Method for quickly debugging hydraulic balance of medium-temperature water system of electronic plant

Abstract

The invention discloses a method for quickly debugging hydraulic balance of a warm water system in an electronic plant, which comprises the following steps of: firstly, building a simulation model comprising a pressure boundary, a main water supply and return pipeline, a branch pipeline, a balance valve and an equivalent resistance loss element according to a design drawing, adjusting the balance valve to a middle circle number, and inputting a corresponding resistance coefficient to the simulation model; uniformly adjusting each branch balance valve to the middle number of turns, measuring the pressure drop, flow and main supply and return water pressure of each branch balance valve under the current working condition, inputting the pressure drop, flow and main supply and return water pressure into the simulation model to calculate a resistance coefficient required to be set by an equivalent resistance loss element of each branch, and setting the opening degree of the most unfavorable branch balance valve to be 1 in combination with the designed flow; calculating adjusting resistance coefficients and turns of balance valves of other branches, actually adjusting the balance valves to the corresponding turns and locking the balance valves, and adjusting the rotating speed of the water pump to enable the total flow to reach the standard so as to realize hydraulic balance. Simulation and field testing are combined, all the balance valves are considered as a whole, compared with a traditional manual debugging and hydraulic calculation method, the set number of turns of all the balance valves can be given at a time, accuracy is high, and debugging time is short.

Description

Technical Field

[0001] The invention relates to the technical field of hydraulic balance regulation of a warm water system, and in particular to a method for rapid hydraulic balance debugging of a warm water system in an electronic factory. Background Art

[0002] The design of clean air conditioning system in semiconductor / flat panel display production plant generally adopts MAU+DCC+FFU mode, in which DCC is the key equipment to remove the heat load in the clean room and control the indoor temperature. DCC dry coil is a heat exchange device, which consists of a series of parallel coils. Medium-temperature chilled water flows through the coil and exchanges heat with the air outside the coil, thereby changing the temperature of the air.

[0003] A medium-temperature water system is formed by connecting a large number of DCC dry coils through pipes. The medium-temperature water system requires that the flow rate at each end is consistent with the design flow rate to achieve a hydraulic balance state in order to ensure the temperature uniformity in the clean room. As the area of ​​the plant becomes larger and larger, the medium-temperature water system becomes larger and more complex, and hydraulic imbalance problems are likely to occur. For this reason, static balancing valves need to be installed in each branch and the balancing valve opening needs to be debugged.

[0004] Among the existing methods for hydraulic balance debugging of medium-temperature water systems, some require multiple adjustments through manual adjustment of the balancing valve. Each adjustment requires measuring the current branch flow and comparing it with the design flow. The deviation is continuously reduced through repeated comparison and adjustment until the deviation is within 10%. This method takes a long time. In addition, since each branch is adjusted separately, it is often the case that the originally debugged branch deviates from the balanced state again due to the debugging of other branches, and the problem of losing sight of one thing while focusing on another will occur. With more and more branches in the medium-temperature water system, it is easy to fail in debugging.

[0005] The method of debugging based on 3D simulation of each component also requires trial and error through repeated calculations in the simulation software, and is extremely dependent on the accuracy of the 3D model. In reality, it is difficult to obtain 3D digital models of components such as valves and DCC dry coils, and it is impossible to establish a 3D simulation model of the water system.

[0006] Although the hydraulic calculation method is also used in the debugging of balancing valves, the key parameters of hydraulic calculations are mostly empirical values, which deviate from the actual situation on site, resulting in inaccurate calculation results, such as the resistance coefficient of elbows, valves, tees and other components. Therefore, a fast and accurate method is needed to determine the opening of the balancing valve. Summary of the invention

[0007] Purpose of the invention: The purpose of the present invention is to provide a method for rapid debugging of the hydraulic balance of the warm water system in an electronic factory, which can quickly determine the opening of each branch balancing valve, improve the debugging accuracy, and shorten the debugging time.

