Water-cooled central air conditioner control method, device and water-cooled central air conditioner

Abstract

The present application discloses a water-cooled central air conditioner control method, device and water-cooled central air conditioner, which relate to the field of air conditioning control and are used to solve the technical problems of uneven water flow distribution and high water pump energy consumption in the water-cooled central air conditioning system. The method includes: collecting the physical parameters of the water system of the water-cooled central air conditioner; determining the target opening of the electric regulating valve at each air conditioning terminal according to the physical parameters of the water system; controlling the opening of each electric regulating valve to the target opening corresponding to the electric regulating valve, so that the supply and return water pressure difference between the water pump and each air conditioning terminal reaches the target supply and return water pressure difference, and the difference between the return water temperatures flowing out of each air conditioning terminal reaches the target difference. The water-cooled central air conditioner control method, device and water-cooled central air conditioner disclosed in the present application are used to solve the defects of high water pump power consumption of water-cooled central air conditioners.

Description

Technical Field

[0001] The present application relates to the field of air conditioning control, and in particular to a water-cooled central air conditioning control method, device and water-cooled central air conditioning. Background Art

[0002] Water-cooled central air conditioners can use water as a medium to adjust the indoor temperature. Generally, a water-cooled central air conditioner can include a water pump and at least one air conditioner terminal (i.e., an air conditioner terminal). A pipeline is provided between the water pump and each air conditioner terminal, and an electric regulating valve is provided on the pipeline before the water inlet of each air conditioner terminal. By adjusting the opening of the electric regulating valve, the water flow through the air conditioner terminal can be controlled, thereby achieving the adjustment of the cooling effect or the heating effect.

[0003] In some application scenarios, water-cooled central air conditioners need to maintain flow balance between pipelines to maintain the same cooling or heating effect at each air conditioner terminal. However, when using existing control methods to maintain flow balance between pipelines, the power consumption of the water pump is often high. Summary of the invention

[0004] The main purpose of the present application is to provide a water-cooled central air-conditioning control method, device and water-cooled central air-conditioning, aiming to solve the technical problem of high power consumption of the water pump of the water-cooled central air-conditioning.

[0005] To achieve the above objectives, in a first aspect, the present application provides a water-cooled central air conditioner control method comprising:

[0006] Collecting physical parameters of the water system of the water-cooled central air conditioner;

[0007] Determining the target opening of the electric regulating valve at each air-conditioning terminal according to the physical parameters of the water system;

[0008] The opening of each electric regulating valve is controlled to be the target opening corresponding to the electric regulating valve, so that the supply and return water pressure difference between the water pump and each air-conditioning terminal reaches the target supply and return water pressure difference, and the difference between the return water temperatures flowing out of each air-conditioning terminal reaches the target difference.

[0009] The beneficial effects of the present application are as follows: the target opening of the electric regulating valve of each air-conditioning terminal can be determined by the water system physical parameters of the water flow in the connecting pipeline between the water pump and at least two air-conditioning terminals. By controlling the opening of each electric regulating valve to the target opening corresponding to the electric regulating valve, the water flow of the water pump and each air-conditioning terminal can reach the hydraulic balance target that the supply and return water pressure difference reaches the target supply and return water pressure difference. Through the hydraulic balance target, the water flow pressure in the connecting pipeline between the water pump and each air-conditioning terminal is equal, ensuring the water pressure balance in different connecting pipelines. By making the water flow of the water pump and each air-conditioning terminal reach the hydraulic balance target of the difference between the return water temperatures flowing out of each air-conditioning terminal to reach the target difference, the difference between the return water temperatures of different air-conditioning terminals is within the desired range, ensuring that the heating or cooling effects of different air-conditioning terminals are similar. By maintaining hydraulic balance through the above method, it is not necessary to set a balancing valve in the water-cooled central air-conditioning, and by adjusting the opening of the electric regulating valve, the water flow reaches multiple hydraulic balance targets, improving the accuracy of controlling the opening of the electric regulating valve, thereby reducing the power consumption of the water pump of the water-cooled central air-conditioning.

[0010] Based on the above technical solution, the present application can also be improved as follows.

[0011] Further, determining the target opening of the electric regulating valve at each air-conditioning terminal according to the physical parameters of the water system includes:

[0012] Inputting the physical parameters of the water system into a preset planning model to obtain a planning model to be optimized;

[0013] Under preset constraints, a preset multi-objective optimization algorithm is used to perform multi-objective optimization on the planning model to be optimized to obtain the target opening of the electric regulating valve of each air-conditioning terminal; the objectives of the multi-objective optimization include: minimizing the weighted sum of the difference between the supply and return water pressure difference between the water pump and each air-conditioning terminal and the return water temperature flowing out of each air-conditioning terminal.

[0014] Furthermore, the preset constraints include at least one of the following: the supply and return water pressure differences between the water pump and each of the air-conditioning terminals are equal, the water flow in the connecting pipe between the water pump and each of the air-conditioning terminals is greater than or equal to a first water flow threshold and less than or equal to a second water flow threshold, and the return water temperature of each of the air-conditioning terminals is greater than or equal to a first preset return water temperature and less than or equal to a second preset return water temperature.

[0015] Further, the preset constraint condition includes: the supply and return water pressure difference between the water pump and each of the air-conditioning terminals is equal, and for any of the air-conditioning terminals, the water system physical parameters include: the water flow rate in the connecting pipe between the water pump and the air-conditioning terminal; under the preset constraint condition, before performing multi-objective optimization on the planning model to be optimized using a preset multi-objective optimization algorithm, the method further includes:

[0016] According to the type of the electric regulating valve at the air conditioner terminal, an electric regulating valve resistance characteristic coefficient equation corresponding to the electric regulating valve is determined; the variables in the electric regulating valve resistance characteristic coefficient equation include: the opening of the electric regulating valve;

[0017] The supply and return water pressure difference between the water pump and the air conditioner terminal is obtained according to the electric regulating valve resistance characteristic coefficient equation corresponding to the electric regulating valve and the water flow in the connecting pipeline between the water pump and the air conditioner terminal.

[0018] Further, the preset constraint conditions include: the water flow rate in the connecting pipe between the water pump and each of the air-conditioning terminals is greater than or equal to the first water flow rate threshold and less than or equal to the second water flow rate threshold; for any of the air-conditioning terminals, the water system physical parameters include: the water flow rate in the connecting pipe between the water pump and the air-conditioning terminal, the water supply temperature of the water pump of the water-cooled central air-conditioning, and the return water temperature flowing out of the air-conditioning terminal; under the preset constraint conditions, before performing multi-objective optimization on the planning model to be optimized using a preset multi-objective optimization algorithm, the method also includes:

[0019] According to the specific heat of water, the water flow in the connecting pipe between the water pump and the air conditioner terminal, and the temperature difference between the water supply temperature of the water pump and the return water temperature flowing out of the air conditioner terminal, the cooling capacity in the connecting pipe between the water pump and the air conditioner terminal is obtained;

[0020] According to the cooling capacity in the connecting pipeline between the water pump and the air-conditioning terminal, and the preset temperature difference threshold between the water supply temperature of the water pump and the return water temperature flowing out of each air-conditioning terminal, a second water flow threshold corresponding to the connecting pipeline between the water pump and the air-conditioning terminal is obtained.

[0021] Further, the controlling the opening of each of the electric regulating valves to be the target opening corresponding to the electric regulating valve, so that the supply and return water pressure difference between the water pump and each of the air-conditioning terminals reaches the target supply and return water pressure difference, and the difference between the return water temperatures flowing out of each of the air-conditioning terminals reaches the target difference, includes:

[0022] The opening of each electric regulating valve is controlled to be the target opening corresponding to the electric regulating valve, so that the supply and return water pressure differences between the water pump and each air-conditioning terminal reach the target supply and return water pressure difference, and the mean absolute error MAE between the return water temperatures flowing out of each air-conditioning terminal reaches the target MAE; the MAE between the return water temperatures is positively correlated with the difference between the return water temperatures.

[0023] Further, the water system physical parameters include: the water supply temperature of the water pump of the water-cooled central air conditioner, the return water temperature flowing out of the air conditioner terminal, and the water flow in the connecting pipeline between the water pump and the air conditioner terminal; before determining the target opening of the electric regulating valve of each air conditioner terminal according to the water system physical parameters, the method further includes:

[0024] According to the physical parameters of the water system, the total load of the hydraulic network formed by the connecting pipelines of the water pump and each of the air conditioner terminals is obtained;

[0025] When the change rate of the total load of the hydraulic network is less than or equal to the preset change rate threshold for a continuous preset period of time, the target opening of the electric regulating valve at each air-conditioning terminal is determined according to the physical parameters of the water system.

