CN100443814C - Adjustment method of regional central cooling cooling capacity adjustment system - Google Patents

Abstract

The invention provides a regional centralized cooling cooling capacity adjustment system, which includes a freezing station server, a freezing station controller, a secondary cooling exchange station controller, a terminal controller, a remote monitoring computer, and a local monitoring computer. The freezing station server communicates with the The controller of the freezing station is connected to the controller of the secondary cooling capacity exchange station. Multiple remote monitoring computers are connected to the controller of the freezing station and multiple secondary cooling capacity exchange station controllers through converters. Each secondary cooling capacity exchange station controls The controller is connected to the local monitoring computer and multiple terminal controllers respectively through the industrial control network; it adopts three-level reverse adjustment of regional centralized cooling, that is, the cooling capacity adjustment of the central air-conditioning terminal air-conditioning equipment, and the cooling of the secondary cooling capacity exchange station of the regional centralized cooling. Volume adjustment, regional centralized cooling pipe network water supply temperature adjustment. The invention can increase the temperature difference between the supply and return water of the cooling pipe network, reduce the power consumption of the cooling water pump, greatly improve the water supply temperature of the cooling pipe network and the operating efficiency of the refrigeration host, and reduce the loss of cooling capacity of the cooling pipe.

Description

Adjustment method of regional central cooling cooling capacity adjustment system

technical field

The invention relates to a central air-conditioning energy-saving control technology, in particular to an adjustment method for an area centralized cooling supply adjustment system.

Background technique

District centralized cooling has the advantages of improved energy efficiency, low environmental heat pollution, and can effectively reduce equipment capacity and reduce the floor area of the machine room. It is being rapidly promoted and used worldwide, and has become an important aspect of the development of modern air conditioning. However, district central cooling also brings the following technical difficulties:

(1) The energy efficiency ratio of the refrigeration system is reduced: the design supply and return water temperature of HVAC in conventional buildings is 7°C/12°C, and the return water temperature of the pipe network is determined by the heat transfer characteristics of the plate heat exchanger in the secondary cooling exchange station of the district cooling system. Lower than the return water temperature of building air conditioners, in order to improve the chilled water delivery efficiency of the pipe network and reduce the investment in the district cooling pipe network, the current regional centralized cooling generally adopts the method of reducing the water supply temperature of the pipe network (generally 2-3°C) to achieve a large temperature difference ( Generally around 10 ℃), small flow and low temperature water supply. In the process of operation, in order to ensure that the pipeline network achieves large temperature difference and small flow process design parameters, the cooling capacity adjustment of the secondary cooling capacity exchange station adopts the following two methods: ①Constant temperature difference control, that is, with constant temperature difference as the control target, The water supply flow rate on the primary side (pipe network side) of the plate heat exchanger meets the changes in the user's cooling load. ②Constant water supply temperature control, that is, the constant water supply temperature on the user side is the control target, and the water supply temperature on the user side is constant by adjusting the water supply flow rate on the primary side (pipe network side) of the plate heat exchanger. These two control methods will make the temperature of the chilled water supply in the pipe network too low, resulting in a decrease in the efficiency of the refrigeration unit of the refrigeration station (under the premise of constant cooling capacity, the energy consumption of the main unit will increase by 2% for every 1°C decrease in the chilled water outlet temperature of the electric refrigeration unit. 3%), the energy consumption required to produce the same cooling capacity increases. (In the ice-making process of the district cooling system using ice storage technology, the efficiency of the refrigerator is much lower than the cooling state), so the low-temperature water supply brings about the problem of lower energy efficiency ratio of the refrigeration system;

(2) The energy consumption of the cooling water pump is large: due to the long distance of regional cooling and the large resistance of the pipe network, the power and head of the cooling water pump are much larger than that of the conventional central air-conditioning cooling water pump. How to effectively reduce the water flow and reduce the power consumption of the pump is a must One of the key issues to be solved to improve the efficiency of district cooling;

(3) The cooling capacity loss of the outdoor pipe network of the district cooling is large: Since the distance of the regional centralized cooling pipe network reaches several kilometers to tens of kilometers, the temperature difference between the low-temperature water supply pipe and the surrounding medium will increase the cooling capacity loss.

Contents of the invention

The purpose of the present invention is to overcome the shortcomings and deficiencies of the above-mentioned prior art, and provide an adjustment method for the regional centralized cooling cooling capacity adjustment system, which can greatly increase the water supply temperature of the cooling pipe network, improve the operating efficiency of the refrigeration host, and can Increase the temperature difference between the supply and return water of the cooling pipe network to a certain extent, reduce the power consumption of the cooling water pump, and reduce the loss of cooling capacity of the cooling pipe.

The object of the present invention is achieved through the following technical solutions: the regional centralized cooling cooling capacity adjustment system includes a freezing station server, a freezing station controller, a secondary cooling exchange station controller, a terminal controller, a remote monitoring computer, a local monitoring Computer, the freezing station server is connected with the freezing station controller and the secondary cooling capacity exchange station controller through the converter, and multiple remote monitoring computers are connected with the freezing station controller and multiple secondary cooling capacity exchange station controllers through the converter Connection, each secondary cooling exchange station controller is connected to the local monitoring computer and multiple terminal controllers respectively through the industrial control network.