[0008] Technical solution: To achieve the above object, a method for quickly debugging the hydraulic balance of a warm water system in an electronic factory building according to the present invention includes the following steps:

[0009] S1: Open all valves, pumps, and end devices in the warm water system to make the warm water system operate according to the designed working conditions;

[0010] S2: Build a system simulation model based on the design drawings of the warm water system, including pressure boundary elements, main water supply pipes, main return water pipes, branch pipes, balance valves, and branch equivalent resistance loss elements. The main water supply pipe and the return water pipe are connected to the pressure boundary elements, and the inlet pressure and return water pressure of the pipe network are set by inputting pressure values to the pressure boundary elements;

[0011] S3: According to the k v value when adjusting the number of turns of the balance valve, calculate the resistance coefficient ζ v when the balance valve is adjusted to the middle turn position, and input it into the system simulation model;

[0012] S4: Adjust the balance valves of each branch of the warm water system to the middle turn position uniformly, measure the pressure drop and flow rate values of the balance valves of each branch under the current working conditions, and the inlet pressure P s of the main water supply pipe and the return water pressure P r of the main return water pipe;

[0013] S5: Input the flow rate values of the balance valves of each branch, and the inlet pressure P s of the main water supply pipe and the return water pressure P r of the main return water pipe into the system simulation model, and calculate the resistance coefficients that need to be set for the branch equivalent resistance loss elements on each branch;

[0014] S6: Input the resistance coefficient and the designed flow rate of each branch into the system simulation model, set the opening degree of the balance valve of the most unfavorable branch of the warm water system to 1, calculate the resistance coefficients that need to be adjusted for the balance valves of other branches, and obtain the number of turns of the corresponding balance valves according to the resistance coefficients of the balance valves;

[0015] S7: Adjust the balance valves of each branch in the warm water system to the corresponding number of turns, lock the valves, and adjust the pump speed so that the total flow rate is equal to the designed total flow rate to complete the hydraulic balance debugging of the warm water system.

[0016] Among them, before debugging the warm water system, first check whether the fine slag in the system is drained completely. If not, first drain the warm water system and clean the filter.

[0017] Among them, the resistance of the balance valve and the branch equivalent resistance loss element is adjusted by the resistance coefficient.

[0018] Among them, the resistance coefficient ζ of the balance valve v and the number of adjustment turns k v The calculation relationship of the value is:

[0019]

[0020] Among them, A is the cross-sectional area through which water flows.

[0021] Among them, the method for setting the resistance coefficient of the equivalent resistance loss element on each branch road in the calculation is: first calculate the impedance of each branch road, and then calculate the resistance coefficient that needs to be set for the equivalent resistance loss element of the branch road according to the impedance and resistance coefficient conversion formula.

[0022] Among them, for a pipe network with n branch roads, the calculation process of the impedance of each branch road is:

[0023]

[0024] Among them, S a is the impedance of the main pipeline, S o is the impedance of the branch road except the balance valve, P s is the inlet pressure of the main water supply pipe, P r is the return water pressure of the main return water pipe, ΔP p = P s - P r , (ΔP v1 , ΔP v2 , ΔP v3 , ···, ΔP vn ) is the pressure drop of the balance valve of each branch road, (q1, q2, q3, ···, q n ) is the flow value of the balance valve of each branch road.

[0025] Among them, the method for calculating the resistance coefficient that needs to be adjusted for the balance valve of other branch roads is: first calculate the impedance that needs to be adjusted for the balance valve, and then calculate the resistance coefficient that needs to be set for the balance valve according to the impedance and resistance coefficient conversion formula.

[0026] Among them, for a pipe network with n branch roads, the calculation process of the impedance that needs to be adjusted for each balance valve is:

[0027]

[0028] Among them, S a is the impedance of the main pipeline, S o is the impedance of the branch road except the balance valve, is the designed flow rate of the kth branch road.

[0029] Among them, the impedance and resistance coefficient conversion formula is:

[0030]

[0031] Among them, ζ is the resistance coefficient, S is the impedance, A is the cross-sectional area of the water flow, and ρ is the density of water.

[0032] Beneficial effects: The present invention has the following remarkable advantages: 1. The present invention combines simulation and on-site testing, and all balance valves are considered as a whole. Compared with the traditional manual debugging and hydraulic calculation methods, the setting turns of all balance valves can be given at one time, with high accuracy, short debugging time, no need for trial and error and repeated calculations, and no problem of neglecting one thing while attending to another; 2. The present invention only needs to establish a simulation model according to the plane layout diagram of the water system. Compared with the three-dimensional simulation method, the present invention has a low dependence on the three-dimensional model and a faster calculation speed. Description of the Drawings

[0033] Figure 1 It is a schematic diagram of the impedance of the medium-temperature water system described in the present invention;

[0034] Figure 2 It is a schematic diagram of the impedance of the two-branch water system in the embodiment;

[0035] Figure 3 It is a flowchart of the hydraulic balance debugging of the medium-temperature water system described in the present invention;

