Energy-saving control method and device based on multivariable centralized air conditioning system, controller, centralized air conditioning system and readable storage medium

Abstract

The application discloses an energy-saving control method and device based on a multivariable centralized air conditioning system, a controller, a centralized air conditioning system and a readable storage medium. The energy-saving control method based on the multivariable centralized air conditioning system comprises the following steps: obtaining the cold water return water temperature of a medium cold water pump and the cooling water return water temperature of a medium cooling water pump; obtaining the cold water pump frequency, the cold water outlet water temperature setting value of a medium cold water unit, the cooling water pump frequency, and the fan operation state of a medium cooling tower fan based on the cold water return water temperature and the cooling water return water temperature; and controlling each device in the centralized air conditioning system by using the cold water pump frequency, the cold water outlet water temperature setting value, the cooling water pump frequency and the fan operation state. By using the method, the decoupling of multiple devices in the centralized air conditioning system is realized, so that the temperature control accuracy and precision of the centralized air conditioning system are higher.

Description

Technical Field

[0001] This invention relates to the field of air conditioning control technology, and in particular to an energy-saving control method, device, controller, centralized air conditioning system, and readable storage medium based on a multivariable centralized air conditioning system. Background Technology

[0002] In complex centralized air conditioning systems such as those in factories and centralized cooling stations, the cooling station often includes multiple refrigeration units, water pumps, cooling tower fans, and other equipment. Typically, most centralized air conditioning systems in buildings primarily use PID control, internal model control, and corresponding improved algorithms based on single-variable control theory to control the temperature within the building.

[0003] However, when using existing control methods to control the temperature inside a building, the accuracy of temperature control is relatively low. Summary of the Invention

[0004] The main objective of this invention is to provide an energy-saving control method, device, controller, centralized air conditioning system, and readable storage medium based on a multivariable centralized air conditioning system, aiming to solve the technical problem of low accuracy in temperature control when using existing control methods to control the temperature inside a building.

[0005] To achieve the above objectives, this invention proposes an energy-saving control method based on a multivariable centralized air conditioning system, the method comprising the following steps:

[0006] Obtain the chilled water return temperature of the chilled water pump in the centralized air conditioning system and the cooling water return temperature of the cooling water pump in the centralized air conditioning system;

[0007] Based on the cold water return temperature and the cooling water return temperature, the cold water pump frequency of the cold water pump, the cold water outlet temperature setpoint of the chiller unit in the centralized air conditioning system, the cooling water pump frequency of the cooling water pump, and the fan operating status of the cooling tower fan in the centralized air conditioning system are obtained.

[0008] The chilled water pump is controlled using the chilled water pump frequency, the chilled water unit is controlled using the chilled water outlet temperature setpoint, the cooling water pump is controlled using the cooling water pump frequency, and the cooling tower fan is controlled using the fan operating status.

[0009] Optionally, before the step of obtaining the chilled water pump frequency, the chilled water outlet temperature setpoint of the chiller unit in the centralized air conditioning system, the cooling water pump frequency, and the fan operating status of the cooling tower fan in the centralized air conditioning system based on the chilled water return temperature and the cooling water return temperature, the method further includes:

[0010] The system receives result data information sent by the client. The result data information is obtained by encrypting the industrial standard data sent by the server. The industrial standard data is obtained based on the data acquisition request sent by the client.

[0011] The result data is decrypted to obtain the industry standard data;

[0012] The steps of obtaining the chilled water pump frequency, the chilled water outlet temperature setpoint of the chiller unit in the centralized air conditioning system, the cooling water pump frequency, and the fan operating status of the cooling tower fan in the centralized air conditioning system based on the chilled water return temperature and the cooling water return temperature include:

[0013] Based on the industrial standard data, the chilled water return temperature, and the cooling water return temperature, the chilled water pump frequency of the chilled water pump, the chilled water outlet temperature setpoint of the chiller unit in the centralized air conditioning system, the cooling water pump frequency of the cooling water pump, and the fan operating status of the cooling tower fan in the centralized air conditioning system are obtained.

[0014] Optionally, before the step of obtaining the chilled water return temperature of the chilled water pump in the centralized air conditioning system and the cooling water return temperature of the cooling water pump in the centralized air conditioning system, the method further includes:

[0015] Based on the target area corresponding to the central air conditioning system, the maximum load of the central air conditioning system is determined;

[0016] Based on the maximum load, the unit capacity of the chiller, the rated power of the cooling water pump, and the rated power of the chilled water pump are obtained.

[0017] The chiller unit is configured using the unit capacity, the cooling water pump is configured using the rated power of the cooling water pump, and the chilled water pump is configured using the rated power of the chilled water pump.

