A double-cold-source heat-recovery multi-terminal constant-temperature and constant-humidity air conditioner control method and system

Abstract

The application provides a double-cold-source heat recovery type multi-terminal constant-temperature and constant-humidity air conditioner control method and system, which comprises the following steps: a control device acquires environment information and equipment information of a target area, constructs a multivariate joint optimization model under a steady state working condition based on the environment information, the equipment information and a preset constraint condition and takes the minimum total energy consumption of the equipment as a target, constructs a first target function and solves the target function to obtain target operation parameters, adjusts the running state of a water chilling unit, the running frequency of a water pump, the running state of a fan, the opening degree of a pre-cooling coil valve and obtains a water flow upper limit; after temperature deviation and humidity deviation are obtained, a target supply air temperature and a target supply air dew point temperature are generated according to an outer loop proportional integral derivative control model, a second target function is constructed by an inner loop predictive control model and solved to obtain a target pre-cooling coil valve opening degree and a target reheating coil valve opening degree; and the cold quantity of the pre-cooling coil and the pre-cooling coil is distributed to realize temperature and humidity stable control of a large multi-terminal constant-temperature and constant-humidity air conditioner and reduce energy consumption.

Description

Technical Field

[0001] This invention relates to the field of optimized control of constant temperature and humidity air conditioning, and in particular to a dual-source heat recovery type multi-terminal constant temperature and humidity air conditioning control method and system. Background Technology

[0002] With the widespread use of constant temperature and humidity air conditioners in semiconductor manufacturing, electronics industry, precision machining and pharmaceutical production, various fields have strict requirements for indoor air temperature and relative humidity. To meet the corresponding environmental requirements, constant temperature and humidity air conditioners usually use air handling units (AHUs) to pre-cool, deeply cool and dehumidify, and reheat the air. They also achieve precise regulation of indoor environmental parameters through the coordinated operation of chilled water systems, heat recovery systems and air systems.

[0003] Existing control methods typically adjust individual devices or control loops independently, lacking the ability to optimize the overall energy distribution structure of the entire system. Since the air handling process involves multiple heat exchange stages such as precooling coils, cooling coils, and reheating coils, the way different coils distribute cooling capacity has a significant impact on the overall energy consumption of the air conditioning system. Existing control methods usually adopt a fixed serial processing mode of precooling, recooling, and reheating, and the load ratio of each coil mainly depends on experience or fixed design values. The coil load structure is not modeled as an optimizable object, resulting in a large amount of sensible heat load being borne by the low-temperature cold source, heavy burden on the low-temperature water system, high reheat energy consumption, and low overall system energy efficiency.

[0004] On the other hand, existing technologies are designed for controlling and regulating a single air handling unit or a single area, and cannot be directly applied to large-scale constant temperature and humidity air conditioning systems with multiple terminal devices. Relying solely on global optimization control can lead to short-term fluctuations in indoor temperature and humidity due to system dynamic response lag, thus affecting the stability of the indoor environment. Therefore, in large-scale multi-terminal constant temperature and humidity air conditioning systems, it is impossible to reduce system energy consumption while ensuring indoor environmental stability. Summary of the Invention

[0005] This invention provides a dual-cold-source heat recovery type multi-terminal constant temperature and humidity air conditioning control method and system, the main purpose of which is to solve the problems of poor indoor temperature and humidity stability and high air conditioning energy consumption in the prior art.

[0006] To achieve the above objectives, the present invention provides a dual-source heat recovery type multi-terminal constant temperature and humidity air conditioning control method. This method is executed on a control device connected to an air handling unit and an air conditioning water circuit device. The method includes:

[0007] Obtain environmental and equipment information for the target area; environmental information includes indoor temperature and humidity parameters, and equipment information includes air handling unit coil structure parameters, chiller performance parameters, water pump operating parameters, and fan operating parameters;

[0008] Based on environmental information, equipment information, and preset constraints, a multivariate joint optimization model is constructed under steady-state conditions with the goal of minimizing total equipment energy consumption. The multivariate joint optimization model uses the medium-temperature chilled water supply temperature, low-temperature chilled water supply temperature, water pump flow rate, fan air volume, and air handling unit coil load allocation factor as decision variables to construct the first objective function. Solving the first objective function yields the target operating parameters that minimize the total equipment energy consumption. The target operating parameters include the target medium-temperature chilled water supply temperature, the target low-temperature chilled water supply temperature, the target water pump flow rate, the target fan air volume, and the target air handling unit coil load allocation factor.

[0009] The chiller unit's operating status is adjusted according to the target medium-temperature chilled water supply temperature and the target low-temperature chilled water supply temperature. The pump operating frequency is determined according to the target pump flow rate, and the upper limit of the water flow rate is determined based on the pump operating frequency. The fan operating status is adjusted according to the target fan operating frequency. The precooling coil water flow rate is determined according to the target coil load distribution factor, and the precooling coil valve opening is adjusted based on the preset correspondence between the precooling coil water flow rate and the valve opening.

[0010] The indoor temperature is collected in real time and compared with the target temperature to obtain the temperature deviation. The indoor humidity is collected in real time and compared with the target humidity to obtain the humidity deviation. Then, the target supply air temperature and the target supply air dew point temperature are generated according to the outer loop proportional-integral-derivative control model of the control device. The inner loop predictive control model of the control device constructs a second objective function based on the upper limit of water flow, the target supply air temperature, the target supply air dew point temperature, the current supply air temperature, and the current supply air dew point temperature. After solving, the target recooling coil valve opening and the target reheating coil valve opening are obtained.

[0011] Optionally, the total energy consumption of the equipment includes the energy consumption of the medium-temperature chiller, the energy consumption of the low-temperature chiller, the energy consumption of the heat recovery unit, the energy consumption of the water pump, and the energy consumption of the fan.