[0036] Figure 4 It is a comparison diagram of the simulated flow rate and the measured flow rate obtained by using the empirical resistance coefficient;

[0037] Figure 5 It is a comparison diagram of the simulated flow rate and the measured flow rate after on-site measurement. Detailed Embodiment

[0038] As Figure 1 shown, it is a simplified impedance schematic diagram of the pipe network. Several DCC dry coils first form a group through a parallel connection method, and a balance valve controls the flow rate of a group of DCCs. Several groups of DCC dry coils are connected in parallel to the main supply and return water pipes to form a medium-temperature water system. The resistance of the main pipeline, the resistance of the branch pipeline, and the resistance of the balance valve are represented by impedance, where the branch resistance includes all resistances except the balance valve, such as the resistance of the DCC dry coil, the resistance of various types of valves, and the resistance of the filter.

[0039] Among them, S a is the impedance of the main pipeline, S o is the impedance of the branch pipeline except the balance valve, S v is the impedance of the balance valve, ΔP v1 and ΔP v2 are the pressure drops of the balance valve, q is the flow rate, P s is the inlet pressure of the main supply water pipe, P r is the return water pressure of the main return water pipe.

[0040] (1) Before debugging, first check whether the fine slag in the water system has been completely drained. If not, first drain the water system and clean the filter to prevent the fine slag from blocking the instrument ports and valves, affecting the debugging results and damaging the debugging instruments. Open all valves as required. The valve opening is represented by 0-1, where 0 means fully closed and 1 means fully open;

[0041] (2) Open the water pump and all end devices, and adjust the flow rate by adjusting the water pump speed to make the water system operate according to the design conditions, that is, the total water system flow rate is equal to the designed total flow rate;

[0042] (3) Build a simulation model of the medium-temperature water system in the one-dimensional fluid simulation software according to the provided water system design drawings, including pressure boundary elements, main water supply pipelines, main return water pipelines, branch pipelines, balance valves, and branch equivalent resistance loss elements. The main water supply pipeline and the return water pipeline are connected to the pressure boundary elements, and the inlet pressure and return water pressure of the pipe network are set by inputting pressure values to the pressure boundary elements. The resistance of the balance valve and the branch equivalent resistance loss element can be adjusted through the resistance coefficient;

[0043] (4) According to the k v values when the balance valve provided by the manufacturer rotates different numbers of turns, calculate the valve resistance coefficient ζ v at different numbers of turns according to the following relationship. Adjust the balance valve to the position of the middle number of turns, and input the resistance coefficient ζ v at this time into the simulation model;

[0044]

[0045] (5) Adjust all branch balance valves to the position of the middle number of turns. Use the measuring instrument supporting the balance valve to connect to the pressure measuring holes on both sides of the balance valve. The measuring instrument can read the pressure drop and flow rate values of the current balance valve. Measure each branch balance valve to obtain the pressure drops (ΔP v1 , ΔP v2 , ΔP v3 , ···, ΔP vn ) and flow rate values (q1, q2, q3, ···, q n ) of each branch balance valve. The flow rate of the balance valve measured for each branch is the flow rate of each branch;

[0046] (6) Measure the inlet pressure P s of the main water supply pipe and the return water pressure P r of the main return water pipe. Input the inlet and return water pressures and the flow rates of each branch into the simulation software, and calculate the resistance coefficients (ζ o1 , ζ o2 , ζ o3 , ···, ζ on)(First, calculate the impedance of each branch according to the following formulas (7) and (8), and then calculate the resistance coefficient that needs to be set for the equivalent resistance loss element of the branch according to formula (10).) At this time, the resistance loss of the equivalent resistance loss element can represent the sum of all losses of the branch except the balance valve;

[0047] (7) Re-enter the resistance coefficients (ζ o1 , ζ o2 , ζ o3 , ···, ζ on ) obtained in the previous step into the simulation software, and then input the designed flow rate of each branch. Set the opening of the balance valve at the farthest end of the water system, that is, the most unfavorable branch, to 1, and calculate the resistance coefficient that needs to be adjusted for the balance valves of other branches (first calculate the impedance that needs to be adjusted for the balance valve according to the following formula (12), and then calculate the resistance coefficient that needs to be set for the balance valve according to formula (10)). According to the valve resistance coefficient, the number of adjustment turns of the corresponding balance valve can be obtained;

[0048] (8) Adjust the balance valves of each branch to the corresponding number of turns, lock the valves, and adjust the pump speed so that the total flow rate is equal to the designed total flow rate to complete the hydraulic balance debugging.