[0026] Furthermore, before determining the target opening of the electric regulating valve of each air-conditioning terminal according to the physical parameters of the water system, the method further includes:

[0027] Performing data cleaning processing on the physical parameters of the water system to obtain the physical parameters of the water system after the data cleaning processing;

[0028] According to the physical parameters of the water system after the data cleaning process, the target opening of the electric regulating valve at each air-conditioning terminal is determined.

[0029] In a second aspect, the present application further provides a water-cooled central air-conditioning control device, the device comprising:

[0030] A collection module, used to collect physical parameters of the water system of the water-cooled central air conditioner;

[0031] A processing module, used for determining the target opening of the electric regulating valve of each air-conditioning terminal according to the physical parameters of the water system;

[0032] A control module is used to control the opening of each electric regulating valve to be the target opening corresponding to the electric regulating valve, so that the supply and return water pressure difference between the water pump and each air-conditioning terminal reaches the target supply and return water pressure difference, and the difference between the return water temperatures flowing out of each air-conditioning terminal reaches the target difference.

[0033] The beneficial effects of the water-cooled central air-conditioning control device provided in the present application are the same as the beneficial effects of the above-mentioned water-cooled central air-conditioning control method, which will not be repeated here.

[0034] In a third aspect, the present application further provides an electric control box, which is used to execute the water-cooled central air conditioner control method as described in any one of the first aspects.

[0035] In a fourth aspect, the present application further provides a water-cooled central air conditioner, the water-cooled central air conditioner comprising: an electric control box as described in the third aspect.

[0036] In a fifth aspect, the present application further provides a computer-readable storage medium, on which computer execution instructions are stored. When the computer execution instructions are executed by the electronic control box, the method described in any one of the first aspects is implemented.

[0037] In a sixth aspect, the present application further provides a computer program product, including a computer program, which implements any method described in the first aspect when executed by an electronic control box. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0039] Figure 1 It is a structural schematic diagram of a water-cooled central air-conditioning water system;

[0040] Figure 2 A schematic diagram of a flow chart of a water-cooled central air conditioner control method provided in this application;

[0041] Figure 3 A schematic diagram of a resistance characteristic coefficient curve of a different type of electric control valve provided in this application;

[0042] Figure 4 A schematic diagram of the structure of a water-cooled central air conditioner provided in this application;

[0043] Figure 5 A schematic diagram of the structure of a water-cooled central air-conditioning control device provided in this application;

[0044] Figure 6 A flow chart of another water-cooled central air conditioner control method provided in this application;

[0045] Figure 7This is a schematic diagram of the NSGA-II algorithm principle;

[0046] Figure 8 A schematic diagram of the NSGA-II multi-objective optimization solution process provided in this application;

[0047] Fig. 9 A schematic diagram of the last generation of Pareto frontier solution set provided for this application;

[0048] Fig.10 A schematic structural diagram of another water-cooled central air-conditioning control device provided in this application. DETAILED DESCRIPTION

[0049] The water system of the water-cooled central air conditioner may include a water pump and at least one air conditioner terminal (in some embodiments, the air conditioner terminal may also be referred to as an indoor unit). For example, taking the water-cooled central air conditioner including three air conditioner terminals as an example, Figure 1 The figure is a schematic diagram of the structure of a water-cooled central air-conditioning water system. Figure 1 As shown, the water pump can drive water to the air conditioning terminal, so that the air conditioning terminal can adjust the temperature of the space where the air conditioning terminal is located. After flowing through the air conditioning terminal, the water can flow back to the water pump.

[0050] like Figure 1 As shown, a pipeline is provided between the water pump of the water-cooled central air conditioner and each air conditioner terminal, and an electric regulating valve (such as Figure 1 By adjusting the opening of the electric regulating valve, the water flow through the air conditioner terminal can be controlled, thereby adjusting the cooling effect or heating effect.

[0051] In some application scenarios, such as shopping malls, office buildings, apartments, etc., it is necessary to maintain the same cooling or heating effect in each space, that is, it is necessary to maintain the same cooling or heating effect at each air-conditioning terminal. Therefore, water-cooled central air conditioners need to maintain the flow balance of water in the connecting pipes between the water pump and each air-conditioning terminal (or maintain hydraulic balance) to ensure the same cooling or heating effect at each air-conditioning terminal.

[0052] In the related art, in order to maintain the flow balance in different connecting pipelines, a common practice is to use a balancing valve as the above-mentioned electric regulating valve. The balancing valve can be a static balancing valve or a dynamic balancing valve. However, the method of adding a balancing valve not only increases the investment in the project, but also because the balancing valve is a passive regulating valve, it is also necessary for professional engineers to debug each balancing valve in advance. Otherwise, an improperly debugged balancing valve will not only fail to solve the problem of hydraulic imbalance, but will increase the resistance of the connecting pipeline between the water pump and the air conditioner terminal, thereby causing the water pump to require higher power consumption to drive water to the air conditioner terminal, which results in energy waste. In fact, at present, the balancing valves installed on most water-cooled central air conditioners do not function as they should.

[0053] In addition, some related technologies have also proposed controlling the opening of the electric regulating valve by the temperature difference between the water inlet and the water outlet of the air conditioner terminal. In this technology, the temperature of the water entering the air conditioner terminal through the water inlet is measured at time T1 as temperature 1. The water entering the air conditioner terminal through the water inlet at time T1 flows out through the water outlet of the air conditioner terminal at time T2 after a time length t. The temperature of the water flowing out through the water outlet of the air conditioner terminal at time T2 is measured as temperature 2. Then, the opening of the electric regulating valve can be controlled according to the temperature difference between temperature 1 and temperature 2.

[0054] In the related art, the time interval between temperature 1 and temperature 2 is relatively long, which may generally take 30 minutes to 40 minutes. Therefore, the opening of the electric regulating valve is controlled according to the temperature difference between temperature 1 and temperature 2, resulting in a slow change in the control process, which in turn leads to poor accuracy in controlling the opening of the electric regulating valve. When the accuracy of the opening of the electric regulating valve is poor, the water pump may be repeatedly accelerated or decelerated, so the prior art still has the problem of high power consumption of the water pump.

[0055] Considering the above-mentioned high power consumption problem of the existing water-cooled central air conditioner control method, the present application proposes a control method for real-time control and adjustment of the opening of the electric regulating valve so that the water flow in different connecting pipes reaches multiple hydraulic balance targets. Through the above method, the power balance can be achieved without installing a balancing valve, and the water flow reaches multiple hydraulic balance targets by adjusting the opening of the electric regulating valve, thereby improving the accuracy of controlling the opening of the electric regulating valve, and thus reducing the power consumption of the water pump of the water-cooled central air conditioner.

[0056] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0057] In some implementations, the execution subject of the water-cooled central air conditioner control method may be the water-cooled central air conditioner or the electric control box of the water-cooled central air conditioner. In some embodiments, the electric control box may be arranged in the outdoor unit of the water-cooled central air conditioner. The methods executed by the water-cooled central air conditioner described in the following embodiments may be methods executed by the electric control box of the water-cooled central air conditioner.

[0058] Figure 2 The following is a flow chart of a water-cooled central air conditioner control method provided in this application. Figure 2 As shown, the method may include the following steps:

[0059] S101. Collect physical parameters of the water system of the water-cooled central air conditioner.

[0060] Optionally, the water system of the water-cooled central air conditioner may include at least two air-conditioning terminals. Taking the water-cooled central air conditioner including N air-conditioning terminals as an example, the at least two air-conditioning terminals may refer to M air-conditioning terminals among the N air-conditioning terminals. Among them, N may be an integer greater than or equal to 2, and M may be an integer greater than or equal to 2 and less than or equal to N. In other words, the water-cooled central air conditioner may execute the following control method to maintain the hydraulic balance between all air-conditioning terminals. Alternatively, the water-cooled central air conditioner may also receive the identifiers of at least two air-conditioning terminals input by the user, and control the hydraulic balance between the at least two air-conditioning terminals according to the identifiers of the at least two air-conditioning terminals. Exemplarily, the water-cooled central air conditioner may, for example, receive the identifiers of the air-conditioning terminals input by the user through a control panel.