In order to better realize the present invention, the controller of the freezing station is connected with an analog input module, an analog output module, a digital input module, and a digital output module; Frequency conversion circulating water pump of cold storage system, outlet water temperature sensor of refrigeration host, outlet water flowmeter of refrigeration host, outlet water temperature sensor of ice storage system, outlet water flowmeter of ice storage system, primary side water supply temperature sensor of plate heat exchanger of freezing station, plate heat exchanger of freezing station Primary side return water temperature sensor, regional central cooling pipe network water supply temperature sensor, regional central cooling pipe network return water temperature sensor, regional central cooling pipe network frequency conversion circulating water supply pump, regional central cooling pipe network water supply flowmeter, regional The pressure difference sensors of the supply and return water in the centralized cooling pipe network are connected separately; the analog output module, digital input module, and digital output module are respectively connected to the refrigeration main engine, the cold water frequency conversion circulating water pump, the ice storage system frequency conversion circulating water pump, and the regional centralized power supply system. The cooling pipe network is connected to the frequency conversion circulating water supply pump.

The controller of the secondary cooling capacity exchange station, the primary side water supply temperature sensor of the plate heat exchanger of the secondary cooling capacity exchange station, the return water temperature sensor of the primary side of the plate heat exchanger of the secondary cooling capacity exchange station, and the water supply of the building cooling pipe network Temperature sensor, return water temperature sensor of building cooling pipe network, primary side water supply flow regulating valve of plate heat exchanger in secondary cooling capacity exchange station, primary side water supply flow meter of plate heat exchanger in secondary cooling capacity exchange station, building cooling pipe The network frequency conversion circulating water pump and the building cooling pipe network supply and return water pressure difference sensor are connected separately.

The terminal controller is respectively connected with the terminal air-conditioning equipment, the water supply flow regulating valve of the terminal air-conditioning equipment, and the ambient temperature and humidity sensor.

The terminal air conditioner includes a cabinet air conditioner, a fan coil unit, and a fresh air fan; the measurement area of the ambient temperature and humidity sensor includes indoor and fresh air ducts.

The adjustment method of the regional centralized cooling cooling capacity adjustment system adopts the three-stage reverse adjustment method of the regional centralized cooling supply, including the cooling capacity adjustment of the central air-conditioning terminal air-conditioning equipment, the cooling capacity adjustment of the secondary cooling capacity exchange station of the regional centralized cooling supply, and the regional centralized cooling system. Water supply temperature regulation of the cooling pipe network, in which:

(1) The adjustment of the cooling capacity of the central air-conditioning terminal air-conditioning equipment refers to the calculation formula of the cooling capacity of the terminal air-conditioning equipment: Q=Cp*q*ΔT, where Q is the cooling load, Cp is the specific heat capacity of water, and ΔT is the terminal air-conditioning equipment The temperature difference between supply and return water, by maintaining the water supply flow q of the terminal air-conditioning equipment constant, with the temperature and humidity in the cooling area satisfying the set range T≤Tmax, RH≤RHmax as the control target, the water supply temperature of the building cooling pipe network is adjusted, so that ΔT changes to realize the cooling capacity adjustment of the central air-conditioning terminal air-conditioning equipment, and the steps include:

(1) Open the water flow regulating valve of the terminal air-conditioning equipment to 100% through the terminal controller;

(2) Adjust the opening of the water supply regulating valve on the primary side of the plate heat exchanger of the secondary cooling energy exchange station through the analog output module of the controller of the secondary cooling energy exchange station, so that the primary side water supply of the plate heat exchanger of the secondary cooling energy exchange station The flow counter value changes, so that the water supply temperature of the building cooling pipe network and the temperature difference ΔT of the supply and return water of the terminal air-conditioning equipment change, and the cooling capacity of the terminal air-conditioning equipment is adjusted.

(2) The cooling capacity adjustment of the secondary cooling capacity exchange station of the regional centralized cooling supply, the steps include:

(1) Automatically find the terminal air-conditioning equipment whose temperature and humidity are the most unfavorable working points and adjust the cooling capacity: when the secondary cooling capacity exchange station adopting regional centralized cooling starts to work, the cooling load of the building is the largest, and through the secondary The analog quantity output module of the controller of the cooling capacity exchange station adjusts the opening of the water supply flow regulating valve on the primary side of the plate heat exchanger of the secondary cooling capacity exchange station to 100%; The water supply flow regulating valve of air conditioning equipment is opened to 100% to realize rapid cooling;

When the temperature and humidity measured by the ambient temperature and humidity sensors in all cooling areas reach the set range, that is, T≤Tmax, RH≤RHmax, the indoor temperature and humidity begin to drop due to the reduction of the indoor cooling load. At this time, the secondary cooling capacity The exchange station controller reduces the opening of the water supply flow regulating valve on the primary side of the plate heat exchanger of the secondary cooling capacity exchange station through the analog output module, so that the primary side water supply flow rate of the plate heat exchanger of the secondary cooling capacity exchange station is reduced, thereby improving The water supply temperature of the building's cooling pipe network. When the first ambient temperature and humidity measurement in the building exceeds the upper limit of the set value (T>Tmax or RH>RHmax), this temperature and humidity point is the current most unfavorable working point;

