Central air conditioner control system and method based on indoor enthalpy value control

Abstract

The invention discloses a central air conditioner control system and method based on indoor enthalpy value control. The system comprises a sensor module used for monitoring and collecting relevant parameters; the specific enthalpy value obtaining module is used for obtaining an air specific enthalpy value according to the collected parameters; the operation adjusting module controls a panel to adjust the operation mode, the air volume and the temperature according to the relation between the specific enthalpy value and a preset value, and the indoor specific enthalpy value meets the preset requirement; the real-time monitoring and automatic adjusting module is used for adjusting the opening group number of the surface air cooler coil pipe by calculating the enthalpy difference with a set value; the judgment and control module is used for judging whether the specific enthalpy value of the control panel reaches a set range or not; and the parameters are adjusted to enable the specific enthalpy value to reach a set value. The heat and humidity load condition of the indoor environment can be quickly judged and the real-time state is mastered; a specific enthalpy value operation control mode is adopted, fan coil operation and indoor environment parameters are accurately linked, operation is guided according to environment requirement feedback, air conditioner operation scientificity is improved, and accurate regulation and control of an air conditioner system are achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of energy-saving of air-conditioning systems, and relates to a central air-conditioning control system and method based on indoor enthalpy control. Background Art

[0002] In the construction sector, as people's quality of life continues to improve, the demand for indoor environmental comfort is also increasing. Central air conditioning systems, as key equipment for regulating a building's indoor environment, have a direct impact on people's indoor work and living experience. Scientifically and efficiently controlling central air conditioning systems to meet indoor comfort requirements while reducing energy consumption has become a critical issue facing the current construction industry. For indoor air conditioning systems in buildings, the control panel is a key component for user interaction with the system, responsible for controlling the air conditioning's operating status and adjusting indoor environmental parameters. Currently, conventional control panels for indoor building air conditioning systems primarily utilize temperature control. While this control method met people's basic need for indoor temperature regulation for a period of time, its drawbacks have gradually become apparent with the deepening of research on indoor environmental comfort and the growing awareness of energy conservation.

[0003] The working principle of the existing fan coil control panel mainly revolves around temperature control, as follows: Fan coil temperature control: A thermostat automatically controls the opening and closing of electric two- and three-way valves and the fan's three-speed switching based on a comparison and calculation between the set temperature and the actual measured temperature. Alternatively, the thermostat directly controls the fan's three-speed switching and starts and stops, thereby achieving a constant temperature by controlling the system's water flow or air volume. The thermostat detects the room temperature in real time and compares it to the set temperature. Based on the comparison result, the electric valve is turned on and off to maintain a constant room temperature. If the indoor temperature is above the set point, the "modulation / on / off" valve is activated, and chilled water provided by the building's central system flows through the coil. A fan draws air through the chilled water coil, cooling the air and lowering the room's temperature. If the indoor temperature is below the set point, the heating function is activated to raise the indoor temperature.

[0004] Fan control: Users can control the fan's start and stop by pressing the on / off button on the control panel. Some advanced control panels also provide a fan speed adjustment function, allowing users to select high, medium, or low fan speeds according to their needs.

[0005] Temperature control: The control panel is typically equipped with a temperature setter. Users can adjust the desired indoor temperature by adjusting the knob or buttons on the setter. When the indoor temperature rises above or falls below the set value, the control panel automatically activates or deactivates the fan coil unit's heating or cooling function to maintain a constant indoor temperature.

[0006] Mode selection: Some fan coil unit control panels also offer different operating modes, such as cooling mode, heating mode, dehumidification mode, and air supply mode. Users can choose the appropriate mode according to their actual needs to meet the indoor environment adjustment requirements in different scenarios.

[0007] Fault alarm: When the fan coil unit or control panel fails, the indicator light on the control panel will light up or an alarm will sound to remind the user to check and repair in time to ensure the normal operation of the air conditioning system.

[0008] Energy-saving function: Some advanced fan coil control panels are also equipped with energy-saving functions, such as sleep mode, timed power on and off, etc. They can help users save energy and reduce operating costs, and to a certain extent respond to the needs of energy conservation and emission reduction.

[0009] Existing control panel parameters fail to accurately and comprehensively reflect the actual indoor environmental parameters: Temperature isn't the only indicator affecting indoor comfort; comfort is a subjective reflection of the combined influence of multiple factors, including temperature and humidity. For example, in summer, at the same temperature, higher humidity makes it more difficult for sweat to evaporate and dissipate heat, resulting in decreased comfort. Existing control panels rely solely on temperature as a control basis, failing to account for the impact of other factors, such as humidity, on comfort. This inability to accurately and comprehensively reflect the actual indoor environmental parameters results in an unscientific control approach.

