Automatic shunting method and device for circulating liquid of cooling-water machine

Abstract

The invention discloses an automatic flow dividing method and device for circulating liquid of a cooling-water machine, and solves the problems of high energy consumption, large occupied space and inconvenience in operation due to the fact that an existing cooling-water machine is independently provided with control equipment. The method comprises the steps that the device is started, and each branch pipe valve is set as initial flow; temperature differences of circulating liquid of all branch pipes are obtained, and candidate flow is distributed to all branch pipe valves according to the temperature differences; based on the total flow analysis, the candidate flow is adjusted, and the target flow of each branch pipe valve is set; and each branch pipe valve is controlled to operate at the target flow. One cooling-water machine is divided into a plurality of devices to work, temperature control devices do not need to be independently configured for the devices, cost is greatly reduced, installation of the temperature control devices is reduced, and space and energy are saved. And different flow setting of each branch pipe is realized through control, so that the control precision and the operation convenience are improved. Differentiation setting is carried out on the branch flow according to the cooling requirement degree of the equipment, optimal configuration of flow resources is achieved, and the cooling requirement of the equipment is better met.

Description

Technical Field

[0001] The invention relates to the technical field of refrigeration, and in particular to a method and a device for automatically dividing circulating fluid of a chiller. Background Art

[0002] Chillers are equipment widely used in industrial production, medical and health care, building air conditioning and other fields. Their main function is to provide precise and stable temperature control.

[0003] The traditional method of using chillers is "one-to-one", that is, one chiller controls the temperature of one load. This method has the following main disadvantages: 1. High energy consumption; 2. It takes up a large space. In industrial-intensive places, each load equipment must be equipped with a chiller, which greatly increases energy consumption and also occupies a large space; 3. It is inconvenient to operate. Some chillers do not have flow control devices at the outflow end of the circulating fluid. When setting or adjusting the flow, such models can only use manual adjustment with a hand valve. On the one hand, the accuracy of manual adjustment is poor, and on the other hand, it is inconvenient to operate in a narrow space. Summary of the invention

[0004] The present invention mainly solves the problems that the existing chiller is equipped with a separate control device, has high energy consumption, occupies a large space and is inconvenient to operate, and provides a method and device for automatically diverting circulating fluid of a chiller.

[0005] The present invention also solves the problem that the cooling demand of the equipment is not taken into consideration in the flow diversion control of the chiller, resulting in unbalanced flow distribution and waste of resources, and provides a method and device for automatically diverting the circulating fluid of a chiller.

[0006] The above technical problem of the present invention is mainly solved by the following technical solution: A method for automatically diverting circulating fluid of a chiller, characterized in that it comprises the following steps: Start the device and set each branch valve to the initial flow rate; Obtain the temperature difference of the circulating fluid in each branch pipe, and allocate candidate flow rates to each branch valve according to the temperature difference; Based on the total flow analysis, the candidate flow is adjusted and the target flow of each branch valve is set; Control each branch valve to operate at the target flow rate.

[0007] The present invention realizes the diversion of one chiller to multiple devices, and there is no need to configure a temperature control device for each device separately, which greatly reduces the cost, reduces the installation of temperature control devices, and saves space and energy. Different flow settings for each branch can be achieved through control, which greatly improves the control accuracy and operational convenience. Differentiated settings are made for the branch flow according to the cooling requirements of the equipment, and resource optimization configuration is achieved while the overall total flow remains unchanged, better meeting the cooling requirements of the equipment. The branch flow can be independently controlled, which greatly improves the scope of use of traditional chillers.

[0008] In the device using diversion, although a branch valve is provided to control the flow of the branch, the flow is generally simply set, and the flow is not optimized and distributed according to the cooling demand of the equipment, resulting in a branch flow that cannot meet the cooling demand of the equipment, and in setting the flow of each branch, the sum of the flow of each branch is less than the main flow, which causes waste in the allocation of flow resources. In addition, other branch flows are not comprehensively considered when setting the branch flow. For example, a higher flow is set for a branch, so that the total flow is greater than the main flow. Not only does the flow fail to be achieved, but it also affects other branches and causes diversion, thereby affecting the cooling operation of other branch equipment. The present invention differentiates the branch flow according to the cooling demand of the equipment, realizes resource optimization allocation when the overall total flow remains unchanged, and better meets the cooling demand of the equipment.