[0012] Energy consumption of medium-temperature chiller units Energy consumption of low-temperature chiller units Energy consumption of heat recovery units Water pump energy consumption Energy consumption of air conditioner The expression is:

[0013] ;

[0014] ;

[0015] ;

[0016] ;

[0017] ;

[0018] ;

[0019] in, Indicates the serial number of the air handling unit; This indicates the load of the precooling coil under steady-state operating conditions; This indicates the number of medium-temperature chillers that are currently in operation. This indicates the coefficient of performance (COP) of a medium-temperature chiller unit. Indicates the evaporation temperature; Indicates the unit's condensing temperature; Indicates the unit load rate; This indicates the load on the recooling coil under steady-state operating conditions; This indicates the number of devices in the low-temperature chiller unit that are currently in operation. This indicates the coefficient of performance (COP) of a low-temperature chiller unit. This indicates the load on the reheat coil under steady-state conditions; This represents the coefficient of performance (COP) of the heat recovery unit. Represents the coefficients of a quadratic polynomial; Indicates the water flow rate of the water pump; Indicates the fan air volume; Indicates the coil load distribution factor; Indicates the enthalpy of the mixed air; This indicates the enthalpy value at the dew point of the air at the outlet of the recooling coil. Indicates the supply air temperature; This indicates the supply air dew point temperature.

[0020] Optionally, the expression for the coil load distribution factor is:

[0021] ;

[0022] ;

[0023] in, Indicates the enthalpy of the mixed air; This indicates the enthalpy value of the air at the precooling coil outlet; This indicates the enthalpy value at the dew point of the air at the outlet of the recooling coil. This represents the enthalpy value at the dew point of the mixed air.

[0024] Optionally, the multivariate joint optimization model constructs a first objective function using the medium-temperature chilled water supply temperature, the low-temperature chilled water supply temperature, the water pump flow rate, the fan air volume, and the air handling unit coil load allocation factor as decision variables. The expression of the first objective function is as follows:

[0025]

[0026] ;

[0027] in, Indicates the coil load distribution factor; Indicates the temperature of the chilled water supply entering the air handling unit; Indicates the water flow rate of the water pump; This indicates the air volume of the air handling unit's fan; Indicates the air volume of the cooling tower fan; This indicates the energy consumption of the low-temperature chiller unit; This indicates the energy consumption of the medium-temperature chiller unit; Indicates the energy consumption of the heat recovery unit; Indicates the energy consumption of the water pump; This indicates the energy consumption of the air handling unit's fan; This indicates the energy consumption of the cooling tower fan.

[0028] Optionally, the expression for the preset constraint condition is:

[0029] ;

[0030] ;

[0031] ;

[0032] ;

[0033] ;

[0034] in, Indicates the coil load distribution factor; It represents water; Indicates air; Indicates the direction in which the medium enters; Indicates the rated parameters; Indicates the temperature of the chilled water supply entering the air handling unit; Indicates the water flow rate of the water pump; This indicates the air volume of the air handling unit's fan; Indicates the air volume of the cooling tower fan; The flow coefficient that indicates the safe operation of a water pump; The flow coefficient represents the safe operation of the fan.

[0035] Optionally, indoor temperature With preset target temperature Temperature deviation was obtained by comparison Indoor humidity With target humidity Compare to obtain humidity deviation The expression is:

[0036] ;

[0037] ;

[0038] The target supply air temperature is generated based on the outer loop proportional-integral-differential control model of the control device. and target supply air dew point temperature The expression is:

[0039] ;

[0040] ;

[0041] ;

[0042] in, This represents the temperature loop proportionality coefficient; This represents the integral coefficient of the temperature loop; This represents the differential coefficient of the temperature ring; This represents the time sequence of temperature acquisition. This represents the total time sequence of temperature acquisition. Indicates the control cycle; Indicates the reference supply air temperature; Indicates the humidity ring proportionality coefficient; Indicates the integral coefficient of the humidity loop; Indicates the humidity ring differential coefficient; This indicates the reference supply air dew point temperature.

[0043] Optionally, the expression for the second objective function is:

[0044] ;

[0045] ;

[0046] ;

[0047] ;

[0048] ;

[0049] ;

[0050] ;

[0051] in, Indicates the prediction step size; This indicates the predicted supply air temperature. Indicates the target supply air temperature; This indicates the predicted value of the supply air dew point temperature; Indicates the target supply air dew point temperature; Indicates the control step size; and Indicates the weighting coefficient; express The opening degree of the recooling coil valve at any given time; express The opening degree of the reheat coil valve at any given time; Indicates the total number of air handling units; express Chilled water flow rate of the air handling unit at all times; This indicates the upper limit of water flow.

[0052] To address the aforementioned issues, this invention also provides a dual-source heat recovery multi-terminal constant temperature and humidity air conditioning control system, comprising a processor, a memory, and a computer program / instructions stored in the memory. The processor executes the computer program / instructions, and when the computer program / instructions are executed, the system implements the steps of the method described in the claims.

[0053] To address the above problems, the present invention also provides an electronic device, the electronic device comprising:

[0054] At least one processor; and,

[0055] A memory communicatively connected to the at least one processor; wherein,

[0056] The memory contains a computer program that can be executed by the at least one processor, which enables the at least one processor to implement the above-described dual-cold-source heat recovery multi-terminal constant temperature and humidity air conditioning control method.

[0057] To address the aforementioned problems, the present invention also provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements any of the methods described above.

[0058] The beneficial effects of this invention are as follows:

[0059] This invention provides a control method and system for a dual-source heat recovery multi-terminal constant temperature and humidity air conditioner. A multivariate joint optimization model uses coil load allocation factors as decision variables to achieve continuous and adjustable allocation of cooling capacity between pre-cooling and re-cooling coils. The control device provides global guidance by controlling the dual-source heat recovery multi-terminal constant temperature and humidity air conditioner according to target operating parameters. The combination of an outer-loop proportional-integral-derivative control model and an inner-loop predictive control model transforms temperature and humidity control into a bivariate tracking problem, improving control accuracy and response performance, achieving stable control of a large-scale multi-terminal constant temperature and humidity air conditioner system, and reducing energy consumption.