At this time, the terminal controller continues to maintain the most unfavorable working point of the water supply flow regulating valve of the terminal air-conditioning equipment with the largest opening. The station controller adjusts the opening of the water supply flow regulating valve on the primary side of the plate heat exchanger of the secondary cooling capacity exchange station, so that the flow rate of the primary side water supply of the plate heat exchanger of the secondary cooling capacity exchange station changes, so that the water supply temperature of the building cooling pipe network and The temperature difference ΔT of the supply and return water of the terminal air-conditioning equipment changes to realize the control of the ambient temperature and humidity of the most unfavorable working point and the automatic adjustment of the cooling load corresponding to the most unfavorable working point; the water supply temperature value of the building cooling pipe network obtained at this time Tg is the current water supply temperature control target value of the building's cooling pipe network at the secondary cooling exchange station of the building; at this time, the adjustment of the ambient temperature and humidity of the non-most unfavorable working point is controlled by the terminal controller by adjusting the water supply of the terminal air-conditioning equipment Adjust the opening of the valve to adjust the water supply flow of the terminal air-conditioning equipment;

(2) Dynamic identification of the most unfavorable working point and dynamic adjustment of the water supply temperature Tg of the building cooling pipe network: due to the change of the cooling load inside the building, the most unfavorable working point is not constant. When the cooling system has a second terminal air conditioner The ambient temperature and humidity of the refrigeration area corresponding to the equipment are higher than the set value (T>Tmax or RH>RHmax), and the opening degree of the water flow regulating valve of the terminal air-conditioning equipment measured by the terminal controller is 100%, and the terminal air-conditioning equipment has been When it is in the cooling operation state, the temperature and humidity point becomes the new most unfavorable working point at present. At this time, the water supply temperature of the building cooling pipe network is based on the new most unfavorable working point according to the cooling capacity of the regional centralized cooling secondary cooling capacity exchange station. The adjustment step (1) is to adjust and control;

(3) When the most unfavorable working point RH=RHmax, the adjustment of the ambient temperature is realized by the terminal controller by adjusting the opening of the water flow regulating valve of the terminal air-conditioning equipment to adjust the water supply flow of the terminal air-conditioning equipment.

(3) Adjusting the water supply temperature of the regional centralized cooling pipe network, the steps include:

(1) Automatically find the most unfavorable working point with the minimum Tg and the maximum opening of the water supply flow regulating valve on the primary side of the plate heat exchanger at the secondary cooling exchange station. The secondary cooling exchange station: implement steps ( After 1) and (2), the freezing station server collects the water supply temperature value Tg of the building cooling pipe network in the controllers of all secondary cooling capacity exchange stations through the converter, and the water supply flow rate adjustment of the primary side of the plate heat exchanger of the secondary cooling capacity exchange station Valve opening value K, and compare all Tg and K to get Tg minimum Tg-min and K maximum Kmax, the secondary cooling capacity exchange station corresponding to Tg-min and Kmax is the secondary of the most unfavorable working point Cooling capacity exchange station (under normal circumstances, since the smaller the Tg, the greater the demand for q, the greater the K, Tg-min and Kmax appear in the same secondary cooling capacity exchange station);

(2) Temperature adjustment of cooling outlet water in the freezing station: the freezing station server sends the Tg-min and Kmax values to the freezing station controller through the converter, and the freezing station controller takes Tg-min as the control target so that Kmax≤90% ( The remaining 10% is used as the cooling capacity adjustment margin reserved by the secondary cooling capacity exchange station) as a constraint condition, adjust the given value of the outlet water temperature of the refrigeration host through the analog output module, or adjust the frequency given by the variable frequency circulating water pump of the ice storage system Adjust the ice water flow to adjust the water supply temperature value of the regional cooling pipe network to realize the follow-up control of Tg-min;

(3) Determination of the minimum supply and return water pressure difference ΔPmin for cooling in the freezing station and adjustment of the water supply flow: the server of the freezing station sends water supply to the primary side of the plate heat exchanger of the secondary cooling exchange station to the controllers of all secondary cooling exchange stations through the converter Open the regulating valve to 100% mandatory command, and read the opening value of the water supply regulating valve on the primary side of the plate heat exchanger of all secondary cooling capacity exchange stations. After reaching 100%, read the q value of the water supply flow rate at the primary side of the plate heat exchanger in the secondary cooling exchange station and issue a pipe network flow adjustment command to the controller of the freezing station. The module adjusts the frequency and number of variable frequency water supply pumps for district cooling, so that the flow rate q of the primary side water supply of plate heat exchangers in all secondary cooling exchange stations reaches the design flow rate. At this time, the cooling supply and return water of the refrigeration station measured by the controller of the refrigeration station The pressure difference ΔP is the minimum supply and return water pressure difference ΔPmin. After obtaining ΔPmin, the server of the freezing station sends a signal to the controllers of all secondary cooling exchange stations through the converter. When the command is released to 100%, the controller of the refrigeration station takes ΔPmin as the set value of the pressure difference between the supply and return water, and adjusts the frequency and number of district cooling variable frequency water supply pumps through the analog output module and digital output module to keep ΔPmin constant and achieve Regulation of district cooling flow;

(4) Dynamic identification of the most unfavorable secondary cooling exchange station: the server of the freezing station continuously collects the water supply temperature value Tg of the building cooling pipe network in the controller of all secondary cooling exchange stations through the converter, the plate type of the secondary cooling exchange station The opening value K of the water supply flow regulating valve on the primary side of the heat exchanger, and compare all Tg and K to obtain the current Tg minimum value Tg-min and K maximum value Kmax, and the secondary cooling capacity exchange station corresponding to Tg-min and Kmax It is the secondary cooling capacity exchange station at the most unfavorable working point at present. At this time, the freezing station is adjusted according to the above-mentioned step (2) of water supply temperature adjustment of the regional centralized cooling pipe network.