[0009] As a preferred solution, the method of setting each branch valve to an initial flow rate includes: Get the number of branches, calculate the average flow of each branch according to the total flow of the main pipe, use the average flow as the initial flow, and control each branch valve to operate at the initial flow.

[0010] Before the branch valves are differentiated for flow distribution, the present invention needs to detect the cooling demand of each device, then calculate the average flow according to the number of branches, and operate each branch valve at the same initial flow to obtain the cooling demand of the equipment on each branch valve.

[0011] As a preferred solution, the circulating fluid temperature at the input end of the branch connection device and the circulating fluid temperature at the output end are obtained, and the temperature difference of the branch circulating fluid is obtained by subtracting the circulating fluid temperature at the output end from the circulating fluid temperature at the input end.

[0012] The corresponding equipment is connected to the branch pipe, and the circulating fluid is input into the equipment for cooling and then output. By calculating the temperature difference between the input and output of the circulating fluid, the cooling demand of the equipment can be reflected. When the temperature difference is large, it means that the equipment needs a larger flow input for cooling.

[0013] As a preferred solution, candidate flow rates are allocated to each branch valve according to the temperature difference, including: Set the temperature difference threshold, and compare the temperature difference of each branch circulating fluid with the temperature difference threshold. If the temperature difference exceeds the temperature difference threshold, the corresponding branch valve is assigned the first flow rate. If the temperature difference is less than the temperature threshold, the corresponding branch valve is assigned the second flow rate. The allocated first flow rate and second flow rate are candidate flow rates of each branch valve.

[0014] This solution sets a temperature difference threshold. For the temperature range exceeding the temperature difference threshold, the first flow rate corresponds to the temperature range below the temperature difference threshold, and for the temperature range below the temperature difference threshold, the second flow rate corresponds to the temperature range below the temperature difference threshold. The first flow rate must be greater than the second flow rate. When the temperature difference exceeds the threshold, it means that the equipment has a large cooling demand and requires a larger flow rate. If it is below the threshold, it means that the equipment has a small cooling demand or has not yet reached the change, and the circulating fluid is input at a relatively small flow rate. This solution initially divides the equipment cooling demand into two parts based on the temperature difference threshold. Based on the fact that specific equipment or a small number of equipment have a high cooling demand in reality, more flow needs to be allocated to a small number of equipment. In addition, considering the problem of smaller flow after diversion, the number of branches should not be too many. Generally, 3 to 4 branches are set for diversion. Therefore, the temperature difference threshold is set larger, and there are generally only 1 to 2 branches that meet the temperature difference threshold, and in some cases, the temperature difference threshold is not exceeded.

[0015] As a preferred solution, a first distribution quantity of the first flow and a second distribution quantity of the second flow are set, and the sum of the first flow of the first distribution quantity and the second flow of the second distribution quantity is equal to the main pipe flow.

[0016] This solution is based on the fact that the main pipe flow remains unchanged and the sum of the branch flow is equal to the main pipe flow. The number of branch valves allocated to the first flow is set as the first allocation number, and the number of branch valves allocated to the second flow is set as the second allocation number. The sum of the first flow of the first allocation number and the sum of the second flow of the second allocation number is equal to the main pipe flow. This allocation makes the sum of the flow of each branch equal to the main pipe flow, making full use of the main pipe flow resources. The setting of the allocation number is based on conventional situations. For example, if only one device has a high cooling demand, the branch is allocated to the first flow, and the others are allocated to the second flow. When the candidate flow is preliminarily allocated to each branch valve according to the temperature difference, there will be some differences from the set first flow and second flow allocation numbers. It is necessary to adjust according to the situation to optimize the flow allocated to each branch valve.

[0017] As a preferred solution, the subsequent flow rate is adjusted to set the target flow rate of each branch valve, including: Compare the candidate flow of the allocated branch valve with the set allocable flow of the branch valve. When the set first allocation quantity and the second allocation quantity are the same as the allocated first flow quantity and the second flow quantity, the allocated candidate flow is used as the target flow of each branch valve; When there is an allocated second flow rate and there is no allocated first flow rate, the allocated candidate flow rate is used as the target flow rate of each branch valve.

[0018] When the allocated flow rate is the same as the set flow rate, no adjustment is made, and the allocated candidate flow rate is used as the target flow rate of each corresponding branch valve.