[0061] Exemplarily, for any air-conditioning terminal, the physical parameters of the water system of the above-mentioned water flow may include, for example, at least one of the following: the water flow rate in the connecting pipe between the water pump and the air-conditioning terminal, the water supply temperature of the water pump (also known as the water temperature at the water inlet of the air-conditioning terminal), the return water temperature flowing out of the air-conditioning terminal (also known as the water temperature at the water outlet of the air-conditioning terminal), etc.

[0062] For example, taking the water flow in the connecting pipe between the water pump and the air conditioner terminal as an example, the water-cooled central air conditioner can detect the water flow in the connecting pipe between the water pump and the air conditioner terminal through a flow detection device. Optionally, the water-cooled central air conditioner can collect different water system physical parameters by referring to any existing method for collecting water system physical parameters of water flow, which will not be described in detail here.

[0063] S102: Determine the target opening of the electric regulating valve at each air-conditioning terminal according to the physical parameters of the water system.

[0064] As mentioned above, in some embodiments, the electric regulating valve may refer to the water inlet valve at the end of the air conditioner.

[0065] For any air-conditioning terminal, the water-cooled central air-conditioning can determine the target opening of the electric regulating valve of the air-conditioning terminal according to the physical parameters of the water system of the water flow in the connecting pipe between the water pump and the air-conditioning terminal.

[0066] It should be understood that the present application does not limit the type of the above-mentioned electric regulating valve. Exemplarily, the electric regulating valve can be, for example, a butterfly valve, a gate valve, a stop valve, a ball valve, or any other valve that can control the opening of a water-cooled central air conditioner. In addition, according to the flow characteristics of the valve, the above-mentioned electric regulating valve can be, for example, any of the following types of valves: linear, equal percentage, and quick opening. Among them, the flow characteristics refer to the relationship between the relative flow of the controlled medium (water in this application) through the valve and the relative opening of the valve. Among them, the linear type means that the relative flow of the valve is linearly related to the relative opening, and the flow change caused by the change of the valve unit opening is a constant. The equal percentage type means that the relative flow change caused by the change of the valve unit opening is proportional to the relative flow of the point, that is, the amplification factor of the regulating valve is variable, and the flow change is small when the flow is small, and the flow change is large when the flow is large. The quick opening type means that there is a large flow when the opening is small, and as the opening increases, the flow can quickly reach the maximum, and then the opening is increased, and the flow change is very small.

[0067] S103, control the opening of each electric regulating valve to be the target opening corresponding to the electric regulating valve, so that the supply and return water pressure difference between the water pump and each air-conditioning terminal reaches the target supply and return water pressure difference, and the difference between the return water temperatures flowing out of each air-conditioning terminal reaches the target difference.

[0068] For any air conditioner terminal, the above-mentioned supply and return water pressure difference may refer to the difference between the water flow pressure at the water inlet of the air conditioner terminal and the water flow pressure at the water outlet of the air conditioner terminal at the same sampling time. The above-mentioned return water temperature may refer to the water flow temperature at the water outlet of the air conditioner terminal at the same sampling time.

[0069] Optionally, the difference between the return water temperatures of the above-mentioned air-conditioning terminals can be expressed by any one of the following indicators, for example: mean square error (MSE), mean absolute error (MAE), root mean square error (RMSE), mean square logarithmic error (RMSE), etc. between the return water temperatures of the air-conditioning terminals.

[0070] Exemplarily, taking the difference between the return water temperatures of each air-conditioning terminal as represented by the mean absolute error (MAE) between the return water temperatures of each air-conditioning terminal as an example, optionally, the water-cooled central air-conditioning can control the opening of each electric regulating valve to be the target opening corresponding to the electric regulating valve, so that the supply and return water pressure difference between the water pump and each air-conditioning terminal reaches the target supply and return water pressure difference, and the MAE between the return water temperatures flowing out of each air-conditioning terminal reaches the target MAE. Among them, the MAE between the return water temperatures is positively correlated with the difference between the return water temperatures. In other words, the larger the MAE between the return water temperatures, the larger the difference between the return water temperatures. The smaller the MAE between the return water temperatures, the smaller the difference between the return water temperatures.

[0071] It should be understood that the present application does not limit the specific implementation method of controlling the opening of each electric regulating valve of the water-cooled central air conditioner to reach the target opening. Optionally, the method of controlling the opening of different electric regulating valves of the water-cooled central air conditioner to reach the target opening can be the same or different, and can refer to any existing implementation method of controlling the valve to reach the target opening, which will not be repeated here.

[0072] In this embodiment, the target opening of the electric regulating valve of each air-conditioning terminal can be determined by the water system physical parameters of the water flow in the connecting pipeline between the water pump and at least two air-conditioning terminals. By controlling the opening of each electric regulating valve to the target opening corresponding to the electric regulating valve, the water flow of the water pump and each air-conditioning terminal can reach the hydraulic balance target that the supply and return water pressure difference reaches the target supply and return water pressure difference. Through the hydraulic balance target, the water flow pressure in the connecting pipeline between the water pump and each air-conditioning terminal is equal, ensuring the water pressure balance in different connecting pipelines. By making the water flow of the water pump and each air-conditioning terminal reach the hydraulic balance target of the difference between the return water temperatures flowing out of each air-conditioning terminal to reach the target difference, the difference between the return water temperatures of different air-conditioning terminals is within the desired range, ensuring that the heating or cooling effects of different air-conditioning terminals are similar. By maintaining hydraulic balance through the above method, it is not necessary to set a balancing valve in the water-cooled central air-conditioning, and by adjusting the opening of the electric regulating valve, the water flow reaches multiple hydraulic balance targets, thereby improving the accuracy of controlling the opening of the electric regulating valve, thereby reducing the power consumption of the water pump of the water-cooled central air-conditioning.

[0073] The following is a detailed description of how to determine the target opening of the electric regulating valve at each air conditioner terminal according to the physical parameters of the water system for water-cooled central air conditioners:

[0074] As a possible implementation method, the water-cooled central air conditioner can input the above-mentioned water system physical parameters into a preset planning model to obtain a planning model to be optimized. Then, the water-cooled central air conditioner can use a preset multi-objective optimization algorithm under preset constraints to perform multi-objective optimization on the planning model to be optimized to obtain the target opening of the electric regulating valve of each air conditioning terminal. Among them, the objectives of the multi-objective optimization may include: minimizing the weighted sum of the difference between the supply and return water pressure difference between the water pump and each air conditioning terminal and the return water temperature flowing out of each air conditioning terminal.

[0075] Exemplarily, the weight of the supply and return water pressure difference between the water pump and each air-conditioning terminal, and the weight of the difference between the return water temperatures of each air-conditioning terminal can be preset and stored in the water-cooled central air-conditioning.

[0076] Exemplarily, the above preset planning model may be, for example, a nonlinear planning model. Taking the difference between the return water temperatures of each air-conditioning terminal as an example, the difference between the return water temperatures of each air-conditioning terminal is represented by the MAE between the return water temperatures of each air-conditioning terminal, the preset planning model may be, for example, as shown in the following formula (1):

[0077] min y=f(K)=(ΔP(K), MAE(K)) (1)

[0078] Wherein, K represents the opening of the electric regulating valve. ΔP(K) represents the pressure difference between the water flow pressure at the water inlet of the air-conditioning terminal and the water flow pressure at the water outlet of the air-conditioning terminal at the opening K. MAE(K) represents the MAE between the return water temperatures of each air-conditioning terminal at the opening K. Wherein, y=f(K), min y represents the pressure difference between the water flow pressure at the water inlet of the air-conditioning terminal and the water flow pressure at the water outlet of the air-conditioning terminal, and the MAE between the return water temperatures of each air-conditioning terminal are minimized at the same time. Optionally, the above ΔP(K) can be obtained according to the physical parameters of the water system input into the preset planning model. By minimizing the pressure difference between the water flow pressure at the water inlet of the air-conditioning terminal and the water flow pressure at the water outlet of the air-conditioning terminal, the energy consumption required for the water pump to drive water to the air-conditioning terminal can be reduced, thereby further reducing the energy consumption of the water pump.

[0079] Optionally, the preset multi-objective optimization algorithm may be any existing optimization algorithm capable of performing multi-objective optimization, for example, a non-dominated sorting genetic algorithm (NSGA-II).

