Quantifiable pressurized building air tightness testing method and system

Abstract

The invention discloses a quantifiable pressurized building air tightness testing method. The method comprises the steps that the pressurized net volume V of a pressurized building is measured; the interior of the pressurized building is pressurized, so that the air pressure in the pressurized building reaches the set target pressure; detecting air pressure in the supercharged building in real time, and recording corresponding air pressure data; fitting the recorded air pressure data to obtain a time-varying function # imgabs0 # of the air pressure in the supercharged building, and deriving to obtain a derived function # imgabs1 #; and calculating according to a formula # imgabS2 # to obtain the leakage rates of the supercharged building under different air pressures. The method has the beneficial effects that the test method is provided based on consideration of the supercharged net volume of the supercharged building, the air tightness of the supercharged building is quantitatively detected, the absolute leakage amount of a certain supercharged building under a certain set pressure can be obtained, and comparable data is provided for air tightness evaluation of the supercharged building.

Description

Technical Field

[0001] The present invention relates to the technical field of air tightness testing, and in particular to a quantifiable pressurized building air tightness testing method and system. Background Art

[0002] The pressure difference between the indoor and outdoor of a pressurized building is more than 10kPa, which requires the building to have extremely high air tightness. However, the development of pressurized buildings is still in its early stages, and a complete standard system has not yet been established. There is a lack of technical guidance for air tightness testing. At present, the air tightness measurement method currently used by engineering and technical personnel is: use the pressurization equipment to increase the indoor air pressure of the pressurized building to the design air pressure and then stop pressurizing, and use the air pressure change rate after one hour as the air tightness data of the pressurized building. For example, the design air pressure of a pressurized building project is 30KPa. After the pressurization is increased to 30KPa, the pressurization is stopped. Due to leakage, the building pressure becomes 27KPa after one hour, and the air pressure drops by 10%. The air tightness of the pressurized building is recorded as 10% / h.

[0003] However, the airtightness data measured by the existing methods have little practical significance, ignoring the volume of the pressurized building. Take the pressurized buildings with volumes of 5,000 cubic meters and 50 cubic meters as examples. Assuming that both of them leak, the indoor air pressure of the building drops from 30Kpa to 27Kpa in one hour, and the air pressure decreases by 10%. Obviously, the total amount of leakage in the 5,000 cubic meter pressurized building is much greater than that of the 50 cubic meter pressurized building. Because of the leakage, the building needs to be pressurized, but the existing airtightness data cannot provide a basis for the design of building pressure replenishment.

[0004] In addition, the existing measurement methods can only provide leakage data measured under a certain pressure. When a pressurized building is in operation, the indoor pressure will be adjusted according to actual needs. For example, the data of a pressurized building is measured at 30KPa, but the actual operation of the building may be at 25kPa or 35KPa, and the airtightness data of these two air pressure points are missing, so the amount of data obtained by the existing measurement methods is very limited. Summary of the invention

[0005] The purpose of the present invention is to provide a quantifiable pressurized building airtightness testing method and system to address the deficiencies of the prior art, aiming to obtain leakage data of the pressurized building under different pressures in combination with the volume of the pressurized building.

[0006] The technical solution adopted by the present invention is: a quantifiable pressurized building air tightness test method, the method is: Determine the net pressurized volume V of the pressurized building; Increase the pressure inside the pressurized building so that the air pressure inside the pressurized building reaches the set target pressure; Real-time detection of the air pressure inside the pressurized building and recording of the corresponding air pressure data; Fit the recorded air pressure data to obtain the function of the air pressure in the pressurized building changing with time , and take the derivative of the function P(t) with respect to time t to obtain the derivative function ; According to the formula Calculate the leakage of the pressurized building under different air pressures; in this formula, is the internal air pressure of the pressurized building, in Pa; molar gas constant; is the gas temperature inside the pressurized building, in K; is the time, in seconds; is the net volume of the pressurized building, in m 3 ; is the ambient air pressure, in Pa; is the standard atmospheric pressure, the unit is Pa; The volume of air in the pressurized building converted to ambient pressure, in m 3 .