[0018] Optionally, before the step of obtaining the chilled water pump frequency, the chilled water outlet temperature setpoint of the chiller unit in the centralized air conditioning system, the cooling water pump frequency, and the fan operating status of the cooling tower fan in the centralized air conditioning system based on the industrial standard data, the chilled water return temperature, and the cooling water return temperature, the method further includes:

[0019] Obtain the ideal difference value of the chilled water pump, wherein the ideal difference value is the difference between the outlet water temperature of the chiller unit and the return water temperature of the chiller unit;

[0020] The steps of obtaining the chilled water pump frequency, the chilled water outlet temperature setpoint of the chiller unit in the centralized air conditioning system, the cooling water pump frequency, and the fan operating status of the cooling tower fan in the centralized air conditioning system based on the industrial standard data, the chilled water return temperature, and the cooling water return temperature include:

[0021] Based on the ideal difference, the industrial standard data, the chilled water return temperature, and the cooling water return temperature, the chilled water pump frequency of the chilled water pump, the chilled water outlet temperature setpoint of the chiller unit in the centralized air conditioning system, the cooling water pump frequency of the cooling water pump, and the fan operating status of the cooling tower fan in the centralized air conditioning system are obtained.

[0022] Optionally, after the steps of controlling the chilled water pump using the chilled water pump frequency, controlling the chiller unit using the chilled water outlet temperature setpoint, controlling the cooling water pump using the cooling water pump frequency, and controlling the cooling tower fan using the fan operating status, the method further includes:

[0023] When the chilled water pump has been in recirculation mode for a preset time, the chilled water pump is turned off, and the chilled water pump is turned on before the chiller unit is restarted.

[0024] Optionally, the cooling tower fan includes multiple fans; after the steps of controlling the chilled water pump using the chilled water pump frequency, controlling the chiller unit using the chilled water outlet temperature setpoint, controlling the cooling water pump using the cooling water pump frequency, and controlling the cooling tower fan using the fan operating status, the method further includes:

[0025] Monitor the change in the cooling water return temperature of the cooling water pump;

[0026] When the change state meets the first preset condition, multiple cooling tower fans are turned on; or, when the change state meets the second preset condition, the multiple cooling tower fans are turned off.

[0027] Furthermore, to achieve the above objectives, the present invention also proposes an energy-saving control device based on a multivariable centralized air conditioning system, the device comprising:

[0028] The acquisition module is used to acquire the chilled water return temperature of the chilled water pump in the centralized air conditioning system and the cooling water return temperature of the cooling water pump in the centralized air conditioning system.

[0029] The module is used to obtain, based on the cold water return temperature and the cooling water return temperature, the cold water pump frequency of the cold water pump, the cold water outlet temperature setpoint of the chiller unit in the centralized air conditioning system, the cooling water pump frequency of the cooling water pump, and the fan operating status of the cooling tower fan in the centralized air conditioning system.

[0030] The control module is used to control the chilled water pump using the chilled water pump frequency, control the chiller unit using the chilled water outlet temperature setpoint, control the cooling water pump using the cooling water pump frequency, and control the cooling tower fan using the fan operating status.

[0031] Furthermore, to achieve the above objectives, the present invention also proposes a controller, the controller comprising: a memory, a processor, and an energy-saving control program based on a multivariable centralized air conditioning system stored in the memory and running on the processor, wherein when the energy-saving control program based on a multivariable centralized air conditioning system is executed by the processor, the energy-saving control program based on a multivariable centralized air conditioning system implements the steps of the energy-saving control method based on a multivariable centralized air conditioning system as described above.

[0032] Furthermore, to achieve the above objectives, the present invention also proposes a centralized air conditioning system, which includes: a chiller unit, a cooling water pump, a chilled water pump, a cooling tower fan, and a controller as described above. The controller is connected to the chiller unit, the cooling water pump, the chilled water pump, and the cooling tower fan. The controller stores an energy-saving control program based on a multivariable centralized air conditioning system. When the energy-saving control program based on the multivariable centralized air conditioning system is executed by the controller, it implements the steps of the energy-saving control method based on the multivariable centralized air conditioning system as described above.

[0033] Furthermore, to achieve the above objectives, the present invention also proposes a computer-readable storage medium storing an energy-saving control program based on a multivariable centralized air conditioning system, wherein the energy-saving control program based on a multivariable centralized air conditioning system, when executed by a processor, implements the steps of the energy-saving control method based on a multivariable centralized air conditioning system as described in any of the above claims.

[0034] This invention proposes an energy-saving control method for a multivariable centralized air conditioning system. The method includes the following steps: obtaining the chilled water return temperature of the chilled water pump and the cooling water return temperature of the cooling water pump in the centralized air conditioning system; based on the chilled water return temperature and the cooling water return temperature, obtaining the chilled water pump frequency, the chilled water outlet temperature setpoint of the chiller unit in the centralized air conditioning system, the cooling water pump frequency, and the fan operating status of the cooling tower fan in the centralized air conditioning system; controlling the chilled water pump using the chilled water pump frequency, controlling the chiller unit using the chilled water outlet temperature setpoint, controlling the cooling water pump using the cooling water pump frequency, and controlling the cooling tower fan using the fan operating status.

