Central air conditioner group control management system

Abstract

The invention relates to a central air conditioner group control management system, and aims to solve the problem that the energy-saving effect and the intelligent control degree of existing like products are rarely improved by further improving networking and data transmission of the existing like products in the aspect of a tail end air conditioner system. The system is characterized by comprising a two-pipe cold and heat source air conditioner room control PLC and a purified cold and heat source air conditioner room control PLC, the two-pipe cold and heat source air conditioner room control PLC and the purified cold and heat source air conditioner room control PLC are each provided with a system manager, and the other system manager of the system is connected with an air conditioner unit electric cabinet through an air conditioner unit. Each system floor energy balance substation, the energy meter system manager and the multi-split system manager of the system are respectively connected with the temperature, the pressure, the energy meter system manager and the multi-split system manager of supply water and return water through electric control valves, and each system floor energy balance substation is connected with the energy meter system manager and the multi-split system manager through electric control valves. And a corresponding temperature sensor and pressure sensor.

Description

Technical Field

[0001] The invention relates to a central air-conditioning system, in particular to a central air-conditioning group control management system. Background Art

[0002] The central air conditioning system consists of one or more cold and heat source systems and multiple air conditioning systems. It generally adopts the principle of liquid vaporization refrigeration to provide the required cooling capacity for the air conditioning system to offset the heat load of the indoor environment; the heating system provides the required heat for the air conditioning system to offset the cold load of the indoor environment. The refrigeration system is a crucial part of the central air conditioning system. Its type, operation mode, and structural form directly affect the economy, efficiency, and rationality of the central air conditioning system in operation. In order to achieve the effect of energy saving and power saving, the existing central air conditioning system generally realizes automatic adjustment through intelligent control of computer room group control; such as the application publication number CN106979584A disclosed in the Chinese patent literature, the application publication date 2017.07.25, the invention name "Intelligent control method of computer room group control in central air conditioning monitoring system"; another example is the application publication number CN115962546A disclosed in the Chinese patent literature, the application publication date 2023.04.14, the invention name "Comprehensive control method, device and system of central air conditioning unit based on cuckoo algorithm and multi-system linkage". However, the energy-saving effects and system control of the above-mentioned products and similar products need to be further improved, especially in the terminal air-conditioning system. There are few further modifications to improve its networking and data transmission to improve its energy-saving effects and the degree of intelligent control. It is difficult to use it in the central air-conditioning system with a two-pipe cooling and heat source air-conditioning room control PLC and a purification cold and heat source air-conditioning room control PLC. Summary of the invention

[0003] To overcome the above shortcomings, the purpose of the present invention is to provide a central air-conditioning group control management system to the art, so that it can solve the technical problems that the energy-saving effect and system control of existing similar products need to be further improved, especially in the terminal air-conditioning system, which is less likely to improve its energy-saving effect and intelligent control level through further transformation and improvement of its networking and data transmission, and is difficult to be used in a central air-conditioning system with a two-pipe cooling and heat source air-conditioning room control PLC and a purification cold and heat source air-conditioning room control PLC. The purpose is achieved through the following technical solutions.