[0007] According to the above scheme, the method for determining the pressurized net volume V of the pressurized building is as follows: pressurize the inside of the pressurized building, detect the gas volume flow rate in the pressurized pipeline and the air pressure in the pressurized building in real time during the pressurization process, and record the gas volume flow rate data and the air pressure data; perform fitting processing on the recorded gas volume flow rate data and the air pressure data, respectively, to obtain the flow rate versus time function Q(t) and the air pressure versus time function P(t); respectively take the derivative of the function Q(t) and the function P(t) with respect to time t, to obtain the derivative function and ; Select three time points , respectively substitute into the derivative function Evaluate in, and then use the formula Calculate and obtain three time points respectively The corresponding volume , and then ask The average value of the pressurized building is obtained to obtain the net pressurized volume of the pressurized building .

[0008] According to the above scheme, when it is detected that the air pressure inside the pressurized building does not exceed 10kPa, the recording of air pressure data is stopped.

[0009] According to the above scheme, in the method for determining the pressurized net volume V of the pressurized building, when it is detected that the air pressure inside the pressurized building is greater than or equal to 100 Pa, the recording of the air pressure data and the gas volume flow data is stopped.

[0010] According to the above scheme, the time step for recording air pressure data is 2s~1min.

[0011] According to the above scheme, in the method for determining the net pressurized volume V of the pressurized building, the time step for recording the air pressure data and the gas volume flow data is 1s~1min.

[0012] The present invention also discloses a pressurized building air tightness test system, comprising a pressure detection device, a control system, a pressurizing device and a pressurizing pipeline; The pressure detection device is arranged in the boosting building; the interior of the boosting building is connected to one end of the boosting pipeline, and the boosting equipment is arranged on the boosting pipeline; the pressure detection device and the boosting equipment are respectively connected to the control system; Electric valves and volume flow meters are respectively arranged on the boosting pipelines upstream and downstream of the boosting equipment, and the electric valves and volume flow meters are respectively connected to the control system; The pressure detection device is used to detect the air pressure inside the boosted building and send the air pressure data to the control system; the boosting equipment is used to transport air to the boosted building through the boosting pipeline for boosting; the volume flow meter is used to detect the gas volume flow in the boosting pipeline and send the gas volume flow data to the control system; the control system is used to control the opening and closing of the electric valve and the boosting equipment, and receive the air pressure data and the gas volume flow data.

[0013] According to the above scheme, the boosting equipment is one of an air compressor, a Roots blower, a vortex blower and a screw blower.

[0014] According to the above solution, the pressure detection device is a pressure transmitter.

[0015] The beneficial effects of the present invention are: 1. The present invention takes the net volume of the pressurized building into consideration, proposes a testing system and a testing method, and performs quantitative detection on the air tightness of the pressurized building. The absolute leakage of a pressurized building under different set pressures can be obtained, and comparable data is provided for the evaluation of the air tightness of the pressurized building. This is beneficial for the quantitative analysis and evaluation of the air tightness of the pressurized building, and also provides a reference for the later building pressure compensation design.

[0016] 2. The present invention can calculate the absolute leakage amount under non-measured pressure through the data fitting method, and can obtain more data. The fitted data can also predict the pressure change of the pressurized building through integration.

[0017] 3. The present invention provides a method for measuring the net pressurized space (i.e., net volume) inside a pressurized building, which can provide support for the selection of pressurized building equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a structural schematic diagram of a specific embodiment of the present invention.

[0019] Among them: 1. Pressurized building; 2. Pressurized equipment; 3. Volume flow meter; 4. Electric valve; 5. Pressure detection device. DETAILED DESCRIPTION

[0020] In order to better understand the present invention, the present invention is further described below in conjunction with the accompanying drawings and specific embodiments.

[0021] like Figure 1 A quantifiable pressurized building 1 air tightness test system is shown, comprising a pressure detection device 5, a control system, a pressurizing device 2 and a pressurizing pipeline; The pressure detection device 5 is arranged in the boosting building 1; the interior of the boosting building 1 is connected to one end of the boosting pipeline, and the boosting equipment 2 is arranged on the boosting pipeline; the pressure detection device 5 and the boosting equipment 2 are respectively connected to the control system.

[0022] In the present invention, the boosting pipelines upstream and downstream of the boosting device 2 are respectively provided with an electric valve 4 and a volume flow meter 3, and the electric valve 4 and the volume flow meter 3 are respectively connected to the control system.

