Method for rapid debugging of hydraulic balance of water system in electronic factory building

Abstract

The application discloses a kind of electronic factory warm water system hydraulic balance rapid debugging method, first according to design drawing build simulation model including pressure boundary, main supply return water pipe, branch pipe, balance valve and equivalent resistance loss element, balance valve is adjusted to intermediate ring number, corresponding resistance coefficient is input to simulation model, then each branch balance valve is adjusted to intermediate ring number, the pressure drop, flow and main supply return water pressure of each branch balance valve under current working condition are measured, and input simulation model calculates the resistance coefficient that each branch equivalent resistance loss element needs to be set, combined with design flow, the most unfavorable branch balance valve opening degree is set to 1, the resistance coefficient and ring number of other branch balance valve adjustment are calculated, and balance valve is actually adjusted to corresponding ring number and locked, adjust pump speed to make total flow standard, realize hydraulic balance.The application combines simulation and field test, all balance valves are considered as a whole, compared with traditional manual debugging and hydraulic calculation method, the setting ring number of all balance valves can be given at one time, with high accuracy and short debugging time.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of warm water system hydraulic balance adjustment, in particular to a warm water system hydraulic balance rapid debugging method in an electronic plant. BACKGROUND

[0002] The clean air conditioning system design of semiconductor / panel display production plant generally adopts the mode of MAU+DCC+FFU, wherein the DCC is a key equipment for taking away the heat load in the clean room and controlling the temperature in the room. The DCC dry coil is a heat exchange equipment, which is internally composed of a series of parallel arranged coil pipes. The medium temperature chilled water flows through the coil pipes and exchanges heat with the air outside the coil pipes, so as to change the temperature of the air.

[0003] A large number of DCC dry coil pipes are connected through pipelines to form a medium temperature water system. The medium temperature water system requires that the flow of each end is consistent with the designed flow to achieve the hydraulic balance state, so as to ensure the uniformity of the temperature in the clean room. With the increasing area of the plant, the medium temperature water system is larger and more complex, and it is easy to have the problem of hydraulic imbalance. Therefore, the static balance valve needs to be installed on each branch and the opening degree of the balance valve needs to be debugged.

[0004] In the existing medium temperature water system hydraulic balance debugging method, some balance valves are adjusted manually. Therefore, the adjustment needs to be performed for multiple times. The current branch flow needs to be measured and compared with the designed flow for each adjustment. The deviation is continuously reduced through repeated comparison and adjustment until the deviation is within 10%. Such method consumes a long time. In addition, since each branch is adjusted separately, the balance state of the branch which has been adjusted is deviated again due to the adjustment of other branches. In the case that the branches of the medium temperature water system are more and more, the debugging is easy to fail.

[0005] The method of three-dimensional simulation debugging based on components also needs to be tried through repeated calculation in the simulation software, and is extremely dependent on the accuracy of the three-dimensional model. In actual situation, it is difficult to obtain the three-dimensional model of the valve, DCC dry coil and other components, and it is impossible to establish the three-dimensional simulation model of the water system.

[0006] The method of hydraulic calculation is also applied in the balance valve debugging. However, the key parameters of the hydraulic calculation are mostly the experience values, which deviate from the actual situation on site, so that the calculation result is inaccurate. For example, the resistance coefficients of the elbow, valve and tee. Therefore, a rapid and accurate method is needed to determine the opening degree of the balance valve. SUMMARY

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

[0008] Technical scheme: To achieve the above-mentioned purpose, the hydraulic balance rapid debugging method of the medium temperature water system in the electronic factory comprises the following steps:

[0009] S1: open all valves, water pumps and terminal equipment in the medium temperature water system, and make the medium temperature water system operate according to the design working condition;

[0010] S2: based on the design drawing of the medium temperature water system, a system simulation model is built, including a pressure boundary element, a main water supply pipeline, a main water return pipeline, branch pipelines, balance valves and equivalent resistance loss elements of the branch pipelines, the main water supply pipeline and the water return pipeline are connected with the pressure boundary element, and the water inlet pressure and the water return pressure of the pipeline network are set by inputting the pressure value of the pressure boundary element;

[0011] S3: according to the k v value when the balance valve is adjusted, the resistance coefficient ζ v when the balance valve is adjusted to the middle number of turns is calculated, and the system simulation model is inputted;

[0012] S4: the balance valves of each branch pipeline of the medium temperature water system are uniformly adjusted to the position of the middle number of turns, the pressure drop and the flow value of each branch balance valve under the current working condition are measured, and the water inlet pressure P s and the water return pressure P r of the main water supply pipeline are measured;