[0004] A central air-conditioning group control management system, the central air-conditioning of the system includes an air-cooled heat pump host, a hot and cold circulation pump, an air handling unit, a fan coil unit, a manifold and related pipes. The air-cooled heat pump host generates cold and hot water, which is transmitted to the manifold through the hot and cold circulation pump and then to the fan coil unit and the air handling unit. The air-cooled heat pump dissipates the room heat into the atmosphere through air cooling (in winter, it is just the opposite, absorbing heat from the atmosphere and transmitting it to the terminal). The system includes a hot and cold water circulation system, an air-cooled heat pump host system, and a terminal air-conditioning system. The system is remotely controlled by a mobile phone and a server, and locally controlled by a management computer. The terminal air-conditioning system is mainly composed of fan coil units and air handling units distributed in each terminal room on each floor of each building, and energy balancing valves on each pipeline well on each floor. The water pump transmits the refrigerant hot water after the temperature is reduced to the fan coil unit and air handling unit installed indoors. The fan coil unit and air handling unit The air conditioning unit exchanges heat with the indoor air by locally sending return air and fresh air; the system is characterized in that it includes a two-tube cooling and heat source air-conditioning room control PLC and a purification cooling and heat source air-conditioning room control PLC, and the two-tube cooling and heat source air-conditioning room control PLC and the purification cooling and heat source air-conditioning room control PLC are respectively provided with a system manager, and another system manager of the system is connected to the air-conditioning unit electric control box through the air-conditioning unit, and is connected to the corresponding electric control box of each hoisted fresh air unit through each hoisted fresh air fan, the system has each system floor energy balance substation, energy meter system manager and multi-connection system manager, the system floor energy balance substation is respectively connected to the supply and return water temperature, pressure, and corresponding temperature sensors and pressure sensors through electric regulating valves, the electric regulating valves are installed on the water distributor and each branch of the terminal floor pipeline well, and the above-mentioned electric regulating valve is an electric proportional integral electric regulating valve. The corresponding programmable controller PLC adopts Siemens S7-300PLC control components. To ensure the safe operation of the equipment, all logically related devices are included in the same controller and are operated and controlled by a CPU module. The control programs of all logically related devices run in the same controller without relying on other devices (such as other controllers, host computers, network controllers, etc.). Each controller is configured with at least 5% I / O point margin. The CPU is at least a 16-bit processor, and point-to-point communication can be carried out between them. The maximum execution cycle of all specified tasks does not exceed 250ms. It has the characteristics of being used as a centralized controller on centralized and distributed I / O production lines, and has a medium-sized program volume. In addition to distributed I / O structures, it can also be used for distributed automation structures. The processor execution cycle of switch quantity control does not exceed 100ms. For analog and sequential control loops that require fast processing, its processing capacity is at least executed once every 125ms and 50ms respectively, which is convenient for connecting with the host computer using Ethernet. The number of I / O points meets the actual control requirements and leaves a 5% I / O point margin for expansion.

[0005] One side of the screw-type air-cooled heat pump unit of the two-tube refrigeration heat source air-conditioning room control PLC is respectively connected to the hot and cold water circulation pump and the intelligent full-process water treatment device of the pipeline. The hot and cold water circulation pump is connected to the water pump connector through a cold and warm pump intelligent controller. The intelligent full-process water treatment device is connected to the return water collector. The other side of the screw-type air-cooled heat pump unit is connected to the water supply manifold. The pipeline between the water supply manifold and the return water collector is provided with a constant-pressure water replenishment and exhaust device.

[0006] Another cooling and heating pump intelligent controller, outdoor wet-bulb temperature sensor and outdoor temperature and humidity sensor of the two-tube refrigeration and heat source air-conditioning room control PLC are connected to the cooling and heat source system manager; a hot water tank, a booster tank assembly and a freezing pump intelligent controller are provided on one side of the plate heat exchange water tank of the purification cooling and heat source air-conditioning room control PLC, and a hot water tank, a booster tank assembly and a heating pump intelligent controller are provided on the other side of the plate heat exchange water tank. The hot water tanks are respectively provided with pressure differential bypass valves, and the pressure replenishing pipeline, pressure relief pipeline and water replenishing pipeline of the booster tank assembly are respectively connected to the atmospheric pressure tank and the pressure tank, and the freezing pump intelligent controller and the heating pump intelligent controller are connected to the purification cooling and heat source system manager.

[0007] The air conditioning water pipes of the fan coil units in one of the rooms in the pipe shaft of each building at the floor energy balance substation of the terminal air-conditioning system are respectively provided with fixed brackets, and the fixed brackets are respectively provided with central air-conditioning energy-saving system control boxes. The fan coil units in each room in the pipe shaft are connected to the water distributor through the main pipeline.

[0008] The room fan coils of the terminal air conditioning system are respectively equipped with intelligent networked thermostat panels. Each intelligent networked thermostat panel on each floor of each building is connected to the building manager and multi-connection system manager in the weak current well through lines. The network manager of each building is connected to the central air conditioning cold and hot source group control system PLC through lines. The central air conditioning cold and hot source group control system PLC is equipped with another multi-connection system manager. The power distribution of the above-mentioned building manager is taken from the special distribution box of the weak current well on this floor, and the wiring distance does not exceed 100 meters.