[0023] In the present invention, the pressure detection device 5 can be a pressure changer, which is used to detect the air pressure inside the boosted building 1 and send the air pressure data to the control system; the boosting equipment 2 can be one of an air compressor, a Roots blower, a vortex blower and a screw blower, which is used to transport air to the boosted building 1 through a boosting pipeline for boosting; the volume flow meter 3 is used to detect the gas volume flow in the boosting pipeline, and send the gas volume flow data to the control system; the control system is used to receive air pressure data and gas volume flow data, and control the opening and closing of the electric valve 4 and the boosting equipment 2.

[0024] A quantifiable pressurized building airtightness test method, the method is: Determine the net pressurized volume V of the pressurized building; Open the boosting equipment and electric valve to increase the pressure inside the boosting building so that the air pressure inside the boosting building reaches the design pressure; The pressure detection device detects the air pressure inside the pressurized building in real time and transmits the air pressure signal to the control system. The control system receives the air pressure data and records the corresponding air pressure data. The recording time step is 2s~1min; When the pressure detection device detects that the air pressure inside the pressurized building does not exceed 10kPa (since the pressurized pressure of the pressurized building is greater than 10kPa, it is meaningless to detect a value lower than this pressure), the control system stops recording; Fit the recorded air pressure data to obtain the function of the air pressure in the pressurized building changing with time ; The derivative function P(t) of the building air pressure changing with time is obtained by taking the derivative function ; According to the formula Calculate the leakage of pressurized buildings under different air pressures. In this formula, is the internal air pressure of the pressurized building, in Pa; molar gas constant; is the gas temperature inside the pressurized building, in K; is time, unit is s; is the net volume of the pressurized building, in m 3 ; is the ambient air pressure, in Pa; is the standard atmospheric pressure, the unit is Pa; The volume of air in the pressurized building converted to ambient pressure, in m 3 .

[0025] In the present invention, the method for determining the pressurized net volume V of the pressurized building is: 1) The control system simultaneously turns on the boosting device 2 and the electric valve 4 to increase the pressure inside the boosting building; 2) The volume flow meter 3 detects the volume flow of gas in the boosting pipeline and transmits the corresponding data to the control system. The pressure detection device 5 detects the air pressure in the boosting building and transmits the corresponding data to the control system. The control system records the data detected by the volume flow meter 3 and the pressure detection device 5 in real time (to form a corresponding relationship between pressure flow and time). The data recording time step is 1s~1min. When the pressure detection device detects that the air pressure value in the boosting building is greater than or equal to 100Pa, it stops recording. 3) The control system fits the data detected by the flow meter 3 and the pressure transmitter 5 respectively to obtain the flow rate versus time function and the pressure as a function of time ; 4) The flow rate is a function of time. and the pressure as a function of time Separately for time Take the derivative and get the derivative function and ; 5) Choose three time points at random , respectively substitute into the derivative function Then, through the formula Calculate and obtain three time points respectively The corresponding volume ; 6) Take the average value , This is the net volume of the pressurized building.

[0026] In the present invention, the principle of quantitative pressurized building air tightness detection is as follows: According to the gas state equation: (1); During the building pressurization process, the indoor temperature of the building changes little, and the effect of temperature on pressure is ignored. In addition, the volume of the pressurized net space is constant during the pressurization process. We have: …… (2); Calculate the amount of gas substance n, ……(3); According to formulas (2) and (3), we can get: ……(4); Formula (4) can be transformed into: ……(5); In formulas (1) to (5), is the internal air pressure of the pressurized building, in Pa; Represents the amount of gaseous material inside the pressurized building; molar gas constant; is the gas temperature inside the pressurized building, in K; is time, unit is s; The volume of air when the pressurized building air is converted to ambient pressure, in m 3 ; is the net volume of the pressurized building, in m 3 ; is the ambient air pressure, in Pa; It is the standard atmospheric pressure, the unit is Pa.

[0027] In the present invention, the net pressurized volume of a pressurized building refers to the space after deducting the non-compressible substances that occupy the gas space inside the building, including partition walls, furniture, household appliances, etc. The space occupied by such substances does not participate in the pressure increase or decrease action of the building.

[0028] It can be seen from formula (5) that the leakage of the pressurized building under different air pressures can be determined by measuring the rate of change of air pressure over time ( ), but the prerequisite is to know the net space of the pressurized building. After the building is completed, it is impossible to directly obtain the accurate net space through the drawings because there are a lot of decorations, home appliances and equipment inside.