[0019] When there is only the allocated second flow rate but no allocated first flow rate, the total allocated second flow rate is less than the main pipe flow rate, so no adjustment is made and the allocated candidate flow rate is used as the target flow rate of each branch valve.

[0020] As a preferred solution, the candidate flow rate of the allocated branch valve is compared with the set allocable flow rate of the branch valve. When the allocated first flow quantity is greater than the set first allocated quantity and there is an allocated second flow, the average flow of the allocated remaining flow is calculated, the average flow is used as the target flow of the corresponding branch valve, the allocated second flow is used as the target flow of the corresponding branch valve, and the allocated remaining flow is the difference between the main pipe flow and the sum of the allocated second flows.

[0021] In this solution, when the allocated first flow quantity is greater than the set first flow first allocation quantity, and there is an allocated second flow, and the sum of the allocated first flow and the second flow is greater than the main pipe flow, the allocated second flow is used as the target flow of the corresponding branch valve, and the remaining allocated flow except the second flow is averaged according to the allocated first flow quantity, and the average flow obtained is the target flow of the branch valve corresponding to the allocated first flow. Here, the allocated remaining flow is averaged, and the branch valves corresponding to each allocated first flow are evenly allocated flow to prevent the allocated flow from being less than the second flow and failing to match the cooling requirements of the equipment.

[0022] As a preferred solution, the candidate flow rate of the allocated branch valve is compared with the set allocable flow rate of the branch valve. When there is a distributed first flow rate and there is no distributed second flow rate, the proportional flow rate is calculated in proportion to the temperature difference of the circulating fluid in each branch pipe, and the proportional flow rate is used as the target flow rate of the corresponding branch pipe valve.

[0023] This scheme is the case where all the first candidate flows are allocated. At this time, all the equipment in charge have a large cooling demand, and the sum of the allocated first flows must be greater than the main pipe flow. The proportion of the temperature difference of the circulating fluid in each branch is calculated, and then the proportional flow of each corresponding branch valve is calculated according to the proportion of the main pipe flow. The proportional flow is used as the target flow of each branch valve.

[0024] A chiller circulating fluid automatic diversion device comprises a chiller and a control module, wherein the chiller output end is connected to a diverter through a main pipe, each output end of the diverter is connected to equipment through a branch pipe, and the equipment output end is commonly connected to the chiller input end, a first temperature sensor, a pressure sensor, a flow sensor, and a branch valve are arranged on the branch pipe at each equipment input end, and a second temperature sensor is arranged on the branch pipe at the equipment output end. The control module obtains the temperature difference of the circulating fluid in each branch, allocates candidate flow rates to each branch valve according to the temperature difference, adjusts the candidate flow rates based on the total flow analysis, sets the target flow rates of each branch valve, and controls each branch valve to operate at the target flow rates.

[0025] The present invention realizes the diversion of one chiller to multiple devices, and there is no need to configure a temperature control device for each device separately, which greatly reduces the cost, reduces the installation of temperature control devices, and saves space and energy. Different flow settings for each branch can be achieved through control, which greatly improves the control accuracy and operational convenience. Differentiated settings are made for the branch flow according to the cooling requirements of the equipment, and resource optimization configuration is achieved while the overall total flow remains unchanged, better meeting the cooling requirements of the equipment. The branch flow can be independently controlled, which greatly improves the scope of use of traditional chillers.

[0026] The first temperature sensor is used to detect the circulating liquid temperature at the input end of the equipment, the second temperature sensor is used to detect the circulating liquid temperature at the output end of the equipment, the pressure sensor is used to detect the water pressure in the branch pipe, the flow sensor is used to detect the flow in the branch pipe, the branch valve opens and closes the branch pipe, and the first temperature sensor, the second temperature sensor, the pressure sensor, the flow sensor and the control end of the branch valve are respectively connected to the control module and controlled by the control module.

[0027] As a preferred solution, a bypass pipe is connected between the chiller and the water distributor, and a bypass valve is arranged on the bypass pipe.

[0028] The device is also equipped with a water pump on the main pipe to drive the circulating fluid to circulate. This solution also sets a bypass pipe between the chiller and the water distributor. The bypass pipe is used to balance the pressure and flow through the bypass valve to prevent the water pump from overheating due to excessive pressure at the end when the flow is small, thus affecting the service life of the water pump and even directly causing mechanical damage.