[0010] This is detrimental to the energy-saving operation of central air conditioning systems: Using the set temperature as the control standard can lead to energy waste. For example, when the control panel temperature is set to 20°C, based on the ambient humidity on a particular day (55%), the indoor temperature only needs to be 26°C to meet human comfort requirements. However, under the existing control method, when the indoor temperature reaches 26°C, the fan coil unit's fan will continue to operate until the indoor temperature drops to 20°C. During the process of decreasing the ambient temperature from 26°C to 20°C, the fan coil unit's continued operation generates excess electricity consumption, which is detrimental to the energy-saving operation of the central air conditioning system. Summary of the Invention

[0011] The purpose of the present invention is to solve the problem in the prior art that panel parameters cannot accurately and comprehensively reflect indoor environmental parameters, which is not conducive to energy-saving operation of air-conditioning systems, and to provide a central air-conditioning control system and method based on indoor enthalpy control.

[0012] In order to achieve the above object, the present invention adopts the following technical solutions: A central air-conditioning control system based on indoor enthalpy control, comprising: Sensor module: including temperature sensor, humidity sensor, and air pressure sensor, which are used to monitor and collect the indoor dry-bulb temperature of the fan coil when the panel is turned on.t , ambient relative humidity φ and atmospheric pressure Pa; Specific enthalpy value acquisition module: based on the collected dry bulb temperature data t and humidity data φ , get the air specific enthalpy i ; Operation adjustment module: According to the relationship between the specific enthalpy value and the preset value, the operation mode, air volume and temperature are adjusted through the control panel to achieve the specific enthalpy value in the room meeting the preset requirements; Real-time monitoring and automatic adjustment module: During equipment operation, the system monitors the indoor air specific enthalpy in real time and automatically adjusts the number of open groups of the surface cooler coils by calculating the enthalpy difference with the set value, thereby accurately controlling the indoor temperature, humidity and airflow speed; Judgment and control module: After adjusting the initial parameters, it is determined whether the specific enthalpy value of the control panel reaches the set range; if so, it is determined that the indoor environment adjustment is complete, and the fan coil unit is operated according to the pre-set specific enthalpy value, and the fan coil unit is automatically stopped or operated at low power to save energy; otherwise, the fan coil unit operation is extended or the parameters are further adjusted until the current indoor enthalpy value is less than or equal to the set enthalpy value, and the fan coil unit is controlled to stop or operate at low power.

[0013] A further improvement of the present invention is: The specific enthalpy of air i , set the formula as: i =1.01 t +(2490+1.84 t ) d in d =622 φPs / ( P - φPs ) Where: i represents the air enthalpy value (kJ / kg dry air); t Indicates the monitored dry bulb temperature data (℃); d Indicates moisture content (g / kg (dry air)); P Indicates atmospheric pressure (Pa); P.S Indicates the saturated vapor pressure of water vapor (Pa); φ Indicates the monitored relative humidity data (%).

[0014] The specific working process of the sensor module is as follows: When the user turns on the central air conditioning control panel by operating the control switch on the control panel or other preset turning-on methods, the microprocessor inside the control panel receives the turning-on signal and starts the initialization program to perform self-test and configuration on each module of the control panel; The microprocessor configures the specific communication interface for data transmission between the temperature sensor, humidity sensor and air pressure sensor and the microprocessor, and sets the communication parameters; Temperature sensor collects dry bulb temperature t :The temperature sensor converts the sensed temperature changes into electrical signals. When analog output is used, the microprocessor converts the analog electrical signals into digital signals through the internal analog-to-digital converter. When digital output is used, the microprocessor reads the digital temperature data through the communication interface. Humidity sensor collects ambient relative humidity φ : The humidity sensor senses the water vapor content in the air to perceive the relative humidity of the environment; the humidity sensor converts the sensed humidity changes into electrical signals. When the analog output is used, the microprocessor converts the signal into a digital signal through the internal analog-to-digital converter. When the digital output is used, the microprocessor reads the digital humidity data through the communication interface. The air pressure sensor collects atmospheric pressure Pa: The air pressure sensor uses sensitive elements to sense changes in atmospheric pressure; the air pressure sensor converts the sensed air pressure changes into electrical signals. When analog output is used, the microprocessor converts the signal into a digital signal through the internal analog-to-digital converter. When digital output is used, the microprocessor reads the digital air pressure data through the communication interface. The temperature sensor, humidity sensor and air pressure sensor collect and process the dry bulb temperature t , ambient relative humidity φ The data of atmospheric pressure Pa are transmitted to the microprocessor through their respective communication interfaces.

