A control method and control system for cooling balance in a pipe network

Abstract

The present invention discloses a control method and control system for cooling balance in a pipe network, which adopts a method to meet the needs of the first unfavorable cooling user. First, the normal return water temperature range value of the user is preset; then, the return water temperature value and valve opening of each user are monitored; then, the first unfavorable cooling user is obtained, and when the user is monitored to have a maximum valve opening and a return water temperature value not within the preset normal return water temperature range value, it is determined to be the first unfavorable cooling user; the working frequency of the cooling water pump can be adjusted, and the cooling water pump can adjust the water supply again, or only the valve opening can be adjusted to adjust the water supply amount for different users; finally, it is ensured that the return water temperature value of each user is within the preset normal return water temperature value, and the pipe network enters a cooling balance state; this solves the problem in the prior art that a centralized cooling system generally uses a balancing valve for cooling balance control, resulting in poor cooling balance control effect caused by control disorder.

Description

Technical Field

[0001] The present invention belongs to the technical field of cooling control, and in particular relates to a control method and control system for cooling balance in a pipe network. Background Art

[0002] Pipeline cooling refers to the supply of cooling to individual buildings within the cooling area through a pipeline network. This involves a centralized cooling system, which generally includes a cooling source, a refrigeration station, a pipeline network, and end users. The working principle of a centralized cooling system is to use high-temperature, high-pressure hot water, originally used for centralized heating, as a cooling source. This is transported through a pipeline network to the refrigeration station, where it is used to power the chiller. The resulting low-temperature cold water is then transported to the end user, where it is blown out through fan coil units to meet their cooling needs. After heat exchange, the water returns to the refrigeration station through the pipeline network.

[0003] In addition, the current control method of the centralized cooling system is: (1) The cooling unit of the refrigeration station operates at a fixed water outlet temperature. The cooling unit of the refrigeration station calculates the temperature difference according to the return water temperature, and loads or reduces the supply according to the size of the temperature difference to control the supply of the cold source; (2) As disclosed in the patent for the automatic control method and control system for the centralized cooling system with application number 202111059836.5, the cold source is supplied according to the predicted cooling supply results.

[0004] To achieve cooling balance, most systems currently add pressure differential balancing valves to the pipe network. This involves monitoring the pressure values ​​of the pipes. When a pipe with a lower pressure value is detected, the valve opening can be adjusted accordingly, or a secondary pump can be controlled to operate, thereby achieving pressure balance. For example, the existing patent publication 201420543608.4 discloses a central air-conditioning multi-zone cooling capacity balance control device, comprising external sensors, a zone balance control cabinet, a zone balance regulating valve, and an intelligent control unit. The external sensors include pressure sensors, temperature sensors, humidity sensors, and flow sensors. The external sensors are installed on the zone loop of the central air-conditioning system. The output ends of the external sensors are connected to the zone balance control cabinet. The zone balance control cabinet is connected to a zone balance regulating valve via a pipe fitting. The zone balance regulating valve is installed on the return water pipe of the central air-conditioning zone loop. The control objective is to balance the cooling demand of each zone. By monitoring the actual cooling demand of each zone, the corresponding zone balance regulating valve is dynamically adjusted so that each zone obtains the required cooling capacity, achieving a dynamic energy balance and achieving energy saving.

[0005] However, the method using a balancing valve has a relatively complex control system and a design defect of control disorder, resulting in poor cooling balance control effect. Summary of the Invention

[0006] In order to solve the problem that the centralized cooling system in the prior art generally uses a balancing valve for cooling balance control, which leads to poor cooling balance control effect caused by control disorder, the present invention provides a simple and easy-to-implement pipe network cooling balance control method.

[0007] The technical solution of the present invention is:

[0008] The present invention provides a method for controlling cooling balance in a pipe network, which is applied to a centralized cooling system and includes the following steps:

[0009] S1. Preset the user's normal return water temperature range;

[0010] S2. Monitor the return water temperature and valve opening of each user;

[0011] S3. Obtaining unfavorable cooling users. When it is monitored that the valve opening of the current user is at the maximum value and the return water temperature is not within the normal return water temperature range, the current user is determined to be the first unfavorable cooling user. When it is monitored that the valve opening of the current user is not at the maximum value and the return water temperature is not within the normal return water temperature range, the current user is determined to be the second unfavorable cooling user. The remaining users are normal cooling users.