[0049] This embodiment further provides a calculation principle for the number of turns of the balance valve:

[0050] As Figure 2 shown, take the two-branch medium-temperature water system as an example:

[0051] Obtain the following two equations according to the two-branch medium-temperature water system diagram

[0052]

[0053] S o2 and S a2 are in series. Let S o2 + S a2 = S2, then the equation becomes:

[0054]

[0055] Obviously, the values of S o1 , S a1 and S2 are the keys to solving the pressure drop of the balance valve.

[0056] According to the built simulation model, the value of S a1 can be calculated. ΔP p = P s - P r , ΔP v1 , ΔP v2 , q1, q2 can all be measured by measuring the pressure drop and flow rate of the balance valve, and then S o1 and S2 can be calculated:

[0057]

[0058] For a pipe network with n branches:

[0059]

[0060] The impedance of each branch obtained by the method combining simulation calculation and test has a very small difference from the actual value. Converting this impedance value into a resistance coefficient and inputting it into the simulation model will make the model close to the actual state of the pipe network.

[0061]

[0062] Where A is the cross-sectional area through which water flows.

[0063] Now S o1 and S2 have been obtained. The second branch is the most unfavorable branch, so the balance valve of this branch is fully open, that is, S v2 = 0, then:

[0064]

[0065] For a pipe network with n branches:

[0066]

[0067] Then, according to formula (10), the resistance coefficients that need to be set for the balance valves to make the flow rates of each branch reach the designed flow rates can be obtained.

[0068] Taking the warm water system in an electronic factory building with 28 branches as an example, a balance valve and a set of DCC dry coils, as well as butterfly valves, Y-type filters, etc. are installed on each branch. As Figure 3 shown, the hydraulic balance debugging process is as follows:

[0069] (1) Before debugging, first check whether the fine slag in the system has been drained. If not, first drain the system and clean the filter to prevent the fine slag from blocking the instrument ports and valves, affecting the debugging results and damaging the debugging instruments. All valves are opened as required. For the branches of a set of DCC, in addition to the balance valves, there are also ball valves, butterfly valves, Y-type filters, etc., and keep the valves in the open state;

[0070] (2) Open the water pump and all the terminal equipment systems to make the water system operate according to the designed working conditions, that is, the total water flow rate of the water system is equal to the designed total flow rate;

[0071] (3) Build a simulation model of the warm water system in the simulation software according to the provided design drawings of the warm water system, including pressure boundary elements, main water supply pipelines, main return water pipelines, branch pipelines, balance valves, and branch equivalent resistance loss elements;

[0072] (4) Adjust the balance valve to the middle number of turns position, measure the pressure drop and flow rate of the balance valve, obtain the resistance coefficient of the balance valve, measure the inlet and return water pressures of the main supply and return water pipes, adjust the resistance coefficient of the balance valve to the same value as the on-site setting value in the simulation model, keep the total flow rate equal, and calculate the resistance coefficients of the equivalent resistance loss components of each branch;

[0073] (5) Input the resistance coefficients of the equivalent resistance loss components of each branch into the simulation model, set the flow rate of the balance valve of each branch to the designed flow rate, set the opening degree of the balance valve of the most unfavorable branch of the water system to 1, calculate the resistance coefficients that the balance valves of other branches should be adjusted to, and find the corresponding number of turns;

[0074] (6) Adjust the number of turns of the on-site balance valve to the number of turns of the balance valve obtained from the simulation in the fifth step, lock the balance valve, adjust the pump speed so that the total flow rate is equal to the designed total flow rate, and complete the debugging.

[0075] As Figure 4 shown, it is the comparison of the simulated flow rate and the measured flow rate of each branch calculated using the empirical resistance coefficient. As Figure 5 shown, it is the comparison of the simulated flow rate and the measured flow rate of each branch after using the resistance coefficient calculated through on-site measurement.