[0060] Additional advantages, objects, and features of the invention will be set forth in part in the description which follows, and will also become apparent in part to those skilled in the art upon studying the description, or may be learned by practice of the invention. The objects and other advantages of the invention can be realized and obtained by means of the structures specifically pointed out in the description and drawings.

[0061] Those skilled in the art will understand that the objectives and advantages achievable with the present invention are not limited to those specifically described above, and that the above and other objectives achievable with the present invention will become clearer from the following detailed description. Attached Figure Description

[0063] Figure 1 This is a flowchart illustrating the dual-cold-source heat recovery type multi-terminal constant temperature and humidity air conditioning control method according to an embodiment of the present invention.

[0064] Figure 2 This is a schematic diagram of a dual-cold-source heat recovery type multi-terminal constant temperature and humidity air conditioner according to an embodiment of the present invention.

[0065] Figure 3 This is a schematic diagram of the control device according to an embodiment of the present invention.

[0066] Figure 4 This is a graph showing the change in indoor temperature before and after the control device described in an embodiment of the present invention is optimized.

[0067] Figure 5 This is a graph showing the change in indoor humidity before and after the control device described in an embodiment of the present invention is optimized.

[0068] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0070] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the embodiments and accompanying drawings. Here, the illustrative embodiments and descriptions of this invention are used to explain the invention, but are not intended to limit the invention.

[0071] It should also be noted that, in order to avoid obscuring the invention with unnecessary details, only the structures and / or processing steps closely related to the solution according to the invention are shown in the accompanying drawings, while other details that are not closely related to the invention are omitted.

[0072] It should be emphasized that the term "including / comprises" as used herein refers to the presence of a feature, element, step, or component, but does not exclude the presence or addition of one or more other features, elements, steps, or components.

[0073] It should also be noted that, unless otherwise specified, the term "connection" in this article can refer not only to a direct connection, but also to an indirect connection involving an intermediary.

[0074] In the following description, embodiments of the invention will be illustrated with reference to the accompanying drawings. In the drawings, the same reference numerals represent the same or similar parts, or the same or similar steps.

[0075] Figure 1 This is a flowchart illustrating a dual-source heat recovery multi-terminal constant temperature and humidity air conditioning control method according to an embodiment of the present invention. This application provides a dual-source heat recovery multi-terminal constant temperature and humidity air conditioning control method, which is executed on a control device connected to an air handling unit and an air conditioning water circuit device. The method includes the following steps S101~S104:

[0076] Step S101: Obtain environmental and equipment information for the target area; environmental information includes indoor temperature and humidity parameters, and equipment information includes air handling unit coil structure parameters, chiller performance parameters, water pump operating parameters, and fan operating parameters.

[0077] Step S102: Based on environmental information, equipment information, and preset constraints, construct a multivariate joint optimization model under steady-state conditions with the goal of minimizing total equipment energy consumption. The multivariate joint optimization model constructs a first objective function with medium-temperature chilled water supply temperature, low-temperature chilled water supply temperature, water pump flow rate, fan air volume, and air handling unit coil load allocation factor as decision variables. Solve the first objective function to obtain the target operating parameters that minimize the total equipment energy consumption. The target operating parameters include the target medium-temperature chilled water supply temperature, the target low-temperature chilled water supply temperature, the target water pump flow rate, the target fan air volume, and the target air handling unit coil load allocation factor.

[0078] Step S103: Adjust the chiller unit's operating status according to the target medium-temperature chilled water supply temperature and the target low-temperature chilled water supply temperature; determine the pump operating frequency according to the target pump flow rate; determine the upper limit of water flow rate based on the pump operating frequency; adjust the fan operating status according to the target fan operating frequency; determine the precooling coil water flow rate according to the target coil load distribution factor; and adjust the precooling coil valve opening based on the preset correspondence between the precooling coil water flow rate and the valve opening.

[0079] Step S104: Real-time acquisition of indoor temperature and comparison with target temperature to obtain temperature deviation; real-time acquisition of indoor humidity and comparison with target humidity to obtain humidity deviation; generating target supply air temperature and target supply air dew point temperature according to the outer loop proportional-integral-derivative control model of the control device; constructing a second objective function based on the upper limit of water flow, target supply air temperature, target supply air dew point temperature, current supply air temperature and current supply air dew point temperature, and solving it to obtain the target recooling coil valve opening and target reheating coil valve opening.

[0080] Figure 2 This is a schematic diagram of a dual-cold-source heat recovery type multi-terminal constant temperature and humidity air conditioner according to an embodiment of the present invention. Figure 3 This is a schematic diagram of the control device according to an embodiment of the present invention. In step S101, the dual-source heat recovery multi-terminal constant temperature and humidity air conditioner includes an air unit, a water unit, and a control device, which are connected through pipelines, signal lines, and control interfaces. The air unit includes multiple air handling units, each of which includes a precooling coil, a recooling coil, a reheating coil, and a fan. Each coil inlet is equipped with a continuously adjustable valve. The water unit includes a low-temperature air conditioning water circuit device and a medium-temperature air conditioning water circuit device. The low-temperature air conditioning water circuit device includes a low-temperature chiller, a low-temperature chilled water pump, and a low-temperature cooling water pump. The medium-temperature air conditioning water circuit device includes a chiller and a heat recovery unit. The low-temperature air conditioning water circuit device provides cooling water to the recooling coil of the air handling unit. The medium-temperature air conditioning water circuit device provides cooling capacity to the precooling coil of the air handling unit. The medium-temperature air conditioning water circuit device includes a heat recovery unit. Part of the heat generated by the heat recovery unit is used to provide a heat source for the reheat coil of the air handling unit, and the remainder is transferred to the cooling tower. The control device optimizes the dual-source heat recovery multi-terminal constant temperature and humidity air conditioner through the upper-level steady-state optimization control unit and the lower-level control unit, and exchanges data through the communication network. The upper-level steady-state optimization control unit outputs the globally optimal target operating parameters and resource constraints, and the lower-level control unit realizes the control of the dual-source heat recovery multi-terminal constant temperature and humidity air conditioner based on the target operating parameters and resource constraints.