[0035] In existing methods, the controller in a centralized air conditioning system controls various devices based on single-variable control theory, resulting in strong coupling between the devices and making precise temperature control difficult. However, the method of this invention uses data from multiple devices in the centralized air conditioning system as inputs and outputs (multivariables), achieving decoupling of these devices and thus improving the accuracy and precision of temperature control in the centralized air conditioning system. Attached Figure Description

[0036] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0037] Figure 1 This is a schematic diagram of the controller structure of the hardware operating environment involved in the embodiments of the present invention;

[0038] Figure 2 This is a flowchart illustrating the first embodiment of the energy-saving control method for a multivariable centralized air conditioning system according to the present invention.

[0039] Figure 3 This is a schematic diagram of the centralized air conditioning system structure of the present invention;

[0040] Figure 4 This is a diagram illustrating the implementation process of the energy-saving control method for a multivariable centralized air conditioning system according to the present invention.

[0041] Figure 5 This is a structural block diagram of the first embodiment of the energy-saving control device based on a multivariable centralized air conditioning system according to the present invention.

[0042] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0043] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0044] Reference Figure 1 , Figure 1 This is a schematic diagram of the controller structure of the hardware operating environment involved in the embodiments of the present invention.

[0045] Typically, the controller includes: at least one processor 301, a memory 302, and an energy-saving control program based on a multivariable centralized air conditioning system stored in the memory and executable on the processor, the energy-saving control program based on a multivariable centralized air conditioning system being configured to implement the steps of the energy-saving control method based on a multivariable centralized air conditioning system as described above.

[0046] Processor 301 may include one or more processing cores, such as a quad-core processor or an octa-core processor. Processor 301 may be implemented using at least one hardware form selected from DSP (Digital Signal Processing), FPGA (Field-Programmable Gate Array), and PLA (Programmable Logic Array). Processor 301 may also include a main processor and a coprocessor. The main processor, also known as a CPU (Central Processing Unit), is used to process data in the wake-up state; the coprocessor is a low-power processor used to process data in the standby state. In some embodiments, processor 301 may integrate a GPU (Graphics Processing Unit), which is responsible for rendering and drawing the content to be displayed on the screen. Processor 301 may also include an AI (Artificial Intelligence) processor, which processes operations related to energy-saving control methods for multivariable centralized air conditioning systems, enabling the energy-saving control method model for multivariable centralized air conditioning systems to learn autonomously, improving efficiency and accuracy.

[0047] The memory 302 may include one or more computer-readable storage media, which may be non-transitory. The memory 302 may also include high-speed random access memory and non-volatile memory, such as one or more disk storage devices or flash memory devices. In some embodiments, the non-transitory computer-readable storage media in the memory 302 are used to store at least one instruction, which is executed by the processor 301 to implement the energy-saving control method based on a multivariable centralized air conditioning system provided in the method embodiments of this application.

[0048] In some embodiments, the terminal may also optionally include a communication interface 303 and at least one peripheral device. The processor 301, memory 302, and communication interface 303 can be connected via a bus or signal line. Each peripheral device can be connected to the communication interface 303 via a bus, signal line, or circuit board. Specifically, the peripheral device includes at least one of a radio frequency circuit 304, a display screen 305, and a power supply 306.

[0049] The communication interface 303 can be used to connect at least one I / O (Input / Output) related peripheral device to the processor 301 and the memory 302. In some embodiments, the processor 301, the memory 302, and the communication interface 303 are integrated on the same chip or circuit board; in some other embodiments, any one or two of the processor 301, the memory 302, and the communication interface 303 can be implemented on separate chips or circuit boards, which is not limited in this embodiment.

[0050] The radio frequency (RF) circuit 304 is used to receive and transmit RF (Radio Frequency) signals, also known as electromagnetic signals. The RF circuit 304 communicates with communication networks and other communication devices via electromagnetic signals. The RF circuit 304 converts electrical signals into electromagnetic signals for transmission, or converts received electromagnetic signals back into electrical signals. Optionally, the RF circuit 304 includes: an antenna system, an RF transceiver, one or more amplifiers, a tuner, an oscillator, a digital signal processor, a codec chipset, a user identity module card, etc. The RF circuit 304 can communicate with other terminals through at least one wireless communication protocol. This wireless communication protocol includes, but is not limited to: metropolitan area networks (MANs), various generations of mobile communication networks (2G, 3G, 4G, and 5G), wireless local area networks (WLANs), and / or WiFi (Wireless Fidelity) networks. In some embodiments, the RF circuit 304 may also include circuitry related to NFC (Near Field Communication), which is not limited in this application.

