Air conditioner air system debugging method based on BIM

Abstract

The invention discloses a BIM (Building Information Modeling)-based air-conditioning air system debugging method, which comprises the following steps of: dividing a to-be-debugged building into different debugging areas by taking a service area of a single air handling unit as an independent individual so as to synchronously perform air-conditioning air system debugging work on each debugging area; calculating the opening value of each air valve on the pipeline system by using the BIM model; preliminarily setting an air valve opening value according to a calculation result, and measuring and recording the air volume of an air port at the tail end of the pipeline system one by one; and the measurement result is compared with the design air volume corresponding to the preliminarily set air valve opening value, and the air valve opening value on the branch corresponding to the tail end air port with the comparison result exceeding the preset range is adjusted, so that the air volume of all the tail end air ports meets the design requirement. The time for debugging personnel to measure and condition is greatly reduced, the project cost is saved, and the method has high popularization value.

Description

Technical Field

[0001] The present invention relates to the technical field of building engineering, and in particular to a BIM-based air conditioning system debugging method. Background Art

[0002] With the development of social economy, residents' requirements for environmental comfort, temperature and humidity in buildings are gradually increasing. To create a comfortable indoor environment, it is necessary to debug the air-conditioning system, ensure the hydraulic balance of each piping system, and ensure that the air volume, wind speed, temperature and noise at the terminal outlet meet the design requirements.

[0003] The traditional method of debugging air conditioning systems is to rely on experienced debugging personnel to measure the air volume at the terminal outlets, and adjust the opening of each branch air valve based on the measurement results, and repeat the above operations until the air volume at each terminal meets the design requirements. However, the above method is time-consuming and labor-intensive, and requires high debugging experience from the overall debugging personnel. At the same time, as the scale of buildings gradually increases, it becomes increasingly difficult to achieve hydraulic balance of the air conditioning system through repeated measurement and adjustment. Summary of the invention

[0004] In order to overcome the defects in the prior art, the present invention provides a BIM-based air conditioning system debugging method, which greatly reduces the measurement and condition time of debugging personnel and saves project costs.

[0005] In order to achieve the above object, the present invention provides a BIM-based air conditioning system debugging method, comprising the following steps:

[0006] The building to be debugged is divided into different debugging areas with the service area of ​​a single air handling unit as an independent entity, so that the air conditioning system debugging work can be carried out in each debugging area simultaneously;

[0007] Use the BIM model to calculate the opening value of each air valve on the piping system;

[0008] The air valve opening value is preliminarily set according to the calculation results, and the air volume at the end air outlet of the pipeline system is measured and recorded one by one;

[0009] The measurement results are compared with the design air volume corresponding to the initially set air valve opening value, and the air valve opening value on the branch corresponding to the terminal air outlet whose comparison result exceeds the preset range is adjusted to make the air volume of all terminal air outlets meet the design requirements.

[0010] Preferably, before using the BIM model to calculate the opening values ​​of each air valve on the pipeline system, the air duct system in each area to be debugged is inspected to ensure that the pipeline system is unobstructed as a whole.

[0011] Preferably, after the air duct system in each area to be debugged is inspected, the air handling units in the area to be debugged are inspected before trial operation.

[0012] Preferably, before using the BIM model to calculate the opening values ​​of each air valve on the piping system, a completed BIM model of the building to be debugged is provided, and the air volume and air valve parameters required by the piping system design are entered into the completed BIM model to calculate the opening values ​​of each air valve on the piping system.

[0013] Preferably, when calculating the opening value of each air valve on the pipeline system using the BIM model, the following steps are specifically included:

[0014] Input the designed air volume of each terminal air outlet of each pipeline system in the design drawing into the corresponding air outlet on the BIM model one by one, and find out the most unfavorable loop of the air conditioning system, wherein the most unfavorable loop is the longest loop of the entire air conditioning system;

[0015] The air duct sections of the most unfavorable loop are numbered in the order from the end of the pipe section on the most unfavorable loop to the air handling unit, and the air duct sections of the remaining parallel loops are numbered in the order from the end of the pipe section on the remaining parallel loops to the air handling unit;

[0016] Input the duct section number into the corresponding duct parameter on the BIM model to obtain the air conditioning system number diagram;

[0017] Input the basic parameters of the air conditioning system into the hydraulic calculation software and create a hydraulic calculation table for the air conditioning system;

[0018] According to the hydraulic calculation table of the air conditioning system and the numbering diagram of the air conditioning system, calculate the total pressure loss of each pipe section in the most unfavorable loop to obtain the pressure loss value of the most unfavorable loop of the air conditioning system;

[0019] Calculate the pressure loss of the parallel pipelines except the most unfavorable loop, and compare it with the pressure loss value of the most unfavorable loop;

[0020] Based on the comparison results and in order to achieve hydraulic balance for the entire air conditioning system, the air valve opening value on each parallel pipeline is calculated in turn.