[0081] In step S102, the upper-level steady-state optimization control unit uses key operating parameters as decision variables and introduces the coil load allocation factor of the air handling unit as an adjustment variable to construct a multivariate joint optimization model and solve it with the goal of minimizing energy consumption. The optimization cycle of the upper-level steady-state optimization control unit is on the order of hours. Furthermore, in the air handling process, the precooling coil bears the sensible heat load and performs medium-temperature staged cooling on the mixed air. The recooling coil bears the remaining sensible heat load and all latent heat load. The air reaches the target supply air dew point temperature through deep dehumidification. The dew point temperature directly represents the relative humidity of the supply air. The load of the reheating coil is adaptively determined according to the difference between the air state at the outlet of the recooling coil and the target supply air temperature, and is adjusted in real time with the change of the load allocation factor. The precooling and reheating processes use the logarithmic mean temperature difference method (LMTD) to calculate the load, and the recooling coil uses the efficiency-to-heat transfer unit number method (ε-NTU) to calculate the load. The operating energy consumption of the water pump and the fan is related to the fluid flow rate and is modeled using a quadratic polynomial. In this embodiment of the invention, the total energy consumption of the equipment includes the energy consumption of the medium-temperature chiller unit, the energy consumption of the low-temperature chiller unit, the energy consumption of the heat recovery unit, the energy consumption of the water pump, and the energy consumption of the fan.

[0082] Energy consumption of medium-temperature chiller units Energy consumption of low-temperature chiller units Energy consumption of heat recovery units Water pump energy consumption Energy consumption of air conditioner The expression is:

[0083] ;

[0084] ;

[0085] ;

[0086] ;

[0087] ;

[0088] ;

[0089] ;

[0090] ;

[0091] in, Indicates the serial number of the air handling unit; This indicates the load of the precooling coil under steady-state operating conditions; This indicates the number of medium-temperature chillers that are currently in operation. This indicates the coefficient of performance (COP) of a medium-temperature chiller unit. Indicates the evaporation temperature; Indicates the unit's condensing temperature; Indicates the unit load rate; This indicates the load on the recooling coil under steady-state operating conditions; This indicates the number of devices in the low-temperature chiller unit that are currently in operation. This indicates the coefficient of performance (COP) of a low-temperature chiller unit. This indicates the load on the reheat coil under steady-state conditions; This represents the coefficient of performance (COP) of the heat recovery unit. Represents the coefficients of a quadratic polynomial; Indicates the water flow rate of the water pump; Indicates the fan air volume; Indicates the coil load distribution factor; Indicates the enthalpy of the mixed air; This indicates the enthalpy value at the dew point of the air at the outlet of the recooling coil. Indicates the supply air temperature; This represents the supply air dew point temperature. The unit's performance coefficient is related to the unit's evaporating temperature, condensing temperature, and load factor. The expression for the unit load factor is: , This indicates the actual output of the generator unit. Rated output of the unit

[0092] The coil load allocation factor represents the proportion of cooling capacity borne by the precooling coil, and is expressed as the ratio of the difference between the enthalpy of the mixed air and the enthalpy of the air at the precooling coil outlet to the difference between the enthalpy of the mixed air and the enthalpy of the dew point at the recooling coil outlet. Adjusting the coil load allocation factor optimizes the load sharing ratio between the precooling and recooling coils to achieve optimal distribution in the air handling process, with the outlet air temperature higher than the dew point temperature of the mixed air. In this embodiment of the invention, the expression for the coil load allocation factor is:

[0093] ;

[0094] ;

[0095] in, Indicates the enthalpy of the mixed air; This indicates the enthalpy value of the air at the precooling coil outlet; This indicates the enthalpy value at the dew point of the air at the outlet of the recooling coil. This represents the enthalpy value at the dew point of the mixed air.

[0096] In this embodiment of the invention, the multivariate joint optimization model uses the medium-temperature chilled water supply temperature, the low-temperature chilled water supply temperature, the water pump flow rate, the fan air volume, and the air handling unit coil load allocation factor as decision variables to construct a first objective function. The expression of the first objective function is as follows:

[0097]

[0098] ;

[0099] in, Indicates the coil load distribution factor; Indicates the temperature of the chilled water supply entering the air handling unit; Indicates the water flow rate of the water pump; This indicates the air volume of the air handling unit's fan; Indicates the air volume of the cooling tower fan; This indicates the energy consumption of the low-temperature chiller unit; This indicates the energy consumption of the medium-temperature chiller unit; Indicates the energy consumption of the heat recovery unit; Indicates the energy consumption of the water pump; This indicates the energy consumption of the air handling unit's fan; This indicates the energy consumption of the cooling tower fan.

[0100] In this embodiment of the invention, the expression for the preset constraint condition is:

[0101] ;

[0102] ;

[0103] ;

[0104] ;

[0105] ;

[0106] in, Indicates the coil load distribution factor; It represents water; Indicates air; Indicates the direction in which the medium enters; Indicates the rated parameters; Indicates the temperature of the chilled water supply entering the air handling unit; Indicates the water flow rate of the water pump; This indicates the air volume of the air handling unit's fan; Indicates the air volume of the cooling tower fan; The flow coefficient that indicates the safe operation of a water pump; The flow coefficient represents the safe operation of the fan.

[0107] In step S103, the upper steady-state optimization control unit outputs the target medium-temperature chilled water supply temperature and the target low-temperature chilled water supply temperature to the chiller unit, converts the target water pump flow rate into the water pump operating frequency and executes it by the frequency converter, adjusts the opening of the precooling coil valve based on the target coil load distribution factor, determines the upper limit of the available water flow rate under the current operating conditions according to the target water pump operating frequency, and transmits the upper limit of the water flow rate as a constraint condition to the lower control unit.