[0012] S4. When the presence of an unfavorable cooling user is detected, the valve opening of each current user is adjusted first, and the current return water temperature and valve opening of each user are continuously monitored. When no first unfavorable cooling user or second unfavorable cooling user appears, the cooling supply of the pipe network is balanced. If the presence of the first unfavorable cooling user and / or the second unfavorable cooling user is still detected after adjusting the valve opening of each current user, it is determined that the current operating frequency of the cooling water pump cannot meet the cooling demand of all current users, and step S5 is executed.

[0013] S5. Increase the cooling capacity of the cooling station's cooling water pump by increasing the operating frequency of the cooling water pump and continue to monitor the return water temperature of each user. If the return water temperature values ​​of each user are all within the normal return water temperature range, it indicates that the cooling network is balanced. Otherwise, return to step S4.

[0014] Furthermore, when executing step S4, adjusting the valve opening of each current user specifically includes the following sub-steps:

[0015] S41, presetting corresponding standard return water temperature values ​​according to the refrigeration temperature settable by the user, and forming a standard return water temperature value table corresponding to different refrigeration temperatures;

[0016] S42: Under the premise of ensuring that the return water temperature value of each user is within the normal return water temperature range, for each user,

[0017] If the current user's return water temperature is 0.6℃-1℃ lower than the standard return water temperature, the valve opening will be controlled to decrease gradually by 1% each time;

[0018] If the difference between the current user's return water temperature and the standard return water temperature is 0.1℃-0.5℃, the valve opening will remain unchanged;

[0019] If the current user's return water temperature is 0.6℃-1℃ higher than the standard return water temperature, the valve opening will be controlled to increase gradually by 1% each time.

[0020] If the current user's return water temperature is higher than the standard return water temperature by more than 5°C, the valve opening is controlled to gradually increase by 5% each time.

[0021] Furthermore, the method further includes step S6: for a fixed user group, the total load of each time period of the pipe network cooling supply on the day is recorded in units of hours, the cumulative total load of each time period of the pipe network cooling supply within a month, a quarter, or a year is calculated, and the average total load of each time period of the pipe network cooling supply is calculated;

[0022] Monitor the cooling sub-load of each user in each time period. If the total cooling sub-load of all users in the current time period is not equal to the average total cooling load of the pipe network in the current time period, adjust the valve opening of each user and ensure that the return water temperature of each user is within the normal return water temperature range.

[0023] Furthermore, it also includes step S7, formulating predicted pipeline cooling capacity data for each time period based on historically recorded pipeline cooling capacity data, monitoring the current pipeline cooling capacity data of the current time period, and if it is monitored that the current pipeline cooling capacity of the current time period is less than or equal to the corresponding predicted pipeline cooling capacity, preliminarily determining the current pipeline cooling balance, and if it is simultaneously monitored that there are unfavorable cooling users, executing step S4.

[0024] Furthermore, in step S4, when there are multiple second disadvantageous cooling users, the return water temperature values ​​of the second disadvantageous cooling users are prioritized from high to low, and the second disadvantageous cooling user with the highest priority has its valve opening increased first.

[0025] Furthermore, in step S5, while increasing the operating frequency of the cooling water pump, the valve opening of the first unfavorable cooling user is preferably kept at the maximum; when it is monitored that the return water temperature of the first unfavorable cooling user is within the normal return water temperature range, the valve opening of the second unfavorable cooling user is increased one by one in order of priority until the return water temperature of each first unfavorable cooling user and the second unfavorable cooling user is within the normal return water temperature range; at the same time, the valve opening of the normal cooling user is adjusted synchronously, and the valve opening of the normal cooling user is gradually reduced while ensuring that the return water temperature of the normal cooling user is within the normal return water temperature range.

[0026] Furthermore, in step S6,

[0027] When it is monitored that the total amount of the cooling sub-loads in the current time period is greater than the calculated average value of the total cooling load of the pipe network in the current time period and there are unfavorable cooling users, step S4 is preferentially executed;

[0028] When it is monitored that the total amount of cooling sub-loads in the current time period is less than the calculated average of the total cooling load of the pipe network in the current time period and there are no unfavorable cooling users, the valve opening of each user is reduced, while ensuring that the return water temperature of each user is within the normal return water temperature range;

[0029] When it is monitored that the total amount of the cooling sub-loads in the current time period is equal to the calculated average value of the total cooling load of the pipe network in the current time period, the adjustment of the valve opening of each user is stopped.