[0076] After using the resistance coefficient calculated through on-site measurement, the coincidence degree of the simulated flow rate and the measured flow rate of each branch is relatively good, which can be used as the basis for precise debugging. Set the flow rate of each branch to the designed flow rate. After calculation by the simulation model, the preset pressure drop and the corresponding number of turns of the balance valve of each branch are shown in Table 1:

[0077] Table 1 Balance Valve Opening Degree Indicator Table

[0078]

Claims

1. A method for rapid debugging of hydraulic balance of warm water system in electronic workshop, characterized in that: The following steps are involved: S1: Open all valves, water pumps and terminal equipment in the medium-temperature water system to make the medium-temperature water system operate according to the designed working conditions; S2: Build a system simulation model based on the design drawings of the medium-temperature water system, including pressure boundary elements, main water supply pipes, main return pipes, branch pipes, balancing valves, and branch equivalent resistance loss elements. The main water supply pipes and return pipes are connected to pressure boundary elements, and the inlet pressure and return pressure of the pipe network are set by inputting pressure values ​​into the pressure boundary elements. S3: k when adjusting the number of turns according to the balancing valve v value, calculate the resistance coefficient ζ when the balancing valve is adjusted to the middle number of turns v , and input the system simulation model; S4: Adjust the balancing valves of each branch of the medium-temperature water system to the middle position, measure the pressure drop and flow value of each branch balancing valve under the current working conditions, and the water inlet pressure P of the main water supply pipe s And the return water pressure of the main return pipe P r ; S5: The flow value of each branch balancing valve and the water inlet pressure P of the main water supply pipe are s And the return water pressure of the main return pipe P r Input the system simulation model to calculate the resistance coefficient that needs to be set for the branch equivalent resistance loss element on each branch; S6: Input the resistance coefficient and the design flow of each branch into the system simulation model, set the opening of the balancing valve of the most unfavorable branch of the medium-temperature water system to 1, calculate the resistance coefficient that needs to be adjusted for the balancing valves of other branches, and obtain the number of adjustment turns of the corresponding balancing valve according to the resistance coefficient of the balancing valve; S7: Adjust the balancing valves of each branch in the medium-temperature water system to the corresponding number of turns, lock the valves, adjust the water pump speed so that the total flow is equal to the designed total flow, and complete the hydraulic balance debugging of the medium-temperature water system.

2. According to claim 1, a method for rapid debugging of hydraulic balance of a warm water system in an electronic factory is characterized in that: Before debugging the medium-temperature water system, check whether the fine residue in the system is completely discharged. If not, drain the medium-temperature water system and clean the filter.

3. According to claim 1, a method for rapid debugging of hydraulic balance of a warm water system in an electronic factory is characterized in that: The resistance of the balancing valve and the branch equivalent resistance loss element is adjusted by the resistance coefficient.

4. According to claim 1, a method for rapid debugging of hydraulic balance of a warm water system in an electronic factory is characterized in that: The resistance coefficient of the balancing valve ζ v And the number of adjustment turns k v The calculation relationship of the value is: Where A is the cross-sectional area through which the water flows.

5. According to claim 1, a method for rapid debugging of hydraulic balance of a warm water system in an electronic factory is characterized in that: The method for calculating the resistance coefficient that needs to be set for the branch equivalent resistance loss element on each branch is: first calculate the impedance of each branch, and then calculate the resistance coefficient that needs to be set for the branch equivalent resistance loss element according to the impedance and resistance coefficient conversion formula.

6. According to claim 5, a method for rapid debugging of hydraulic balance of a warm water system in an electronic factory is characterized in that: For a pipe network with n branches, the impedance calculation process of each branch is: Among them, S a is the main pipeline impedance, S o is the impedance of the branch except the balancing valve, P s The water inlet pressure of the main water supply pipe, P r Main return pipe return pressure, ΔP p =P s -P r , (ΔP v1 ,ΔP v2 ,ΔP v3 ,···,ΔP vn ) is the pressure drop of each branch balancing valve, (q1, q2, q3.···, q n ) is the flow value of each branch balancing valve.

7. According to claim 1, a method for rapid debugging of hydraulic balance of a warm water system in an electronic factory is characterized in that: The method for calculating the resistance coefficient that needs to be adjusted for other branch balancing valves is: firstly calculate the impedance that needs to be adjusted for the balancing valve, and then calculate the resistance coefficient that needs to be set for the balancing valve according to the impedance and resistance coefficient conversion formula.

8. A method for rapid debugging of hydraulic balance of a warm water system in an electronic factory according to claim 7, characterized in that: For a pipe network with n branches, the calculation process of the impedance that each balancing valve needs to adjust is: Among them, S a is the main pipeline impedance, S o is the impedance of the branch except the balancing valve, Design flow for the kth branch.

9. A method for rapid debugging of hydraulic balance of a warm water system in an electronic factory according to claim 5 or 7, characterized in that: The impedance and resistance coefficient conversion formula is: Among them, ζ is the resistance coefficient, S is the impedance, A is the cross-sectional area through which the water flows, and ρ is the density of water.

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