[0108] Figure 4 This is a graph showing the change in indoor temperature before and after the control device described in an embodiment of the present invention is optimized. Figure 5 This is a graph showing the change in indoor humidity before and after control optimization of the control device according to an embodiment of the present invention. In step S104, a distributed bottom-level control unit with the air handling unit as the basic unit is constructed according to the temperature and humidity adjustment requirements. The air handling unit controls the indoor temperature and humidity of the corresponding terminal area by adjusting the opening of the recooling coil and reheat coil valves. The control cycle is set to the minute level. The bottom-level control unit of the control device includes an outer loop proportional-integral-derivative control model (PID) and an inner loop predictive control model (MPC). The bottom-level control unit uses the supply air dew point temperature as the humidity adjustment variable to transform the temperature and humidity control into supply air temperature and supply air dew point temperature control.

[0109] Furthermore, environmental sensors acquire indoor temperature and humidity, compare them with preset target values, and adjust the temperature by adjusting the supply air temperature and the humidity by adjusting the supply air dew point temperature. In this embodiment of the invention, the indoor temperature... With preset target temperature Temperature deviation was obtained by comparison Indoor humidity With target humidity Compare to obtain humidity deviation The expression is:

[0110] ;

[0111] ;

[0112] The target supply air temperature is generated based on the outer loop proportional-integral-differential control model of the control device. and target supply air dew point temperature The expression is:

[0113] ;

[0114] ;

[0115] ;

[0116] in, This represents the temperature loop proportionality coefficient; This represents the integral coefficient of the temperature loop; This represents the differential coefficient of the temperature ring; This represents the time sequence of temperature acquisition. This represents the total time sequence of temperature acquisition. Indicates the control cycle; Indicates the reference supply air temperature; Indicates the humidity ring proportionality coefficient; Indicates the integral coefficient of the humidity loop; Indicates the humidity ring differential coefficient; This indicates the reference supply air dew point temperature.

[0117] Furthermore, the inner-loop predictive control model controls the supply air temperature and supply air dew point temperature by adjusting the valve openings of the recooling and reheating coils. The target recooling coil valve opening and the target reheating coil valve opening are obtained through a second objective function. In this embodiment of the invention, the expression for the second objective function is:

[0118] ;

[0119] ;

[0120] ;

[0121] ;

[0122] ;

[0123] ;

[0124] ;

[0125] in, Indicates the prediction step size; This indicates the predicted supply air temperature. Indicates the target supply air temperature; This indicates the predicted value of the supply air dew point temperature; Indicates the target supply air dew point temperature; Indicates the control step size; and Indicates the weighting coefficient; express The opening degree of the recooling coil valve at any given time; express The opening degree of the reheat coil valve at any given time; Indicates the total number of air handling units; express Chilled water flow rate of the air handling unit at all times; This indicates the upper limit of water flow.

[0126] On the other hand, the present invention also provides a dual-source heat recovery multi-terminal constant temperature and humidity air conditioning control system, including a processor, a memory, and a computer program / instructions stored in the memory. The processor is used to execute the computer program / instructions, and when the computer program / instructions are executed, the system implements the steps of the above method.

[0127] On the other hand, embodiments of the present invention also provide an electronic device, the electronic device including at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory has a computer program executable by the at least one processor, the computer program being executed by the at least one processor to enable the at least one processor to execute in order to implement the above-described dual-cold-source heat recovery type multi-terminal constant temperature and humidity air conditioning control method.

[0128] On the other hand, embodiments of the present invention also provide a computer-readable storage medium storing at least one computer program, which is executed by a processor in an electronic device to implement the above-described dual-cold-source heat recovery type multi-terminal constant temperature and humidity air conditioning control method.

[0129] The present invention will now be described with reference to a specific embodiment:

[0130] Figure 3 The diagram shows the changes in indoor temperature before and after the control device provided in this embodiment of the invention is optimized. Figure 4 This invention presents a diagram showing the indoor humidity changes before and after control optimization using the control device provided in an embodiment of the invention. The invention proposes a dual-source heat recovery type multi-terminal constant temperature and humidity air conditioning control method and system. It includes an air system device, a water system device, and a control device, which are connected via pipelines, signal lines, and control interfaces to form an air-water linkage control system. The air conditioning air system device includes multiple air handling units (AHUs), each with built-in pre-cooling coils, re-cooling coils, reheat coils, and a fan. Each coil inlet is equipped with a continuously adjustable valve. Table 1 shows the rated parameters of each device in the dual-source heat recovery type multi-terminal constant temperature and humidity air conditioning system.

[0131] Table 1. Rated parameters of various equipment in a dual-source heat recovery multi-terminal constant temperature and humidity air conditioner.

[0132]

[0133] The water system is divided into a low-temperature water system and a medium-temperature water system. The low-temperature water system provides cooling capacity for the recooling coils of the air handling unit, while the medium-temperature water system provides cooling capacity for the precooling coils of the air handling unit. The medium-temperature water system also includes a heat recovery unit, which generates heat to provide a heat source for the reheat coils of the air handling unit. The control device includes an upper-level steady-state optimization control device and a lower-level control device. The two devices interact with each other through a communication network. The upper-level steady-state optimization control device outputs globally optimal operating parameters and resource constraints. Based on these parameters and constraints, the lower-level control device achieves constant temperature and humidity control at the terminal and meets the resource constraints.

[0134] Step 1: The upper-level steady-state optimization control device aims to minimize the total energy consumption of the system. Based on the steady-state operating condition assumptions, it optimizes the global operating parameters and outputs the optimal operating parameters and system resource constraints. The upper-level steady-state optimization control operates on a relatively slow time scale, with an optimization period on the order of hours, and is used to describe the ideal steady-state operating point of the system under given operating conditions.

[0135] During the upper-level control process, it is assumed that the target values ​​for indoor temperature and relative humidity remain constant within the optimization cycle. The upper-level control module acquires multi-source information, including indoor temperature and humidity status parameters, air handling unit coil structural characteristics, chiller unit performance parameters, and pump and fan operating characteristics, by collecting environmental monitoring system and equipment operation data. This information is then used as boundary conditions for optimization calculations to characterize the system's operating status.