Compared with the prior art, the present invention has the following advantages and beneficial effects:

(1) Reduce water flow and reduce energy consumption of water pumps: The cooling capacity adjustment method of the central air-conditioning terminal equipment and the cooling capacity adjustment method of the regional centralized cooling secondary cooling capacity exchange station can effectively improve the water supply temperature and return rate of the building cooling pipe network. The temperature of the water will increase the temperature difference between the supply and return water of the regional cooling pipe network and reduce the flow of cooling water. On the premise that the water supply temperature of the central cooling pipe network remains unchanged, the return water temperature of the pipe network can be increased by more than 30%, so that the flow rate of the water supply pump can be reduced by more than 30%, and the water supply pump can save energy by more than 30%.

(2) Reduce the energy consumption of the main engine and improve the efficiency of the refrigeration main engine: By adopting the above-mentioned water supply temperature adjustment method of the regional centralized cooling pipe network, the cooling pipe can be adjusted under the premise that the water supply and return water temperature difference of the central cooling primary side pipe network remains unchanged The temperature of the water supply and return water in the network is increased by 3-6°C, which increases the efficiency of the refrigeration host of the refrigeration station by about 6%-18%;

(3) Reduce the loss of cooling capacity in the outdoor pipe network of district cooling: due to the increase in the temperature of the supply and return water, the loss of cooling capacity during the transportation of chilled water can be reduced by 10% to 30%.

(4) Under dry climate conditions, due to the increase in the water supply temperature of the building's cooling pipe network, it can effectively reduce indoor water loss, avoid low ambient humidity, improve environmental comfort, and reduce the latent heat load cooling capacity consumption of the air conditioning system.

(5) Reduce the unit price cost of the cooling capacity of the regional centralized cooling system, and reduce the user's air-conditioning expenses.

Description of drawings

Figure 1 is a structural schematic diagram of the regional centralized cooling system;

Figure 2 is a structural schematic diagram of the cooling system of the freezing station;

Figure 3 is a structural schematic diagram of the central air-conditioning system for building cooling;

Figure 4 is a schematic diagram of the cooling capacity adjustment of the central air-conditioning terminal equipment;

Fig. 5 is a structural principle diagram of the regional centralized cooling cooling capacity adjustment system of the present invention;

Fig. 6 is a structural schematic diagram of the controller of the freezing station shown in Fig. 5;

Fig. 7 is a structural schematic diagram of the controller of the secondary cooling capacity exchange station shown in Fig. 5 .

Detailed ways

The present invention will be described in further detail below in conjunction with the embodiments and the accompanying drawings, but the embodiments of the present invention are not limited thereto.

Example

As shown in Figures 1 to 3, the system structure of the current regional centralized cooling system, its refrigeration station cooling system, and building cooling central air-conditioning system is shown in turn, among which:

1. Freezing station, 2. Water supply pipeline of regional centralized cooling pipe network, 3. Return water pipe of regional centralized cooling pipe network, 4. Secondary cooling capacity exchange station, 5. Water supply pipe of building cooling pipe network, 6. Building Cooling pipe network return pipe, 7. Terminal air-conditioning equipment (including cabinet air conditioners, fan coil units and fresh air fans), 8. Refrigeration host, 9. Cold water frequency conversion circulating water pump, 10. Ice storage tank, 11. Ice storage System frequency conversion circulating water pump, 12. Water outlet temperature sensor of refrigeration host, 13. Water outlet flowmeter of refrigeration host, 14. Ice storage system outlet water temperature sensor, 15. Ice storage system outlet water flowmeter, 16. Freezing station plate heat exchanger, 17, Primary side water supply temperature sensor of the plate heat exchanger in the freezing station, 18. Primary side return water temperature sensor of the plate heat exchanger in the freezing station, 19. Water supply temperature sensor of the regional centralized cooling pipe network, 20. Return water temperature of the regional centralized cooling pipe network Sensors, 21. Frequency conversion circulating water pump of regional centralized cooling pipe network, 22. Water supply flow meter of regional centralized cooling pipe network, 23. Pressure difference sensor of supply and return water of regional centralized cooling pipe network, 24. Plate type of secondary cooling capacity exchange station Heat exchanger, 25. Primary side water supply temperature sensor of the plate heat exchanger of the secondary cooling capacity exchange station, 26. Primary side return water temperature sensor of the plate type heat exchanger of the secondary cooling capacity exchange station, 27. Water supply temperature of the building cooling pipe network Sensor, 28. Return water temperature sensor of building cooling pipe network, 29. Water supply flow regulating valve on the primary side of the plate heat exchanger in the secondary cooling capacity exchange station, 30. Water supply flowmeter on the primary side of the plate heat exchanger in the secondary cooling capacity exchange station , 31. Frequency conversion circulating water pump of building cooling pipe network, 32. Pressure difference sensor of supply and return water of building cooling pipe network, 33. Water supply flow regulating valve of terminal air-conditioning equipment, 34. Terminal controller, 35. Environmental temperature and humidity sensor

The cooling capacity adjustment system for regional centralized cooling of the present invention is suitable for adjusting the cooling capacity of the above-mentioned regional centralized cooling system, its refrigeration station cooling system, and building cooling central air-conditioning system. As shown in Figure 5, the regional centralized cooling cooling capacity adjustment system includes a freezing station server 40, a freezing station controller 36, a secondary cooling capacity exchange station controller 37, a terminal controller 34, a remote monitoring computer 41, a local monitoring Computer 38, freezing station server 40 are connected with freezing station controller 36 and secondary refrigeration exchange station controller 37 through converter 39, and multiple remote monitoring computers 41 are connected with freezing station controller 36 and multiple secondary cooling station controllers through converter 39 The cooling capacity exchange station controller 37 is connected, and each secondary cooling capacity exchange station controller 37 is connected with a local monitoring computer 38 and a plurality of terminal controllers 34 through an industrial control network.