[0051] Power supply 305 is used to supply power to various components in an electronic device. Power supply 305 can be AC ​​power, DC power, a disposable battery, or a rechargeable battery. When power supply 305 includes a rechargeable battery, the rechargeable battery can support wired or wireless charging. The rechargeable battery can also be used to support fast charging technology. Those skilled in the art will understand that... Figure 1 The structure shown does not constitute a limitation on the controller and may include more or fewer components than shown, or combine certain components, or have different component arrangements.

[0052] Furthermore, embodiments of the present invention also propose a computer-readable storage medium storing an energy-saving control program based on a multivariable centralized air conditioning system. When executed by a processor, the energy-saving control program implements the steps of the energy-saving control method for a multivariable centralized air conditioning system as described above. Therefore, it will not be repeated here. Additionally, the beneficial effects of using the same method will not be repeated. For technical details not disclosed in the embodiments of the computer-readable storage medium involved in this application, please refer to the description of the method embodiments of this application. As an example, program instructions can be deployed to execute on a single controller, or on multiple controllers located at one location, or on multiple controllers distributed across multiple locations and interconnected via a communication network.

[0053] Those skilled in the art will understand that all or part of the processes in the above embodiments can be implemented by a computer program instructing related hardware. The program can be stored in a computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. The computer-readable storage medium can be a magnetic disk, optical disk, read-only memory (ROM), or random access memory (RAM), etc.

[0054] Based on the above hardware structure, an embodiment of the energy-saving control method for a multivariable centralized air conditioning system according to the present invention is proposed.

[0055] Reference Figure 2 , Figure 2 This is a flowchart illustrating the first embodiment of the energy-saving control method for a multivariable centralized air conditioning system according to the present invention. The method is used in a controller and includes the following steps:

[0056] Step S11: Obtain the chilled water return temperature of the chilled water pump in the centralized air conditioning system and the cooling water return temperature of the cooling water pump in the centralized air conditioning system.

[0057] It should be noted that the executing entity of this invention is a controller, which is equipped with an energy-saving control program based on a multivariable centralized air conditioning system. When the controller executes the energy-saving control program based on a multivariable centralized air conditioning system, it implements the steps of the energy-saving control method based on a multivariable centralized air conditioning system of this invention.

[0058] The controller is used to acquire parameters and output control for various devices in a centralized air conditioning system. (Refer to...) Figure 3 , Figure 3 This is a schematic diagram of the centralized air conditioning system structure of the present invention.

[0059] The centralized air conditioning system includes: a chiller unit 3, a cooling water pump 2, a chilled water pump 1, a cooling tower fan 4, and a controller 5 as described above. The controller 5 is connected to the chiller unit 3, the cooling water pump 2, the chilled water pump 1, and the cooling tower fan 4.

[0060] It is understood that during the operation of the air conditioning system of the present invention, the method of the present invention is executed in real time. At different times, when executing step S11, the obtained cold water return temperature and cooling water return temperature may be different.

[0061] The controller can obtain the chilled water return temperature from the chilled water pump and the cooling water return temperature from the cooling water pump in the central air conditioning system by issuing acquisition commands.

[0062] The method of this invention is mainly aimed at energy-saving construction of centralized air conditioning systems. When the air conditioning system adopts a single-stage pump variable flow unit, the chilled water flow rate can be adjusted within a range of 50%-100%. Without affecting the operation of the main unit, the pump's output power can be adjusted in real time according to the actual load, ensuring that the pump's output power always matches the load and avoiding waste caused by overloading. Simultaneously, this method provides an optimal operating condition ratio between the main units, pumps (chilled water pumps and cooling water pumps), and cooling tower fans to improve the overall operating performance of the centralized air conditioning system.

[0063] Furthermore, prior to the step of obtaining the chilled water return temperature of the chilled water pump and the cooling water return temperature of the cooling water pump in the centralized air conditioning system, the method further includes: determining the maximum load of the centralized air conditioning system based on the target area corresponding to the centralized air conditioning system; obtaining the unit capacity of the chiller, the rated power of the cooling water pump, and the rated power of the chilled water pump based on the maximum load; configuring the chiller using the unit capacity, configuring the cooling water pump using the rated power of the cooling water pump, and configuring the chilled water pump using the rated power of the chilled water pump.

[0064] Based on the target area (e.g., factory, plant, or office building) of the centralized air conditioning system, the maximum load of the system needs to be determined. The chiller unit capacity is then determined according to the maximum load. Additionally, when selecting matching cooling water pumps and chilled water pumps, a margin of approximately 20% (20% of the rated power) is allowed. After determining these parameters, the centralized air conditioning system is configured to obtain the desired system configuration.

[0065] Step S12: Based on the cold water return temperature and the cooling water return temperature, obtain the cold water pump frequency of the cold water pump, the cold water outlet temperature setpoint of the chiller unit in the centralized air conditioning system, the cooling water pump frequency of the cooling water pump, and the fan operating status of the cooling tower fan in the centralized air conditioning system.