[0015] The operation adjustment module: according to the relationship between the specific enthalpy value and the preset value, adjusts the operation mode, air volume, and temperature through the control panel to achieve the specific enthalpy value in the room to meet the preset requirements; specifically: The microprocessor calculates the current indoor air specific enthalpy value i Compared with the target specific enthalpy value pre-set in the control panel iset Compare and determine the deviation between the current indoor air state and the target state: like i = iset , maintain the current operating mode, air volume and temperature settings of the air conditioning system; like i > iset , indicating that the indoor air has too much heat and the specific enthalpy needs to be reduced; like i < iset , indicating that the indoor air heat is insufficient and the specific enthalpy needs to be increased.

[0016] The real-time monitoring and automatic adjustment module: During the operation of the equipment, the system monitors the indoor air specific enthalpy in real time and automatically adjusts the number of open groups of the surface cooler coil by calculating the enthalpy difference with the set value, thereby accurately controlling the indoor temperature, humidity and airflow speed; specifically: when i > iset When: If the air conditioning system is currently in heating mode, the microprocessor switches the operating mode to cooling mode through the control panel; if it is currently in cooling mode, the cooling mode remains unchanged and the cooling effect is enhanced; the microprocessor controls the fan to increase the speed and increase the air supply volume; the microprocessor reduces the set temperature of the air conditioner according to the deviation between the current specific enthalpy value and the preset value; when i < iset When: If the air conditioning system is currently in cooling mode, the microprocessor switches the operating mode to heating mode through the control panel; if it is currently in heating mode, the heating mode is maintained and the heating effect is enhanced; the microprocessor controls the fan to reduce the speed and reduce the air supply; the microprocessor appropriately increases the set temperature of the air conditioner according to the degree of deviation between the current specific enthalpy value and the preset value.

[0017] The system also includes a manual adjustment module: providing a manual adjustment function, the user can directly adjust the number of coil groups, temperature settings and air volume as needed to quickly reach the target specific enthalpy value state.

[0018] In the manual adjustment module, the adjustment strategy is as follows: Cooling mode: When the air specific enthalpy value is higher than the set threshold, the number of surface cooler coil groups opened is increased. Each additional coil group increases the heat exchange area by 15-20%, improving the cooling capacity. The air supply volume is increased, and the variable frequency fan speed is increased by 10-15% to enhance the sensible heat exchange. The priority is to increase the number of coil groups first, and then adjust the air volume, to balance energy efficiency and cooling speed. When the air specific enthalpy is lower than the set threshold, the number of coil groups is reduced or switched to partial load operation to avoid overcooling.

[0019] The adjustment parameters in the judgment and control module are specifically as follows: if the current specific enthalpy value still does not reach the set range after the fan coil operation time is extended, the control module continues to adjust the parameters, including the temperature setting value, air volume size, and humidity setting value; Adjust the temperature setting value: Increase or decrease the temperature setting value based on the deviation direction of the current specific enthalpy value and the set range. If the current specific enthalpy value is too high, it means that the indoor temperature is too high, and the temperature setting value will be lowered to enhance the cooling effect; if the current specific enthalpy value is too low, it means that the indoor temperature is too low, and the temperature setting value will be increased to enhance the heating effect; Adjust the air volume: Increase or decrease the fan speed to change the air supply volume. If you need to adjust the specific enthalpy of the indoor air more quickly, you can increase the air volume to speed up the heat exchange between the air and the fan coil unit. Adjust the humidity set value: If the deviation of the specific enthalpy value is related to humidity, the control module will adjust the humidity set value; in a humid environment, if the current specific enthalpy value is too high, by lowering the humidity set value, the dehumidification function is activated to reduce the moisture content in the air, thereby lowering the specific enthalpy value.

[0020] A central air-conditioning control method based on indoor enthalpy control comprises the following steps: Data collection: When the control panel is turned on, the temperature sensor, humidity sensor, and air pressure sensor are used to monitor and collect the dry-bulb temperature of the indoor environment where the fan coil unit is located. t , ambient relative humidity φ and atmospheric pressure And ; Specific enthalpy value acquisition: Based on dry bulb temperature data t and humidity data φ , get the air specific enthalpy i ; Operation adjustment: According to the relationship between the specific enthalpy value and the preset value, the operation mode, air volume and temperature of the air conditioning system are adjusted through the control panel to achieve the specific enthalpy value in the room to meet the preset requirements; Real-time monitoring and automatic adjustment: During the operation of the equipment, the indoor air specific enthalpy value is monitored in real time. By calculating the enthalpy difference with the set value, the number of open groups of the surface cooler coils is automatically adjusted to accurately control the indoor temperature, humidity and airflow speed. Judgment and control: After adjusting the air-conditioning system according to the initial parameters, determine whether the specific enthalpy value on the control panel reaches the set range; if so, determine that the indoor environment adjustment is complete, operate according to the pre-set specific enthalpy value, and control the fan coil to automatically stop or operate at low power to save energy; if not, extend the fan coil operation or further adjust the parameters until the current indoor enthalpy value is less than or equal to the set enthalpy value, and control the fan coil to stop or operate at low power.