[0030] Furthermore, in step S1, the normal return water temperature range of the user is preset to be 10°C-13°C.

[0031] The present invention also provides a pipe network cooling balance control system for executing the above-mentioned pipe network cooling balance control method, comprising a monitoring unit, a data processing unit and a control terminal.

[0032] The monitoring unit is used to obtain user cooling data, specifically including temperature data, load data, cooling capacity data, and valve opening data, and transmit the obtained cooling data of each user to the data processing unit;

[0033] The data processing unit is used to obtain the data obtained by the monitoring unit, perform data processing, and transmit the processed data to the control terminal;

[0034] The control terminal is used to control the opening of each user valve and the operation of the cooling water pump according to the data processed by the data processing unit.

[0035] Furthermore, the monitoring unit includes a temperature monitoring module, a load monitoring module, a flow monitoring module and a valve opening monitoring module; the temperature monitoring module is used to obtain the return water temperature data of each user, the load monitoring module is used to obtain the load data of each user in each time period, the flow monitoring module is used to obtain the total cooling capacity data of the current pipe network and the cooling capacity data of each user, and the valve opening monitoring module is used to obtain the valve opening data of each user;

[0036] The data processing unit includes a calculation module, which is used to calculate and count the cumulative total load of each user or all users in each time period of the pipe network cooling supply within a preset time, and calculate the average total load of each time period of the pipe network cooling supply, and / or calculate the total amount of cooling sub-loads in the current time period;

[0037] The control terminal includes a storage module, a judgment module and a control module. The storage module receives and stores data sent by the monitoring unit and the data processing unit, and is used to store the normal return water temperature range value of the preset user, the standard return water temperature value table under different refrigeration temperatures, the valve opening adjustment table, the total load average of each time period of the pipe network cooling supply, and the predicted pipe network cooling capacity data for each time period;

[0038] The judgment module is used to compare the cooling data of each user obtained by the monitoring unit or the data calculated by the data processing unit with the data stored in the corresponding storage module, and obtain a comparison result;

[0039] The control module is used to send corresponding control instructions to the valve control equipment and / or water pump control equipment of each user according to the comparison result of the judgment module.

[0040] The beneficial effects of the present invention are: a method that satisfies the first unfavorable cooling user is adopted instead of a pressure difference balancing method, first, a normal return water temperature range value of the user is preset; then, the return water temperature value and valve opening of each user are monitored; then, the first unfavorable cooling user is obtained, and when a user is monitored to have a maximum valve opening and a return water temperature value that is not within the preset normal return water temperature range value, it is judged as the first unfavorable cooling user; the operating frequency of the cooling water pump can be adjusted, and the cooling water pump can adjust the water supply again, or only the valve opening can be adjusted to adjust the water supply amount for different users; finally, it is ensured that the return water temperature value of each user is within the preset normal return water temperature value, and the pipe network enters a cooling balance state; there is no need to frequently control the operation of the cooling water pump according to the pipeline pressure value, and a simple and quick method is used to solve the problem that the cooling balance control method in the prior art that a balancing valve is commonly used in a centralized cooling system leads to poor cooling balance control effect caused by control disorder. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1This is a flow chart of a method for controlling cooling balance in a pipe network according to the present invention;

[0042] Figure 2 This is a connection block diagram of a control system for cooling balance in a pipe network according to the present invention;

[0043] Figure 3 This is a diagram showing the connection between the central cooling system and each user.

[0044] Reference numerals: 1. regulating valve, 2. temperature sensor, 3. cooling water pump. DETAILED DESCRIPTION

[0045] The technical solutions in the embodiments of the present invention will be described clearly and completely below with reference to the accompanying drawings of the present invention.

[0046] Please refer to Figure 1 The present invention provides a method for controlling cooling balance in a pipe network, which is applied to a centralized cooling system and does not require a balancing valve, and includes the following steps:

[0047] S1, preset the user's normal return water temperature range is 10℃-13℃;

[0048] S2. Monitor the return water temperature and valve opening of each user;

[0049] S3. Obtaining unfavorable cooling users. When it is monitored that the valve opening of the current user is at the maximum value and the return water temperature is not within the normal return water temperature range, the current user is determined to be the first unfavorable cooling user. When it is monitored that the valve opening of the current user is not at the maximum value and the return water temperature is not within the normal return water temperature range, the current user is determined to be the second unfavorable cooling user. The remaining users are normal cooling users.