[0066] In this invention, based on the cold water return temperature and the cooling water return temperature, the parameters corresponding to the four devices in the centralized air conditioning system are determined respectively: the cold water pump frequency of the cold water pump, the cold water outlet temperature setpoint of the chiller unit in the centralized air conditioning system, the cooling water pump frequency of the cooling water pump, and the fan operating status of the cooling tower fan in the centralized air conditioning system.

[0067] Reference Figure 4 , Figure 4 This diagram illustrates the implementation process of the energy-saving control method for a multivariable centralized air conditioning system according to the present invention. In the centralized air conditioning system, the chilled water return temperature and the cooling water return temperature are the input variables, and the chilled water outlet temperature setpoint, chilled water pump frequency, cooling water pump frequency, and fan operating status are the four output variables. It can be seen that in this application, there are multiple input and output variables, rather than a single variable, thus achieving decoupled control of the centralized air conditioning system.

[0068] Specifically, the operating frequency of the chilled water pump is determined based on the chilled water return temperature, and the operating frequency of the cooling water pump is determined based on the cooling water return temperature. When the chiller unit's main unit load is low, the setpoint for the chilled water outlet temperature is automatically increased. During chiller unit recirculation, the cooling water pump is automatically switched on and off. The number of fans activated is controlled based on the activation status of the cooling water pumps and the cooling water return temperature. The operating status of the central air conditioning system is controlled via a one-button start / stop button. The operating points of each component are adjusted according to load changes and indoor / outdoor temperature fluctuations to achieve the optimal operating ratio among the components.

[0069] In some embodiments, the chilled water pump frequency, chilled water outlet temperature setpoint of the chiller unit in the centralized air conditioning system, cooling water pump frequency, and cooling tower fan operating status in the centralized air conditioning system can also be obtained based on the outdoor temperature, the chilled water return temperature, and the cooling water return temperature. That is, the outdoor temperature is also an input variable used to obtain the above four parameters.

[0070] This invention also relates to a control system, which is mainly divided into three layers: a system management layer (controller), a network control layer (server), and a field equipment layer (front-end equipment of the centralized air conditioning system, including the chilled water pump, cooling water pump, chiller unit, and cooling tower fan mentioned above).

[0071] The system management layer (controller) is connected to the server via Ethernet. The server, in turn, connects to the controller (e.g., PLC control module) and front-end devices via gateways to achieve functions such as data processing, parameter adjustment, control optimization, and remote monitoring. The equipment layer mainly includes 5 main units (a chiller unit consisting of 4 centrifugal chillers and 1 screw chiller), 5 chilled water pumps, 5 cooling water pumps, and 12 cooling tower fans. All chilled water pumps are equipped with ACS510 frequency converters, enabling online continuous adjustment.

[0072] Furthermore, prior to step S12, before the step of obtaining the chilled water pump frequency, the chilled water outlet temperature setpoint of the chiller unit in the centralized air conditioning system, the cooling water pump frequency, and the fan operating status of the cooling tower fan in the centralized air conditioning system based on the chilled water return temperature and the cooling water return temperature, the method further includes: receiving result data information sent by the client, wherein the result data information is obtained by encrypting industrial standard data sent by the server, and the industrial standard data is obtained based on the data acquisition request sent by the client; decrypting the result data to obtain the industrial standard... The standard data; correspondingly, the step of obtaining the chilled water pump frequency of the chilled water pump, the chilled water outlet temperature setpoint of the chiller unit in the centralized air conditioning system, the cooling water pump frequency of the cooling water pump, and the fan operating status of the cooling tower fan in the centralized air conditioning system based on the chilled water return temperature and the cooling water return temperature includes: obtaining the chilled water pump frequency of the chilled water pump, the chilled water outlet temperature setpoint of the chiller unit in the centralized air conditioning system, the cooling water pump frequency of the cooling water pump, and the fan operating status of the cooling tower fan in the centralized air conditioning system based on the industrial standard data, the chilled water return temperature, and the cooling water return temperature.

[0073] Users can send a request to the server to obtain industry standard data (OLE for process control, OPC) in real time. The server then publishes this industry standard data in the form of message data (OPT). The client receives this industry standard data and converts it into encrypted result data. The controller receives the result data sent by the client, decrypts it to obtain the industry standard data, and then uses this industry standard data, the chilled water return temperature, and the cooling water return temperature to obtain the chilled water pump frequency, the chilled water outlet temperature setpoint of the chiller unit in the centralized air conditioning system, the cooling water pump frequency, and the fan operating status of the cooling tower fan in the centralized air conditioning system, thereby achieving optimized control of the centralized air conditioning system.

[0074] In this embodiment, the data is encrypted before transmission, ensuring data security.