[0021] Preferably, the benchmark for the entire air conditioning system to achieve hydraulic balance is that the ratio of the pressure loss difference between all parallel pipelines and the most unfavorable loop is no more than 15% and the pressure loss value of the parallel pipeline is always less than the most unfavorable loop pressure loss value of the corresponding pipe section.

[0022] Preferably, when calculating the air valve opening value on each parallel pipeline in turn, if the ratio of the pressure loss difference between the parallel pipeline and the most unfavorable loop is greater than 15%, the air valve opening value in the parallel pipeline is reduced and the local resistance of the air valve is increased.

[0023] Preferably, the air conditioning air system numbering diagram includes all air ducts, air valves, air outlets from the air handling unit to the air outlet end, and the pipe section number, pipe section length, pipe section air volume and pipe section cross-sectional size marked on each air duct section.

[0024] Preferably, when calculating the total pressure loss of each pipe section in the most unfavorable loop according to the hydraulic calculation table of the air conditioning system and the numbering diagram of the air conditioning system, the calculation method includes:

[0025] Add pipe sections to the hydraulic calculation table of the air conditioning system, and input the pipe section number, pipe section air volume, pipe section length, and pipe section cross-sectional dimensions according to the air conditioning system number diagram;

[0026] Input the pipe fitting types on the pipe segment in sequence and determine the local resistance coefficient corresponding to each pipe fitting;

[0027] The total pressure loss of the pipe section corresponding to each number is calculated based on the local resistance coefficient.

[0028] Preferably, when the air valve opening value is initially set according to the calculation result, the air valve opening value of each branch air duct when the entire air conditioning air system reaches hydraulic balance is marked on the air conditioning air system numbering diagram;

[0029] When adjusting the air valve opening value, adjust the opening values ​​of all air valves on the air conditioning system in sequence according to the marked air conditioning system number diagram.

[0030] Due to the adoption of the above technical solution, the present invention has the following beneficial effects:

[0031] 1) It replaces the traditional air conditioning system debugging method of repeated measurement and adjustment, enters the air volume of the air outlet design and the working parameter information of the air valve into the BIM model, and calculates the opening value of each branch air valve when the system is balanced according to the software. The debugging personnel preset the opening of each air valve according to the provided air valve opening value, and measure the air volume of each terminal air outlet after the air valve is preset. Then, according to the measurement results, the opening of a small number of branch air valves is fine-tuned, and finally the overall air conditioning system is debugged and each branch reaches hydraulic balance. This method provides a preset value for the opening of each air valve. Compared with the debugging in which all air valves are fully opened as the starting point in traditional debugging, it reduces the number of times the air volume of all terminal air outlets is measured, the number of times the air valve opening is adjusted, and a lot of time is saved. The hydraulic balance of the air conditioning system is calculated by the software, which has a basis to rely on, reduces the dependence on rich debugging experience during the debugging process, makes it easier for debugging personnel to get started with debugging, and the reduction in workload also reduces the number of debugging personnel required, improving the overall debugging efficiency.

[0032] 2) It reduces the measurement and adjustment time of the debugging personnel, reduces the use of lifting machinery, and saves costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0034] Figure 1 It is a flow chart of an air conditioning system debugging method based on BIM in an embodiment of the present invention.

[0035] Figure 2 It is the most unfavorable loop numbering diagram in the embodiment of the present invention.

[0036] Figure 3 It is a numbering diagram of the air conditioning system in an embodiment of the present invention.

[0037] Figure 4 It is a calculation diagram of the pressure loss of the air conditioning system in the embodiment of the present invention.

[0038] Figure 5 It is a calculation diagram of the most unfavorable loop pressure loss of the air conditioning system in the embodiment of the present invention.