[0029] In order to obtain the accurate net pressurized volume of the pressurized building, the following method is used: Formula (4) can be transformed into: ……(6); It can be seen from formula (6) that by pressurizing the pressurized building, the air flow rate ( ) and the rate of change of pressurized building air pressure ( ) two parameters, the net space of the pressurized building can be obtained. Because the pressurized building will have obvious leakage under a large pressure difference, the net space should be measured under a small pressure difference between indoors and outdoors; combined with field experience, it is believed that the pressure difference between the inside and outside of the pressurized building should be less than 100Pa during the test.

[0030] The contents not described in detail in this specification belong to the prior art known to professional and technical personnel in this field.

[0031] Finally, it should be noted that the above are only preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments or to replace some of the technical features therein with equivalents. However, any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A quantifiable pressurized building air tightness test method, characterized in that: The method is: Determine the net pressurized volume V of the pressurized building; Increase the pressure inside the pressurized building so that the air pressure inside the pressurized building reaches the set target pressure; Real-time detection of air pressure inside the pressurized building and recording of corresponding air pressure data; Fit the recorded air pressure data to obtain the function of the air pressure in the pressurized building changing with time , and take the derivative of the function P(t) with respect to time t to obtain the derivative function ; According to the formula , the leakage of the pressurized building under different air pressures can be calculated; where, is the internal air pressure of the pressurized building, in Pa; molar gas constant; is the gas temperature inside the pressurized building, in K; is time, unit is s; is the net volume of the pressurized building, in m 3 ; is the ambient air pressure, in Pa; is the standard atmospheric pressure, the unit is Pa; The volume of air in the pressurized building converted to ambient pressure, in m 3 .

2. The quantifiable pressurized building airtightness test method according to claim 1, characterized in that: The method for determining the pressurized net volume V of the pressurized building is as follows: pressurizing the inside of the pressurized building, detecting the gas volume flow rate in the pressurized pipeline and the air pressure in the pressurized building in real time during the pressurization process, and recording the gas volume flow rate data and the air pressure data; fitting the recorded gas volume flow rate data and the air pressure data respectively to obtain the flow rate versus time function Q(t) and the air pressure versus time function P(t); Derivatives of function Q(t) and function P(t) with respect to time t are obtained to obtain derivative functions and ; Select three time points , respectively substitute into the derivative function Evaluate in, and then use the formula Calculate and obtain three time points respectively The corresponding volume , and then ask The average value of the pressurized building is obtained to obtain the net pressurized volume of the pressurized building .

3. The quantifiable pressurized building airtightness test method according to claim 1, characterized in that: When it is detected that the air pressure inside the pressurized building does not exceed 10kPa, stop recording the air pressure data.

4. The quantifiable pressurized building airtightness test method according to claim 2, characterized in that: In the method for determining the pressurized net volume V of a pressurized building, when it is detected that the air pressure inside the pressurized building is greater than or equal to 100 Pa, the recording of air pressure data and gas volume flow data is stopped.

5. The quantifiable pressurized building airtightness test method according to claim 1, characterized in that: The time step for recording air pressure data is 2s~1min.

6. The quantifiable pressurized building airtightness test method according to claim 2, characterized in that: In the method for determining the net pressurized volume V of a pressurized building, the time step for recording the air pressure data and the gas volume flow data is 1 s to 1 min.

7. A pressurized building airtightness testing system for use in the pressurized building airtightness testing method according to any one of claims 1 to 6, characterized in that: It includes pressure detection device, control system, boosting equipment and boosting pipeline; The pressure detection device is arranged in the boosting building; the interior of the boosting building is connected to one end of the boosting pipeline, and the boosting equipment is arranged on the boosting pipeline; the pressure detection device and the boosting equipment are respectively connected to the control system; Electric valves and volume flow meters are respectively arranged on the boosting pipelines upstream and downstream of the boosting equipment, and the electric valves and volume flow meters are respectively connected to the control system; The pressure detection device is used to detect the air pressure inside the boosted building and send the air pressure data to the control system; the boosting equipment is used to transport air to the boosted building through the boosting pipeline for boosting; the volume flow meter is used to detect the gas volume flow in the boosting pipeline and send the gas volume flow data to the control system; the control system is used to control the opening and closing of the electric valve and the boosting equipment, and receive the air pressure data and the gas volume flow data.

8. The pressurized building airtightness testing system according to claim 7, characterized in that: The boosting equipment is one of an air compressor, a Roots blower, a vortex blower and a screw blower.

9. The pressurized building airtightness testing system according to claim 7, characterized in that: The pressure detection device is a pressure transmitter.

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