[0075] Furthermore, before the step of obtaining the chilled water pump frequency, the chilled water outlet temperature setpoint of the chiller unit in the centralized air conditioning system, the cooling water pump frequency, and the cooling tower fan operating status in the centralized air conditioning system based on the industrial standard data, the chilled water return temperature, and the cooling water return temperature, the method further includes: obtaining the ideal difference of the chilled water pump, wherein the ideal difference is the difference between the outlet temperature of the chiller unit and the return temperature of the chiller unit; correspondingly, the step of obtaining the chilled water pump frequency, the chilled water return temperature, and the cooling water return temperature based on the industrial standard data, the chilled water return temperature, and the cooling water return temperature is further refined. The steps of obtaining the cooling water return temperature, the chilled water pump frequency of the chilled water pump, the chilled water outlet temperature setpoint of the chiller unit in the centralized air conditioning system, the cooling water pump frequency of the cooling water pump, and the fan operating status of the cooling tower fan in the centralized air conditioning system include: obtaining the chilled water pump frequency of the chilled water pump, the chilled water outlet temperature setpoint of the chiller unit in the centralized air conditioning system, the cooling water pump frequency of the cooling water pump, and the fan operating status of the cooling tower fan in the centralized air conditioning system based on the ideal difference, the industrial standard data, the chilled water return temperature, and the cooling water return temperature.

[0076] In this embodiment, the ideal difference is typically 5 degrees Celsius. The change in the chilled water outlet temperature of the chiller unit is achieved by following its temperature setpoint. From this, we can obtain the outlet setpoint temperature variation as 7℃--7.8℃--7.1℃--7.8℃, which closely matches the load variation of the day. When the weather is not very hot, the chilled water outlet temperature setpoint of the main unit can be higher than 7℃. At this time, the main unit has energy-saving potential, and the specific amount of energy saving depends on the weather conditions.

[0077] Based on the data from the chiller units, the chilled water outlet temperature control point of the tower is mainly maintained at 8℃, resulting in energy savings of approximately 4% for the main unit. In the following month, the average chilled water outlet temperature control point of the tower is maintained at around 7.5℃, resulting in energy savings of approximately 2% for the main unit. At the same time, the recirculation time delay of the chiller units is more than 20 minutes longer, which reduces mechanical wear and extends the service life of the air conditioning equipment.

[0078] When the change in chilled water return temperature of the chilled water pump matches the change in room load, the chilled water pump has significant energy-saving potential, avoiding the phenomenon of over-powering the system. The relationship between the output power P of the chilled water pump and its rotational speed n is: P1 / P2=(n1 / n2)³. It can be seen that the output power of the chilled water pump is directly proportional to the cube of the rotational speed. Since the rotational speed n of the chilled water pump motor is directly proportional to its power supply frequency f, we can obtain: P1 / P2=(f1 / f2)³. After the chilled water pump is turned on, its operating frequency varies between 30 and 48 Hz, resulting in an average daily operating frequency of around 35 Hz. In existing technology, the operating frequency of the chilled water pump is always maintained at 50 Hz. Based on P1 / P2=(f1 / f2)³, when the chilled water pump actually operates at a power supply frequency of 35 Hz, the actual average energy saving is approximately 55%.

[0079] It is evident that controlling the frequency of the chilled water pump in this invention can save a significant amount of electrical energy and improve the economic efficiency of the centralized air conditioning system.

[0080] Furthermore, after the steps of controlling the chilled water pump using the chilled water pump frequency, controlling the chiller unit using the chilled water outlet temperature setpoint, controlling the cooling water pump using the cooling water pump frequency, and controlling the cooling tower fan using the fan operating status, the method further includes: shutting down the cooling water pump when the chilled water pump has been in recirculation mode for a preset duration, and turning on the cooling water pump before restarting the chiller unit. The preset duration can be a time interval set by the user based on requirements; when the chilled water pump has been in recirculation mode for the preset duration, the cooling water pump can be shut down after it has been in recirculation mode.

[0081] Furthermore, the cooling tower fan includes multiple fans; after the steps of controlling the chilled water pump using the chilled water pump frequency, controlling the chiller unit using the chilled water outlet temperature setpoint, controlling the cooling water pump using the cooling water pump frequency, and controlling the cooling tower fan using the fan operating status, the method further includes:

[0082] The system monitors the temperature change of the cooling water pump's return water. When the temperature change meets a first preset condition, multiple cooling tower fans are turned on; or, when the temperature change meets a second preset condition, the multiple cooling tower fans are turned off. Specifically, the first preset condition is met when the temperature rises sharply from 25°C to 34°C, and the second preset condition is met when the temperature change remains at a relatively stable low temperature (e.g., around 25°C-30°C).

