3<Th1, the central control unit turns on the first heater 3 with a power of W1;

[0112] If Th1≤T3<Th2, the central control unit turns on the first heater 3 with a power of W2;

[0113] If Th2≤T3<Th3, the central control unit turns on the first heater 3 with a power of W3;

[0114] If Th3≤T3<Th4, the central control unit turns on the first heater 3 with a power of W4;

[0115] If Th4≤T3<Th5, the central control unit turns on the first heater 3 with a power of W5;

[0116] If Th5≤T3, the central control unit turns off the first heater 3.

[0117] During specific implementation, the working powers of different first heaters 3 under different temperature gradients can be set according to specific circumstances and requirements.

[0118] In a preferred embodiment, the central control unit controls the working mode of the heat exchanger 4 based on the working mode, the return air temperature T2 and the return air humidity RH2, specifically including:

[0119] When the system is in cooling mode,

[0120] When T2>Tmax, the central control unit controls the heat exchanger 4 to pass chilled water, the chilled water flow is set to a preset maximum flow, the chilled water temperature is set to a preset minimum temperature, and the mixed air is cooled;

[0121] When the return air temperature Tmin<T2<Tmax, the central control unit further controls the working mode of the heat exchanger according to the return air humidity RH2, specifically including:

[0122] If RH2>RHmin, the central control unit controls the heat exchanger 4 to increase the chilled water temperature based on the current chilled water temperature and / or to reduce the chilled water flow rate based on the current chilled water flow rate.

[0123] If RH2<RHmin, the central control unit controls the heat exchanger 4 to lower the chilled water temperature based on the current chilled water temperature and / or to increase the chilled water flow rate based on the current chilled water flow rate.

[0124] If RHmin<RH2<RHmax, the central control unit controls the temperature and flow rate of the chilled water in the heat exchanger 4 to remain unchanged;

[0125] When the system working mode is the heating mode, the central control unit controls the heat exchanger 4 to pass hot water, and the mixed air performs heat exchange processing.

[0126] In an optional preferred embodiment, the central control unit further controls the working mode of the second heater 5, specifically including:

[0127] A maximum air supply temperature difference ΔTmax is preset, and the central control unit calculates the air supply temperature difference ΔT based on the maximum air supply temperature difference.

[0128] When the system working mode is the heating mode, the central control unit turns on the second heater 5 to heat the mixed air so that the final supply air temperature T4=T2-ΔT. In specific implementation, the supply air temperature difference ΔT can be calculated by the following formula:

[0129]

[0130] In an optional preferred embodiment, the central control unit also controls the working mode of the humidifier 5, specifically including the preset air supply condition humidity RHm,

[0131] When RH2<RHmin, the central control unit turns on the humidifier 6 to humidify the mixed air so that RHmin<RH2<RHmin+RHm.

[0132] During specific implementation, the RHm is set according to the indoor humidity. For example, in this embodiment, the RHmin+RHm≤90%.

[0133] Obviously, the above embodiments of the present application are merely examples for clearly illustrating the technical solutions of the present application, and are not limitations on the specific implementation methods of the present application. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the claims of the present application should be included in the protection of the claims of the present application.

Claims

1. A method for controlling an air conditioning system, characterized in that: The system includes a central control unit, a main unit and a return air handling unit. The host unit includes a heat exchanger electrically connected to the central control unit, and the heat exchanger is also connected to the air conditioning unit. The return air processing unit includes an air heat exchanger for performing heat exchange processing on the indoor return air. The method comprises: Fresh air enters the host group through the fresh air inlet of the host group; The heat exchanged fresh air enters the air heat exchanger, exchanges heat with the indoor return air entering the return air handling unit, and then is discharged; The return air enters the return air processing unit through the indoor return air inlet, and after heat exchange treatment by the air heat exchanger, enters the main unit through the return air outlet; The return air after heat exchange treatment enters the main unit and mixes with the fresh air entering the main unit to obtain mixed air; The mixed air is subjected to heat exchange treatment by the heat exchanger to obtain supply air, and the supply air is delivered into the room through the air supply outlet of the main unit; Obtaining the fresh air temperature and fresh air humidity, the return air temperature and return air humidity entering the return air processing unit, the mixed air temperature of the mixed air, the supply air temperature and supply air humidity of the supply air, the preset temperature threshold, and the humidity threshold; Determining a system operating mode based on the return air temperature and the temperature threshold; The working modes of the return air handling unit and the main unit are controlled according to the system working mode, the fresh air temperature and fresh air humidity, the return air temperature and return air humidity, the mixed air temperature, the supply air temperature and supply air humidity, and the preset temperature threshold and humidity threshold.

2. The air conditioning system control method according to claim 1, characterized in that: The determining of the system operating mode based on the return air temperature and the temperature threshold specifically includes: A first temperature difference is preset, the first temperature difference is greater than 0°C, If the return air temperature is less than the difference between the lower limit of the temperature threshold and the first temperature difference, the central control unit control system enters a heating mode; If the return air temperature is greater than or equal to the difference between the lower limit of the temperature threshold and the first temperature difference, and less than the lower limit of the temperature threshold, the central control unit control system enters the standby mode; If the return air temperature is greater than or equal to the lower limit of the temperature threshold, the central control unit control system enters the cooling mode.

3. The air conditioning system control method according to claim 2, characterized in that: The main unit further comprises a first heater, a second heater and a humidifier, wherein the fresh air passes through the fresh air inlet of the main unit, first passes through the first heater and then mixes with the return air processed by the return air processing unit to obtain the mixed air; the mixed air passes through the heat exchanger, the second heater and the humidifier in sequence to reach the air supply outlet of the main unit; The return air processing unit also includes a spray component and a fan. The spray component is used to perform heat exchange treatment on the heat exchange fresh air, and the heat exchange fresh air exchanges heat with the indoor return air after passing through the spray component; the fan is used to discharge the heat exchange fresh air after heat exchange with the indoor return air.