[0009] The invention has reasonable structural design, outstanding overall energy-saving effect, high intelligence, convenient zoning and time-sharing, and convenient transformation and upgrading of existing central air-conditioning systems; it is suitable for use as a central air-conditioning group control management system, as well as a structural improvement of similar products. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is a schematic diagram of the system network topology structure of the present invention.

[0011] Figure 2 It is a schematic structural diagram of the working principle of the air conditioning cold and heat source system of the present invention.

[0012] Figure 3It is a structural schematic diagram of the floor energy balance system of the present invention.

[0013] Figure 4 It is a schematic diagram of the structure of the thermostat networking system of the present invention.

[0014] Serial numbers and names in the figure: 1. Screw-type air-cooled heat pump unit, 2. Hot and cold water circulation pump, 3. Water supply manifold, 4. Return water collector, 5. Constant pressure water replenishment and exhaust device, 6. Intelligent full-process water treatment device, 7. Plate heat exchange water tank, 8. Pressure differential bypass valve, 9. Intelligent networked thermostat panel. Implementation

[0015] Now, the structure and use of the present invention will be further described in conjunction with the accompanying drawings. Figure 1-Figure 4 As shown, the central air-conditioning of the system includes an air-cooled heat pump host, a hot and cold circulation pump, an air handling unit, a fan coil, a manifold and related pipes. The air-cooled heat pump host generates hot and cold water, which is transmitted to the manifold through the hot and cold circulation pump and then to the fan coil and air handling unit. The air-cooled heat pump dissipates the room heat into the atmosphere through air cooling. The system includes a hot and cold water circulation system, an air-cooled heat pump host system and a terminal air-conditioning system. The system is remotely controlled by a mobile phone and a server, and locally controlled by a management computer. The terminal air-conditioning system is mainly composed of fan coils and air handling units distributed in each terminal room on each floor of each building, and energy balance valves on each pipe well on each floor. The water pump transports the refrigerant hot water after the temperature is reduced to the fan coil and air handling unit installed indoors, and the fan coil and air handling unit exchange heat with the indoor air by sending return air and fresh air on the spot.

[0016] The system includes a two-tube cooling and heat source air-conditioning room control PLC and a purification cooling and heat source air-conditioning room control PLC. The two-tube cooling and heat source air-conditioning room control PLC and the purification cooling and heat source air-conditioning room control PLC are respectively provided with a system manager. Another system manager of the system is connected to the air-conditioning unit electric control box through the air-conditioning unit, and is connected to the corresponding electric control box of each hoisted fresh air unit through each hoisted fresh air fan. The system includes each system floor energy balance substation, energy meter system manager and multi-split system manager. The system floor energy balance substation is respectively connected to the supply and return water temperature and pressure, and the corresponding temperature sensor and pressure sensor through an electric regulating valve. The electric regulating valve is installed on the water distributor and each branch of the terminal floor pipeline well. The above-mentioned electric regulating valve is an electric proportional integral electric regulating valve. One side of the screw-type air-cooled heat pump unit 1 of the two-tube refrigeration heat source air-conditioning room control PLC is respectively connected to the hot and cold water circulation pump 2 and the intelligent full-process water treatment device 6 of the pipeline. The hot and cold water circulation pump is connected to the water pump connector through a cold and warm pump intelligent controller. The intelligent full-process water treatment device is connected to the return water collector 4. The other side of the screw-type air-cooled heat pump unit is connected to the water supply manifold 3. The pipeline between the water supply manifold and the return water collector is provided with a constant pressure water replenishment exhaust device 5. Another intelligent controller of the cold and warm pump, outdoor wet-bulb temperature sensor and outdoor temperature and humidity sensor of the two-tube cooling and heat source air-conditioning room control PLC are connected to the cold and heat source system manager; one side of the plate heat exchange water tank 7 of the purification cold and heat source air-conditioning room control PLC is provided with a hot water tank, a booster tank assembly and a refrigeration pump intelligent controller, and the other side of the plate heat exchange water tank is provided with a hot water tank, a booster tank assembly and a heating pump intelligent controller, the hot water tank is respectively provided with a pressure difference bypass valve 8, the pressure replenishment pipeline, the pressure relief pipeline and the water replenishment pipeline of the booster tank assembly are respectively connected to the atmospheric pressure tank and the pressure tank, and the refrigeration pump intelligent controller and the heating pump intelligent controller are connected to the purification cold and heat source system manager. The air conditioning water pipes of the fan coil units in one of the rooms in the pipeline well of each building at the floor energy balance substation of the terminal air-conditioning system are respectively provided with fixed brackets, and the fixed brackets are respectively provided with central air conditioning energy-saving system control boxes, and the fan coil units of each room in the pipeline well are connected to the water distributor through the main pipeline. The room fan coils of the terminal air-conditioning system are respectively provided with an intelligent networked thermostat panel 9. Each intelligent networked thermostat panel on each floor of each building is connected to the building manager and the multi-connected system manager in the weak current well through lines. The network manager of each building is connected to the central air-conditioning cold and heat source group control system PLC through lines. The central air-conditioning cold and heat source group control system PLC is provided with another multi-connected system manager.