[0083] This invention proposes an energy-saving control method for a multivariable centralized air conditioning system. The method includes the following steps: obtaining the chilled water return temperature of the chilled water pump and the cooling water return temperature of the cooling water pump in the centralized air conditioning system; based on the chilled water return temperature and the cooling water return temperature, obtaining the chilled water pump frequency, the chilled water outlet temperature setpoint of the chiller unit in the centralized air conditioning system, the cooling water pump frequency, and the fan operating status of the cooling tower fan in the centralized air conditioning system; controlling the chilled water pump using the chilled water pump frequency, controlling the chiller unit using the chilled water outlet temperature setpoint, controlling the cooling water pump using the cooling water pump frequency, and controlling the cooling tower fan using the fan operating status.

[0084] In existing methods, the controller in a centralized air conditioning system controls various devices based on single-variable control theory, resulting in strong coupling between the devices and making precise temperature control difficult. However, the method of this invention uses data from multiple devices in the centralized air conditioning system as inputs and outputs (multivariables), achieving decoupling of these devices and thus improving the accuracy and precision of temperature control in the centralized air conditioning system.

[0085] Meanwhile, this invention controls multiple devices in a centralized air conditioning system separately, thereby reducing the energy consumption of the centralized air conditioning system and improving its economic efficiency under precise control.

[0086] Reference Figure 5 , Figure 5 This is a structural block diagram of the first embodiment of the energy-saving control device for a multivariable centralized air conditioning system according to the present invention. The device is used as a controller and, based on the same inventive concept as the aforementioned embodiments, includes:

[0087] The acquisition module 10 is used to acquire the chilled water return temperature of the chilled water pump in the centralized air conditioning system and the cooling water return temperature of the cooling water pump in the centralized air conditioning system.

[0088] The module 20 is used to obtain, based on the cold water return temperature and the cooling water return temperature, the cold water pump frequency of the cold water pump, the cold water outlet temperature setpoint of the chiller unit in the centralized air conditioning system, the cooling water pump frequency of the cooling water pump, and the fan operating status of the cooling tower fan in the centralized air conditioning system.

[0089] The control module 30 is used to control the chilled water pump using the chilled water pump frequency, control the chiller unit using the chilled water outlet temperature setpoint, control the cooling water pump using the cooling water pump frequency, and control the cooling tower fan using the fan operating status.

[0090] It should be noted that since the steps performed by the device in this embodiment are the same as those in the aforementioned method embodiments, the specific implementation methods and the technical effects that can be achieved can be referred to the aforementioned embodiments, and will not be repeated here.

[0091] The above description is merely an optional embodiment of the present invention and does not limit the patent scope of the present invention. All equivalent structural transformations made using the contents of the present invention's specification and drawings under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. An energy-saving control method based on a multivariable centralized air conditioning system, characterized in that, The method includes the following steps: Obtain the chilled water return temperature of the chilled water pump in the centralized air conditioning system and the cooling water return temperature of the cooling water pump in the centralized air conditioning system; Based on the chilled water return temperature and the cooling water return temperature, the chilled water pump frequency, the chilled water outlet temperature setpoint of the chiller unit in the centralized air conditioning system, the cooling water pump frequency, and the fan operating status of the cooling tower fan in the centralized air conditioning system are obtained. The chilled water pump is controlled using the chilled water pump frequency, the chilled water unit is controlled using the chilled water outlet temperature setpoint, the cooling water pump is controlled using the cooling water pump frequency, and the cooling tower fan is controlled using the fan operating status. The steps for obtaining the chilled water pump frequency, the chilled water outlet temperature setpoint of the chiller unit in the centralized air conditioning system, the cooling water pump frequency, and the fan operating status of the cooling tower fan in the centralized air conditioning system based on the chilled water return temperature and the cooling water return temperature include: The frequency of the cold water pump is obtained based on the cold water return temperature; The frequency of the cooling water pump is obtained based on the cooling water return temperature. The number of fans to be turned on is determined based on the status of the cooling water pump and the return temperature of the cooling water. Before the step of obtaining the chilled water pump frequency, the chilled water outlet temperature setpoint of the chiller unit in the centralized air conditioning system, the cooling water pump frequency, and the fan operating status of the cooling tower fan in the centralized air conditioning system based on the chilled water return temperature and the cooling water return temperature, the method further includes: The system receives result data information sent by the client. The result data information is obtained by encrypting the industrial standard data sent by the server. The industrial standard data is obtained based on the data acquisition request sent by the client. The result data is decrypted to obtain the industry standard data; Obtain the ideal difference value of the chilled water pump, wherein the ideal difference value is the difference between the outlet water temperature of the chiller unit and the return water temperature of the chiller unit; The steps of obtaining the chilled water pump frequency, the chilled water outlet temperature setpoint of the chiller unit in the centralized air conditioning system, the cooling water pump frequency, and the fan operating status of the cooling tower fan in the centralized air conditioning system based on the chilled water return temperature and the cooling water return temperature include: Based on the ideal difference, the industrial standard data, the chilled water return temperature, and the cooling water return temperature, the chilled water pump frequency, the chilled water outlet temperature setpoint of the chiller unit in the centralized air conditioning system, the cooling water pump frequency, and the fan operating status of the cooling tower fan in the centralized air conditioning system are obtained. Before the step of obtaining the chilled water return temperature of the chilled water pump in the centralized air conditioning system and the cooling water return temperature of the cooling water pump in the centralized air conditioning system, the method further includes: Based on the target area corresponding to the central air conditioning system, the maximum load of the central air conditioning system is determined; Based on the maximum load, the unit capacity of the chiller, the rated power of the cooling water pump, and the rated power of the chilled water pump are obtained. The chiller unit is configured using the unit capacity, the cooling water pump is configured using the rated power of the cooling water pump, and the chilled water pump is configured using the rated power of the chilled water pump. After the steps of controlling the chilled water pump using the chilled water pump frequency, controlling the chiller unit using the chilled water outlet temperature setpoint, controlling the cooling water pump using the cooling water pump frequency, and controlling the cooling tower fan using the fan operating status, the method further includes: When the chilled water pump has been in recirculation mode for a preset time, the chilled water pump is turned off, and the chilled water pump is turned on before the chiller unit is restarted.