[0029] After the device is started, the above method is based on cooling all the equipment, and all the branch valves are open at this time. In this solution, some equipment is cooled, and by detecting whether the equipment is cooling, the corresponding branch valve is closed when the equipment is not cooling. Set the water pressure threshold, detect the water pressure in the branch with flow in the working state, and when the water pressure in the branch exceeds the water pressure threshold, open the bypass valve to balance the pressure and flow.

[0030] Therefore, the advantages of the present invention are: 1. One chiller can be used to work on multiple devices without the need to configure temperature control devices for each device, which greatly reduces costs, reduces the installation of temperature control devices, and saves space and energy.

[0031] 2. Through control, different flow settings for each branch can be achieved, which greatly improves the control accuracy and operation convenience. The flow of each branch can be controlled independently, which greatly expands the scope of use of traditional chillers.

[0032] 3. Differentiate the flow rates according to the cooling requirements of the equipment, optimize resource allocation while keeping the total flow rate unchanged, and better meet the cooling requirements of the equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a structural frame diagram of the present invention.

[0034] Figure 2 It is a schematic diagram of a process of the present invention.

[0035] 1- chiller 2- flow divider 21- first temperature sensor 22- pressure sensor 23- flow sensor 24- check valve 25- branch valve 26- second temperature sensor 3- equipment 4- main pipe 5- branch pipe 6- bypass pipe 61- bypass valve. DETAILED DESCRIPTION

[0036] The technical solution of the present invention is further specifically described below through embodiments and in conjunction with the accompanying drawings.

[0037] Example: This embodiment provides an automatic flow diversion device for circulating liquid of a chiller, such as Figure 1 As shown, it includes a chiller 1, a diverter 2, and a control module. The output end of the chiller is connected to the input end of the diverter 2 through a main pipe 4. The diverter includes multiple output ends. Each output end of the diverter is connected to the input end of its corresponding device 3 through a branch pipe 5. The output end of each device is commonly connected to the input end of the chiller.

[0038] A first temperature sensor 21, a pressure sensor 22, a flow sensor 23, a one-way valve 24, and a branch valve 25 are arranged on the branch pipe connected to the input end of the device, and a second temperature sensor 26 is arranged on the branch pipe connected to the output end of the device. The control ends of the first temperature sensor 21, the pressure sensor 22, the flow sensor 23, the branch valve 25, and the second temperature sensor 26 are respectively connected to the control module and controlled by the control module. A water pump is arranged on the main pipe. A bypass pipe 6 is also connected between the chiller 1 and the water distributor 2, and a bypass valve 61 is arranged on the bypass pipe.

[0039] This device physically divides the circulating fluid output by the chiller from a single stream into multiple streams through a flow divider. The flow sensor and the branch valve together form an electric control system. The flow sensor monitors the actual flow of the branch circulating fluid in real time, and sends the monitoring information to the control module. The control module compares the monitored actual flow with the set flow value, and then adjusts the opening of the branch valve through PID control to adjust the flow, and finally realizes the control of the single branch flow. The first temperature sensor is used to detect the temperature of the circulating fluid at the input end of the equipment, the second temperature sensor is used to detect the temperature of the circulating fluid at the output end of the equipment, and the pressure sensor is used to detect the water pressure in the branch. The first temperature sensor, the second temperature sensor, and the pressure sensor send the detected information to the control module, and the control module sets the target flow of each branch valve according to the information. Specifically, the control module calculates and obtains the temperature difference of each branch circulating fluid according to the information of the first temperature sensor and the second temperature sensor, allocates candidate flow to each branch valve according to the temperature difference, adjusts the candidate flow based on the total flow analysis, sets the target flow of each branch valve, and controls each branch valve to operate at the target flow. In addition, the control module receives the water pressure information sent by the pressure sensor. By judging the water pressure, when the water pressure is too high, the bypass valve is controlled to open to balance the pressure and flow, to prevent the water pump from overheating when the end requires a small flow, which will affect the service life of the water pump and even directly cause mechanical damage. The one-way valve is used to prevent the circulating fluid from backflowing after shutdown.

[0040] The device of the present invention realizes the diversion of one chiller to multiple devices, and there is no need to configure a temperature control device for each device separately, which greatly reduces the cost, reduces the installation of temperature control devices, and saves space and energy. Different flow settings for each branch can be achieved through control, which greatly improves the control accuracy and operational convenience. Differentiated settings are made for the branch flow according to the cooling requirements of the equipment, and resource optimization configuration is achieved while the overall total flow remains unchanged, better meeting the cooling requirements of the equipment. The branch flow can be controlled independently, which greatly improves the scope of use of traditional chillers.