[0021] Compared with the prior art, the present invention has the following beneficial effects: The central air-conditioning control system based on indoor enthalpy control in the present invention can evaluate the indoor environment intuitively and conveniently. By reading the specific enthalpy data on the air-conditioning control panel, the heat and humidity load of the indoor environment can be quickly judged and its real-time status can be grasped. The operation control method based on specific enthalpy rather than a single temperature is adopted to make the fan coil operation accurately linked with the indoor environmental parameters, and the operation is guided by feedback from environmental needs, which improves the scientific nature of the air-conditioning operation and realizes the precise regulation of the air-conditioning system. In addition, the fan coil operation is adjusted based on the actual demand of the indoor load. When the indoor enthalpy value is lower than the set target value in summer, the fan coil automatically stops or operates at a low efficiency, which can effectively achieve more energy saving compared with the temperature control method. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0023] Figure 1 This is a module diagram of a central air-conditioning control system based on indoor enthalpy control according to the present invention; Figure 2 This is the overall appearance of the device of the present invention.

[0024] Among them: (1) control switch, (2) control mode, (3) control air volume, (4) heating switch, (5) cooling switch, (6) fault alarm light, (7) panel screen, (8) surface cooler panel controller. DETAILED DESCRIPTION

[0025] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations.

[0026] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention as claimed, but rather merely represents selected embodiments of the present invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort shall fall within the scope of protection of the present invention.

[0027] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0028] The present invention is described in further detail below with reference to the accompanying drawings: See also Figure 1 , is a module diagram of a central air-conditioning control system based on indoor enthalpy control in the present invention, comprising: Sensor module: including temperature sensor, humidity sensor, and air pressure sensor, which are used to monitor and collect the indoor dry-bulb temperature of the fan coil when the panel is turned on. t , ambient relative humidity φ And atmospheric pressure Pa. The specific working process of the sensor module is: When the user turns on the central air conditioning control panel by operating the control switch on the control panel or other preset turning-on methods, the microprocessor inside the control panel receives the turning-on signal and starts the initialization program to perform self-test and configuration on each module of the control panel; The microprocessor configures the specific communication interface for data transmission between the temperature sensor, humidity sensor and air pressure sensor and the microprocessor, and sets the communication parameters; Temperature sensor collects dry bulb temperature t :The temperature sensor converts the sensed temperature changes into electrical signals. When analog output is used, the microprocessor converts the analog electrical signals into digital signals through the internal analog-to-digital converter. When digital output is used, the microprocessor reads the digital temperature data through the communication interface. Humidity sensor collects ambient relative humidity φ : The humidity sensor senses the water vapor content in the air to perceive the relative humidity of the environment; the humidity sensor converts the sensed humidity changes into electrical signals. When the analog output is used, the microprocessor converts the signal into a digital signal through the internal analog-to-digital converter. When the digital output is used, the microprocessor reads the digital humidity data through the communication interface. The air pressure sensor collects atmospheric pressure Pa: The air pressure sensor uses sensitive elements to sense changes in atmospheric pressure; the air pressure sensor converts the sensed air pressure changes into electrical signals. When analog output is used, the microprocessor converts the signal into a digital signal through the internal analog-to-digital converter. When digital output is used, the microprocessor reads the digital air pressure data through the communication interface. The temperature sensor, humidity sensor and air pressure sensor collect and process the dry bulb temperature t , ambient relative humidity φ The data of atmospheric pressure Pa are transmitted to the microprocessor through their respective communication interfaces.

[0029] Specific enthalpy value acquisition module: based on the collected dry bulb temperature data t and humidity data φ , get the air specific enthalpy i .

[0030] The specific enthalpy of air i , set the formula as: i =1.01 t +(2490+1.84 t ) d in d =622 φPs / ( P - φPs ) Where: i represents the air enthalpy value (kJ / kg dry air); t Indicates the monitored dry bulb temperature data (℃); d Indicates moisture content (g / kg (dry air)); P Indicates atmospheric pressure (Pa); P.S Indicates the saturated vapor pressure of water vapor (Pa); φ Indicates the monitored relative humidity data (%).

[0031] Operation adjustment module: According to the relationship between the specific enthalpy value and the preset value, the operation mode, air volume and temperature are adjusted through the control panel to achieve the indoor specific enthalpy value reaching the preset requirements.