[0017] The central air-conditioning group control system includes the principle of maximum COP energy efficiency ratio, control of hot and cold water systems, control of air-conditioning host systems, control of terminal cold and heat balance and control of terminal air handling units.

[0018] The highest COP energy efficiency ratio is the principle. As a simple and practical dynamic soft measurement model for evaluating the efficiency (heat and cooling) generated by the unit electric energy consumption of central air-conditioning, COP index is a performance indicator for measuring the overall economy of the central air-conditioning system. All control logics and strategies of central air-conditioning should be implemented in accordance with the maximum COP principle. Any control strategy can be of great help to energy conservation and comfort improvement as long as it has a small improvement on the COP performance index.

[0019] For the control of the hot and cold water system, the temperature difference between the supply and return water is used as the control basis for the hot and cold water circulation pump, which is more reasonable for achieving constant temperature difference control of the inlet and return water. A large temperature difference indicates a large demand for hot and cold loads, and the speed of the hot and cold water circulation pump should be increased to increase the circulation volume of the hot and cold water pump; a small temperature difference indicates a small demand for hot and cold loads, and the speed of the hot and cold water pump can be reduced to slow down the circulation speed of the hot and cold water pump to save energy. However, in order to ensure the air conditioning effect of overcoming the most unfavorable point at the terminal, the control of the minimum pressure difference between the inlet and return water needs to be considered. In addition, the response speed of the pressure difference control is much faster than that of the temperature difference control. From the perspective of modern automatic control principles, the temperature difference is used as the outer loop controller and the pressure difference is used as the inner loop controller to form a composite loop controller (cascade control), which can not only improve the response of the hot and cold water pump frequency control to the hot and cold load demand, but also ensure the comfort of the most unfavorable point of the terminal air conditioning. The generally recommended setting value for the temperature difference between hot and cold water in summer is 5°C, and the setting value for the temperature difference in winter is 7°C. However, under different cold and hot load conditions, it is not optimal to always set it to 5°C or 7°C. It is necessary to consider COP optimal control and use an optimization algorithm to dynamically adjust the setting value of the cold and hot water temperature difference to achieve optimal energy saving for the hot and cold water pumps.

[0020] The control of the air conditioning host system, for the control of the air conditioning host, needs to have the function of resetting the outlet water temperature and having the function of adding and subtracting machines and the host dormant only retaining the cold and hot water circulation pump. The air conditioning unit can automatically adjust the number of air conditioning units opened according to the changes in the system load. When the cold and heat supply at the end is excessive, it can timely shut down one of the multiple units. When the cold and heat supply of the unit is insufficient, it can automatically load the second host to run. In the transition season or at night when the host is running at low load, the host can also automatically sleep and wake up according to parameters such as the host outlet water temperature and the percentage of operating current. When dormant, only the cold and hot water pump is circulated. When the temperature conditions are not met, the host is re-awakened and the corresponding cold and hot water circulation pump is turned on, so that the host always runs in the high-efficiency zone. In this way, the cold and heat load and cold and heat supply as well as the main operating parameters of the host are monitored in real time, and the cold and hot water temperature of the cold water host is adaptively set according to parameters such as the air conditioning operation time section, the external atmospheric environment parameters and the efficiency characteristics of the host, so as to ensure the high-efficiency operation of the host and achieve the best energy-saving effect. Generally, the host chilled water outlet temperature setting value is 7°C. However, under different host current percentage load conditions, it is not optimal to always set it to 7°C. According to COP optimal control considerations, an optimization algorithm is used to dynamically adjust the host cold and hot water outlet temperature setting values ​​to achieve optimal energy saving for the host.