[0050] When there is a first disadvantageous cooling user or a second disadvantageous cooling user, there are two different situations: the first situation is: the current cooling capacity of the pipe network is greater than the actual cooling demand; the second situation is: the current cooling capacity of the pipe network is less than the actual cooling demand. When the current cooling capacity of the pipe network is greater than the actual cooling demand, it proves that the current cooling capacity is sufficient, and the valve opening of each user can be directly adjusted to meet the first disadvantageous cooling user, that is, enter step S4;

[0051] S4. When the presence of an unfavorable cooling user is detected, the valve opening of each current user is adjusted first. The actual operation is: the valve opening of all users except the first unfavorable cooling user is reduced to deliver more cooling source to the first unfavorable cooling user, and the current return water temperature and valve opening of each user are continuously monitored. When the first unfavorable cooling user or the second unfavorable cooling user does not appear, the cooling supply of the pipe network is balanced. If the first unfavorable cooling user and / or the second unfavorable cooling user is still detected after the valve opening of each current user is adjusted, it is confirmed that the current operating frequency of the cooling water pump cannot meet the cooling demand of all current users, and step S5 is executed.

[0052] S5. Increase the cooling capacity of the cooling station cooling water pump by increasing the operating frequency of the cooling water pump and continue to monitor the return water temperature of each user. If the return water temperature of each user is within the normal return water temperature range, it indicates that the cooling network is balanced. Otherwise, return to step S4.

[0053] Furthermore, when executing step S4, the valve opening of each current user is adjusted, specifically including the following sub-steps, in order to prevent the valve from overworking and reducing the life of the valve:

[0054] S41, presetting corresponding standard return water temperature values ​​according to the refrigeration temperature settable by the user, and forming a standard return water temperature value table corresponding to different refrigeration temperatures;

[0055] S42: Under the premise of ensuring that the return water temperature value of each user is within the normal return water temperature range, for each user,

[0056] If the current user's return water temperature is 0.6℃-1℃ lower than the standard return water temperature, the valve opening will be controlled to decrease gradually by 1% each time;

[0057] If the difference between the current user's return water temperature and the standard return water temperature is 0.1℃-0.5℃, the valve opening will remain unchanged;

[0058] If the current user's return water temperature is 0.6℃-1℃ higher than the standard return water temperature, the valve opening will be controlled to increase gradually by 1% each time.

[0059] If the current user's return water temperature is higher than the standard return water temperature by more than 5°C, the valve opening is controlled to gradually increase by 5% each time.

[0060] For example, if the current user's standard return water temperature is preset to 11°C, when the user's current return water temperature is 10.5°C-10.9°C or 11.1°C-11.5°C, the valve opening does not need to be adjusted; when the user's current return water temperature is 10°C-10.4°C, the valve opening is gradually reduced by 1% each time, while ensuring that the user's current return water temperature is within the normal return water temperature range; when the user's current return water temperature is 11.6°C-12°C, the valve opening is gradually increased by 1% each time, while ensuring that the user's current return water temperature is within the normal return water temperature range; when the user's current return water temperature is 16°C, the valve opening is gradually increased by 5% each time, while ensuring that the user's current return water temperature is within the normal return water temperature range.

[0061] In addition, if during the valve adjustment process the user's current return water temperature value is not within the user's normal return water temperature range, the valve opening will be increased or decreased by 1% each time according to whether the current return water temperature value is higher or lower than the normal return water temperature range, that is, the valve opening will be adjusted back to the normal return water temperature in a small amount.

[0062] When the current return water temperature values ​​of each user are within the preset normal return water temperature range, the valve adjustment can be stopped.

[0063] In step S4, when there are multiple second disadvantageous cooling users, the return water temperatures of the second disadvantageous cooling users are prioritized from high to low, and the valve opening of the second disadvantageous cooling user with the highest priority is increased first.