[0032] According to the relationship between the specific enthalpy value and the preset value, the operating mode, air volume, and temperature are adjusted through the control panel to achieve the specific enthalpy value in the room to meet the preset requirements; specifically: The microprocessor calculates the current indoor air specific enthalpy value i Compared with the target specific enthalpy value pre-set in the control panel iset Compare and determine the deviation between the current indoor air state and the target state: like i = iset , maintain the current operating mode, air volume and temperature settings of the air conditioning system; like i > iset , indicating that the indoor air has too much heat and the specific enthalpy needs to be reduced; like i < iset , indicating that the indoor air heat is insufficient and the specific enthalpy needs to be increased.

[0033] Real-time monitoring and automatic adjustment module: During equipment operation, the system monitors the indoor air specific enthalpy in real time, and automatically adjusts the number of open groups of the surface cooler coil by calculating the enthalpy difference with the set value, thereby accurately controlling the indoor temperature, humidity and airflow speed.

[0034] During equipment operation, the system monitors the indoor air specific enthalpy in real time and automatically adjusts the number of open groups of the surface cooler coils by calculating the enthalpy difference with the set value, thereby accurately controlling the indoor temperature, humidity and airflow speed; specifically: when i > iset When: If the air conditioning system is currently in heating mode, the microprocessor switches the operating mode to cooling mode through the control panel; if it is currently in cooling mode, the cooling mode remains unchanged and the cooling effect is enhanced; the microprocessor controls the fan to increase the speed and increase the air supply volume; the microprocessor reduces the set temperature of the air conditioner according to the deviation between the current specific enthalpy value and the preset value; when i < iset When: If the air conditioning system is currently in cooling mode, the microprocessor switches the operating mode to heating mode through the control panel; if it is currently in heating mode, the heating mode is maintained and the heating effect is enhanced; the microprocessor controls the fan to reduce the speed and reduce the air supply; the microprocessor appropriately increases the set temperature of the air conditioner according to the degree of deviation between the current specific enthalpy value and the preset value.

[0035] Judgment and control module: After adjusting the initial parameters, it is determined whether the specific enthalpy value of the control panel reaches the set range; if so, it is determined that the indoor environment adjustment is complete, and the fan coil unit is operated according to the pre-set specific enthalpy value, and the fan coil unit is automatically stopped or operated at low power to save energy; otherwise, the fan coil unit operation is extended or the parameters are further adjusted until the current indoor enthalpy value is less than or equal to the set enthalpy value, and the fan coil unit is controlled to stop or operate at low power.

[0036] The adjustment parameters in the judgment and control module are specifically as follows: if the current specific enthalpy value still does not reach the set range after the fan coil operation time is extended, the control module continues to adjust the parameters, including the temperature set value, air volume, and humidity set value; Adjust the temperature setting value: Increase or decrease the temperature setting value based on the deviation direction of the current specific enthalpy value and the set range. If the current specific enthalpy value is too high, it means that the indoor temperature is too high, and the temperature setting value will be lowered to enhance the cooling effect; if the current specific enthalpy value is too low, it means that the indoor temperature is too low, and the temperature setting value will be increased to enhance the heating effect; Adjust the air volume: Increase or decrease the fan speed to change the air supply volume. If you need to adjust the specific enthalpy of the indoor air more quickly, you can increase the air volume to speed up the heat exchange between the air and the fan coil unit. Adjust the humidity set value: If the deviation of the specific enthalpy value is related to humidity, the control module will adjust the humidity set value; in a humid environment, if the current specific enthalpy value is too high, by lowering the humidity set value, the dehumidification function is activated to reduce the moisture content in the air, thereby lowering the specific enthalpy value.

[0037] Manual adjustment module: provides manual adjustment function, users can directly adjust the number of coil groups, temperature settings and air volume as needed to quickly reach the target specific enthalpy value state.

[0038] In the manual adjustment module, the adjustment strategy is as follows: Cooling mode: When the air specific enthalpy value is higher than the set threshold, the number of surface cooler coil groups opened is increased. Each additional coil group increases the heat exchange area by 15-20%, improving the cooling capacity. The air supply volume is increased, and the variable frequency fan speed is increased by 10-15% to enhance the sensible heat exchange. The priority is to increase the number of coil groups first, and then adjust the air volume, to balance energy efficiency and cooling speed. When the air specific enthalpy is lower than the set threshold, the number of coil groups is reduced or switched to partial load operation to avoid overcooling.