[0021] The control of the balance of cold and heat at the terminal mainly solves the contradiction between poor air conditioning effect at high floors and good air conditioning effect at low floors. It is necessary to install electric regulating valves on each branch of the water distributor and the pipeline well of the terminal floor, and install the building manager and multi-connected system manager connected to the PLC of the central air conditioning cold and heat source group control system in each line of the weak current well of the terminal floor. The opening of the electric regulating valve is based on the temperature difference and pressure difference between the supply and return water of the branch as the control basis. When the temperature difference of the branch is greater than the set value, the opening of the valve is increased. When the temperature difference of the branch is less than the set value, the opening of the valve is reduced until the set value and the feedback value are close. The pressure difference control is considered to ensure the air conditioning effect at the most unfavorable point of the terminal. At this time, the valve of the branch near the low floor is often rich in flow, and the opening of the regulating valve automatically becomes smaller, and this part of the cold is transported to the high floor area, thereby realizing the balance and redistribution of terminal energy, so that each load area obtains the matching cold and heat. For example, in some public areas of the hospital, the electric regulating valves on the main pipes in the area are automatically closed after get off work, achieving the purpose of time-sharing and zoning control. For example, the electric regulating valves on the main pipes on the floors of the laboratory, gastroscopy room and other areas are closed uniformly after get off work. The general branch refrigeration temperature difference setting value is 5℃, but under different host water outlet temperature setting values, it is not optimal to always set 5℃. According to the COP optimal control considerations, the optimization algorithm is used to dynamically adjust the branch refrigeration temperature difference setting value to achieve the best energy saving for the overall energy consumption of the central air conditioner.

[0022] Control of terminal air handling units. Terminal air handling units are usually distributed in various areas, some in the machine room, and some in the ceiling. This brings spatial inconvenience to the unified management of equipment and increases the labor intensity of on-duty personnel. If there is no system control, it is easy to cause the air-conditioning units in public areas to run 24 hours a day, which will cause great energy waste. Therefore, the group control system monitors the regulating valve and air-conditioning effect. If the maintenance personnel open all the out-of-control valves, it is bound to cause some areas to have particularly good air-conditioning effects and some areas to have particularly poor air-conditioning effects; in some areas, the air-conditioning units will produce a large amount of condensed water in summer because the valves are in the open position all year round, and the cooling capacity is wasted very seriously. After the control system of the terminal air handling unit is connected to the network, it has the function of information transmission. The operating parameters and status of the terminal equipment, indoor environmental parameters and other information cannot be shared with the air-conditioning refrigeration control system. The operating status of the terminal equipment is included in the monitoring of the air-conditioning system, and the corresponding information of the refrigeration energy-saving optimization control is realized. In this way, energy-saving control and management of a large number of terminal equipment can be realized, which can effectively reduce the operating energy consumption. It is more practical in the environment of energy-saving requirements and rapid development of building intelligence.

[0023] The control process of the above-mentioned air handling unit intelligent networking system is as follows: The hot and cold water electric valves of the terminal air handling unit are PID controlled according to the difference between the set value of the supply air temperature and the actual value of the supply air temperature, automatically adjusting the opening of the hot and cold water electric valves, and controlling the supply air temperature in real time to achieve energy saving. The hot and cold conversion is controlled by the group control system; The remote module can realize the setting and display of air supply temperature, monitoring of fan operation status, remote power on / off, setting of opening of hot and cold water electric regulating valves, and opening feedback control functions; Monitor the primary filter blockage alarm; Monitor fresh air supply temperature; Monitor the operating status, fault alarm, and remote / local status of the air conditioning fan; Monitor the open and closed status of the fresh air valve, and remotely open and close the fresh air electric switch valve; The fresh air valve is linked to the fan. When the fan is turned off, the fresh air valve is closed; before the fan is turned on, the fresh air valve is opened.