As shown in Figure 7, the freezing station controller 36 is connected with an analog input module, an analog output module, a digital input module, and a digital output module; System frequency conversion circulating water pump 11, refrigeration host water outlet temperature sensor 12, refrigeration host outlet water flow meter 13, ice storage system outlet water temperature sensor 14, ice storage system outlet water flow meter 15, plate heat exchanger primary side water supply temperature sensor 17 of the refrigeration station, Station plate heat exchanger primary side return water temperature sensor 18, regional centralized cooling pipe network water supply temperature sensor 19, regional centralized cooling pipe network return water temperature sensor 20, regional centralized cooling pipe network frequency conversion circulating water supply pump 21, regional centralized The water supply flow meter 22 of the cooling pipe network and the differential pressure sensor 23 of the water supply and return water of the regional centralized cooling pipe network are connected respectively; 1. The frequency conversion circulating water pump 11 of the ice storage system is connected with the frequency conversion circulating water supply pump 21 of the regional centralized cooling pipe network.

As shown in Figure 6, the controller 37 of the secondary cooling capacity exchange station is connected with the primary side water supply temperature sensor 25 of the plate heat exchanger of the secondary cooling capacity exchange station, and the return water temperature sensor 26 of the primary side of the plate heat exchanger of the secondary cooling capacity exchange station. , Building cooling pipe network water supply temperature sensor 27, building cooling pipe network return water temperature sensor 28, secondary cooling capacity exchange station plate heat exchanger primary side water supply flow regulating valve 29, secondary cooling capacity exchange station plate heat exchanger The water supply flowmeter 30 on the primary side, the frequency conversion circulating water pump 31 of the building cooling pipe network, and the differential pressure sensor 32 of the water supply and return water of the building cooling pipe network are respectively connected.

As shown in FIG. 3 , the terminal controller 34 is respectively connected with the terminal air conditioner 7 , the water supply flow regulating valve 33 of the terminal air conditioner, and the ambient temperature and humidity sensor 35 .

The terminal air conditioner 7 includes a cabinet air conditioner, a fan coil unit, and a fresh air fan; the measurement area of the ambient temperature and humidity sensor 35 includes indoor and fresh air ducts.

The adjustment process of the regional centralized cooling capacity adjustment system adopts the three-stage reverse adjustment method of regional centralized cooling, including the adjustment of the cooling capacity of the central air-conditioning terminal air-conditioning equipment, the cooling capacity adjustment of the secondary cooling capacity exchange station of the regional centralized cooling, and the area Central cooling pipe network water supply temperature regulation, of which:

(1) The adjustment of the cooling capacity of the central air-conditioning terminal air-conditioning equipment refers to the calculation formula of the cooling capacity of the terminal air-conditioning equipment: Q=Cp*q*ΔT, where Q is the cooling load, Cp is the specific heat capacity of water, and ΔT is the terminal air-conditioning equipment The temperature difference between supply and return water, by maintaining the water supply flow q of the terminal air-conditioning equipment constant, with the temperature and humidity in the cooling area satisfying the set range T≤Tmax, RH≤RHmax as the control target, the water supply temperature of the building cooling pipe network is adjusted, so that The change of ΔT realizes the adjustment of the cooling capacity of the central air-conditioning terminal air-conditioning equipment.

As shown in Figure 4, Tmax is the upper limit of the temperature setting value of the cooling area, Td is the upper limit of the building cooling water supply temperature corresponding to the upper limit of the humidity setting value RHmax of the cooling area, and curve 3 is the cooling load Q change curve. Curves 1 and 2 are the adjustment curves of the building cooling supply water temperature and the return water temperature of the terminal air-conditioning equipment during the change process of the cooling load Q in the present invention. Curves T1 and T2 are the water supply temperature and return water temperature curves of the terminal air-conditioning equipment in the conventional central air-conditioning system during the change of cooling load Q respectively. The water temperature is constant, and the cooling capacity is adjusted by adjusting the water supply flow. Tg, Th, Tgo, Tho are respectively under a certain cooling load, the working points of the cooling water supply temperature of the building and the return water temperature of the terminal air-conditioning equipment corresponding to the two adjustment methods. It can be seen from the position of the working point in Fig. 4 that the cooling capacity adjustment method of the present invention can effectively increase the cooling water supply temperature of the building and the return water temperature of the terminal air-conditioning equipment.

The cooling capacity adjustment of the central air-conditioning terminal air-conditioning equipment of the present invention, the steps include:

(1) Open the water supply flow regulating valve 33 of the terminal air conditioner to 100% through the terminal controller 34;

(2) Adjust the opening degree of the water supply regulating valve 29 on the primary side of the plate heat exchanger of the secondary cooling energy exchange station through the analog output module of the controller 37 of the secondary cooling energy exchange station, so that the primary side of the plate heat exchanger of the secondary cooling energy exchange station The value of the side water supply flowmeter 30 changes, so that the water supply temperature of the building cooling pipe network and the temperature difference ΔT of the supply and return water of the terminal air-conditioning equipment change, and the cooling capacity of the terminal air-conditioning equipment 7 is adjusted.