[0136] Within a steady-state optimization framework, a multivariate joint optimization model is constructed using key operating parameters of the water system and the chilled water system in the air conditioning system as decision variables. The optimization variables include the medium-temperature chilled water supply temperature. Low-temperature chilled water supply temperature Water pump flow rate Air volume of air handling unit fan Cooling tower fan air volume At the same time, the air handling unit coil load distribution factor is introduced. As regulating variables, the above parameters are solved and output uniformly by the optimization module to minimize the overall energy consumption of the system under steady-state operating conditions. The total system energy consumption consists of the energy consumption of various equipment, including the energy consumption of the cryogenic chiller unit. Energy consumption of medium-temperature chiller units Energy consumption of heat recovery units Water pump energy consumption Energy consumption of air handling unit fans Energy consumption of cooling tower fans The objective function expression is:

[0137]

[0138] ;

[0139] ;

[0140] ;

[0141] ;

[0142] ;

[0143] ;

[0144] Among them, subscript and They represent water and air, respectively. Indicates the direction in which the medium enters. and and represent chiller units for low-temperature and medium-temperature systems, respectively. Indicates a heat recovery unit. Indicates the rated parameters. This indicates the temperature of the chilled water entering the air handling unit, in units of... , This indicates the mass flow rate of the medium in the device, in units of... , The operating power of the equipment is expressed in units of... , This represents the flow coefficient used to ensure the safe operation of the equipment.

[0145] Step 2: To describe the energy distribution relationship between different coils during air handling, a coil load distribution factor is introduced. This is used to indicate the proportion of cooling capacity handled by the precooling coil. The coil load distribution factor is defined as the enthalpy of the mixed air. Enthalpy of air at the outlet of the precooling coil The difference is related to the enthalpy of the mixed air. Enthalpy of the dew point at the outlet of the recooling coil The ratio of their differences is expressed as:

[0146] ;

[0147] By adjusting this allocation factor, the load-sharing ratio between the precooling coil and the recooling coil can be changed, thereby achieving optimized energy allocation in the air handling process. To ensure the precooling coil operates under dry conditions, its outlet air temperature must be higher than the dew point temperature of the mixed air. Therefore, the constraints on the range of values ​​for the load distribution factor are as follows:

[0148] ;

[0149] Step 3: Based on the above definitions, determine the load of the precooling, recooling, and reheating coils under steady-state conditions. , and The expression for is as follows: Indicates the supply air temperature. This indicates the supply air dew point temperature.

[0150] ;

[0151] ;

[0152] ;

[0153] Step 4: During air handling, the precooling coil only bears the sensible heat load and does not cause changes in the air humidity; the recooling coil bears both the remaining sensible heat load and the entire latent heat load, and its outlet air condition must meet the supply air dew point temperature constraint; the reheating coil load is jointly determined by the recooling coil outlet condition and the target supply air temperature, and is not considered an independent optimization variable, but rather adaptively adjusted according to changes in the load distribution factor. In the heat exchange calculations for each coil, the average temperature difference method is used for the precooling and reheating processes, while the recooling coil, due to the involvement of a phase change process, uses... The method is used for modeling and calculation.

[0154] Based on the load distribution of different coils, the medium-temperature chilled water system mainly bears the load of the precooling coil, while the low-temperature chilled water system mainly bears the load of the recooling coil. On this basis, energy consumption models for various types of chillers and heat recovery units under steady-state conditions can be established, and their expressions are as follows:

[0155] ;

[0156] ;

[0157] ;

[0158] in, This indicates the total number of devices in operation, and the device performance parameters, along with the unit's evaporation temperature. Condensation temperature and partial load factor related.

[0159] For water pumps and fans, their operating energy consumption is closely related to the fluid flow rate. A quadratic polynomial model is used for fitting, which is expressed as:

[0160] ;

[0161] The coefficients of the chiller and water pump were obtained by fitting 23,580 sets of valid data. Table 2 shows the fitting coefficients of the equipment.

[0162] Table 2 Fitting coefficients for each device

[0163]

[0164] Step 5: Through the above optimization calculations, the upper-level control module outputs the optimal chilled water supply temperature to each chiller unit and converts the optimal water flow rate into the pump operating frequency, which is then executed by the frequency converter. Simultaneously, the optimized load allocation factor is mapped to the precooling coil valve opening, achieving indirect regulation of the air handling process. The total system water flow rate determined by the pump frequency constitutes the upper limit of available water resources under the current operating conditions. This constraint is transmitted to the lower-level control module, providing an energy-optimal operating boundary for dynamic control.

[0165] Step 6: In the lower-level control, a distributed control structure with air handling units as the basic unit is constructed to meet the temperature and humidity regulation requirements during the dynamic operation of the system. Each air handling unit achieves independent control of the indoor temperature and humidity in the corresponding area by adjusting the opening of the recooling coil and reheat coil valves, with the control cycle set at the minute level.

[0166] Step 7: This invention employs a cascade control strategy combining outer-loop proportional-integral-derivative (PID) control with inner-loop predictive control model predictive control. Specifically, by introducing the supply air dew point temperature as a humidity adjustment variable, the temperature and humidity control problem is uniformly transformed into a bivariate control problem involving both supply air temperature and dew point temperature.

[0167] During operation, indoor temperature is acquired through environmental sensors. and relative humidity and the set target value and A comparison is made; the outer loop PID controller calculates the air supply state setpoint based on the deviation, wherein the temperature control process is as follows:

[0168] ;

[0169] ;

[0170] The temperature control process is regulated by the dew point temperature, expressed as:

[0171] ;

[0172] ;

[0173] in, This represents the temperature loop proportionality coefficient; This represents the integral coefficient of the temperature loop; This represents the differential coefficient of the temperature ring; Indicates the control cycle; This indicates the reference supply air temperature, used to ensure the system operates near its rated conditions; This represents the reference supply air dew point temperature; to ensure the physical rationality of the air handling process, the constraint that the dew point temperature must always be lower than the supply air temperature must be met during the control process. To avoid creating an undesirable state of heat and humidity.