[0080] Exemplarily, the above-mentioned preset constraints may include, for example, at least one of the following: the supply and return water pressure differences between the water pump and each air-conditioning terminal are equal, the water flow rate in the connecting pipe between the water pump and each air-conditioning terminal is greater than or equal to the first water flow rate threshold and less than or equal to the second water flow rate threshold, and the return water temperature of each air-conditioning terminal is greater than or equal to the first preset return water temperature and less than or equal to the second preset return water temperature. It should be understood that the present application does not limit whether the above-mentioned preset constraints also include other conditions. For example, the preset constraint that the water flow rate in the connecting pipe between the water pump and each air-conditioning terminal is greater than or equal to the first water flow rate threshold and less than or equal to the second water flow rate threshold can also be replaced by: the water flow rate in the connecting pipe between the water pump and each air-conditioning terminal is less than or equal to the second water flow rate threshold.

[0081] By taking the supply and return water pressure differences between the water pump and each air-conditioning terminal as the preset constraint condition, the connecting pipes between the water pump and each air-conditioning terminal are connected, and therefore the supply and return water pressure differences between the water pump and each air-conditioning terminal are equal, the target opening of the electric regulating valve determined under the preset constraint condition is consistent with the actual situation, thereby further improving the accuracy of determining the target opening of the electric regulating valve.

[0082] By setting the water flow rate in the connecting pipe between the water pump and each air-conditioning terminal to be greater than or equal to the first water flow rate threshold and less than or equal to the second water flow rate threshold, and the return water temperature of each air-conditioning terminal to be greater than or equal to the first preset return water temperature and less than or equal to the second preset return water temperature as preset constraints, it is ensured that the water flow rate between the water pump and each air-conditioning terminal is within the same range, and the consistency of the heating or cooling effect of each air-conditioning terminal is ensured. Optionally, the first preset return water temperature and the second preset return water temperature can be pre-stored in the water-cooled central air conditioner by the user.

[0083] In this embodiment, under the constraints of preset constraints, a preset multi-objective optimization algorithm is used to perform multi-objective optimization on the planning model to be optimized to obtain the target opening of the electric regulating valve at each air-conditioning terminal. Through the above method, the target opening of the electric regulating valve satisfies the above preset constraints, further improving the accuracy of determining the target opening of the electric regulating valve, thereby further reducing the power consumption of the water pump of the water-cooled central air conditioner.

[0084] The following is a detailed description of how the water-cooled central air conditioner in this application can use the above preset constraints:

[0085] Taking the preset constraint condition including: the supply and return water pressure difference between the water pump and each air-conditioning terminal is equal as an example, for any air-conditioning terminal, the water system physical parameters of the water flow may optionally include: the water flow rate in the connecting pipe between the water pump and the air-conditioning terminal. In this implementation, the water-cooled central air conditioner uses the preset multi-objective optimization algorithm under the preset constraint condition, and before performing multi-objective optimization on the planning model to be optimized, it can also first determine the electric regulating valve resistance characteristic coefficient equation corresponding to the electric regulating valve according to the type of the electric regulating valve at the air-conditioning terminal. Among them, the variables in the electric regulating valve resistance characteristic coefficient equation include: the opening of the electric regulating valve. Then, the water-cooled central air conditioner can obtain the supply and return water pressure difference between the water pump and the air-conditioning terminal according to the electric regulating valve resistance characteristic coefficient equation corresponding to the electric regulating valve, and the water flow rate in the connecting pipe between the water pump and the air-conditioning terminal.

[0086] Optionally, the water-cooled central air conditioner may store, for example, the type identification of the electric regulating valve at each air conditioner terminal, and the mapping relationship between the type identification of the electric regulating valve and the resistance characteristic coefficient equation of the electric regulating valve. Optionally, the mapping relationship between the type identification of the electric regulating valve and the resistance characteristic coefficient equation of the electric regulating valve may be determined offline by a user and pre-stored in the water-cooled central air conditioner.

[0087] For example, taking the electric regulating valve types as linear type, equal percentage type, and quick opening type as an example, the mapping relationship between the type identification of the electric regulating valve and the resistance characteristic coefficient equation of the electric regulating valve can be shown in the following Table 1:

[0088] Table 1

[0089] Type identification of electric control valve Drag characteristic coefficient equation Straight S=A·K+B Equal percentage type <![CDATA[S=A·K 2 +B·K+C]]> Quick opening type S=A·exp(-K / B)+C

[0090] In the above Table 1, S represents the resistance characteristic coefficient of the valve. K represents the opening of the valve. A, B, and C are all constants, which are regression coefficients of the resistance characteristic coefficient equation. The values ​​of A, B, and C can be the same or different between different resistance characteristic coefficient equations. For example, Figure 3 A schematic diagram of a resistance characteristic coefficient curve of a different type of electric regulating valve provided in the present application. The values ​​of A, B, and C in the above resistance characteristic coefficient equations can be determined offline by the user according to the resistance characteristic coefficient curves of the different types of electric regulating valves and pre-stored in the water-cooled central air conditioner. Taking the mapping relationship shown in Table 1 as an example, assuming that the type of the electric regulating valve at the end of the air conditioner is a linear type, the water-cooled central air conditioner can determine the corresponding electric regulating valve resistance characteristic coefficient equation of the electric regulating valve as: S = A·K+B.

[0091] After obtaining the resistance characteristic coefficient equation of the electric regulating valve, for example, the water-cooled central air conditioner can obtain the supply and return water pressure difference between the water pump and the air conditioner terminal by the following formula (2):

[0092]

[0093] Among them, P n Indicates the supply and return water pressure difference between the water pump and the nth air conditioning terminal. S n represents the resistance coefficient of the connecting pipe between the water pump and the nth air conditioner terminal. Optionally, the resistance coefficient of the connecting pipe between the water pump and each air conditioner terminal can be pre-stored in the water-cooled central air conditioner by the user. vn The resistance characteristic coefficient equation of the electric regulating valve of the nth air conditioner terminal is represented. For example, taking Table 1 as an example, assuming that the electric regulating valve is a linear valve, the S vn It can be equal to A·K+B. The above Q n Represents the water flow in the connecting pipe between the water pump and the nth air conditioner terminal.

[0094] In this embodiment, the resistance characteristic coefficient equation of the electric regulating valve corresponding to the electric regulating valve can be determined by the type of the electric regulating valve at the air conditioning terminal, so that the resistance characteristic coefficient equations of different types of electric regulating valves can be different. The supply and return water pressure difference between the water pump and the air conditioning terminal can be obtained by the resistance characteristic coefficient equation of the electric regulating valve corresponding to the electric regulating valve, and the water flow in the connecting pipeline between the water pump and the air conditioning terminal. Through the above method, different resistance characteristic coefficient equations can be used for different types of electric regulating valves to calculate the supply and return water pressure difference, thereby improving the accuracy of determining the supply and return water pressure difference between the water pump and each air conditioning terminal, thereby improving the accuracy of the target opening of the electric regulating valve determined when "the supply and return water pressure difference between the water pump and each air conditioning terminal is equal" is used as a preset constraint condition.

[0095] Taking the preset constraint condition including: the water flow rate in the connecting pipe between the water pump and each air conditioner terminal is greater than or equal to the first water flow rate threshold and less than or equal to the second water flow rate threshold as an example, optionally, the first water flow rate threshold can be, for example, pre-stored by the user in the water-cooled central air conditioner. It should be understood that the first water flow rate thresholds corresponding to the water flow rates in the connecting pipes between the water pump and different air conditioner terminals can be the same or different. For example, the first water flow rate thresholds corresponding to the water flow rates in the connecting pipes between the water pump and each air conditioner terminal can all be 0.

[0096] For the above-mentioned second water flow threshold, optionally, for any air-conditioning terminal, the water system physical parameters of the above-mentioned water flow may include: the water flow in the connecting pipe between the water pump and the air-conditioning terminal, the water supply temperature of the water pump of the water-cooled central air-conditioning, and the return water temperature flowing out of the air-conditioning terminal. In this implementation, the water-cooled central air-conditioning uses a preset multi-objective optimization algorithm under preset constraints. Before performing multi-objective optimization on the planning model to be optimized, the cooling amount in the connecting pipe between the water pump and the air-conditioning terminal can be obtained based on the specific heat of water, the water flow in the connecting pipe between the water pump and the air-conditioning terminal, and the temperature difference between the water supply temperature of the water pump and the return water temperature flowing out of the air-conditioning terminal. In some embodiments, the cooling amount may also be referred to as heat.