[0024] Main control contents: Start and stop the blower according to the pre-programmed sequence; formulate various time operation and energy-saving operation programs according to the season, day and night and holidays to control the optimal start and stop of the blower.

[0025] Interlocking and protection: Shutdown interlocking: The fan stops, the water valve is fully closed in summer and closed to the minimum opening in winter.

[0026] At the same time, the smart networking system of the air handling unit can customize different timetable functions according to the air conditioning usage habits of the user's terminal functional area; and according to the division of each floor and area of ​​the building, different occasions have different requirements for the start and stop time of the air conditioner. This solves the inconsistent requirements for air conditioning use time and helps users save energy to the greatest extent; at the same time, the electric regulating valve of the air handling unit is a key device for accurate control of the outlet temperature. It ensures that the valve opening is in a monitored state, which can not only realize the automatic setting of the valve position, but also provide real-time feedback on the actual valve opening. The above-mentioned timetable mode of dividing the air handling unit by functional area realizes the refined management of terminal fresh air and significantly reduces the overall energy consumption of central air conditioning.

[0027] The control of the fan coil units in the terminal rooms and the management of fan coil units have the following problems: 1. The fan coil units are distributed in various places in the building and in each room. There are many of them and the management is complicated. How can the manager know whether each fan coil unit is turned on and whether it is necessary to turn it on? How to manage the out-of-control fan coil units? 2. The state stipulates that the air conditioning temperature setting cannot be lower than 26℃ in summer and cannot be higher than 20℃ in winter. How can the manager implement the state regulations? Now the intelligent networked thermostat panel can be used to realize centralized network monitoring, and the intelligent management software of fan coil units can achieve effective management and energy saving.

[0028] The intelligent fan coil management software of the above system also adopts artificial intelligence optimization technology to optimize the energy output of cold and heat sources, that is, the central air-conditioning group control system adopts artificial intelligence (AI) algorithm, through continuous analysis and self-learning of historical operation data, continuously optimizes the model, finds the optimal operation strategy, and realizes energy-saving diagnosis and optimization control of system operation. The system realizes the optimal configuration of cold and hot load-energy efficiency ratio LC through the following energy-saving optimization strategies: energy supply on demand, distribution on demand; thus, it can realize energy supply on demand, according to the characteristics of large energy load in various areas during the day and large energy load in various areas at night, the flow is dynamically adjusted by time and area, and the opening of the energy balance valve on the manifold branch and the terminal floor pipeline well is automatically adjusted to achieve the balance and redistribution of cold and heat at the terminal, and the load distribution on each floor is realized on demand, which not only ensures the reasonable distribution of energy but also realizes the maximum energy saving.

[0029] That is, the system adopts the cooling and heating load-energy efficiency ratio LC (Load-Cop) optimal efficiency operation mode to perform optimal host load distribution - according to the system load and equipment energy efficiency ratio, the host's operating load and number of operating units are automatically adjusted to make the host operate in its most efficient operating area.

[0030] When the host current percentage is high and the host cold and hot load is insufficient under cooling and heating conditions, the standby host with the shortest running time will be automatically loaded. When the host current percentage decreases, the host with the longest running time will be turned off. In summer transition season conditions, only the hot and cold water circulation pumps are turned on, and the fresh air mode is turned on for air conditioning cooling. Under low-load operating conditions, the unit is not allowed to operate below the optional operating point (such as 25% load). When the cold and hot load is lower than 25%, it will automatically shut down and sleep to avoid low-efficiency operation. When the temperature is not met, the host with the shortest running time will be automatically started through the delay program.

[0031] Thus, by implementing the transformation of the water source heat pump central air conditioning system, using this system as the main measure of energy-saving control, formulating a scientific and reasonable group control strategy, automatically controlling and adjusting the supply of cold and heat sources on demand, realizing the overall linkage of the system variable flow group control, improving various protection measures, improving the overall operation efficiency of the central air conditioning system, improving the level of automation management, saving energy and reducing consumption, extending the service life of the equipment, and improving the safety of use. The comprehensive energy efficiency ratio COP value can reach 4.7, providing three control modes: administrator mode, linkage mode, and intelligent mode, providing multi-functional and comprehensive real-time data viewing, including list, graph, bar chart and other display modes; providing standard output ratio curve viewing, color-differentiated original overall air conditioning COP value and current overall air conditioning COP value ratio comparison.