[0041] The present embodiment also discloses a method for automatically diverting circulating fluid of a chiller, which is implemented by the above-mentioned device. The automatic diverting method mainly sets the flow of each branch pipe differently. In the device using diversion, although a branch pipe valve is provided to control the flow of the branch pipe, the flow is generally simply set, such as directly setting a given flow, or setting the flow of each branch pipe on average. This simple branch pipe flow setting does not optimize the distribution of flow according to the cooling requirements of the equipment, which easily leads to a branch pipe flow that cannot meet the cooling requirements of the equipment. In addition, when setting the branch pipe flow, the flow information of other branch pipes is not comprehensively considered, and the sum of the flow of each branch pipe after setting is less than the flow of the main pipe, which is a waste of flow resource allocation. Similarly, other branch pipe flows are not comprehensively considered when setting the branch pipe flow, and the sum of the branch pipe flow after setting is greater than the flow of the main pipe. For example, a higher flow of a branch pipe is set separately, so that the total flow is greater than the flow of the main pipe. Not only can the flow not be achieved, but the diversion will also affect other branches, thereby affecting the cooling operation of other branch pipe equipment. Therefore, according to the cooling requirements of the equipment, differentiated settings are made for the sub-flows, so that resource optimization can be achieved while keeping the overall total flow unchanged, thus better meeting the cooling requirements of the equipment. Figure 1 As shown, the method of this embodiment includes the following steps: S1. Start the device and set each branch valve to the initial flow rate.

[0042] This method is for flow control when all equipment is in cooling state. After the device is started, the equipment cooling working state can be judged by the equipment working signal or the flow sensor signal of each branch. If the equipment working signal is on, the equipment starts cooling work, or if the flow sensor detects that there is no flow in the branch, the equipment in charge is not started.

[0043] Before performing differentiated flow distribution on the branch valves, the cooling demand of each device needs to be tested. The average flow is calculated based on the number of branches, and each branch operates at the same initial flow to obtain the cooling demand of the equipment on each branch.

[0044] By checking that all equipment is in working condition, the initial flow is configured for each branch valve. The initial flow setting process is as follows: Obtain the number of branch pipes, calculate the average flow of each branch pipe according to the ratio of the total flow of the main pipe to the number of branch pipes, use the average flow as the initial flow, and control each branch pipe valve to operate at the initial flow.

[0045] S2. Obtain the temperature difference of the circulating fluid in each branch pipe, and allocate candidate flow rates to each branch pipe valve according to the temperature difference.

[0046] S21. Obtain the circulating fluid temperature at the input end and the circulating fluid temperature at the output end of the branch connection device, and obtain the branch circulating fluid temperature difference by subtracting the circulating fluid temperature at the output end from the circulating fluid temperature at the input end.

[0047] After the device distributes the initial flow of the branch valve, it runs for a period of time. After the circulation of the circulating fluid in the device is stable, the temperature of the circulating fluid in the branch pipes at the input and output ends of the device is obtained according to the first temperature sensor and the second temperature sensor. Generally, the temperature of the circulating fluid will rise after entering the device to cool the device, and the temperature of the circulating fluid at the output end will be higher than the temperature of the circulating fluid at the input end. The circulating fluid temperature at the output end is subtracted from the circulating fluid temperature at the input end to obtain the circulating fluid temperature difference. The size of the circulating fluid temperature difference can reflect the cooling demand of the device. When the circulating fluid temperature difference is large, it means that the device needs a larger flow rate of circulating fluid input for cooling treatment. Therefore, the flow of each branch valve can be set according to the circulating fluid temperature difference to meet the cooling demand of the equipment while maximizing the use of flow resources.

[0048] S22. Set the temperature difference threshold, and compare the temperature difference of each branch circulating fluid with the temperature difference threshold. If the temperature difference exceeds the temperature difference threshold, the corresponding branch valve is assigned the first flow rate. If the temperature difference is less than the temperature threshold, the corresponding branch valve is assigned the second flow rate. The allocated first flow rate and second flow rate are candidate flow rates of each branch valve.

[0049] A first distribution quantity of the first flow and a second distribution quantity of the second flow are set simultaneously, and the sum of the first flow of the first distribution quantity and the second flow of the second distribution quantity is equal to the main pipe flow.