[0013] S5: the flow value of each branch balance valve, the water inlet pressure P s of the main water supply pipeline and the water return pressure P r of the main water return pipeline are inputted into the system simulation model, and the resistance coefficient required to be set for the equivalent resistance loss elements of each branch pipeline is calculated;

[0014] S6: the resistance coefficient and the design flow of each branch pipeline are inputted into the system simulation model, the opening degree of the balance valve of the most unfavorable branch pipeline of the medium temperature water system is set to 1, the resistance coefficient required to be adjusted for the balance valves of other branch pipelines is calculated, and the adjustment number of turns of the corresponding balance valve is obtained according to the resistance coefficient of the balance valve;

[0015] S7: the balance valves of each branch pipeline in the medium temperature water system are adjusted to the corresponding number of turns, the valves are locked, the rotation speed of the water pump is adjusted so that the total flow is equal to the design total flow, and the hydraulic balance debugging of the medium temperature water system is completed.

[0016] Before debugging the medium temperature water system, it is checked whether the fine slag in the system is exhausted, if not, the medium temperature water system is discharged and the filter is cleaned.

[0017] The resistance of the balance valve and the equivalent resistance loss element of the branch pipeline is adjusted by the resistance coefficient.

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

[0019]

[0020] Wherein, A is the cross-sectional area of water flow.

[0021] The method for calculating the resistance coefficient of the branch equivalent resistance loss element is to calculate the branch impedance first, and then calculate the resistance coefficient of the branch equivalent resistance loss element according to the impedance and resistance coefficient conversion formula.

[0022] The calculation process of the branch impedance is as follows:

[0023]

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

[0025] The method for calculating the resistance coefficient of the balance valve is to calculate the impedance of the balance valve first, and then calculate the resistance coefficient of the balance valve according to the impedance and resistance coefficient conversion formula.

[0026] The calculation process of the impedance of each balance valve is as follows:

[0027]

[0028] Wherein, S a is the main pipe impedance, S o is the impedance of the branch except the balance valve, is the design flow of the kth branch.

[0029] The impedance and resistance coefficient conversion formula is:

[0030]

[0031] Where ζ is the drag 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 significant advantages: 1. The present invention combines simulation and field testing, and considers all balancing valves in a coordinated manner. Compared with the traditional method of manual debugging and hydraulic calculation, it can give the set number of turns of all balancing valves at one time, with high accuracy, short debugging time, no need for trial and error and repeated calculation, and no problem of neglecting one aspect; 2. The present invention only needs to establish a simulation model based on the water system layout diagram. Compared with the three-dimensional simulation method, the present invention has a low dependence on the three-dimensional model and a faster calculation speed. Attached Figure Description

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

[0034] Figure 2 This is a schematic diagram of the impedance of the second branch water system in the embodiment;

[0035] Figure 3 This is a flowchart of the hydraulic balance commissioning process for the medium-temperature water system described in this invention.

[0036] Figure 4 This is a comparison chart of simulated flow rate and measured flow rate obtained using empirical resistance coefficients;

[0037] Figure 5 This is a comparison chart of simulated flow rate and actual flow rate after on-site measurement. Detailed Implementation

[0038] like Figure 1 The diagram shows a simplified impedance diagram of the pipe network. Several DCC dry coils are first connected in parallel to form a group. A balancing valve controls the flow rate of one 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 branch pipeline, and the balancing valve are represented by impedance. The branch pipeline resistance includes the resistance of the DCC dry coils, the resistance of various types of valves, the filter resistance, and all other resistances except for the balancing valve.

[0039] Among them, S a Main pipeline impedance, S o S is the impedance of the branch excluding the balancing valve. v To balance the valve impedance, ΔP v1 and ΔP v2 For balancing valve pressure drop, q is the flow rate, and P is the pressure drop. s Main water supply pipe inlet pressure, P r The return water pressure of the main return water pipe.

[0040] (1) Before debugging, check if the fine slag in the water system is exhausted. If not, first drain the water system, clean the filter, so as to prevent the fine slag from blocking the instrument port and valve, affecting the debugging result and damaging the debugging instrument. All valves are opened according to the requirements, and the valve opening degree is represented by 0-1, 0 means full closing, and 1 means full opening;

[0041] (2) Open the water pump and all end devices, adjust the flow by adjusting the water pump speed, so that the water system operates according to the design condition, that is, the total flow of the water system is equal to the designed total flow;