[0174] The inner-loop predictive control model uses the supply air temperature and supply air dew point temperature as control inputs. The input is the valve opening degree of the recooling coil and the reheating coil. The dynamic behavior of the system is predicted based on a discrete state-space model, and the optimal control sequence is solved by optimizing the objective function. The objective function expression is:

[0175] ;

[0176] ;

[0177] ;

[0178] ;

[0179] ;

[0180] The first term is used to penalize the deviation between the supply air temperature and the target value, the second term is used to penalize the deviation of the supply air dew point temperature, and the third term is used to limit the range of change of the control input to ensure a smooth and stable control process. Indicates the prediction step size; Indicates the control step size; and Indicates the weighting coefficient; When multiple air handling units are operating in parallel, the chilled water flow rate of each unit needs to meet the optimal water flow rate constraint determined by the upper-level steady-state optimization module. This constraint enables coordinated resource allocation among multiple units by incorporating the functional relationship between valve opening and water flow into the model predictive controller.

[0181] In actual control operations, the model predictive controller solves the aforementioned optimization problem at each sampling time to obtain the optimal solution for the future control sequence. It then applies only the control input for the current time step to the system, recalculating the remaining control inputs at the next time step, thus forming a rolling optimization control mechanism. This approach effectively addresses disturbance changes while considering the system's dynamic characteristics, improving the robustness and response performance of the control system.

[0182] Through the synergistic effect of the outer-loop PID and inner-loop MPC, precise regulation of indoor temperature and humidity can be achieved. The recooling coil primarily regulates the supply air dew point temperature to control humidity, while the reheat coil regulates the supply air temperature to compensate for sensible heat load. Both are coordinated and optimized under a model predictive control framework, overcoming the coupling interference problem inherent in traditional single-loop control methods. Simultaneously, by introducing resource constraints determined by upper-level optimization, the lower-level control achieves local dynamic adjustment while meeting the overall optimal operating requirements of the system, thereby reducing system energy consumption and improving operational stability.

[0183] In summary, this invention provides a dual-source heat recovery type multi-terminal constant temperature and humidity air conditioning control method and system. The control device acquires environmental and equipment information of the target area, and constructs a multivariate joint optimization model under steady-state conditions based on the environmental and equipment information and preset constraints, with the goal of minimizing total equipment energy consumption. The multivariate joint optimization model constructs a first objective function with the medium-temperature chilled water supply temperature, low-temperature chilled water supply temperature, water pump flow rate, fan air volume, and air handling unit coil load allocation factor as decision variables. Solving the first objective function yields the target medium-temperature chilled water supply temperature, target low-temperature chilled water supply temperature, target water pump flow rate, and target temperature and humidity of the target medium-temperature chilled water supply temperature that minimize total equipment energy consumption. The target fan air volume and target air handling unit coil load distribution factor are used to adjust the chiller unit operating status, water pump operating frequency, fan operating status, and precooling coil valve opening, and to obtain the upper limit of water flow. After real-time acquisition of indoor temperature and humidity and comparison with target temperature and humidity to obtain temperature and humidity deviations, the target supply air temperature and target supply air dew point temperature are generated according to the outer loop proportional integral differential control model of the control device. The inner loop predictive control model of the control device constructs a second objective function based on the upper limit of water flow, target supply air temperature, target supply air dew point temperature, current supply air temperature, and current supply air dew point temperature, and solves it to obtain the target recooling coil valve opening and the target reheat coil valve opening.

[0184] This invention also provides an electronic device, which includes:

[0185] At least one processor; and,

[0186] A memory that is communicatively connected to at least one processor; wherein,

[0187] The memory contains a computer program that can be executed by at least one processor, and the computer program is executed by at least one processor to enable at least one processor to execute in order to implement the above-described dual-cold-source heat recovery type multi-terminal constant temperature and humidity air conditioning control method.

[0188] This invention also provides a computer-readable storage medium storing at least one computer program, which is executed by a processor in an electronic device to implement the above-described dual-cold-source heat recovery type multi-terminal constant temperature and humidity air conditioning control method.

[0189] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0190] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the appended claims.

Claims

1. A dual-source heat recovery type multi-terminal constant temperature and humidity air conditioning control method, characterized in that, The method is executed on a control device connected to an air handling unit and an air conditioning water circuit device, and the method includes: Obtain environmental and equipment information for the target area; environmental information includes indoor temperature and humidity parameters, and equipment information includes air handling unit coil structure parameters, chiller performance parameters, water pump operating parameters, and fan operating parameters; Based on environmental information, equipment information, and preset constraints, a multivariate joint optimization model is constructed under steady-state conditions with the goal of minimizing total equipment energy consumption. The multivariate joint optimization model uses the medium-temperature chilled water supply temperature, low-temperature chilled water supply temperature, water pump flow rate, fan air volume, and air handling unit coil load allocation factor as decision variables to construct the first objective function. Solving the first objective function yields the target operating parameters that minimize the total equipment energy consumption. The target operating parameters include the target medium-temperature chilled water supply temperature, the target low-temperature chilled water supply temperature, the target water pump flow rate, the target fan air volume, and the target air handling unit coil load allocation factor. The chiller unit's operating status is adjusted according to the target medium-temperature chilled water supply temperature and the target low-temperature chilled water supply temperature. The pump operating frequency is determined according to the target pump flow rate, and the upper limit of the water flow rate is determined based on the pump operating frequency. The fan operating status is adjusted according to the target fan operating frequency. The precooling coil water flow rate is determined according to the target coil load distribution factor, and the precooling coil valve opening is adjusted based on the preset correspondence between the precooling coil water flow rate and the valve opening. The indoor temperature is collected in real time and compared with the target temperature to obtain the temperature deviation. The indoor humidity is collected in real time and compared with the target humidity to obtain the humidity deviation. Then, the target supply air temperature and the target supply air dew point temperature are generated according to the outer loop proportional-integral-derivative control model of the control device. The inner loop predictive control model of the control device constructs a second objective function based on the upper limit of water flow, the target supply air temperature, the target supply air dew point temperature, the current supply air temperature, and the current supply air dew point temperature. After solving, the target recooling coil valve opening and the target reheating coil valve opening are obtained.