[0097] For example, the water-cooled central air conditioner can obtain the cold (heat) amount in the connecting pipe between the water pump and the air conditioner terminal by the following formula (3):

[0098] Load n =c·Q n ·(T rn -T s ) (3)

[0099] Among them, Load n represents the cooling capacity of the water flow in the pipeline connecting the water pump and the nth air conditioner terminal. c represents the specific heat capacity of water, which can also be called the specific heat of water. Optionally, c can be pre-stored by the user in the water-cooled central air conditioner. Q n Indicates the water flow in the connecting pipe between the water pump and the nth air conditioner terminal. rn represents the return water temperature flowing out of the nth air conditioner terminal, T s Indicates the water supply temperature of the water pump of the water-cooled central air conditioner.

[0100] After obtaining the cooling capacity in the connecting pipe between the water pump and the air-conditioning terminal, the water-cooled central air-conditioning can obtain a second water flow threshold value corresponding to the connecting pipe between the water pump and the air-conditioning terminal based on the cooling capacity in the connecting pipe between the water pump and the air-conditioning terminal and the temperature difference threshold value between the preset water supply temperature of the water pump and the return water temperature flowing out of each air-conditioning terminal.

[0101] Exemplarily, the temperature difference threshold can be determined offline by the user and pre-stored in the water-cooled central air conditioner. Exemplarily, the water-cooled central air conditioner can obtain the second water flow threshold by the following formula (4):

[0102]

[0103] Among them, Load n Indicates the cooling capacity of the water flow in the pipeline connecting the water pump and the nth air conditioner terminal. c indicates the specific heat capacity of water. ΔTmax The preset temperature difference threshold between the water supply temperature of the water pump and the return water temperature flowing out of each air conditioning terminal. For example, the ΔT max It may be equal to 8° C. H represents a second water flow threshold corresponding to the connecting pipeline between the water pump and the nth air conditioner terminal.

[0104] In this embodiment, based on the water flow in the connecting pipeline between the water pump and the air conditioner terminal, the temperature difference between the water supply temperature of the water pump and the return water temperature flowing out of the air conditioner terminal, and the preset temperature difference threshold between the water supply temperature of the water pump and the return water temperature flowing out of each air conditioner terminal, the second water flow threshold corresponding to the connecting pipeline between the water pump and each air conditioner terminal can be determined in real time. Through the above method, the preset constraint condition is determined in real time according to the water flow conditions in different pipelines, thereby improving the accuracy of determining the target opening of the electric regulating valve based on the preset constraint condition, thereby further reducing the power consumption of the water pump.

[0105] As a possible implementation method, the water-cooled central air conditioner can also start to execute the method of adjusting the opening of the electric regulating valve when the water-cooled central air conditioner is in a stable state, so as to avoid abnormal physical parameters of the water system of the water flow when the water-cooled central air conditioner is unstable, so as to improve the accuracy of determining the target opening of the electric regulating valve based on the physical parameters of the water system of the water flow.

[0106] Taking the water system physical parameters of the above-mentioned water flow including: the water supply temperature of the water pump of the water-cooled central air-conditioning, the return water temperature flowing out of the air-conditioning terminal, and the water flow rate in the connecting pipe between the water pump and the air-conditioning terminal as an example, optionally, before the water-cooled central air-conditioning determines the target opening of the electric regulating valve of each air-conditioning terminal according to the physical parameters of the water system, it can also first obtain the total load of the hydraulic network composed of the connecting pipes between the water pump and each air-conditioning terminal according to the above-mentioned physical parameters of the water system.

[0107] The above-mentioned total load of the hydraulic network can be used to indicate the amount of water in the hydraulic network formed by the connecting pipes between the water pump and each air-conditioning terminal. Optionally, the total load of the hydraulic network formed by the connecting pipes between the water pump and each air-conditioning terminal can be obtained by referring to any existing method for determining the total load of the hydraulic network based on the physical parameters of the water system of the water flow, and the present application does not limit this. For example, a water-cooled central air conditioner can determine the total load of the hydraulic network based on the water supply temperature of the water pump of the water-cooled central air conditioner, the return water temperature flowing out of the air-conditioning terminal, the water flow rate in the connecting pipe between the water pump and the air-conditioning terminal, and the mapping relationship between "water supply temperature, return water temperature, water flow rate and total load of the hydraulic network".

[0108] Then, the water-cooled central air conditioner can determine whether the change rate of the total load of the hydraulic pipe network is less than or equal to the preset change rate threshold for a continuous preset time period. Optionally, the preset time period and the preset change rate threshold can be pre-stored in the water-cooled central air conditioner by the user. Optionally, the water-cooled central air conditioner can, for example, take the total load of the hydraulic pipe network at the current collection time minus the value of the total load of the hydraulic pipe network at the previous collection time, and divide it by the total load of the hydraulic pipe network at the previous collection time, as the change rate of the total load of the hydraulic pipe network.

[0109] When the change rate of the total load of the hydraulic network is less than or equal to the preset change rate threshold for a continuous preset time period, it indicates that the water flow in the hydraulic network of the water-cooled central air conditioner is stable. Therefore, the water-cooled central air conditioner can perform the aforementioned step of determining the target opening of the electric regulating valve at each air conditioner terminal according to the physical parameters of the water system to ensure the accuracy of the target opening of the electric regulating valve.

[0110] If the rate of change of the total load of the hydraulic network is not less than or equal to the preset rate of change threshold for a continuous preset time, it means that the water flow in the hydraulic network of the water-cooled central air conditioner is unstable. Optionally, the water-cooled central air conditioner may not execute the aforementioned step S102 to avoid the situation where the accuracy of the target opening of the electric regulating valve is not high when the water-cooled central air conditioner is unstable, resulting in high power consumption of the water pump. Then, the water-cooled central air conditioner can continue to determine whether the rate of change of the total load of the hydraulic network is less than or equal to the preset rate of change threshold for a continuous preset time, and execute step S102 when the rate of change of the total load of the hydraulic network is less than or equal to the preset rate of change threshold for a continuous preset time.

[0111] As a possible implementation method, the water-cooled central air conditioner can also perform data cleaning processing on the water system physical parameters of the water flow before determining the target opening of the electric regulating valve at each air-conditioning terminal based on the water system physical parameters to obtain the water system physical parameters after data cleaning processing, and then determine the target opening of the electric regulating valve at each air-conditioning terminal based on the water system physical parameters after data cleaning processing.

[0112] Exemplarily, the data cleaning process may include at least one of the following: consistency check of water system physical parameters of water flow, invalid value check of water system physical parameters of water flow, missing value filling of water system physical parameters of water flow, etc. Among them, the consistency check of water system physical parameters of water flow may be, for example, checking water system physical parameters of water flow between water pump and the same air conditioner terminal.

[0113] By performing data cleaning on the physical parameters of the water system, the accuracy of the physical parameters of the water system used to determine the target opening of the electric regulating valve at each air-conditioning terminal is guaranteed, thereby improving the accuracy of the target opening of the electric regulating valve, thereby further reducing the power consumption of the water pump of the water-cooled central air-conditioning.

[0114] The following is an example of a water-cooled central air conditioner including three air-conditioning terminals to illustrate the water-cooled central air conditioner control method provided by the present application:

[0115] first, Figure 4 This is a schematic diagram of the structure of a water-cooled central air conditioner provided in this application. Figure 4 As shown, M represents an electric regulating valve, AHU1, AHU2 and AHU3 represent air conditioning terminals. EM1, EM2 and EM3 are heat meters. The heat meter can be used to measure the temperature and flow rate of water flowing through the heat meter. Ts represents the water supply temperature of the water pump. Ps represents the water supply pressure of the water pump (it can also be used as the water inlet pressure of the air conditioning terminal). Tr1, Tr2 and Tr3 represent the return water temperature of the air conditioning terminal. Pr represents the water flow pressure of the water outlet of the air conditioning terminal. As shown Figure 4 As shown, the water pump can drive the water flow through the water distributor into each air conditioning terminal. After the water flows out of each air conditioning terminal, it can be recovered to the water pump through the water collector.

[0116] Optional, such as Figure 4 The water-cooled central air conditioner shown in the figure may be installed with a building management system (BMS) or without a BMS. Figure 5 This is a schematic diagram of the structure of a water-cooled central air-conditioning control device provided in this application. Figure 5 As shown, the water-cooled central air-conditioning control device may include: an interactive interface, a storage module, a collection module, a multi-objective optimization module, and a control module.