(2) The cooling capacity adjustment of the secondary cooling capacity exchange station of the regional centralized cooling supply, the steps include:

(1) Automatically find the terminal air-conditioning equipment whose temperature and humidity point is the most unfavorable working point and adjust the cooling capacity: when the secondary cooling capacity exchange station adopting regional centralized cooling starts to work, the cooling load of the building is the largest, and the secondary cooling capacity The quantity exchange station controller 37 adjusts the opening degree of the water supply flow regulating valve 29 on the primary side of the plate heat exchanger of the secondary cooling quantity exchange station to 100% through the analog quantity output module; through the terminal controller 34, the terminal air conditioner 7 that needs refrigeration is started, And open the water supply flow regulating valve 33 of the terminal air-conditioning equipment to 100% to realize rapid cooling;

When the temperature and humidity measured by the ambient temperature and humidity sensors 35 in all areas that need cooling reach the set range, that is, T≤Tmax, RH≤RHmax, due to the reduction of the indoor cooling load, the indoor temperature and humidity begin to drop. The cooling capacity exchange station controller 37 reduces the opening degree of the water supply flow regulating valve 29 on the primary side of the plate heat exchanger of the secondary cooling capacity exchange station through the analog quantity output module, so that the water supply flow meter 30 of the plate heat exchanger of the secondary cooling capacity exchange station The numerical value decreases, so that the water supply temperature of the building's cooling pipe network increases. When the first ambient temperature and humidity measurement value in the building is higher than the upper limit of the set value (T>Tmax or RH>RHmax), the temperature and humidity point It is the most unfavorable working point at present;

At this time, the terminal controller 34 continues to keep the most unfavorable working point of the water supply flow regulating valve 33 of the terminal air-conditioning equipment at the largest opening. The controller 37 of the volume exchange station adjusts the opening degree of the water supply flow regulating valve 29 on the primary side of the plate heat exchanger of the secondary cooling energy exchange station, so that the flow rate of the primary side water supply of the plate heat exchanger of the secondary cooling energy exchange station changes, so that the cooling pipe of the building The change of network water supply temperature and the temperature difference ΔT between supply and return water of terminal air-conditioning equipment realizes the control of the ambient temperature and humidity of the most unfavorable working point and the automatic adjustment of the cooling load corresponding to the most unfavorable working point; the building cooling pipe obtained at this time The network water supply temperature value Tg is the current building cooling pipe network water supply temperature control target value of the secondary cooling capacity exchange station of the building; Adjust the opening degree of the water supply regulating valve 33 of the terminal air-conditioning equipment, and adjust the water supply flow rate of the terminal air-conditioning equipment 7;

(2) Dynamic identification of the most unfavorable working point and dynamic adjustment of the water supply temperature Tg of the building cooling pipe network: due to the change of the cooling load inside the building, the most unfavorable working point is not constant. When the cooling system has a second terminal air conditioner The ambient temperature and humidity corresponding to the equipment 7 are higher than the set value, and the opening degree of the water flow regulating valve 33 of the terminal air-conditioning equipment measured by the terminal controller 34 is 100%, and the terminal air-conditioning equipment 7 is always in the running state, then the The temperature and humidity points become the new most unfavorable working point at present. At this time, the water supply temperature of the building cooling pipe network is adjusted and controlled according to the new most unfavorable working point according to the cooling capacity adjustment step (1) of the regional centralized cooling secondary cooling capacity exchange station. ;

(3) Adjustment of the ambient temperature when the most unfavorable operating point RH=RHmax: the terminal controller 34 adjusts the water supply flow rate of the terminal air conditioner 7 by adjusting the opening of the water supply flow regulating valve 33 of the terminal air conditioner.

(3) Adjusting the water supply temperature of the regional centralized cooling pipe network, the steps include:

(1) Automatically find the minimum Tg and the secondary cooling exchange station at the most unfavorable working point with the largest opening of the water supply flow regulating valve on the primary side of the plate heat exchanger: realized in all secondary cooling exchange stations 4 After steps (1) and (2), the freezing station server 40 collects the water supply temperature values Tg of the building cooling pipe network in the controller 37 of all secondary cooling capacity exchange stations, the plate heat exchangers of the secondary cooling capacity exchange stations through the converter 39 The primary side water supply flow regulating valve 29 has an opening value K, and compares all Tg and K to obtain the minimum Tg Tg-min and the maximum K Kmax, and the secondary cooling exchange station 4 corresponding to Tg-min and Kmax is Secondary cooling exchange station 4 at the most unfavorable working point:

(2) Adjustment of the cooling outlet water temperature of the freezing station: the freezing station server 40 sends the Tg-min and Kmax values to the freezing station controller 36 through the converter 39, and the freezing station controller 36 takes Tg-min as the control target so that Kmax ≤90% (the remaining 10% is reserved as the cooling capacity adjustment margin of the secondary cooling capacity exchange station) as the constraint condition, adjust the given value of the outlet water temperature of the cooling host 8 through the analog output module, or adjust the frequency conversion circulating water pump of the ice storage system The frequency of 11 is given to adjust the flow of ice water to adjust the water supply temperature value of the regional cooling pipe network to realize the follow-up control of Tg-min;