[0064] In step S5, while increasing the operating frequency of the cooling water pump, the valve opening of the first disadvantageous cooling user is kept at the maximum. When it is monitored that the return water temperature of the first disadvantageous cooling user is within the normal return water temperature range, the valve opening of the second disadvantageous cooling user is increased one by one in the order of priority until the return water temperature of each of the first disadvantageous cooling user and the second disadvantageous cooling user is within the normal return water temperature range. At the same time, the valve opening of the normal cooling user is adjusted synchronously. On the premise of ensuring that the return water temperature of the normal cooling user is within the normal return water temperature range, the valve opening of the normal cooling user is gradually reduced.

[0065] Specifically, when there are two second unfavorable cooling users, the return water temperature of one second unfavorable cooling user is 16°C, and the return water temperature of the other second unfavorable cooling user is 14°C;

[0066] There are two situations: (1) The current cooling capacity is not less than the actual cooling capacity required, and the cooling water pump does not need to be used for secondary water supply: when adjusting the valve opening, first adjust the valve opening of the second unfavorable cooling user with a return water temperature of 16°C to the original 95% opening, and adjust the valve opening of the second unfavorable cooling user with a return water temperature of 14°C to 80%, and the valve openings of the remaining users are also reduced. When the second unfavorable cooling user with a return water temperature of 16°C receives more water, the return water temperature is reduced to the normal return water temperature range; then increase the valve opening of the second unfavorable cooling user with a return water temperature of 14°C, and continue to reduce the valve openings of the remaining users. When the second unfavorable cooling user with a return water temperature of 14°C also receives more water, the return water temperature is reduced to the normal return water temperature range, and the return water temperatures of the remaining users are all within the normal return water temperature range, that is, the cooling balance is achieved;

[0067] (2) The current cooling capacity is less than the actual cooling capacity required, and the cooling water pump is required to deliver the secondary water source: when adjusting the valve opening, first adjust the valve opening of the second unfavorable cooling user with a return water temperature of 16°C to the original 95% opening, and adjust the valve opening of the second unfavorable cooling user with a return water temperature of 14°C to 80%, and the valve openings of the remaining users are also reduced. When the second unfavorable cooling user with a return water temperature of 16°C receives more water, the return water temperature is reduced to the normal return water temperature range; if the second unfavorable cooling user with a return water temperature of 14°C receives enough water at the same time, the return water temperature is reduced to the normal return water temperature range, and the return water temperatures of the remaining users are all within the normal return water temperature range, that is, the cooling balance is achieved;

[0068] This method does not require adjusting the cooling water pump according to the pressure data of the water pipe. Instead, it finds out the unfavorable cooling users through temperature monitoring and valve opening monitoring, solves the problem of unfavorable cooling users, and achieves cooling balance. Therefore, it is necessary to design each valve to automatically control the opening size of the regulating valve according to the cold water volume provided by the cooling water pump and its return water temperature, so as to ensure that while meeting the needs of unfavorable cooling users, the return water temperature of other users is not affected. The regulating valve replaces the balancing valve, and there is no need to frequently control the operation of the cooling water pump according to the pipeline pressure value, which also reduces the resistance of the pipeline network.

[0069] Furthermore, after achieving cooling balance, cooling can be further optimized to implement energy-saving and automated cooling. The cooling load mentioned below refers to the power consumed by the centralized cooling system when it is in operation. Assuming that users in a building only use air conditioning, since the cooling of each building has its own daily routine, if it is a residential building, there are many people going to work during the day, so there are relatively fewer users who need cooling during the day, entering a period of low load. If it is an office building, after get off work in the evening, the company turns off the cooling, also entering a period of low load.

[0070] S6. For a fixed user group, the total load of the cooling network in each time period on the day of the cooling network is recorded in hourly units, and the cumulative total load of the cooling network in each time period within a month, a quarter, or a year is calculated, and the average total load of the cooling network in each time period is calculated;

[0071] Monitor the cooling sub-load of each user in each time period. If the total cooling sub-load of all users in the current time period is not equal to the average total cooling load of the pipe network in the current time period, adjust the valve opening of each user and ensure that the return water temperature of each user is within the normal return water temperature range.

[0072] Specifically, the cooling sub-load of each user in each time period can be read from a cooling capacity meter installed on each user.

[0073] When it is monitored that the total amount of the cooling sub-loads in the current time period is greater than the calculated average value of the total cooling load of the pipe network in the current time period and there are unfavorable cooling users, step S4 is preferentially executed;

[0074] When it is monitored that the total amount of cooling sub-loads in the current time period is less than the calculated average of the total cooling load of the pipe network in the current time period and there are no unfavorable cooling users, the valve opening of each user is reduced, while ensuring that the return water temperature of each user is within the normal return water temperature range;

[0075] When it is monitored that the total amount of the cooling sub-loads in the previous time period is equal to the calculated average value of the total cooling load of the pipe network in the current time period, the adjustment of the valve opening of each user is stopped.