[0050] This embodiment adopts a centralized resource allocation method to screen out a small number of devices with high cooling demand and configure them with a large flow rate, while the remaining devices with low or similar cooling demand are configured with a conventional flow rate. By setting a temperature difference threshold, the temperature difference threshold setting threshold can be higher, the temperature range exceeding the temperature difference threshold corresponds to the first flow rate, and the temperature range below the temperature difference threshold corresponds to the second flow rate, wherein the first flow rate is greater than the second flow rate. When the temperature difference exceeds the threshold, it means that the device has a large cooling demand and requires a larger flow rate, while if it is below the threshold, it means that the device has a small cooling demand or has not yet reached the change, and the circulating fluid is input at a relatively small flow rate. The device cooling demand is initially divided into two parts by the temperature difference threshold. Based on the fact that specific devices or a few devices have a high cooling demand in reality, only a small number of devices need to be allocated with more flow. In addition, considering the problem of smaller flow after diversion, the number of branches should not be too many. In practice, 3 to 4 branches are generally set for diversion. When the temperature difference threshold is set larger, there are generally only 1 to 2 branches that meet the temperature difference threshold, and there are situations where the temperature difference threshold is not exceeded.

[0051] When allocating candidate flows to each branch valve, a preferred flow configuration is set based on the fact that the main flow remains unchanged and the sum of the branch flows is equal to the main flow, and based on the division of the first flow and the second flow. The preferred flow configuration can be modified according to the situation. According to the preferred flow configuration scheme, the first allocation quantity of the first flow and the second allocation quantity of the second flow are obtained. The number of branch valves allocated to the first flow is the first allocation quantity, and the number of branch valves allocated to the second flow is the second allocation quantity. The sum of the first flow of the first allocation quantity and the sum of the second flow of the second allocation quantity is equal to the main flow. This allocation makes the sum of the flows of each branch equal to the main flow, making full use of the main flow resources. The setting of the allocation quantity is based on conventional situations. For example, if only one device has a high cooling demand, the branch is allocated to the first flow, and the others are allocated to the second flow. When the candidate flows are initially allocated to each branch valve according to the temperature difference, there will be some differences from the set first flow and second flow allocation quantities. It is necessary to adjust according to the situation to optimize the flow allocated to each branch valve.

[0052] For example Figure 1 As shown, in the case of three sub-managements, a preferred flow configuration is that the flow of one sub-management is the first flow, and the flows of the other two sub-managements are the second flow, respectively. The sum of the first flow and the two second flows is equal to the total flow of the main management, and the first allocation quantity of the first flow is set to 1, and the second allocation quantity of the second flow is set to 2. The set flow situation may be different from the candidate flow situation allocated by the threshold judgment, and the next step needs to be adjusted.

[0053] S3. Based on the total flow analysis, the candidate flow is adjusted and the target flow of each branch valve is set.

[0054] Compare the candidate flow of the allocated branch valve with the set allocable flow of the branch valve. When the set first allocation quantity and the second allocation quantity are the same as the allocated first flow quantity and the second flow quantity, the allocated candidate flow is used as the target flow of each branch valve.

[0055] If the currently allocated flow rate is the same as the set flow rate, no adjustment is made, and the allocated candidate flow rate is used as the target flow rate of each corresponding branch valve.

[0056] When there is an allocated second flow rate and there is no allocated first flow rate, the allocated candidate flow rate is used as the target flow rate of each branch valve.

[0057] The flow distribution is that only the second flow is distributed, but not the first flow. That is, there is no equipment with high cooling demand, and the cooling demand of all equipment is not much different, so there is no need to distribute high flow. According to the above three-division example, the three-division valves are all distributed with the second flow. According to the set flow distribution, all the divisions are distributed with the second flow at this time, and the sum of all the second flows is less than the main flow, so no adjustment is made, and the distributed candidate flow is used as the target flow of each division valve. In this case, there is still flow margin, and flow distribution can be increased for a certain division according to the situation later.

[0058] When the allocated first flow quantity is greater than the set first allocated quantity and there is an allocated second flow, the average flow of the allocated remaining flow is calculated, the average flow is used as the target flow of the corresponding branch valve, the allocated second flow is used as the target flow of the corresponding branch valve, and the allocated remaining flow is the difference between the main pipe flow and the sum of the allocated second flows.