(3) Determination of the minimum supply and return water pressure difference ΔPmin for cooling of the freezing station and adjustment of the water supply flow: the server 40 of the freezing station sends the plate heat exchanger of the secondary cooling station to all the controllers 37 of the secondary cooling station through the converter 39 The water supply regulating valve 29 on the primary side is opened to 100% mandatory command, and read the opening value of the water supply regulating valve 29 on the primary side of all secondary cooling capacity exchange station plate heat exchangers, when all the secondary cooling capacity exchange station plate heat exchangers After the side water supply regulating valve 29 is opened to 100%, read the value of the primary side water supply flowmeter 30 of the plate heat exchanger of the secondary cooling exchange station, and send a pipe network flow adjustment command to the freezing station controller 36, and the freezing station controller 36 Adjust the frequency and number of variable frequency circulating water pumps 21 in the regional central cooling pipe network through the analog output module and digital output module, so that the values of the water supply flowmeters 30 on the primary side of the plate heat exchangers in all secondary cooling exchange stations reach the design flow. The pressure difference ΔP of the cooling supply and return water of the refrigeration station 1 measured by the controller 36 of the refrigeration station is the minimum supply and return water pressure difference ΔPmin. The controller 37 issues an instruction to release the water supply regulating valve on the primary side of the plate heat exchanger of the secondary cooling capacity exchange station until it reaches 100%. The volume output module adjusts the frequency and number of variable frequency circulating water pumps 21 in the regional centralized cooling pipe network to keep ΔPmin constant and realize the adjustment of the regional cooling flow;

(4) Dynamic identification of the most unfavorable secondary cooling capacity exchange station: the server 40 of the freezing station continuously collects the water supply temperature value Tg and the secondary cooling capacity of the building cooling pipe network in the controller 37 of all secondary cooling capacity exchange stations through the converter 39 The opening value K of the water supply flow regulating valve 29 on the primary side of the plate heat exchanger in the exchange station, and compare all Tg and K to obtain the current minimum Tg Tg-min and K maximum Kmax, and the secondary level corresponding to Tg-min and Kmax The cooling capacity exchange station 4 is the secondary cooling capacity exchange station 4 at the current most unfavorable working point. At this time, the refrigeration station 1 is adjusted according to the step (2) of the water supply temperature adjustment of the regional centralized cooling network.

As described above, the present invention can be preferably carried out.

Claims (4)