[0076] While achieving cooling balance, another way to achieve energy-saving cooling is:

[0077] S7. Based on the historically recorded cooling capacity data of the pipe network, the predicted cooling capacity data of the pipe network is formulated for each time period, and the current cooling capacity data of the pipe network in the current time period is monitored. If it is monitored that the current cooling capacity of the pipe network in the current time period is less than or equal to the corresponding predicted cooling capacity of the pipe network, a preliminary determination is made on the current cooling balance of the pipe network. If it is simultaneously monitored that there are unfavorable cooling users, step S4 is executed.

[0078] The above-mentioned monitoring cooling capacity data refers to the amount of water delivered by the cooling water pump, and the data can be read through a flow meter.

[0079] The user return water mentioned above refers to the water source after heat exchange. Under normal circumstances, when the outlet water temperature of the refrigeration station is 7°C, the temperature after heat exchange by the heat exchanger is 11°C; therefore, the normal return water temperature range can be set to 10°C-13°C; the above-mentioned valve opening value is 0%-100%. The smaller the valve opening, the relatively smaller the water flow in the pipeline; the larger the valve opening, the relatively larger the water flow in the pipeline.

[0080] Reference Figure 2 The present invention also provides a pipe network cooling balance control system for executing the above-mentioned pipe network cooling balance control method, comprising a monitoring unit, a data processing unit and a control terminal.

[0081] The monitoring unit is used to obtain user cooling data, specifically including temperature data, load data, cooling capacity data, and valve opening data, and transmit the obtained cooling data of each user to the data processing unit;

[0082] The data processing unit is used to obtain the data obtained by the monitoring unit, perform data processing, and transmit the processed data to the control terminal;

[0083] The control terminal is used to control the opening of each user valve and the operation of the cooling water pump according to the data processed by the data processing unit.

[0084] Furthermore, the monitoring unit includes a temperature monitoring module, a load monitoring module, a flow monitoring module and a valve opening monitoring module. The temperature monitoring module is used to obtain the return water temperature data of each user, the load monitoring module is used to obtain the load data of each user in each time period, the flow monitoring module is used to obtain the total cooling capacity data of the current pipe network and the cooling capacity data of each user, and the valve opening monitoring module is used to obtain the valve opening data of each user;

[0085] The data processing unit includes a calculation module, which is used to calculate and count the cumulative total load of each user or all users in each time period of the pipe network cooling supply within a preset time, and calculate the average total load of each time period of the pipe network cooling supply, and / or calculate the total amount of cooling sub-loads in the current time period;

[0086] The control terminal includes a storage module, a judgment module and a control module. The storage module receives and stores data sent by the monitoring unit and the data processing unit, and is used to store the normal return water temperature range value of the preset user, the standard return water temperature value table under different refrigeration temperatures, the valve opening adjustment table, the total load average of each time period of the pipe network cooling supply, and the predicted pipe network cooling capacity data for each time period;

[0087] The judgment module is used to compare the cooling data of each user obtained by the monitoring unit or the data calculated by the data processing unit with the data stored in the corresponding storage module, and obtain a comparison result;

[0088] The control module is used to send corresponding control instructions to the valve control device and / or water pump control device of each user based on the comparison results of the judgment module. For example, if a comparison result is received indicating that a first unfavorable cooling user exists, the control module proceeds to step S4 to preferably adjust the valve opening of each user, and then continues to monitor the return water temperature. If a comparison result is received again indicating that a first unfavorable cooling user still exists, the control module proceeds to step S5 to control the operating frequency of the cooling water pump, increase the water supply flow of the cooling water pump, and then continue to monitor the return water temperature. When the return water temperature is normal, the control module enters the cooling balance state. After the cooling balance is reached, the control module further receives cooling load data and actual cooling capacity data. Under the premise of ensuring cooling balance, the control module controls the valve opening to a more reasonable state, further achieving energy-saving cooling.