[0059] In this solution, there are both the allocated first flow and the second flow, and the first flow quantity is greater than the set first allocation quantity of the first flow. According to the above three examples of division, at this time, two of the branch valves are allocated to the first flow, and the remaining branch valve is allocated to the second flow. According to the flow distribution situation set by comparison, if the sum of the allocated first flow and the second flow is greater than the main pipe flow, the allocated candidate flow needs to be adjusted, and the allocated second flow is used as the target flow of the corresponding branch valve. For the allocated remaining flow other than the second flow, that is, the difference between the main pipe flow and the sum of the allocated second flow, the average is calculated by dividing the allocated remaining flow by the allocated first flow quantity, and the average flow obtained is used as the target flow of the branch valve corresponding to the allocated first flow. The average flow is greater than the second flow. Here, the allocated remaining flow is averaged, and the branch valves corresponding to each allocated first flow are evenly allocated flows to prevent the allocated flow from being less than the second flow and failing to match the cooling requirements of the equipment.

[0060] When there is a distributed first flow rate and there is no distributed second flow rate, the proportional flow rate is calculated in proportion to the temperature difference of the circulating fluid in each branch pipe, and the proportional flow rate is used as the target flow rate of the corresponding branch pipe valve.

[0061] In this case, all the first candidate flows are allocated. At this time, the cooling demand of all the equipment in charge is high, and the sum of the first flows allocated is greater than the main flow. Then the temperature difference of the circulating fluid in each branch is calculated, and then the main flow is used to calculate the proportional flow of each branch valve according to the proportion, and the proportional flow is used as the target flow of each branch valve. Since the cooling demand of each device is high and the total flow is insufficient, the flow is allocated in proportion to the temperature difference, which can more accurately allocate the flow to each branch and reasonably allocate the most appropriate flow to each branch while maximizing the use of resources.

[0062] S4. Control each branch valve to operate at the target flow rate.

[0063] According to the current flow of the branch, at this time, the branch is the initial flow, the initial flow is compared with the target flow, and then the opening of the branch valve is adjusted through PID control to adjust the flow, and finally the branch flow is controlled. The process of adjusting the opening of the branch valve through PID control includes: S41. The flow sensor detects the actual flow currently in charge and makes a difference between the actual flow and the allocated target flow.

[0064] S42. Calculate the opening size of the current branch valve that needs to be adjusted to reach the target flow rate based on the difference.

[0065] S43. Convert the opening size of the branch valve to be adjusted into a pulse signal for controlling the rotation of the branch valve motor, and adjust the opening size of the branch valve by rotating the motor.

[0066] S44. Determine whether the current flow rate reaches the target flow rate. If so, the control ends. If not, repeat steps S41-S44 until the actual flow rate reaches the target flow rate.

[0067] The present invention differentiates the flow rates of the sub-pipes according to the cooling requirements of the equipment, realizes resource optimization configuration under the condition that the overall total flow rate remains unchanged, and better meets the cooling requirements of the equipment. The flow rates of the sub-pipes can be controlled independently, which greatly increases the application scope of the traditional chiller.

[0068] Before the execution of this method, it also includes judging whether the equipment is cooling down, judging the equipment cooling down status through the equipment working signal or the flow sensor signal of each branch. If the equipment working signal is on, the equipment starts cooling down, if the equipment working signal is off, the equipment does not start cooling down, or if the flow sensor detects that there is flow in the branch, the equipment in charge starts cooling down, if it detects that there is no flow in the branch, the equipment in charge does not start cooling down. In the case that all equipments are not cooling down, the following steps are performed: Set the water pressure threshold to detect the water pressure in the branch pipe with flow in working state. Determine whether the water pressure in the branch exceeds the water pressure threshold. If the water pressure in the branch pipe exceeds the water pressure threshold, the bypass valve is opened to balance the pressure and flow.

[0069] When there are more than two branch pipes, it is determined whether the total water pressure of all branch pipes exceeds the water pressure threshold. If so, the bypass valve is opened to balance the pressure and flow.

[0070] The specific embodiments described herein are merely examples of the spirit of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in similar ways, but they will not deviate from the spirit of the present invention or exceed the scope defined by the appended claims.

[0071] Although the terms such as chiller, flow divider, first temperature sensor, pressure sensor, flow sensor, etc. are used more frequently in this article, the possibility of using other terms is not excluded. These terms are used only to more conveniently describe and explain the essence of the present invention; interpreting them as any additional restrictions is contrary to the spirit of the present invention.