[0039] Figure 6 It is a pressure loss diagram of the parallel pipelines of the air conditioning system in the example of the present invention. DETAILED DESCRIPTION

[0040] The specific embodiments of the present invention are further described below in conjunction with the accompanying drawings. It should be noted that the description of these embodiments is used to help understand the present invention, but does not constitute a limitation of the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0041] See also Figures 1 to 6 As shown, an embodiment of the present invention provides a BIM-based air conditioning system debugging method, comprising the following steps:

[0042] 1) The building to be debugged is divided into different debugging areas with the service area of ​​a single air handling unit as an independent individual, so that the air conditioning system debugging work can be carried out in each debugging area simultaneously;

[0043] 2) Use the BIM model to calculate the opening value of each air valve on the piping system;

[0044] 3) Preliminarily set the air valve opening value based on the calculation results, and measure and record the air volume at the end of the pipeline system one by one;

[0045] 4) Compare the measurement results with the design air volume corresponding to the initially set air valve opening value, and adjust the air valve opening value on the branch corresponding to the terminal air outlet whose comparison result exceeds the preset range, so that the air volume of all terminal air outlets meets the design requirements.

[0046] Furthermore, before using the BIM model to calculate the opening values ​​of each air valve on the pipeline system, it is necessary to conduct a pipeline inspection on the air duct system in each area to be debugged to ensure that the pipeline system is unobstructed as a whole, and at the same time, the air leakage test must be performed. Preferably, after the pipeline inspection of the air duct system in each area to be debugged, it is also necessary to conduct a pre-trial inspection on the air handling unit in the area to be debugged. After the inspection is completed, all air valves in the area to be debugged are opened, and the air handling unit is turned on to operate at rated power.

[0047] Furthermore, before using the BIM model to calculate the opening values ​​of each air valve on the pipeline system, it is necessary to provide the completed BIM model of the building to be debugged, and enter the air volume and air valve parameters required by the pipeline system design into the completed BIM model, and perform system analysis in advance, so as to calculate the opening values ​​of each air valve on the pipeline system, and by using BIM software to perform hydraulic balance calculation of the air conditioning system, it can save trial and error time and improve debugging efficiency. Specifically, when using the BIM model to calculate the opening values ​​of each air valve on the pipeline system, the following steps are included:

[0048] a. Input the designed air volume of each end outlet of each piping system in the design drawing into the corresponding outlet on the BIM model one by one, and find out the most unfavorable loop of the air conditioning system, where the most unfavorable loop is the longest loop of the entire air conditioning system.

[0049] b. Number the duct sections of the most unfavorable loop in the order from the end of the duct section on the most unfavorable loop to the air handling unit, and number the duct sections of the remaining parallel loops in the order from the end of the duct section on the remaining parallel loops to the air handling unit.

[0050] like Figure 2As shown, the riser duct connected to the terminal outlet in the most unfavorable loop is numbered 1-1. When entering the terminal branch from the duct riser, the duct air volume remains unchanged. Due to the change in the design wind speed range, the duct cross-sectional area changes, and the actual wind speed of the duct also changes. The resistance along the duct section and the local resistance are both positively correlated with the wind speed. At this time, the duct section number should be progressively 1-2. At the air confluence, the duct air volume changes. The change in the duct cross-sectional area within the design wind speed range causes the actual wind speed to change. The duct section number should continue to be progressive. When the local duct air volume remains unchanged, the duct cross-sectional area changes at the reducer, the actual wind speed in the duct changes, and the duct section number should continue to be progressive. After the most unfavorable loop sections are numbered according to the above principles, the remaining parallel loops are numbered in sequence, and they are also numbered from 2-1 starting from the riser duct connected to the terminal outlet of the pipeline. The duct main sections that have been assigned numbers will no longer be assigned numbers repeatedly until all duct branches are numbered.

[0051] c. Input the duct section number into the corresponding duct parameter on the BIM model to obtain the air conditioning system number diagram, such as Figure 3 As shown, the air conditioning system numbering diagram includes all air ducts, air valves, air outlets from the air handling unit to the air outlet end, as well as the pipe section number, pipe section length, pipe section air volume and pipe section cross-sectional size marked on each air duct section.