[0032] The above system is based on the COP extreme value search algorithm for online optimization and energy saving. The extreme value search algorithm is a real-time optimization control algorithm for efficient online search of the optimization target value. This method does not rely on the mathematical model of the object and has strong applicability to control systems whose dynamic characteristics are difficult to accurately obtain. It first obtains the gradient signal of the COP system performance index relative to the temperature difference and pressure difference setting value parameters by perturbing the setting parameters such as temperature difference and pressure difference, and then continuously searches online for the optimal values ​​of the air-conditioning hot and cold water temperature difference and pressure difference parameters based on the gradient signal. The basic idea of ​​extreme value search control is to first perform a modulation process, superimpose a periodic excitation signal with a small amplitude and a slow change on the target value to be optimized, so that the output of the controlled object or a certain performance indicator changes, and then continuously estimate the derivative of the performance indicator relative to the target value through a high-pass filter and demodulation process, and finally use the gradient method to obtain the local optimal solution.

[0033] The economic benefits of the system are as follows: according to the national regulations that the air conditioning temperature in office spaces should be set at no less than 26°C in summer and no more than 20°C in winter, 7%-10% of electricity can be saved for every 1°C increase in air conditioning temperature in summer; 10%-13% of electricity can be saved for every 1°C decrease in air conditioning temperature in winter. Through data comparison, the central air conditioning power consumption was 19.9 million kWh before the transformation, and the total power consumption of the central air conditioning after the transformation was 7.69 million kWh, saving 12.2 million kWh of electricity; saving standard coal: 12.2 million kWh×1.229=14.99 million tons of standard coal; carbon reduction of carbon dioxide: 12.2 million kWh×2.6885=32.7 million tons of carbon dioxide.

Claims

1. A central air-conditioning group control management system, the central air-conditioning of the system includes an air-cooled heat pump host, a hot and cold circulation pump, an air handling unit, a fan coil, a manifold and related pipes. The air-cooled heat pump host generates cold and hot water, which is transmitted to the manifold through the hot and cold circulation pump and then to the fan coil and air handling unit. The air-cooled heat pump dissipates the room heat into the atmosphere through air cooling. The system includes a hot and cold water circulation system, an air-cooled heat pump host system and a terminal air-conditioning system. The system is remotely controlled by a mobile phone and a server, and locally controlled by a management computer. The terminal air-conditioning system is mainly composed of fan coils and air handling units distributed in each terminal room on each floor of each building, and energy balance valves on each pipeline well on each floor. The water pump transports the refrigerant hot water after the temperature is reduced to the fan coil and air handling unit installed indoors, and the fan coil and air handling unit exchange heat with the indoor air by sending return air and fresh air on the spot. It is characterized in that The system includes a two-tube cooling and heat source air-conditioning room control PLC and a purification cooling and heat source air-conditioning room control PLC. The two-tube cooling and heat source air-conditioning room control PLC and the purification cooling and heat source air-conditioning room control PLC are respectively provided with a system manager. Another system manager of the system is connected to the air-conditioning unit electric control box through the air-conditioning unit, and is connected to the corresponding electric control box of each hoisted fresh air unit through each hoisted fresh air fan. The system includes each system floor energy balance substation, energy meter system manager and multi-split system manager. The system floor energy balance substation is respectively connected to the supply and return water temperature and pressure, and the corresponding temperature sensor and pressure sensor through an electric regulating valve. The electric regulating valve is installed on the water distributor and each branch of the terminal floor pipeline well. The above-mentioned electric regulating valve is an electric proportional integral electric regulating valve.

2. The central air conditioning group control management system according to claim 1 is characterized in that One side of the screw-type air-cooled heat pump unit (1) of the two-pipe refrigeration heat source air conditioning room control PLC is respectively connected to the cold and hot water circulation pump (2) and the intelligent full-process water treatment device (6) of the pipeline, the cold and hot water circulation pump is connected to the water pump connector through a cold and hot pump intelligent controller, the intelligent full-process water treatment device is connected to the return water collector (4), and the other side of the screw-type air-cooled heat pump unit is connected to the water supply manifold (3), and the pipeline between the water supply manifold and the return water collector is provided with a constant pressure water replenishment exhaust device (5).