[0039] An embodiment of the present invention is a central air conditioning control method based on indoor enthalpy control, comprising the following steps: Data collection: When the control panel is turned on, the temperature sensor, humidity sensor, and air pressure sensor are used to monitor and collect the dry-bulb temperature of the indoor environment where the fan coil unit is located. t , ambient relative humidity φ and atmospheric pressure And ; Specific enthalpy value acquisition: Based on dry bulb temperature data t and humidity data φ , get the air specific enthalpy i ; Operation adjustment: According to the relationship between the specific enthalpy value and the preset value, the operation mode, air volume and temperature of the air conditioning system are adjusted through the control panel to achieve the specific enthalpy value in the room to meet the preset requirements; Real-time monitoring and automatic adjustment: During the operation of the equipment, the indoor air specific enthalpy value is monitored in real time. By calculating the enthalpy difference with the set value, the number of open groups of the surface cooler coils is automatically adjusted to accurately control the indoor temperature, humidity and airflow speed. Judgment and control: After adjusting the air-conditioning system according to the initial parameters, determine whether the specific enthalpy value on the control panel reaches the set range; if so, determine that the indoor environment adjustment is complete, operate according to the pre-set specific enthalpy value, and control the fan coil to automatically stop or operate at low power to save energy; if not, extend the fan coil operation or further adjust the parameters until the current indoor enthalpy value is less than or equal to the set enthalpy value, and control the fan coil to stop or operate at low power.

[0040] Example Data collection When the control panel is turned on, the temperature sensor, humidity sensor, and air pressure sensor installed in the room where the fan coil unit is located are activated.

[0041] The temperature sensor continuously monitors the dry-bulb temperature of the indoor environment at a preset sampling frequency t , the humidity sensor continuously monitors the relative humidity of the indoor environment at the same or different preset sampling frequencies φ The air pressure sensor continuously monitors the indoor atmospheric pressure at a preset sampling frequency. And and transmits the collected data to the central control unit.

[0042] Specific enthalpy value acquisition The central control unit receives dry bulb temperature data from the sensor t and humidity data φ .

[0043] According to the thermodynamic formula pre-stored in the central control unit, combined with the collected dry bulb temperature t and ambient relative humidity φ , calculate the current specific enthalpy of indoor air i .

[0044] Operation adjustment The central control unit calculates the specific enthalpy value i Compared with the preset target specific enthalpy value iset Make a comparison.

[0045] If the current specific enthalpy value is equal to the preset value ( i = iset ), maintain the current operating mode, air volume and temperature settings of the air conditioning system.

[0046] If the current specific enthalpy value is greater than the preset value ( i > iset ): If the air conditioning system is currently in heating mode, switch the operating mode to cooling mode through the control panel; if it is currently in cooling mode, maintain the cooling mode unchanged and further enhance the cooling effect.

[0047] Control the fan to increase the speed and increase the air supply.

[0048] According to the degree of deviation between the current specific enthalpy value and the preset value, the set temperature of the air conditioner is appropriately lowered.

[0049] If the current specific enthalpy value is less than the preset value ( i < iset ): If the air conditioning system is currently in cooling mode, switch the operating mode to heating mode through the control panel; if it is currently in heating mode, keep the heating mode unchanged and further enhance the heating effect.

[0050] Control the fan to reduce the speed and air supply.

[0051] According to the degree of deviation between the current specific enthalpy value and the preset value, the set temperature of the air conditioner is appropriately increased.

[0052] Real-time monitoring and automatic adjustment During the operation of the equipment, the sensor module continuously monitors the dry bulb temperature of the indoor air in real time. t , ambient relative humidity φ and atmospheric pressure And , and transmit it to the central control unit to recalculate the indoor air specific enthalpy value.

[0053] The central control unit calculates the enthalpy difference Δ between the current specific enthalpy value and the set value i =∣ i − iset ∣.

[0054] According to the enthalpy difference Δ i The system automatically adjusts the number of active condenser coils based on the enthalpy difference. When the enthalpy difference is large, the system increases the number of active condenser coils to enhance the cooling or heating effect. When the enthalpy difference is small, the system reduces the number of active condenser coils to precisely control indoor temperature, humidity, and airflow speed.

[0055] Judgment and Control After the air conditioning system is regulated according to the initially set temperature, air volume and other parameters, after a period of operation, it is determined whether the current indoor air specific enthalpy value displayed or calculated by the control panel reaches the preset specific enthalpy value range. imine , imax ].

[0056] If the current specific enthalpy value is within the set range ( imine ≤ i ≤ imax ), after determining that the indoor environment has been adjusted, the central control unit instructs the air-conditioning system to operate according to the preset specific enthalpy value, and at the same time controls the fan coil unit to automatically stop or switch to low-power operation mode to save energy.

[0057] If the current specific enthalpy value does not reach the set range ( i < imine or i > imax ): Prolong the running time of the fan coil unit and increase the heat exchange time between the air and the surface cooler.

[0058] According to the deviation between the specific enthalpy value and the set range, the temperature setting value, air volume and other parameters of the air conditioning system are further adjusted.

[0059] Repeat the above process of real-time monitoring, judgment and adjustment until the current indoor enthalpy value is less than or equal to the set enthalpy value upper limit imax When the fan coil is turned off or the fan coil is turned off, it can be controlled to stop or run at low power.