1. The cooling capacity adjustment method of regional centralized cooling, which is characterized in that it adopts a three-stage reverse adjustment method of regional centralized cooling, which successively includes the cooling capacity adjustment of central air-conditioning terminal equipment, and the cooling capacity adjustment of the secondary cooling capacity exchange station of regional centralized cooling 1. The three steps of water supply temperature adjustment of regional centralized cooling pipe network. 2. According to the method for adjusting the cooling capacity of regional centralized cooling according to claim 1, it is characterized in that the adjustment of the cooling capacity of the central air-conditioning terminal air-conditioning equipment refers to the cooling capacity Q=Cp*q*ΔT of the terminal air-conditioning equipment, where Q is Cooling load, Cp is the specific heat capacity of water, ΔT is the temperature difference between the supply and return water of the terminal air-conditioning equipment, by maintaining the water supply flow q of the terminal air-conditioning equipment constant, the temperature and humidity of the cooling area meet the set range T≤Tmax, RH≤RHmax is the control target , to adjust the water supply temperature of the building cooling pipe network, so as to change ΔT, and realize the cooling capacity adjustment of the central air-conditioning terminal air-conditioning equipment. The steps include: (1) Open the water flow regulating valve of the terminal air-conditioning equipment to 100% through the terminal controller; (2) Adjust the opening of the water supply regulating valve on the primary side of the plate heat exchanger of the secondary cooling energy exchange station through the analog output module of the controller of the secondary cooling energy exchange station, so that the primary side water supply of the plate heat exchanger of the secondary cooling energy exchange station The flow counter value changes, so that the water supply temperature of the building cooling pipe network and the temperature difference ΔT of the supply and return water of the terminal air-conditioning equipment change, and the cooling capacity of the terminal air-conditioning equipment is adjusted. 3. According to claim 2, the cooling capacity adjustment method for regional centralized cooling is characterized in that the cooling capacity of the secondary cooling capacity exchange station for regional centralized cooling is adjusted, and the steps include: (1) Automatically find the terminal air-conditioning equipment whose temperature and humidity are the most unfavorable working points and adjust the cooling capacity: when the secondary cooling capacity exchange station adopting regional centralized cooling starts to work, the cooling load of the building is the largest, and through the secondary The analog quantity output module of the controller of the cooling capacity exchange station adjusts the opening of the water supply flow regulating valve on the primary side of the plate heat exchanger of the secondary cooling capacity exchange station to 100%; The water supply flow regulating valve of air conditioning equipment is opened to 100% to realize rapid cooling; When the temperature and humidity measured by the ambient temperature and humidity sensors in all cooling areas reach the set range, that is, T≤Tmax, RH≤RHmax, the indoor temperature and humidity begin to drop due to the reduction of the indoor cooling load. At this time, the secondary cooling capacity The exchange station controller reduces the opening of the water supply flow regulating valve on the primary side of the plate heat exchanger of the secondary cooling capacity exchange station through the analog output module, so that the primary side water supply flow rate of the plate heat exchanger of the secondary cooling capacity exchange station is reduced, thereby improving The water supply temperature of the building's cooling pipe network. When the first ambient temperature and humidity measurement in the building exceeds the upper limit of the set value, that is, T>Tmax or RH>RHmax, this temperature and humidity point is the current most unfavorable working point; At this time, the terminal controller continues to maintain the most unfavorable working point of the water supply flow regulating valve of the terminal air-conditioning equipment with the largest opening. The station controller adjusts the opening of the water supply flow regulating valve on the primary side of the plate heat exchanger of the secondary cooling capacity exchange station, so that the flow rate of the primary side water supply of the plate heat exchanger of the secondary cooling capacity exchange station changes, so that the water supply temperature of the building cooling pipe network and The temperature difference ΔT of the supply and return water of the terminal air-conditioning equipment changes to realize the control of the ambient temperature and humidity of the most unfavorable working point and the automatic adjustment of the cooling load corresponding to the most unfavorable working point; the water supply temperature value of the building cooling pipe network obtained at this time Tg is the current water supply temperature control target value of the building's cooling pipe network at the secondary cooling exchange station of the building; at this time, the adjustment of the ambient temperature and humidity of the non-most unfavorable working point is controlled by the terminal controller by adjusting the water supply of the terminal air-conditioning equipment Adjust the opening of the valve to adjust the water supply flow of the terminal air-conditioning equipment; (2) Dynamic identification of the most unfavorable working point and dynamic adjustment of the water supply temperature Tg of the building cooling pipe network: due to the change of the cooling load inside the building, the most unfavorable working point is not constant. When the cooling system has a second terminal air conditioner The ambient temperature and humidity corresponding to the equipment are higher than the set value, that is, T>Tmax or RH>RHmax, and the opening degree of the water flow regulating valve of the terminal air-conditioning equipment measured by the terminal controller is 100%, and the terminal air-conditioning equipment is always in the running state , then the temperature and humidity point becomes the new most unfavorable working point at present. At this time, the water supply temperature of the building cooling pipe network is adjusted according to the new most unfavorable working point according to the cooling capacity of the regional centralized cooling secondary cooling capacity exchange station (1 ) for regulatory control; (3) When the most unfavorable working point RH=RHmax, the adjustment of the ambient temperature is realized by the terminal controller by adjusting the opening of the water flow regulating valve of the terminal air-conditioning equipment to adjust the water supply flow of the terminal air-conditioning equipment. 4. The cooling capacity adjustment method for regional centralized cooling according to claim 3, characterized in that the water supply temperature of the regional centralized cooling pipe network is adjusted, and the steps include: (1) Automatically find the most unfavorable working point with the minimum Tg and the maximum opening of the water supply flow regulating valve on the primary side of the plate heat exchanger at the secondary cooling capacity exchange station. After the two steps of adjusting the cooling capacity of the terminal equipment and adjusting the cooling capacity of the secondary cooling capacity exchange station for regional centralized cooling, the server of the freezing station collects the water supply temperature values of the building cooling pipe network in the controllers of all the secondary cooling capacity exchange stations through the converter Tg, the opening value K of the water supply flow regulating valve on the primary side of the plate heat exchanger in the secondary cooling exchange station, and compare all Tg and K to obtain the minimum value of Tg Tg-min and the maximum value of K Kmax, Tg-min and Kmax The corresponding secondary cooling exchange station is the secondary cooling exchange station of the most unfavorable working point; (2) Temperature adjustment of the cooling outlet water of the freezing station: the server of the freezing station sends the Tg-min and Kmax values to the controller of the freezing station through the converter, and the controller of the freezing station takes Tg-min as the control target so that Kmax≤90% is Constraint conditions, through the analog output module to adjust the given value of the outlet water temperature of the refrigeration main engine, or adjust the frequency given by the frequency conversion circulating water pump of the ice storage system to adjust the water supply temperature value of the cooling pipe network in the ice water flow adjustment area, and realize the Tg-min follow-up control; (3) Determination of the minimum supply and return water pressure difference ΔPmin for cooling in the freezing station and adjustment of the water supply flow: the server of the freezing station sends water supply to the primary side of the plate heat exchanger of the secondary cooling exchange station to the controllers of all secondary cooling exchange stations through the converter Open the regulating valve to 100% mandatory command, and read the opening value of the water supply regulating valve on the primary side of the plate heat exchanger of all secondary cooling capacity exchange stations. After reaching 100%, read the q value of the water supply flow rate at the primary side of the plate heat exchanger in the secondary cooling exchange station and issue a pipe network flow adjustment command to the controller of the freezing station. The module adjusts the frequency and number of variable frequency water supply pumps for district cooling, so that the flow rate q of the primary side water supply of plate heat exchangers in all secondary cooling exchange stations reaches the design flow rate. At this time, the cooling supply and return water of the refrigeration station measured by the controller of the refrigeration station The pressure difference ΔP is the minimum supply and return water pressure difference ΔPmin. After obtaining ΔPmin, the server of the freezing station sends a signal to the controllers of all secondary cooling exchange stations through the converter. When the command is released to 100%, the controller of the refrigeration station takes ΔPmin as the set value of the pressure difference between the supply and return water, and adjusts the frequency and number of district cooling variable frequency water supply pumps through the analog output module and digital output module to keep ΔPmin constant and achieve Regulation of district cooling flow; (4) Dynamic identification of the most unfavorable secondary cooling exchange station: the server of the freezing station continuously collects the water supply temperature value Tg of the building cooling pipe network in the controller of all secondary cooling exchange stations through the converter, the plate type of the secondary cooling exchange station The opening value K of the water supply flow regulating valve on the primary side of the heat exchanger, and compare all Tg and K to obtain the current Tg minimum value Tg-min and K maximum value Kmax, and the secondary cooling capacity exchange station corresponding to Tg-min and Kmax It is the secondary cooling capacity exchange station at the most unfavorable working point at present. At this time, the freezing station is adjusted according to the above-mentioned step (2) of water supply temperature adjustment of the regional centralized cooling pipe network.

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