2. The dual-cold-source heat recovery type multi-terminal constant temperature and humidity air conditioning control method according to claim 1, characterized in that, The total energy consumption of the equipment includes the energy consumption of medium-temperature chillers, low-temperature chillers, heat recovery units, water pumps, and fans. Energy consumption of medium-temperature chiller units Energy consumption of low-temperature chiller units Energy consumption of heat recovery units Water pump energy consumption Energy consumption of air conditioner The expression is: ； ； ； ； ； ； ； ； in, Indicates the serial number of the air handling unit; This indicates the load of the precooling coil under steady-state operating conditions; This indicates the number of medium-temperature chillers that are currently in operation. This indicates the coefficient of performance (COP) of a medium-temperature chiller unit. Indicates the evaporation temperature; Indicates the unit's condensing temperature; Indicates the unit load rate; This indicates the load on the recooling coil under steady-state operating conditions; This indicates the number of devices in the low-temperature chiller unit that are currently in operation. This indicates the coefficient of performance (COP) of a low-temperature chiller unit. This indicates the load on the reheat coil under steady-state conditions. This represents the coefficient of performance (COP) of the heat recovery unit. Represents the coefficients of a quadratic polynomial; Indicates the water flow rate of the water pump; Indicates the fan air volume; Indicates the coil load distribution factor; Indicates the enthalpy of the mixed air; This indicates the enthalpy value of the air at the outlet dew point of the recooling coil. Indicates the supply air temperature; This indicates the supply air dew point temperature.

3. The dual-cold-source heat recovery type multi-terminal constant temperature and humidity air conditioning control method according to claim 2, characterized in that, The expression for the coil load distribution factor is: ； ； in, Indicates the enthalpy of the mixed air; This indicates the enthalpy value of the air at the precooling coil outlet; This indicates the enthalpy value of the air at the outlet dew point of the recooling coil. This represents the enthalpy value at the dew point of the mixed air.

4. The dual-cold-source heat recovery type multi-terminal constant temperature and humidity air conditioning control method according to claim 1, characterized in that, The multivariate joint optimization model uses the medium-temperature chilled water supply temperature, low-temperature chilled water supply temperature, water pump flow rate, fan air volume, and air handling unit coil load allocation factor as decision variables to construct the first objective function. The expression of the first objective function is as follows: ； in, Indicates the coil load distribution factor; Indicates the temperature of the chilled water supply entering the air handling unit; Indicates the water flow rate of the water pump; This indicates the air volume of the air handling unit's fan; Indicates the air volume of the cooling tower fan; This indicates the energy consumption of the low-temperature chiller unit; This indicates the energy consumption of the medium-temperature chiller unit; Indicates the energy consumption of the heat recovery unit; Indicates the energy consumption of the water pump; This indicates the energy consumption of the air handling unit's fan; This indicates the energy consumption of the cooling tower fan.

5. The dual-cold-source heat recovery type multi-terminal constant temperature and humidity air conditioning control method according to claim 1, characterized in that, The expression for the preset constraint condition is: ； ； ； ； ； in, Indicates the coil load distribution factor; It represents water; Indicates air; Indicates the direction in which the medium enters; Indicates the rated parameters; Indicates the temperature of the chilled water supply entering the air handling unit; Indicates the water flow rate of the water pump; This indicates the air volume of the air handling unit's fan; Indicates the air volume of the cooling tower fan; The flow coefficient that indicates the safe operation of a water pump; The flow coefficient represents the safe operation of the fan.

6. The dual-cold-source heat recovery type multi-terminal constant temperature and humidity air conditioning control method according to claim 1, characterized in that, Indoor temperature With preset target temperature Temperature deviation was obtained by comparison Indoor humidity With target humidity Compare to obtain humidity deviation The expression is: ； ； The target supply air temperature is generated based on the outer loop proportional-integral-differential control model of the control device. and target supply air dew point temperature The expression is: ； ； ； in, This represents the temperature loop proportionality coefficient; This represents the integral coefficient of the temperature loop; This represents the differential coefficient of the temperature ring; This represents the time sequence of temperature acquisition. This represents the total time sequence of temperature acquisition. Indicates the control cycle; Indicates the reference supply air temperature; Indicates the humidity ring proportionality coefficient; Indicates the integral coefficient of the humidity loop; Indicates the humidity ring differential coefficient; This indicates the reference supply air dew point temperature.

7. The dual-cold-source heat recovery type multi-terminal constant temperature and humidity air conditioning control method according to claim 1, characterized in that, The expression for the second objective function is: ； ； ； ； ； ； ； in, Indicates the prediction step size; This indicates the predicted supply air temperature. Indicates the target supply air temperature; This indicates the predicted value of the supply air dew point temperature; Indicates the target supply air dew point temperature; Indicates the control step size; and Indicates the weighting coefficient; express The opening degree of the recooling coil valve at any given time; express The opening degree of the reheat coil valve at any given time; Indicates the total number of air handling units; express Chilled water flow rate of the air handling unit at all times; This indicates the upper limit of water flow.

8. A dual-source heat recovery multi-terminal constant temperature and humidity air conditioning control system, comprising a processor, a memory, and computer programs / instructions stored in the memory, characterized in that, The processor is used to execute computer programs / instructions, and when the computer programs / instructions are executed, the system implements the steps of any one of claims 1 to 7.

9. An electronic device, characterized in that, The electronic device includes: At least one processor; A memory communicatively connected to the at least one processor; wherein, The memory stores a computer program that can be executed by the at least one processor, the computer program being executed by the at least one processor to enable the at least one processor to perform the dual-cold-source heat recovery multi-terminal constant temperature and humidity air conditioning control method as described in any one of claims 1 to 7.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the dual-cold-source heat recovery type multi-terminal constant temperature and humidity air conditioning control method as described in any one of claims 1 to 7.

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