[0089] Specifically, refer to Figure 3 , a connection relationship diagram between the centralized cooling system and each user, including each user regulating valve 1, each user temperature sensor 2, and a cooling water pump 3. The control system for the cooling balance of the pipe network is communicatively connected to the user regulating valve 1, each user temperature sensor 2, and the cooling water pump 3. The user regulating valve 1 and each user temperature sensor 2 are respectively connected to the user heat exchanger. Each user heat exchanger includes a water inlet and a water outlet. The user regulating valve 1 is provided at the water inlet of the user heat exchanger. The user temperature sensor 2 is provided at the water outlet of the user heat exchanger. One end of the cooling water pump 3 is connected to the user regulating valve 1, and the other end of the cooling water pump 3 is connected to the refrigeration station.

[0090] Specifically, the hardware equipment also includes: a valve opening monitor, a user cooling meter and a flow meter for the cooling water pump. The valve opening monitor collects and monitors the valve opening in real time, reads the cooling load data according to the user cooling meter, and reads the cooling capacity data according to the flow meter. In addition, the valve openings expressed above are all the openings of the regulating valves. Among them, the temperature monitoring module is electrically connected to the temperature sensor 2 of each user, the load monitoring module is connected to the user cooling meter, the flow monitoring module is connected to the flow meter, and the valve opening monitoring module is connected to the valve opening monitor.

[0091] The above-described embodiment merely represents one embodiment of the present invention. While the description is relatively specific and detailed, it should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art may make various modifications and improvements without departing from the spirit of the present invention, and these modifications and improvements fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims.

Claims

1. A method for controlling cooling balance in a pipe network, applied to a centralized cooling system, characterized in that: The following steps are involved: S1. Preset the user's normal return water temperature range; S2. Monitor the return water temperature and valve opening of each user; S3. Obtaining unfavorable cooling users. When it is monitored that the valve opening of the current user is at the maximum value and the return water temperature is not within the normal return water temperature range, the current user is determined to be the first unfavorable cooling user. When it is monitored that the valve opening of the current user is not at the maximum value and the return water temperature is not within the normal return water temperature range, the current user is determined to be the second unfavorable cooling user. The remaining users are normal cooling users. S4. When the presence of an unfavorable cooling user is detected, the valve opening of each current user is adjusted first, and the current return water temperature and valve opening of each user are continuously monitored. When no first unfavorable cooling user or second unfavorable cooling user appears, the cooling supply of the pipe network is balanced. If the presence of the first unfavorable cooling user and / or the second unfavorable cooling user is still detected after adjusting the valve opening of each current user, it is determined that the current operating frequency of the cooling water pump cannot meet the cooling demand of all current users, and step S5 is executed. S41, presetting corresponding standard return water temperature values ​​according to the refrigeration temperature settable by the user, and forming a standard return water temperature value table corresponding to different refrigeration temperatures; S42: Under the premise of ensuring that the return water temperature value of each user is within the normal return water temperature range, for each user, If the current user's return water temperature is 0.6℃-1℃ lower than the standard return water temperature, the valve opening will be controlled to decrease gradually by 1% each time; If the difference between the current user's return water temperature and the standard return water temperature is 0.1℃-0.5℃, the valve opening will remain unchanged; If the current user's return water temperature is 0.6℃-1℃ higher than the standard return water temperature, the valve opening will be controlled to increase gradually by 1% each time. If the current user's return water temperature is 5°C higher than the standard return water temperature, the valve opening will be controlled to increase gradually by 5% each time. S5. Increase the cooling capacity of the cooling station's cooling water pump by increasing the operating frequency of the cooling water pump and continue to monitor the return water temperature of each user. If the return water temperature values ​​of each user are all within the normal return water temperature range, it indicates that the cooling network is balanced. Otherwise, return to step S4.

2. The method for controlling cooling balance in a pipe network according to claim 1, characterized in that: The method further includes step S6: for a fixed user group, the total load of each time period of the cooling pipe network on the day is recorded in units of hours, the cumulative total load of each time period of the cooling pipe network within a month, a quarter, or a year is calculated, and the average total load of each time period of the cooling pipe network is calculated; Monitor the cooling sub-load of each user in each time period. If the total cooling sub-load of all users in the current time period is not equal to the average total cooling load of the pipe network in the current time period, adjust the valve opening of each user and ensure that the return water temperature of each user is within the normal return water temperature range.