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

[0043] (4) According to the k v value of the balance valve when it rotates different number of turns provided by the manufacturer, calculate the valve resistance coefficient ζ v when it rotates different number of turns according to the following relationship, adjust the balance valve to 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 middle number of turns, connect the balance valve with the pressure measuring hole on both sides using the balance valve matching measuring instrument, which can read the current balance valve pressure drop and flow value. Each branch balance valve needs to be measured to obtain the branch balance valve pressure drop (ΔP v1 , ΔP v2 , ΔP v3 ,···, ΔP vn ) and flow value (q1, q2, q3.···, q n ). The measured balance valve flow of each branch is the flow of each branch;

[0046] (6) Measure the main water inlet pressure P s and the main return water pressure P r , input the inlet and return water pressure and the branch flow into the simulation software, and calculate the required resistance coefficient (ζ o1 , ζ o2 , ζ o3 ,···, ζ on(First calculate the impedance of each branch according to formulas (7) and (8) below, and then calculate the resistance coefficient that the equivalent resistance loss element of the branch needs to be set 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 for the balance valve.

[0047] (7) The drag coefficients (ζ) obtained in the previous step o1 ,ζ o2 ,ζ o3 ,···,ζ on Re-enter the simulation software, then input the design flow rate of each branch, set the opening of the balance valve of the farthest branch of the water system to 1, calculate the resistance coefficient that the balance valve of other branches needs to be adjusted (first calculate the impedance that the balance valve needs to be adjusted according to the formula (12) below, and then calculate the resistance coefficient that the balance valve needs to be set according to the formula (10). The number of adjustment turns of the corresponding balance valve can be obtained according to the valve resistance coefficient.

[0048] (8) Adjust the balance valves of each branch to the corresponding number of turns, lock the valves, adjust the pump speed to make the total flow equal to the design total flow, and complete the hydraulic balance test.

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

[0050] like Figure 2 As shown, taking a two-branch medium-temperature water system as an example:

[0051] Based on the diagram of the medium-temperature water system in the second branch, the following two equations are obtained.

[0052]

[0053] S o2 and S a2 It is a series relationship, let S o2 +S a2 =S2, then the equation becomes:

[0054]

[0055] Obviously S o1 S a1 The values ​​of S2 and S2 are key to solving the pressure drop of the balancing valve.

[0056] S can be calculated based on the constructed simulation model. a1 The value of ΔP p =P s -P r ΔP v1 ΔP v2 q1 and q2 can both be measured by measuring the pressure drop and flow rate of the balancing valve, and then S can be calculated. o1 And S2:

[0057]

[0058] For the pipe network with n branches:

[0059]

[0060] The difference between the actual value and the value obtained by the simulation calculation and test combination method is very small. Converting the impedance value into 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 of the water flow.

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

[0064]

[0065] For the pipe network with n branches:

[0066]

[0067] According to formula (10), the resistance coefficient required to set the balance valve to achieve the design flow rate of each branch can be obtained.

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

[0069] (1) Before debugging, check whether the fine sludge in the system is completely discharged. If not, first discharge the system, clean the filter, and prevent the fine sludge from blocking the instrument port and the valve, affecting the debugging result and damaging the debugging instrument. All valves are fully opened according to the requirements. In addition to the balance valve, a set of DCC branches also have ball valves, butterfly valves, Y-type filters, etc. Keep the valves in the open state;

[0070] (2) Open the water pump and all end device systems, and make the water system operate according to the design condition, i.e. the total flow of the water system is equal to the design total flow;

[0071] (3) According to the provided design drawing of the warm water system, build a simulation model of the warm water system in the simulation software, including pressure boundary elements, main water supply pipes, main return water pipes, branch pipes, balance valves, and equivalent resistance loss elements of branches;

[0072] (4) The balancing valve is adjusted to the middle number of turns, the pressure drop and flow of the balancing valve are measured, the resistance coefficient of the balancing valve is obtained, the water inlet and return pressures of the main water supply and return pipes are measured, the resistance coefficient of the balancing valve in the simulation model is adjusted to be the same as the field setting value, the total flow is kept equal, and the equivalent resistance loss element resistance coefficients of each branch are calculated;

[0073] (5) The equivalent resistance loss element resistance coefficients of each branch are input into the simulation model, the balancing valve flow of each branch is set to the design flow, the balancing valve opening of the most unfavorable branch of the water system is set to 1, the resistance coefficients of the balancing valves of other branches that should be adjusted are calculated, and the corresponding number of turns is found;

[0074] (6) The balancing valve number of turns is adjusted to the balancing valve number of turns obtained by the simulation in the fifth step, the balancing valve is locked, the pump speed is adjusted to make the total flow equal to the design total flow, and the debugging is completed.