[0052] d. Input the basic parameters of the air conditioning system into the hydraulic calculation software and create a hydraulic calculation table for the air conditioning system. It should be noted that in this embodiment, the atmospheric temperature is 20°C and the atmospheric pressure is 1.01×10 5 pa, the duct material is galvanized steel plate, the absolute roughness value is 0.16mm, the air speed range of the air conditioning main duct is 5m / s-6.5m / s, and the branch duct wind speed is 3m / s-4.5m / s

[0053] e. According to the hydraulic calculation table of the air conditioning system and the numbering diagram of the air conditioning system, calculate the total pressure loss of each pipe section in the most unfavorable loop to obtain the pressure loss value of the most unfavorable loop of the air conditioning system. The calculation method includes:

[0054] Add pipe sections to the hydraulic calculation table of the air conditioning system, and input the pipe section number, pipe section air volume, pipe section length, and pipe section cross-sectional dimensions according to the air conditioning system number diagram;

[0055] Input the pipe fitting types on the pipe section in sequence, determine the local resistance coefficient corresponding to each pipe fitting, and calculate the local resistance coefficient of the air duct regulating valve on the most unfavorable loop as if the air valve is fully open;

[0056] The total pressure loss of the pipe section corresponding to each number is calculated based on the local resistance coefficient.

[0057] f. Calculate the pressure loss of the remaining parallel pipelines except the most unfavorable loop, and compare it with the pressure loss value of the most unfavorable loop;

[0058] g. According to the comparison results, the air valve opening value on each parallel pipeline is calculated in turn in principle to make the entire air conditioning system reach hydraulic balance. It should be noted that in this embodiment, the benchmark for the entire air conditioning system to reach hydraulic balance is: the ratio of the pressure loss difference between all parallel pipelines and the most unfavorable loop is not greater than 15%, and the pressure loss value of the parallel pipeline is always less than the most unfavorable loop pressure loss value of the corresponding pipe section. When calculating the air valve opening value on each parallel pipeline in turn, if the ratio of the pressure loss difference between the parallel pipeline and the most unfavorable loop is greater than 15%, reduce the air valve opening value in the parallel pipeline and increase the local resistance of the air valve.

[0059] It should be noted that when the air valve opening value is initially set according to the calculation results, the air valve opening value of each branch duct when the entire air conditioning system reaches hydraulic balance is marked on the air conditioning system number diagram. When adjusting the air valve opening value, the opening values ​​of all air valves on the air conditioning system are adjusted in sequence according to the marked air conditioning system number diagram. Whether the final air volume of the air handling unit meets the requirements needs to be adjusted in combination with the design requirements and the air handling unit's own operating curve to adjust the fan operating frequency of the unit, which can meet the unit's high-efficiency operation and achieve energy saving. After the adjustment is completed, the noise of each part of the air conditioning system needs to be finally tested to make it meet the design requirements.

[0060] See also Figure 6 As shown, taking the air conditioning system of a conference center of a certain project as an example, according to the air conditioning system numbering diagram, the pressure loss of the most unfavorable loop pipe section is calculated one by one, and finally the most unfavorable total pressure loss value of the loop is 227.91pa. The pressure loss of the 2-1 parallel pipeline is calculated, and the pressure loss value of the parallel pipeline is calculated to be 33.1pa according to the full opening of the regulating valve. Since the most unfavorable loop section corresponding to the 2-1 parallel pipeline is 1-4, it is calculated that the cumulative pressure loss of the most unfavorable loop up to the 1-4 section is 36.69pa. Through calculation, the pressure loss ratio of the 2-1 parallel pipeline is (36.69-33.1) / 36.69=9.78%, which is less than 15%, so the 2-1 parallel pipeline achieves pipeline balance.

[0061] The embodiments of the present invention are described in detail above with reference to the accompanying drawings, but the present invention is not limited to the described embodiments. For those skilled in the art, various changes, modifications, substitutions and variations of these embodiments are made without departing from the principles and spirit of the present invention, and still fall within the scope of protection of the present invention.

Claims

1. A BIM-based air conditioning system debugging method, characterized in that: The following steps are involved: The building to be debugged is divided into different debugging areas with the service area of ​​a single air handling unit as an independent entity, so that the air conditioning system debugging work can be carried out in each debugging area simultaneously; Use the BIM model to calculate the opening value of each air valve on the piping system; The air valve opening value is preliminarily set according to the calculation results, and the air volume at the end air outlet of the pipeline system is measured and recorded one by one; The measurement results are compared with the design air volume corresponding to the initially set air valve opening value, and the air valve opening value on the branch corresponding to the terminal air outlet whose comparison result exceeds the preset range is adjusted to make the air volume of all terminal air outlets meet the design requirements.