3. The central air conditioning group control management system according to claim 1 is characterized in that Another cooling and heating pump intelligent controller, an outdoor wet-bulb temperature sensor and an outdoor temperature and humidity sensor of the two-pipe cooling and heat source air-conditioning room control PLC are connected to the cooling and heat source system manager; a hot water tank, a booster tank assembly and a freezing pump intelligent controller are arranged on one side of the plate heat exchange water tank (7) of the purification cooling and heat source air-conditioning room control PLC, and a hot water tank, a booster tank assembly and a heating pump intelligent controller are arranged on the other side of the plate heat exchange water tank, the hot water tanks are respectively provided with a pressure differential bypass valve (8), the pressure replenishment pipeline, the pressure relief pipeline and the water replenishment pipeline of the booster tank assembly are respectively connected to the atmospheric pressure tank and the pressure tank, and the freezing pump intelligent controller and the heating pump intelligent controller are connected to the purification cooling and heat source system manager.

4. The central air conditioning group control management system according to claim 1 is characterized in that The air conditioning water pipes of the fan coil units in one of the rooms in the pipe shaft of each building at the floor energy balance substation of the terminal air-conditioning system are respectively provided with fixed brackets, and the fixed brackets are respectively provided with central air-conditioning energy-saving system control boxes. The fan coil units in each room in the pipe shaft are connected to the water distributor through the main pipeline.

5. The central air conditioning group control management system according to claim 1 is characterized in that The room fan coils of the terminal air conditioning system are respectively provided with an intelligent networked thermostat panel (9). Each intelligent networked thermostat panel on each floor of each building is connected to the building manager and the multi-connected system manager in the weak current shaft through a line. The network manager of each building is connected to the central air conditioning cold and heat source group control system PLC through a line. The central air conditioning cold and heat source group control system PLC is provided with another multi-connected system manager.

6. The central air conditioning group control management system according to claim 1 is characterized in that The control process of the air handling unit intelligent networking system is as follows: The hot and cold water electric valves of the terminal air handling unit are PID controlled according to the difference between the set value of the air supply temperature and the actual value of the air supply temperature, and the opening of the hot and cold water electric valves is automatically adjusted to control the air supply temperature in real time to achieve energy saving. The hot and cold conversion is controlled by the group control system; The remote module can realize the setting and display of air supply temperature, monitoring of fan operation status, remote power on / off, setting of opening of hot and cold water electric regulating valves, and opening feedback control functions; Monitor the primary filter blockage alarm; Monitor fresh air supply temperature; Monitor the operating status, fault alarm, and remote / local status of the air conditioning fan; Monitor the open and closed status of the fresh air valve, and remotely open and close the fresh air electric switch valve; The fresh air valve is linked to the fan. When the fan is turned off, the fresh air valve is closed; before the fan is turned on, the fresh air valve is opened.

7. The central air conditioning group control management system according to claim 6 is characterized in that The air handling unit intelligent networking system customizes different schedule functions according to the air conditioning usage habits of the user's terminal functional area; and according to the division of each floor and area of ​​the building, different occasions have different requirements for the air conditioning start and stop time.

8. The central air conditioning group control management system according to claim 7 is characterized in that The air handling unit intelligent networking system is equipped with a cooling and heating load-energy efficiency ratio LC optimization configuration and a COP extreme value search algorithm, and provides three control modes: administrator mode, linkage mode, and intelligent mode; when the host current percentage is high and the host cooling and heating load is insufficient under cooling and heating conditions, the standby host with the shortest running time is automatically loaded, and when the host current percentage decreases, the host with the longest running time is turned off; in summer transition season conditions, only the hot and cold water circulation pumps are turned on, and the fresh air mode is turned on for air conditioning and cooling; under low-load operating conditions, the unit is not allowed to operate below the optional operating point; when the cooling and heating load is lower than 25%, it will automatically shut down and sleep to avoid low-efficiency operation. When the temperature is not met, the host with the shortest running time is automatically started through a delay program.

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