3. The method for controlling cooling balance in a pipe network according to claim 1, characterized in that: It also includes step S7, formulating predicted pipe network cooling capacity data for each time period based on historically recorded pipe network cooling capacity data, monitoring the current pipe network cooling capacity data of the current time period, and if it is monitored that the current pipe network cooling capacity of the current time period is less than or equal to the corresponding predicted pipe network cooling capacity, preliminarily determining the current pipe network cooling balance, and if it is simultaneously monitored that there are unfavorable cooling users, executing step S4.

4. The method for controlling cooling balance in a pipe network according to claim 1, characterized in that: In step S4, when there are multiple second disadvantageous cooling users, the return water temperatures of the second disadvantageous cooling users are prioritized from high to low, and the valve opening of the second disadvantageous cooling user with the highest priority is increased first.

5. The method for controlling cooling balance in a pipe network according to claim 4, characterized in that: In step S5, while increasing the operating frequency of the cooling water pump, the valve opening of the first disadvantageous cooling user is kept at the maximum. When it is monitored that the return water temperature of the first disadvantageous cooling user is within the normal return water temperature range, the valve opening of the second disadvantageous cooling user is increased one by one in the order of priority until the return water temperature of each of the first disadvantageous cooling user and the second disadvantageous cooling user is within the normal return water temperature range. At the same time, the valve opening of the normal cooling user is adjusted synchronously. On the premise of ensuring that the return water temperature of the normal cooling user is within the normal return water temperature range, the valve opening of the normal cooling user is gradually reduced.

6. The method for controlling cooling balance in a pipe network according to claim 2, characterized in that: In step S6, When it is monitored that the total amount of the cooling sub-loads in the current time period is greater than the calculated average value of the total cooling load of the pipe network in the current time period and there are unfavorable cooling users, step S4 is preferentially executed; When it is monitored that the total amount of cooling sub-loads in the current time period is less than the calculated average of the total cooling load of the pipe network in the current time period and there are no unfavorable cooling users, the valve opening of each user is reduced, while ensuring that the return water temperature of each user is within the normal return water temperature range; When it is monitored that the total amount of the cooling sub-loads in the current time period is equal to the calculated average value of the total cooling load of the pipe network in the current time period, the adjustment of the valve opening of each user is stopped.

7. The method for controlling cooling balance in a pipe network according to claim 1, characterized in that: In step S1, the normal return water temperature range of the user is preset to be 10°C-13°C.

8. A pipe network cooling balance control system for executing the pipe network cooling balance control method according to any one of claims 1 to 7, characterized in that: Including monitoring unit, data processing unit and control terminal, The monitoring unit is used to obtain user cooling data, specifically including temperature data, load data, cooling capacity data, and valve opening data, and transmit the obtained cooling data of each user to the data processing unit; The data processing unit is used to obtain the data obtained by the monitoring unit, perform data processing, and transmit the processed data to the control terminal; The control terminal is used to control the opening of each user valve and the operation of the cooling water pump according to the data processed by the data processing unit.

9. The control system for cooling balance in a pipe network according to claim 8, characterized in that: The monitoring unit includes a temperature monitoring module, a load monitoring module, a flow monitoring module and a valve opening monitoring module. The temperature monitoring module is used to obtain the return water temperature data of each user, the load monitoring module is used to obtain the load data of each user in each time period, the flow monitoring module is used to obtain the total cooling capacity data of the current pipe network and the cooling capacity data of each user, and the valve opening monitoring module is used to obtain the valve opening data of each user; The data processing unit includes a calculation module, which is used to calculate and count the cumulative total load of each user or all users in each time period of the pipe network cooling supply within a preset time, and calculate the average total load of each time period of the pipe network cooling supply, and / or calculate the total amount of cooling sub-loads in the current time period; The control terminal includes a storage module, a judgment module and a control module. The storage module receives and stores data sent by the monitoring unit and the data processing unit, and is used to store the normal return water temperature range value of the preset user, the standard return water temperature value table under different refrigeration temperatures, the valve opening adjustment table, the total load average of each time period of the pipe network cooling supply, and the predicted pipe network cooling capacity data for each time period; The judgment module is used to compare the cooling data of each user obtained by the monitoring unit or the data calculated by the data processing unit with the data stored in the corresponding storage module, and obtain a comparison result; The control module is used to send corresponding control instructions to the valve control equipment and / or water pump control equipment of each user according to the comparison result of the judgment module.

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