Claims

1. A method for automatically diverting circulating fluid of a chiller, characterized in that: The following steps are involved: Start the device and set each branch valve to the initial flow rate; Obtain the temperature difference of the circulating fluid in each branch pipe, and allocate candidate flow rates to each branch valve according to the temperature difference; Based on the total flow analysis, the candidate flow is adjusted and the target flow of each branch valve is set; Control each branch valve to operate at the target flow rate.

2. The method for automatically diverting circulating fluid of a chiller according to claim 1, characterized in that: The step of setting each branch valve to an initial flow rate includes: Get the number of branches, calculate the average flow of each branch according to the total flow of the main pipe, use the average flow as the initial flow, and control each branch valve to operate at the initial flow.

3. The method for automatically diverting circulating fluid of a chiller according to claim 1, characterized in that: The circulating fluid temperature at the input end of the branch connection equipment and the circulating fluid temperature at the output end are obtained, and the circulating fluid temperature difference at the output end is obtained by subtracting the circulating fluid temperature from the circulating fluid temperature at the input end.

4. The method for automatically diverting circulating fluid of a chiller according to claim 3, characterized in that: Allocate candidate flow rates to each branch valve based on temperature difference, including: Set the temperature difference threshold, and compare the temperature difference of each branch circulating fluid with the temperature difference threshold. If the temperature difference exceeds the temperature difference threshold, the corresponding branch valve is assigned the first flow rate. If the temperature difference is less than the temperature threshold, the corresponding branch valve is assigned the second flow rate. The allocated first flow rate and second flow rate are candidate flow rates of each branch valve.

5. The method for automatically diverting circulating fluid of a chiller according to claim 4, characterized in that: A first distribution quantity of the first flow and a second distribution quantity of the second flow are set, and a sum of a first flow sum of the first distribution quantity and a second flow sum of the second distribution quantity is equal to a main pipe flow.

6. The method for automatically diverting circulating fluid of a chiller according to claim 5, characterized in that: The subsequent flow rate is adjusted to set the target flow rate of each branch valve, including: Compare the candidate flow of the allocated branch valve with the set allocable flow of the branch valve. When the set first allocation quantity and the second allocation quantity are the same as the allocated first flow quantity and the second flow quantity, the allocated candidate flow is used as the target flow of each branch valve; When there is an allocated second flow rate and there is no allocated first flow rate, the allocated candidate flow rate is used as the target flow rate of each branch valve.

7. The method for automatically diverting circulating fluid of a chiller according to claim 6, characterized in that: Compare the candidate flow of the allocated branch valve with the set allocable flow of the branch valve. When the allocated first flow quantity is greater than the set first allocated quantity and there is an allocated second flow, the average flow of the allocated remaining flow is calculated, the average flow is used as the target flow of the corresponding branch valve, the allocated second flow is used as the target flow of the corresponding branch valve, and the allocated remaining flow is the difference between the main pipe flow and the sum of the allocated second flows.

8. The method for automatically diverting circulating fluid of a chiller according to claim 1, characterized in that: Compare the candidate flow of the allocated branch valve with the set allocable flow of the branch valve. When there is a distributed first flow rate and there is no distributed second flow rate, the proportional flow rate is calculated in proportion to the temperature difference of the circulating fluid in each branch pipe, and the proportional flow rate is used as the target flow rate of the corresponding branch pipe valve.

9. An automatic flow diversion device for circulating liquid of a chiller, implementing the method described in any one of claims 1 to 8, characterized in that: It includes a chiller and a control module. The output end of the chiller is connected to the diverter through a main pipe. Each output end of the diverter is connected to the equipment through a branch pipe. The output end of the equipment is commonly connected to the input end of the chiller. A first temperature sensor, a pressure sensor, a flow sensor, and a branch valve are arranged on the branch pipe at the input end of each equipment. A second temperature sensor is arranged on the branch pipe at the output end of the equipment. The control module obtains the temperature difference of the circulating fluid in each branch, allocates candidate flow rates to each branch valve according to the temperature difference, adjusts the candidate flow rates based on the total flow analysis, sets the target flow rates of each branch valve, and controls each branch valve to operate at the target flow rates.

10. The automatic flow diversion device for circulating liquid of a chiller according to claim 9, characterized in that: A bypass pipe is also connected between the chiller and the water distributor, and a bypass valve is arranged on the bypass pipe.

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