[0117] Among them, the interactive interface can display real-time data such as temperature, pressure, flow, load, etc. collected from the hydraulic network. It can also be used to receive setting parameters input by the user for configuring the nonlinear programming model. The storage module can be used to record historical data and optimization results, and can generate and export data reports. The acquisition module can collect data from hydraulic network sensors (such as heat meters) by wired or wireless means. The multi-objective optimization module can be configured with a nonlinear programming model, an NSGA-II algorithm, and an optimal solution screening algorithm, which can serve as the core of the device. The multi-objective optimization module can perform multi-objective optimization calculations by reading the data of the acquisition module to obtain the target opening of the electric control valve that enables the network to achieve hydraulic balance and the lowest energy consumption at the same time. The control module can be responsible for sending the calculation results of the multi-objective optimization module to each electric control valve to control the electric control valve to reach the target opening.

[0118] If the water-cooled central air conditioner is equipped with a BMS, the functions of the above-mentioned modules of the BMS can be used, for example, an interactive interface can be realized through the BMS.

[0119] The following is based on Figure 4 The water-cooled central air conditioner shown in Figure 5 The water-cooled central air-conditioning control device shown in the figure, Figure 6 This is a flow chart of another water-cooled central air conditioner control method provided by the present application. Starting with the water-cooled central air conditioner being turned on and ending with adjusting the opening of the electric regulating valve once, such as Figure 6 As shown, the method may include the following steps:

[0120] Step 1: Collect the supply and return water temperature and flow rate data of the air conditioner terminal in real time through the heat meters of each branch as the physical parameters of the water system.

[0121] Step 2: Calculate the total load of the hydraulic network based on the physical parameters of the water system of the above water flow.

[0122] Step 3: According to the change rate of the total load, determine whether the total load is stable. If yes, proceed to step 4. If no, return to step 1.

[0123] For example, when the total load change rate does not exceed ±10% for 15 consecutive minutes, it is determined that the total load is in a stable state.

[0124] Step 4: Taking the supply and return water pressure difference and the return water temperature MAE value as the optimization objectives, the Pareto solution set (also called the Pareto frontier solution set) is obtained through a multi-objective optimization algorithm.

[0125] Before step 4, the original data in step 1 can also be cleaned by performing consistency checks, invalid value and missing value processing, and other data cleaning tasks.

[0126] Assume that the default chilled water supply temperature is 7°C, that is, assume that the above Ts is 7°C, and assume that the diameters of the three branch pipes are all DN200, and the electric regulating valves installed on each branch pipe are electric butterfly valves of the same specifications and models. Since the three branches are connected to the same manifold and collector, the supply and return water pressure difference between the water pump and each air conditioning terminal is the same. Assume that based on the test data provided by the electric butterfly valve manufacturer, the butterfly valve resistance characteristic coefficient equation is obtained as shown in the following formula (5):

[0127]

[0128] Among them, S v Indicates the resistance characteristic coefficient of the butterfly valve. K indicates the opening of the butterfly valve.

[0129] In some embodiments, if the test data provided by the electric butterfly valve manufacturer cannot be obtained in an actual project, the water pressure difference and water flow data before and after the electric regulating valve can be collected through the BMS for regression to obtain the resistance characteristic coefficient of the valve. Specifically, the regression based on the water pressure difference and water flow data before and after the electric regulating valve can refer to the following formula (6):

[0130] S=ΔP1 / Q 2 (6)

[0131] Among them, ΔP1 represents the water pressure difference before and after the electric regulating valve. Q represents the water flow rate flowing through the electric regulating valve. S represents the resistance characteristic coefficient of the valve.

[0132] Based on the energy-pressure difference balance relationship, the hydraulic network nonlinear programming model established can refer to the aforementioned formula (1), which will not be repeated here. The following is an exemplary explanation of the preset constraints used for multi-objective optimization of the hydraulic network nonlinear programming model. The following st represents the constraint condition, and formula (7) represents the constraint condition that the supply and return water pressure difference between the water pump and each air-conditioning terminal is equal. Formula (8)-Formula (10) is a formula for calculating the cold (heat) amount in the connecting pipeline between the water pump and each air-conditioning terminal. Formula (11)-Formula (13) is the resistance characteristic coefficient equation of each electric regulating valve. Formula (14)-Formula (16) represents: the water flow in the connecting pipeline between the water pump and each air-conditioning terminal is greater than or equal to the first water flow threshold and less than or equal to the second water flow threshold. Formula (17) represents the constraint condition that the return water temperature of each air-conditioning terminal is greater than or equal to the first preset return water temperature and less than or equal to the second preset return water temperature.

[0133]

[0134] Among them, T r，minT is the lower limit of the branch return water temperature (that is, the first preset return water temperature mentioned above), which can generally be set to Ts (that is, the water supply temperature of the water pump). r，max is the maximum return water temperature of the branch (that is, the second preset return water temperature mentioned above), which can generally be set to Ts+8°C. The meanings of the parameters in formulas (7) to (17) can refer to the meanings of the parameters in the above formulas, and will not be repeated here. For example, the above S1=5.6Pa·(m 3 / h)-2, S2=11.5Pa·(m 3 / h)-2, S3=20.3Pa·(m 3 / h)-2. ΔT max =8°C. T r，min =7℃, T r，max =15℃.

[0135] The following is a detailed description of the multi-objective optimization based on the NSGA-II algorithm:

[0136] The NSGA-II algorithm can effectively solve the above nonlinear programming problems due to its strong variable processing ability, maximally maintaining the independence between the optimization objectives and good global optimization ability. Figure 7 This is a schematic diagram of the NSGA-II algorithm principle. Figure 7 As shown, the NSGA-II algorithm principle can include the following steps:

[0137] Step 1: Randomly generate a population P0 with N individuals, initialize the level values ​​of all individuals in the population, and the evolutionary generation n=0.

[0138] Step 2: Randomly select individuals from Pn for genetic operations, using binary tournament selection operations, and the crossover operation adopts the proposed normal distribution strategy to generate offspring Xn.

[0139] Step 3: Combine Pn and Xn to generate Qn and calculate the objective function value, and perform a fast non-dominated sorting operation on Qn:

[0140] 1) Assign two key quantities to each solution p: the number of solutions np that dominate p and the set of solutions Sp dominated by p;

[0141] 2) Set i = 1 and assign individuals with np = 0 to the set Fi;

[0142] 3) For each individual in Fi, traverse the Sp of each solution p and reduce the np of each solution by 1;

[0143] 4) i+=1, the solution of np=0 is assigned to Fi;

[0144] 5) Repeat 3) and 4) until all individuals in the solution set are classified into a certain Fi.

[0145] Fast non-dominated sort is the process of decomposing the solution set into Pareto fronts of different orders.

[0146] Step 4: Calculate the crowding distance of each Pareto level in the non-dominated sorting result. The so-called crowding distance refers to the density of individuals around a specified individual in the population. The crowding of all individuals in the population is calculated as shown in the following formula (18):

[0147]

[0148] In the above formula, i d represents the congestion degree of point i, represents the function value of the jth objective function at point i+1, Represents the function value of the j-th objective function at point i-1.

[0149] Step 5: Generate a new population using an elite strategy.

[0150] According to the order of Pareto level from low to high, the entire layer of population is placed in the parent population Pn+1 until the individuals in a certain layer cannot all be placed in the parent population Pn+1; the individuals in this layer are arranged from large to small according to the crowding degree, and placed in the parent population Pn+1 in turn until Pn+1 is filled.

[0151] Step 6: If the iteration condition reaches the iteration termination condition, the Pareto frontier of the last generation is output, otherwise the iteration continues to update the population.

[0152] For example, the total load of the hydraulic network = 2000 kilowatts (kW) is taken to solve the above optimization problem, and the initialization parameters of the NSGA-II algorithm are set to: population size 500, number of iterations 200, number of offspring generated 200, crossover rate 0.9, and mutation rate 0.01. Figure 8 A schematic diagram of the NSGA-II multi-objective optimization solution process provided in this application. Figure 8 As shown in the figure, with the increase of the number of iterations, the population distribution is getting closer and closer to the minimum target value, and the number of individuals in the Pareto frontier solution set is increasing. Fig. 9 A schematic diagram of the last generation of Pareto frontier solutions provided in this application. Fig. 9 As shown in the figure, through iterative calculation, the last generation of Pareto frontier solution set is finally obtained. Among them, Pressure Drop represents the supply and return water pressure difference.