[0060] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A central air conditioning control system based on indoor enthalpy control, characterized in that: include: Sensor module: including temperature sensor, humidity sensor, and air pressure sensor, which are used to monitor and collect the indoor dry-bulb temperature of the fan coil unit when the panel is turned on. t , ambient relative humidity φ and atmospheric pressure Pa; Specific enthalpy value acquisition module: based on the collected dry bulb temperature data t and humidity data φ , get the air specific enthalpy i ; Operation adjustment module: According to the relationship between the specific enthalpy value and the preset value, the operation mode, air volume and temperature are adjusted through the control panel to achieve the specific enthalpy value in the room meeting the preset requirements; Real-time monitoring and automatic adjustment module: During equipment operation, the system monitors the indoor air specific enthalpy in real time and automatically adjusts the number of open groups of the surface cooler coils by calculating the enthalpy difference with the set value, thereby accurately controlling the indoor temperature, humidity and airflow speed; Judgment and control module: after adjusting the initial parameters, it determines whether the specific enthalpy value of the control panel reaches the set range; If so, it is determined that the indoor environment adjustment is complete and the fan coil unit is operated according to the preset specific enthalpy value, and the fan coil unit automatically stops or operates at low power to save energy; otherwise, the fan coil unit operation is extended or the parameters are further adjusted until the current indoor enthalpy value is less than or equal to the set enthalpy value, and the fan coil unit is controlled to stop or operate at low power.

2. A central air-conditioning control system based on indoor enthalpy control according to claim 1, characterized in that: The air specific enthalpy i , set the formula as: i =1.01 t +(2490+1.84 t ) d in d =622 φPs / ( P - φPs ) Where: i represents the air enthalpy value (kJ / kg dry air); t Indicates the monitored dry bulb temperature data (℃); d Indicates moisture content (g / kg (dry air)); P Indicates atmospheric pressure (Pa); Ps Indicates the saturated vapor pressure of water vapor (Pa); φ Indicates the monitored relative humidity data (%).

3. A central air-conditioning control system based on indoor enthalpy control according to claim 1, characterized in that: The specific working process of the sensor module is as follows: When the user turns on the central air conditioning control panel by operating the control switch on the control panel or other preset turning-on methods, the microprocessor inside the control panel receives the turning-on signal and starts the initialization program to perform self-test and configuration on each module of the control panel; The microprocessor configures the specific communication interface for data transmission between the temperature sensor, humidity sensor and air pressure sensor and the microprocessor, and sets the communication parameters; Temperature sensor collects dry bulb temperature t :The temperature sensor converts the sensed temperature changes into electrical signals. When analog output is used, the microprocessor converts the analog electrical signals into digital signals through the internal analog-to-digital converter. When digital output is used, the microprocessor reads the digital temperature data through the communication interface. Humidity sensor collects ambient relative humidity φ : The humidity sensor senses the water vapor content in the air to perceive the relative humidity of the environment; the humidity sensor converts the sensed humidity changes into electrical signals. When the analog output is used, the microprocessor converts the signal into a digital signal through the internal analog-to-digital converter. When the digital output is used, the microprocessor reads the digital humidity data through the communication interface. The air pressure sensor collects atmospheric pressure Pa: The air pressure sensor uses sensitive elements to sense changes in atmospheric pressure; the air pressure sensor converts the sensed air pressure changes into electrical signals. When analog output is used, the microprocessor converts the signal into a digital signal through the internal analog-to-digital converter. When digital output is used, the microprocessor reads the digital air pressure data through the communication interface. The temperature sensor, humidity sensor and air pressure sensor collect and process the dry bulb temperature t , ambient relative humidity φ The data of atmospheric pressure Pa are transmitted to the microprocessor through their respective communication interfaces.

4. A central air-conditioning control system based on indoor enthalpy control according to claim 1, characterized in that: The operation adjustment module: according to the relationship between the specific enthalpy value and the preset value, adjusts the operation mode, air volume, and temperature through the control panel to achieve the specific enthalpy value in the room to meet the preset requirements; specifically: The microprocessor calculates the current indoor air specific enthalpy value i Compared with the target specific enthalpy value pre-set in the control panel iset Compare and determine the deviation between the current indoor air state and the target state: like i = iset , maintain the current operating mode, air volume and temperature settings of the air conditioning system; like i > iset , indicating that the indoor air has too much heat and the specific enthalpy needs to be reduced; like i < iset , indicating that the indoor air heat is insufficient and the specific enthalpy needs to be increased.