2. The BIM-based air conditioning system debugging method according to claim 1, characterized in that: Before using the BIM model to calculate the opening values ​​of each air valve on the piping system, the duct system in each area to be debugged should be inspected to ensure the overall smoothness of the piping system.

3. The BIM-based air conditioning system debugging method according to claim 2, characterized in that: After inspecting the air duct systems in each area to be debugged, conduct a pre-trial operation inspection on the air handling units in the area to be debugged.

4. The BIM-based air conditioning system debugging method according to claim 1, characterized in that: Before using the BIM model to calculate the opening values ​​of each air valve on the piping system, provide the completed BIM model of the building to be debugged, and enter the air volume and air valve parameters required by the piping system design into the completed BIM model to calculate the opening values ​​of each air valve on the piping system.

5. The BIM-based air conditioning system debugging method according to claim 1, characterized in that: When using the BIM model to calculate the opening value of each air valve on the pipeline system, the following steps are specifically included: Input the designed air volume of each terminal air outlet of each pipeline system in the design drawing into the corresponding air outlet on the BIM model one by one, and find out the most unfavorable loop of the air conditioning system, wherein the most unfavorable loop is the longest loop of the entire air conditioning system; The air duct sections of the most unfavorable loop are numbered in the order from the end of the pipe section on the most unfavorable loop to the air handling unit, and the air duct sections of the remaining parallel loops are numbered in the order from the end of the pipe section on the remaining parallel loops to the air handling unit; Input the duct section number into the corresponding duct parameter on the BIM model to obtain the air conditioning system number diagram; Input the basic parameters of the air conditioning system into the hydraulic calculation software and create a hydraulic calculation table for the air conditioning system; According to the hydraulic calculation table of the air conditioning system and the numbering diagram of the air conditioning system, calculate the total pressure loss of each pipe section in the most unfavorable loop to obtain the pressure loss value of the most unfavorable loop of the air conditioning system; Calculate the pressure loss of the parallel pipelines except the most unfavorable loop, and compare it with the pressure loss value of the most unfavorable loop; Based on the comparison results and in order to achieve hydraulic balance for the entire air conditioning system, the air valve opening value on each parallel pipeline is calculated in turn.

6. The BIM-based air conditioning system debugging method according to claim 5, characterized in that: The benchmark for the entire air conditioning system to achieve hydraulic balance is that the ratio of the pressure loss difference between all parallel pipelines and the most unfavorable loop is no more than 15%, and the pressure loss value of the parallel pipeline is always less than the most unfavorable loop pressure loss value of the corresponding pipe section.

7. The BIM-based air conditioning system debugging method according to claim 6, characterized in that: When calculating the air valve opening value on each parallel pipeline in turn, if the ratio of the pressure loss difference between the parallel pipeline and the most unfavorable loop is greater than 15%, the air valve opening value in the parallel pipeline is reduced and the local resistance of the air valve is increased.

8. The BIM-based air conditioning system debugging method according to claim 5, characterized in that: The air conditioning system numbering diagram includes all air ducts, air valves, air outlets from the air handling unit to the air outlet end, and the pipe section number, pipe section length, pipe section air volume and pipe section cross-sectional size marked on each air duct section.

9. The BIM-based air conditioning system debugging method according to claim 8, characterized in that: When calculating the total pressure loss of each pipe section in the most unfavorable loop according to the hydraulic calculation table of the air conditioning system and the numbering diagram of the air conditioning system, the calculation method includes: Add pipe sections to the hydraulic calculation table of the air conditioning system, and input the pipe section number, pipe section air volume, pipe section length, and pipe section cross-sectional dimensions according to the air conditioning system number diagram; Input the pipe fitting types on the pipe segment in sequence and determine the local resistance coefficient corresponding to each pipe fitting; The total pressure loss of the pipe section corresponding to each number is calculated based on the local resistance coefficient.

10. The BIM-based air conditioning system debugging method according to claim 5, characterized in that: When the air valve opening value is initially set according to the calculation results, the air valve opening value of each branch air duct when the entire air conditioning system reaches hydraulic balance shall be marked on the air conditioning system numbering diagram; When adjusting the air valve opening value, adjust the opening values ​​of all air valves on the air conditioning system in sequence according to the marked air conditioning system number diagram.

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