[0075] As shown in Figure 4 , it is the comparison between the simulated flow and the measured flow of each branch calculated by using the empirical resistance coefficient, as shown in Figure 5 , it is the comparison between the simulated flow and the measured flow of each branch after the resistance coefficient is calculated by using the field measurement.

[0076] After using the resistance coefficient calculated by the field measurement, the simulated flow and the measured flow of each branch are well matched, which can be used as the basis for accurate debugging. After setting the flow of each branch to the design flow, the pre-set pressure drop and the corresponding number of turns of the balancing valve of each branch calculated by the simulation model are shown in Table 1:

[0077] Table 1 Balancing valve opening indication table

[0078]

Claims

1. A method for rapid commissioning of hydraulic balance of a warm water system in an electronic factory, characterized in that, The method comprises the following steps: S1: opening all valves, water pumps and terminal devices in the medium-temperature water system, and making the medium-temperature water system operate according to the design working condition; S2: building a system simulation model based on the design drawing of the medium-temperature water system, including pressure boundary elements, main water supply pipelines, main water return pipelines, branch pipelines, balance valves, equivalent resistance loss elements of the branch pipelines, the main water supply pipelines and the water return pipelines being connected with the pressure boundary elements, and the water inlet pressure and the water return pressure of the pipeline network being set by inputting pressure values to the pressure boundary elements; S3: k based on the number of turns adjusted by the balance valve v The value is used to calculate the resistance coefficient ζ when the balance valve is adjusted to the middle number of turns. v And input the system simulation model; S4: uniformly adjust the intermediate number of turns of each branch balancing valve of the medium-temperature water system, measure the pressure drop and flow value of each branch balancing valve under the current working condition, and the inlet water pressure P s and the return water pressure P r of the main water supply pipe; S5: balancing the flow value of each branch valve, and the inlet pressure P of the main water supply pipe s and the return pressure P of the main water return pipe r inputting the system simulation model, and calculating the resistance coefficient required to be set for the branch equivalent resistance loss element on each branch S6: inputting the resistance coefficient and the design flow of each branch pipeline into the system simulation model, setting the opening degree of the balance valve of the most unfavorable branch pipeline of the medium-temperature water system to 1, calculating the resistance coefficient of the balance valve of each branch pipeline which needs to be adjusted, and obtaining the adjustment number of the corresponding balance valve according to the resistance coefficient of the balance valve; S7: adjusting the balance valve of each branch pipeline in the medium-temperature water system to the corresponding number, locking the valve, adjusting the rotating speed of the water pump so that the total flow is equal to the design total flow, and completing the hydraulic balance adjustment of the medium-temperature water system.

2. The method of claim 1, wherein, Before the medium-temperature water system is adjusted, it is checked whether the fine sludge in the system is exhausted, and if not, the medium-temperature water system is discharged and the filter is cleaned.

3. The method of claim 1, wherein, The resistance of the balance valve and the equivalent resistance loss element of the branch pipeline is adjusted by the resistance coefficient.

4. The method of claim 1, wherein, The balance valve resistance coefficient ζ v The calculation relationship of the adjustment number k v The value is: A is the cross-sectional area of the water flow.

5. The method of claim 1, wherein, The method for calculating the resistance coefficient of the equivalent resistance loss element of each branch pipeline is that the impedance of each branch pipeline is calculated first, and then the resistance coefficient of the equivalent resistance loss element of each branch pipeline is calculated according to the impedance-resistance coefficient conversion formula.

6. The method of claim 5, wherein, For a pipeline network with n branch pipelines, the calculation process of the impedance of each branch pipeline is as follows: wherein S a is the impedance of the main pipe, S o is the impedance of the branch pipe except for the balance valve, P s is the water inlet pressure of the main water supply pipe, P r is the water return pressure of the main water return pipe, ΔP p = P s -P r , (ΔP v1 , ΔP v2 , ΔP v3 , ···, ΔP vn ) are the pressure drops of the respective branch balance valves, (q1, q2, q3. ···, q n ) are the flow values of the respective branch balance valves.

7. The method of claim 1, wherein, The method for calculating the resistance coefficient of the balance valve of each branch pipeline is that the impedance of the balance valve of each branch pipeline is calculated first, and then the resistance coefficient of the balance valve of each branch pipeline is calculated according to the impedance-resistance coefficient conversion formula.

8. The method of claim 7, wherein, For a pipeline network with n branch pipelines, the calculation process of the impedance of the balance valve of each branch pipeline is as follows: where S a is the main line impedance, S o is the impedance of the branch except for the balance valve, is the design flow rate of the kth branch.

9. The method of claim 5 or 7, wherein, The impedance-resistance coefficient conversion formula is as follows: 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.

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