[0153] Step 5: Use the optimal solution screening algorithm to obtain the comprehensive optimal solution from the Pareto frontier solution set, that is, to achieve hydraulic balance and minimize pump energy consumption at the same time.

[0154] like Figure 7 As shown in the figure, after outputting the Pareto frontier solution set, the decision maker's satisfaction with the optimization of the target can be reflected by setting a weight factor, and the evaluation equation of the optimal solution is defined as: score = ω × F1 + (1-ω) × F2. Among them, F1 and F2 represent the normalized results of the two optimization targets, and ω is the weight factor (taken as 0.5). The solution with the highest score in the Pareto frontier is selected as the comprehensive optimal solution output.

[0155] Exemplary, the evaluation equation with the optimal solution: For example, and Represent the normalized values ​​of the absolute average error of the pressure difference and the return water temperature respectively. The solution with the largest score is selected as the optimal solution. Fig. 9 As shown, the optimal solution can be obtained from the last generation of Pareto frontier solution set.

[0156] Step 6: Obtain the optimal result of the combined supply and return water pressure difference and the return water temperature MAE value.

[0157] The optimization results of the optimal solution are shown in Table 2 below:

[0158] Table 2

[0159] parameter Optimization results Supply and return water pressure difference (kPa) 194.98 MAE 0.541 Three branch return water temperature (℃) [12.29，12.52，13.42] Water flow of three branches (℃) [97.5，93.3，77.8] Three branch valve opening (%) [47.8，57.5，93.5]

[0160] The optimization results show that under the current load, the openings of the electric control valves of the three branches are adjusted to 47.8%, 57.5% and 93.5% respectively, at which time the supply and return water pressure difference and the return water temperature value MAE can reach the minimum at the same time.

[0161] Step 7: Control the electric regulating valve (such as Figure 7 The inlet valve shown in Figure 1) reaches the target opening.

[0162] In this embodiment, by pre-establishing the resistance characteristic coefficient equations corresponding to different types of valves, the relationship between the resistance characteristic coefficients of different types of electric regulating valves and the valve opening can be quickly obtained. By taking the supply and return water pressure difference and the mean absolute error of the return water temperature of the hydraulic network as the optimization target, the NSGA-II algorithm is used to optimize and solve the target opening of the electric regulating valve, so that the hydraulic balance of the hydraulic network is achieved while minimizing the power consumption of the water pump. In addition, through the above-mentioned water-cooled central air-conditioning control device, the water-cooled central air-conditioning control method is applicable to both BMS scenarios and non-BMS scenarios. Through the above-mentioned method, the hydraulic balance of the pipeline network can be achieved without installing a balancing valve and without manual debugging. And the above-mentioned method can control the hydraulic balance in real time. Compared with the method in the prior art that needs to control the valve opening according to the supply and return water temperature at intervals, the present application avoids the problem of slow fluctuations in the proportional integral differential (PID) control process, and at the same time minimizes the power consumption of the water pump.

[0163] Fig.10 This is a schematic diagram of the structure of another water-cooled central air-conditioning control device provided in this application. Fig.10 As shown, the device may include: a collection module 21, a processing module 22, and a control module 23.

[0164] The collection module 21 is used to collect the physical parameters of the water system of the water-cooled central air conditioner.

[0165] The processing module 22 is used to determine the target opening of the electric regulating valve at each air-conditioning terminal according to the physical parameters of the water system.

[0166] The control module 23 is used to control the opening of each electric regulating valve to be the target opening corresponding to the electric regulating valve, so that the supply and return water pressure difference between the water pump and each air-conditioning terminal reaches the target supply and return water pressure difference, and the difference between the return water temperatures flowing out of each air-conditioning terminal reaches the target difference.

[0167] Optionally, the processing module 22 is specifically used to input the physical parameters of the water system into a preset planning model to obtain a planning model to be optimized; under preset constraints, use a preset multi-objective optimization algorithm to perform multi-objective optimization on the planning model to be optimized to obtain the target opening of the electric regulating valve of each air-conditioning terminal. Wherein, the multi-objectives include: the supply and return water pressure difference between the water pump and each air-conditioning terminal reaches the target supply and return water pressure difference, and the difference between the return water temperatures flowing out of each air-conditioning terminal reaches the target difference.

[0168] Optionally, the preset constraints include at least one of the following: the supply and return water pressure differences between the water pump and each of the air-conditioning terminals are equal, the water flow in the connecting pipe between the water pump and each of the air-conditioning terminals is greater than or equal to a first water flow threshold and less than or equal to a second water flow threshold, and the return water temperature of each of the air-conditioning terminals is greater than or equal to a first preset return water temperature and less than or equal to a second preset return water temperature.

[0169] Taking the preset constraint condition including: the supply and return water pressure difference between the water pump and each of the air-conditioning terminals is equal, for any of the air-conditioning terminals, the water system physical parameters include: the water flow in the connecting pipe between the water pump and the air-conditioning terminal as an example, optionally, the processing module 22 is also used to determine the electric regulating valve resistance characteristic coefficient equation corresponding to the electric regulating valve according to the type of the electric regulating valve of the air-conditioning terminal before performing multi-objective optimization on the planning model to be optimized under the preset constraint condition using the preset multi-objective optimization algorithm; according to the electric regulating valve resistance characteristic coefficient equation corresponding to the electric regulating valve, and the water flow in the connecting pipe between the water pump and the air-conditioning terminal, obtain the supply and return water pressure difference between the water pump and the air-conditioning terminal. Among them, the variables in the electric regulating valve resistance characteristic coefficient equation include: the opening of the electric regulating valve.

[0170] Taking the preset constraint conditions including: the water flow rate in the connecting pipe between the water pump and each of the air-conditioning terminals is greater than or equal to the first water flow rate threshold and less than or equal to the second water flow rate threshold, for any of the air-conditioning terminals, the physical parameters of the water system include: the water flow rate in the connecting pipe between the water pump and the air-conditioning terminal, the water supply temperature of the water pump of the water-cooled central air-conditioning, and the return water temperature flowing out of the air-conditioning terminal as an example, optionally, the processing module 22 is also used to use a preset multi-objective optimization algorithm to optimize the water to be optimized under the preset constraint conditions. Before performing multi-objective optimization on the planning model, the cooling capacity in the connecting pipeline between the water pump and the air-conditioning terminal is obtained according to the specific heat of water, the water flow rate in the connecting pipeline between the water pump and the air-conditioning terminal, and the temperature difference between the water supply temperature of the water pump and the return water temperature flowing out of the air-conditioning terminal; the second water flow rate threshold value corresponding to the connecting pipeline between the water pump and the air-conditioning terminal is obtained according to the cooling capacity in the connecting pipeline between the water pump and the air-conditioning terminal, and the preset temperature difference threshold value between the water supply temperature of the water pump and the return water temperature flowing out of each air-conditioning terminal.

[0171] Optionally, the control module 23 is specifically used to control the opening of each of the electric regulating valves to be the target opening corresponding to the electric regulating valve, so that the supply and return water pressure difference between the water pump and each of the air-conditioning terminals reaches the target supply and return water pressure difference, and the mean absolute error MAE between the return water temperatures flowing out of each of the air-conditioning terminals reaches the target MAE. The MAE between the return water temperatures is positively correlated with the difference between the return water temperatures.

[0172] Optionally, the physical parameters of the water system include: the water supply temperature of the water pump of the water-cooled central air-conditioning, the return water temperature flowing out of the air-conditioning terminal, and the water flow rate in the connecting pipe between the water pump and the air-conditioning terminal; optionally, the processing module 22 is also used to obtain the total load of the hydraulic network formed by the connecting pipes between the water pump and each of the air-conditioning terminals according to the physical parameters of the water system before determining the target opening of the electric regulating valve of each air-conditioning terminal according to the physical parameters of the water system; when the change rate of the total load of the hydraulic network is less than or equal to a preset change rate threshold for a continuous preset time period, determine the target opening of the electric regulating valve of each air-conditioning terminal according to the physical parameters of the water system.

[0173] Optionally, the processing module 22 is also used to perform data cleaning processing on the physical parameters of the water system before determining the target opening of the electric regulating valve of each air-conditioning terminal based on the physical parameters of the water system to obtain the physical parameters of the water system after the data cleaning processing; and determine the target opening of the electric regulating valve of each air-conditioning terminal based on the physical parameters of the water system after the data cleaning processing.