5. A central air-conditioning control system based on indoor enthalpy control according to claim 1, characterized in that: The real-time monitoring and automatic adjustment module: During the operation of the equipment, the system monitors the indoor air specific enthalpy in real time and automatically adjusts the number of open groups of the surface cooler coil by calculating the enthalpy difference with the set value, thereby accurately controlling the indoor temperature, humidity and airflow speed; specifically: when i > iset When: If the air conditioning system is currently in heating mode, the microprocessor switches the operating mode to cooling mode through the control panel; if it is currently in cooling mode, the cooling mode remains unchanged and the cooling effect is enhanced; the microprocessor controls the fan to increase the speed and increase the air supply volume; the microprocessor reduces the set temperature of the air conditioner according to the deviation between the current specific enthalpy value and the preset value; when i < iset When: If the air conditioning system is currently in cooling mode, the microprocessor switches the operating mode to heating mode through the control panel; if it is currently in heating mode, the heating mode remains unchanged and the heating effect is enhanced; the microprocessor controls the fan to reduce the speed and reduce the air supply; The microprocessor appropriately increases the set temperature of the air conditioner according to the degree of deviation between the current specific enthalpy value and the preset value.

6. A central air-conditioning control system based on indoor enthalpy control according to claim 1, characterized in that: The system also includes a manual adjustment module: providing a manual adjustment function, the user can directly adjust the number of coil groups, temperature settings and air volume as needed to quickly reach the target specific enthalpy value state.

7. A central air-conditioning control system based on indoor enthalpy control according to claim 6, characterized in that: In the manual adjustment module, the adjustment strategy is as follows: Cooling mode: When the air specific enthalpy value is higher than the set threshold, the number of surface cooler coil groups opened is increased. Each additional coil group increases the heat exchange area by 15-20%, improving the cooling capacity. The air supply volume is increased, and the variable frequency fan speed is increased by 10-15% to enhance the sensible heat exchange. The priority is to increase the number of coil groups first, and then adjust the air volume, to balance energy efficiency and cooling speed. When the air specific enthalpy is lower than the set threshold, the number of coil groups is reduced or switched to partial load operation to avoid overcooling.

8. A central air-conditioning control system based on indoor enthalpy control according to claim 1, characterized in that: The adjustment parameters in the judgment and control module are specifically as follows: if the current specific enthalpy value still does not reach the set range after the fan coil operation time is extended, the control module continues to adjust the parameters, including the temperature setting value, air volume size, and humidity setting value; Adjust the temperature setting value: Increase or decrease the temperature setting value based on the deviation direction of the current specific enthalpy value and the set range. If the current specific enthalpy value is too high, it means that the indoor temperature is too high, and the temperature setting value will be lowered to enhance the cooling effect; if the current specific enthalpy value is too low, it means that the indoor temperature is too low, and the temperature setting value will be increased to enhance the heating effect; Adjust the air volume: Increase or decrease the fan speed to change the air supply volume. If you need to adjust the specific enthalpy of the indoor air more quickly, you can increase the air volume to speed up the heat exchange between the air and the fan coil unit. Adjust the humidity set value: If the deviation of the specific enthalpy value is related to humidity, the control module will adjust the humidity set value; in a humid environment, if the current specific enthalpy value is too high, by lowering the humidity set value, the dehumidification function is activated to reduce the moisture content in the air, thereby lowering the specific enthalpy value.

9. A central air conditioning control method based on indoor enthalpy control, characterized in that: The following steps are involved: Data collection: When the control panel is turned on, the temperature sensor, humidity sensor, and air pressure sensor are used to monitor and collect the dry-bulb temperature of the indoor environment where the fan coil unit is located. t , ambient relative humidity φ and atmospheric pressure Pa ; Specific enthalpy value acquisition: Based on dry bulb temperature data t and humidity data φ , get the air specific enthalpy i ; Operation adjustment: According to the relationship between the specific enthalpy value and the preset value, the operation mode, air volume and temperature of the air conditioning system are adjusted through the control panel to achieve the specific enthalpy value in the room to meet the preset requirements; Real-time monitoring and automatic adjustment: During the operation of the equipment, the indoor air specific enthalpy value is monitored in real time. By calculating the enthalpy difference with the set value, the number of open groups of the surface cooler coils is automatically adjusted to accurately control the indoor temperature, humidity and airflow speed. Judgment and control: After adjusting the air conditioning system according to the initial parameters, determine whether the specific enthalpy value of the control panel reaches the set range; If it is reached, it is determined that the indoor environment adjustment is completed, and the fan coil unit is operated according to the pre-set specific enthalpy value, and the fan coil unit is controlled to automatically stop or operate at low power to save energy; if it is not reached, the fan coil unit operation is extended or the parameters are further adjusted until the current indoor enthalpy value is less than or equal to the set enthalpy value, and the fan coil unit is controlled to stop or operate at low power.

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