2. An energy-saving control device based on a multivariable centralized air conditioning system, characterized in that, The device, applied to the energy-saving control method for a multivariable centralized air conditioning system as described in claim 1, comprises: The acquisition module is used to acquire the chilled water return temperature of the chilled water pump in the centralized air conditioning system and the cooling water return temperature of the cooling water pump in the centralized air conditioning system. The module is used to obtain, based on the chilled water return temperature and the cooling water return temperature, the chilled water pump frequency, the chilled water outlet temperature setpoint of the chiller unit in the centralized air conditioning system, the cooling water pump frequency, and the fan operating status of the cooling tower fan in the centralized air conditioning system. The control module is used to control the chilled water pump using the chilled water pump frequency, control the chiller unit using the chilled water outlet temperature setpoint, control the cooling water pump using the cooling water pump frequency, and control the cooling tower fan using the fan operating status. The obtaining module is further configured to obtain the frequency of the cold water pump based on the cold water return temperature; obtain the frequency of the cooling water pump based on the cooling water return temperature; and determine the number of fans to be turned on based on the operation status of the cooling water pump and the cooling water return temperature. The acquisition module is further configured to receive result data information sent by the client, wherein the result data information is obtained by encrypting industrial standard data sent by the server, and the industrial standard data is obtained based on the data acquisition request sent by the client; decrypt the result data to obtain the industrial standard data; obtain the ideal difference value of the chilled water pump, wherein the ideal difference value is the difference between the outlet water temperature and the return water temperature of the chiller unit; and based on the ideal difference value, the industrial standard data, the chilled water return water temperature and the cooling water return water temperature, obtain the chilled water pump frequency, the chilled water outlet temperature setpoint of the chiller unit in the centralized air conditioning system, the cooling water pump frequency, and the fan operating status of the cooling tower fan in the centralized air conditioning system; The device is further configured to determine the maximum load of the centralized air conditioning system based on the target area corresponding to the centralized air conditioning system; obtain the unit capacity of the chiller, the rated power of the cooling water pump, and the rated power of the chilled water pump based on the maximum load; configure the chiller using the unit capacity, configure the cooling water pump using the rated power of the cooling water pump, and configure the chilled water pump using the rated power of the chilled water pump. The control module is also used to shut down the cooling water pump when the chilled water pump is in recirculation mode for a preset time, and to turn on the cooling water pump before the chiller unit is restarted.

3. A controller, characterized in that, The controller includes: a memory, a processor, and an energy-saving control program based on a multivariable centralized air conditioning system stored in the memory and running on the processor. When the energy-saving control program based on a multivariable centralized air conditioning system is executed by the processor, it implements the steps of the energy-saving control method based on a multivariable centralized air conditioning system as described in claim 1.

4. A centralized air conditioning system, characterized in that, The centralized air conditioning system includes: a chiller unit, a cooling water pump, a chilled water pump, a cooling tower fan, and a controller as described in claim 3. The controller is connected to the chiller unit, the cooling water pump, the chilled water pump, and the cooling tower fan. The controller stores an energy-saving control program based on a multivariable centralized air conditioning system. When the energy-saving control program based on a multivariable centralized air conditioning system is executed by the controller, it implements the steps of the energy-saving control method based on a multivariable centralized air conditioning system as described in claim 1.

5. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores an energy-saving control program based on a multivariable centralized air conditioning system. When the energy-saving control program based on a multivariable centralized air conditioning system is executed by a processor, it implements the steps of the energy-saving control method based on a multivariable centralized air conditioning system as described in claim 1.

Images