[0174] The water-cooled central air-conditioning control device provided in the present application is used to execute the aforementioned water-cooled central air-conditioning control method embodiment. Its implementation principle and technical effect are similar and will not be described in detail.

[0175] The present application also provides an electric control box. The electric control box can be used to execute the water-cooled central air conditioner control method provided in any of the above embodiments, and its technical effect is similar to the above water-cooled central air conditioner control method, which will not be described in detail here.

[0176] It should be understood that the present application does not limit the structure of the above-mentioned electric control box. Exemplarily, the electric control box may include: at least one processor and other components.

[0177] The present application also provides a water-cooled central air conditioner, which may include the above-mentioned electric control box. The technical effect of the water-cooled central air conditioner is similar to the above-mentioned water-cooled central air conditioner control method, which will not be repeated here.

[0178] It should be understood that the present application does not limit whether the water-cooled central air conditioner includes other components. In addition, it should be understood that the present application does not limit the application scenario of the water-cooled central air conditioner.

[0179] The present application also provides a computer-readable storage medium, which may include: a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a disk or an optical disk, and other media that can store program codes. Specifically, the computer-readable storage medium stores program instructions, and the program instructions are used for the methods in the above embodiments.

[0180] The present application also provides a program product, which includes an execution instruction, which is stored in a readable storage medium. The electric control box of the water-cooled central air conditioner can read the execution instruction from the readable storage medium, and the electric control box executes the execution instruction so that the water-cooled central air conditioner implements the water-cooled central air conditioner control method provided by the various embodiments described above.

[0181] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A water-cooled central air conditioner control method, characterized in that: The method comprises: Collecting physical parameters of the water system of the water-cooled central air conditioner; Determining the target opening of the electric regulating valve at each air-conditioning terminal in the water system according to the physical parameters of the water system; Controlling the opening of each of the electric regulating valves to be the target opening corresponding to the electric regulating valve, so that the supply and return water pressure difference between the water pump and each of the air-conditioning terminals reaches the target supply and return water pressure difference, and the difference between the return water temperatures flowing out of each of the air-conditioning terminals reaches the target difference; Determining the target opening of the electric regulating valve at each air-conditioning terminal according to the physical parameters of the water system includes: Inputting the physical parameters of the water system into a preset planning model to obtain a planning model to be optimized; Under preset constraints, using a preset multi-objective optimization algorithm, the planning model to be optimized is multi-objective optimized to obtain the target opening of the electric regulating valve of each air-conditioning terminal; the objectives of the multi-objective optimization include: minimizing the weighted sum of the difference between the supply and return water pressure difference between the water pump and each air-conditioning terminal and the return water temperature flowing out of each air-conditioning terminal; The controlling the opening of each of the electric regulating valves to be the target opening corresponding to the electric regulating valve, so that the supply and return water pressure difference between the water pump and each of the air-conditioning terminals reaches the target supply and return water pressure difference, and the difference between the return water temperatures flowing out of each of the air-conditioning terminals reaches the target difference, includes: The opening of each electric regulating valve is controlled to be the target opening corresponding to the electric regulating valve, so that the supply and return water pressure differences between the water pump and each air-conditioning terminal reach the target supply and return water pressure difference, and the mean absolute error MAE between the return water temperatures flowing out of each air-conditioning terminal reaches the target MAE; the MAE between the return water temperatures is positively correlated with the difference between the return water temperatures.

2. The method according to claim 1, characterized in that The preset constraints include at least one of the following: the supply and return water pressure differences between the water pump and each of the air-conditioning terminals are equal, the water flow in the connecting pipe between the water pump and each of the air-conditioning terminals is greater than or equal to a first water flow threshold and less than or equal to a second water flow threshold, and the return water temperature of each of the air-conditioning terminals is greater than or equal to a first preset return water temperature and less than or equal to a second preset return water temperature.

3. The method according to claim 2, characterized in that The preset constraint conditions include: the supply and return water pressure difference between the water pump and each of the air-conditioning terminals is equal, and for any of the air-conditioning terminals, the water system physical parameters include: the water flow rate in the connecting pipeline between the water pump and the air-conditioning terminal; under the preset constraint conditions, before performing multi-objective optimization on the planning model to be optimized using a preset multi-objective optimization algorithm, the method further includes: According to the type of the electric regulating valve at the air conditioner terminal, an electric regulating valve resistance characteristic coefficient equation corresponding to the electric regulating valve is determined; the variables in the electric regulating valve resistance characteristic coefficient equation include: the opening of the electric regulating valve; The supply and return water pressure difference between the water pump and the air conditioner terminal is obtained according to the electric regulating valve resistance characteristic coefficient equation corresponding to the electric regulating valve and the water flow in the connecting pipeline between the water pump and the air conditioner terminal.

4. The method according to claim 2 or 3, characterized in that: The preset constraint conditions include: the water flow rate in the connecting pipe between the water pump and each of the air-conditioning terminals is greater than or equal to the first water flow rate threshold and less than or equal to the second water flow rate threshold; for any of the air-conditioning terminals, the water system physical parameters include: the water flow rate in the connecting pipe between the water pump and the air-conditioning terminal, the water supply temperature of the water pump of the water-cooled central air-conditioning, and the return water temperature flowing out of the air-conditioning terminal; under the preset constraint conditions, before performing multi-objective optimization on the planning model to be optimized using a preset multi-objective optimization algorithm, the method further includes: According to the specific heat of water, the water flow in the connecting pipe between the water pump and the air conditioner terminal, and the temperature difference between the water supply temperature of the water pump and the return water temperature flowing out of the air conditioner terminal, the cooling capacity in the connecting pipe between the water pump and the air conditioner terminal is obtained; According to the cooling capacity in the connecting pipeline between the water pump and the air-conditioning terminal, and the preset temperature difference threshold between the water supply temperature of the water pump and the return water temperature flowing out of each air-conditioning terminal, a second water flow threshold corresponding to the connecting pipeline between the water pump and the air-conditioning terminal is obtained.

5. The method according to any one of claims 1 to 3, characterized in that: The water system physical parameters include: the water supply temperature of the water pump of the water-cooled central air conditioner, the return water temperature flowing out of the air conditioner terminal, and the water flow rate in the connecting pipeline between the water pump and the air conditioner terminal; before determining the target opening of the electric regulating valve of each air conditioner terminal according to the water system physical parameters, the method further includes: According to the physical parameters of the water system, the total load of the hydraulic network formed by the connecting pipelines of the water pump and each of the air conditioner terminals is obtained; When the change rate of the total load of the hydraulic network is less than or equal to the preset change rate threshold for a continuous preset period of time, the target opening of the electric regulating valve at each air-conditioning terminal is determined according to the physical parameters of the water system.

6. The method according to any one of claims 1 to 3, characterized in that: Before determining the target opening of the electric regulating valve of each air-conditioning terminal according to the physical parameters of the water system, the method further includes: Performing data cleaning processing on the physical parameters of the water system to obtain the physical parameters of the water system after the data cleaning processing; According to the physical parameters of the water system after the data cleaning process, the target opening of the electric regulating valve at each air-conditioning terminal is determined.

7. A water-cooled central air-conditioning control device, characterized in that: The device is applied to the water-cooled central air conditioner control method according to any one of claims 1 to 6, and the device comprises: A collection module, used to collect physical parameters of the water system of the water-cooled central air conditioner; A processing module, used for determining the target opening of the electric regulating valve at each air-conditioning terminal according to the physical parameters of the water system; A control module is used to control the opening of each electric regulating valve to be the target opening corresponding to the electric regulating valve, so that the supply and return water pressure difference between the water pump and each air-conditioning terminal reaches the target supply and return water pressure difference, and the difference between the return water temperatures flowing out of each air-conditioning terminal reaches the target difference.

8. An electric control box, characterized in that: The electric control box is used to execute the water-cooled central air-conditioning control method as described in any one of claims 1-6.

9. A water-cooled central air conditioner, characterized in that: The water-cooled central air conditioner comprises: an electric control box as described in claim 8.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer-executable instructions, and when the computer-executable instructions are executed by the electric control box, the method described in any one of claims 1 to 6 is implemented.

11. A computer program product, comprising a computer program, characterized in that When the computer program is executed by the electronic control box, the method described in any one of claims 1 to 6 is implemented.

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