4. The air conditioning system control method according to claim 3, characterized in that: The control of the working mode of the return air handling unit includes controlling the working mode of the fan, specifically including: When the system working mode is the cooling mode, the central control unit calculates the fresh air dew point temperature based on the fresh air temperature and the fresh air humidity, and presets a second temperature difference, the second temperature difference is greater than 0°C, presets a first fan condition temperature and a second fan condition temperature, and presets a first fan frequency, a second fan frequency and a third fan frequency, wherein the first fan condition temperature is greater than the second fan condition temperature, the first fan frequency is greater than the second fan frequency, and the second fan frequency is greater than the third fan frequency; If the fresh air dew point temperature is less than the difference between the return air temperature and the second temperature difference, and the return air temperature is greater than the upper limit of the temperature threshold, the central control unit turns on the fan, and the fan frequency is the first fan frequency; If the fresh air dew point temperature is less than the difference between the return air temperature and the second temperature difference, and the return air temperature is within the temperature threshold: when the return air temperature is greater than or equal to the first fan condition temperature, the central control unit turns on the fan, and the fan frequency is the second fan frequency; When the return air temperature is greater than or equal to the second fan condition temperature and less than the first fan condition temperature, the central control unit turns on the fan, and the fan frequency is a third fan frequency; When the return air temperature is lower than the second fan condition temperature, the central control unit turns off the fan.

5. The air conditioning system control method according to claim 3, characterized in that: The control of the working mode of the return air unit includes controlling the working mode of the spray assembly, specifically including: Preset spray condition temperature and spray condition humidity; When the fresh air temperature is greater than or equal to the spray condition temperature, and the fresh air humidity is less than the spray condition humidity, if the fan is turned on at this time, the central control unit turns on the spray component; When the fresh air temperature is lower than the spray condition temperature, and / or the fresh air humidity is higher than the spray condition humidity, the central control unit turns off the spray component.

6. The air conditioning system control method according to claim 3, characterized in that: The operating mode of the control host group includes controlling the operating mode of the first heater, specifically including: The preset values ​​are the first heating condition temperature, the second heating condition temperature, the third heating condition temperature, the fourth heating condition temperature, and the fifth heating condition temperature, which are increased in sequence, and the preset values ​​are the first heating power, the second heating power, the third heating power, the fourth heating power, and the fifth heating power, which are decreased in sequence. When the system is in heating mode, If the mixed air temperature is lower than the first heating condition temperature, the central control unit turns on the first heater at a first heating power; If the mixed air temperature is greater than or equal to the first heating condition temperature and less than the second heating condition temperature, the central control unit turns on the first heater with a second heating power; If the mixed air temperature is greater than or equal to the second heating condition temperature and less than the third heating condition temperature, the central control unit turns on the first heater with a third heating power; If the mixed air temperature is greater than or equal to the third heating condition temperature and less than the fourth heating condition temperature, the central control unit turns on the first heater with a fourth heating power; If the mixed air temperature is greater than or equal to the fourth heating condition temperature and less than the fifth condition temperature, the central control unit turns on the first heater with a power of the fifth heating power; If the mixed air temperature is greater than or equal to the fifth condition temperature, the central control unit turns off the first heater.

7. The air conditioning system control method according to claim 3, characterized in that: The working mode of the control host group includes controlling the working mode of the heat exchanger, specifically including: When the system is in cooling mode, When the return air temperature is greater than the upper limit of the temperature threshold, the central control unit controls the heat exchanger to pass chilled water, sets the chilled water flow rate to the maximum flow rate, sets the chilled water temperature to the preset minimum temperature, and performs cooling treatment on the mixed air; When the return air temperature drops within the temperature threshold, the working mode of the heat exchanger is further controlled according to the return air humidity, specifically including: If the return air humidity is greater than the lower limit of the humidity threshold, the central control unit controls the heat exchanger to increase the chilled water temperature based on the current chilled water temperature and / or reduce the chilled water flow rate based on the current chilled water flow rate; If the return air humidity is less than the lower limit of the humidity threshold, the central control unit controls the heat exchanger to lower the chilled water temperature based on the current chilled water temperature and / or increase the chilled water flow rate based on the current chilled water flow rate; If the return air humidity is within the humidity threshold, the temperature and flow rate of the chilled water in the heat exchanger remain unchanged; When the system working mode is the heating mode, the central control unit controls the heat exchanger to pass hot water to perform heat exchange processing on the mixed air.

8. The air conditioning system control method according to claim 3, characterized in that: The controlling the working mode of the host group further includes controlling the working mode of the second heater, specifically including: A maximum supply air temperature difference is preset, and a supply air temperature difference is calculated based on the maximum supply air temperature difference. When the system working mode is the heating mode, the central control unit turns on the second heater to heat the mixed air so that the temperature difference between the final supply air temperature and the return air temperature is maintained at the supply air temperature difference.

9. The air conditioning system control method according to claim 8, characterized in that: The supply air temperature difference is calculated based on the maximum supply air temperature difference and is expressed as:

10. An air conditioning system control method according to any one of claims 3 to 9, characterized in that: The controlling the working mode of the host group includes controlling the working mode of the humidifier, specifically including: Preset air supply condition humidity; When the return air humidity is less than the lower limit value of the humidity threshold, the central control unit turns on the humidifier to humidify the mixed air so that the supply air humidity is greater than the lower limit value of the humidity threshold and less than or equal to the sum of the lower limit value of the humidity threshold and the supply air condition humidity.

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