A method for testing air exchange rate

Abstract

The present application discloses an air exchange rate testing method, comprising: setting a non-normal pressure environment for a tested enclosed space by means of a fan device, and testing the air flow; obtaining a first correspondence between an abnormal pressure experimental porosity equivalent area determined under the abnormal pressure environment and the abnormal pressure experimental air flow, and obtaining an abnormal pressure experimental porosity equivalent area according to the air flow and the first correspondence; obtaining a second correspondence between a normal pressure experimental porosity equivalent area determined under a normal pressure environment and the normal pressure experimental air exchange rate; and obtaining the normal pressure experimental air exchange rate according to a preset relationship between the abnormal pressure experimental porosity equivalent area under the normal pressure environment and the normal pressure experimental porosity equivalent area, as well as the abnormal pressure experimental porosity equivalent area and the second correspondence; and obtaining the actual air exchange rate of the tested enclosed space according to the obtained first volume of the tested enclosed space, the second volume of the experimental enclosed space, and the normal pressure experimental air exchange rate.

Description

Technical Field

[0001] The present application relates to the field of air exchange rate testing, and in particular to an air exchange rate testing method. Background Art

[0002] At present, how to conduct shelter research and implementation has become a hot topic of concern for technicians in this field. In this regard, the prior art proposes two methods for detecting the airtightness of shelters. One is the pressure method, that is, a method of testing the airtightness of a closed container, which uses a compressor to pressurize to a specified pressure and analyzes the flow rate under the pressure through a flowmeter, and judges the airtightness of the closed container based on this flow rate. The other is the concentration decay method, that is, a method of judging the air exchange rate of a space by injecting a space tracer gas and measuring the concentration of the tracer gas as the leakage decays. However, the pressure method can only detect the airtightness of a pressurized shelter room, and the concentration decay method is subject to specific environmental restrictions. For example, the structure of the house to be tested must be simple and it must be an independent house. It is greatly affected by the structure of the house and is difficult to promote and apply.

[0003] It can be seen that how to accurately obtain the air exchange rate of a complex housing environment under normal pressure has become a problem that needs to be solved urgently by technical personnel in this field. Summary of the invention

[0004] The present application provides a method for testing the porosity equivalent area of ​​a confined space to solve the problem of how to accurately obtain the air exchange rate of a complex housing environment under normal pressure in the prior art.

[0005] The present application provides an air exchange rate testing method, comprising:

[0006] Setting an extraordinary pressure environment for the tested confined space by means of a fan device, and testing the air flow rate generated by the fan device under the extraordinary pressure environment;

[0007] Obtaining a first correspondence between an extraordinary pressure experimental porosity equivalent area and an extraordinary pressure experimental air flow rate determined in a pre-experiment under an extraordinary pressure environment, and obtaining an extraordinary pressure experimental porosity equivalent area corresponding to the air flow rate based on the air flow rate and the first correspondence;

[0008] A second corresponding relationship between a normal pressure experimental porosity equivalent area and a normal pressure experimental air exchange rate determined in a pre-experiment under a normal pressure environment is obtained; and based on a preset relationship between an extraordinary pressure experimental porosity equivalent area and a normal pressure experimental porosity equivalent area under a normal pressure environment, and the extraordinary pressure experimental porosity equivalent area and the second corresponding relationship, the normal pressure experimental air exchange rate corresponding to the extraordinary pressure experimental porosity equivalent area is obtained;

[0009] Obtain a first volume of the tested enclosed space and a second volume of the experimental enclosed space, and obtain an actual air exchange rate of the tested enclosed space based on the first volume, the second volume and the normal pressure experimental air exchange rate; wherein the actual air exchange rate of the tested enclosed space is the air exchange rate under normal pressure.

[0010] Preferably, the step of obtaining a first corresponding relationship between an abnormal pressure experimental porosity equivalent area and an abnormal pressure experimental air flow rate determined in a previous experiment under an abnormal pressure environment includes:

[0011] Setting different groups of openings on the experimental box and selecting the number of openings in each group; the openings on the experimental box are used to simulate the pores existing in houses in the real world;

[0012] Obtaining the normal pressure experimental porosity equivalent area of ​​the openings under the number of openings in each group, and obtaining the normal pressure experimental air flow corresponding to the normal pressure experimental porosity equivalent area;

[0013] According to the extraordinary pressure experimental porosity equivalent area and the corresponding extraordinary pressure experimental air flow rate under each group, a first corresponding relationship between the extraordinary pressure experimental porosity equivalent area and the extraordinary pressure experimental air flow rate is established.

[0014] Preferably, the method of setting different groups of openings on the test box and selecting the number of openings in each group includes:

[0015] At the same temperature, set different groups of openings on the test box and select the number of openings in each group; or

[0016] At different temperatures, different groups of openings are set on the experimental box, and the number of openings in each group is selected.

[0017] Preferably, the method further comprises: no opening is provided on the test box or the opening is closed, the corresponding abnormal pressure test porosity equivalent area is zero, and the abnormal pressure test air flow corresponding to the abnormal pressure test porosity equivalent area being zero is the background abnormal pressure test air flow, and the background abnormal pressure porosity equivalent area is obtained according to the background abnormal pressure test air flow;

[0018] Accordingly, obtaining the normal pressure experimental porosity equivalent area of ​​the openings under the number of openings in each group, and obtaining the normal pressure experimental air flow corresponding to the normal pressure experimental porosity equivalent area, includes:

[0019] The normal pressure experimental porosity equivalent area of ​​the openings under the number of openings in each group is obtained by including the sum of the background normal pressure porosity equivalent area and the normal pressure experimental porosity equivalent area of ​​the openings under the number of openings;

[0020] The extraordinary pressure experimental air flow corresponding to the extraordinary pressure experimental porosity equivalent area is obtained as the sum of the background extraordinary pressure experimental air flow and the extraordinary pressure experimental air flow corresponding to the extraordinary pressure experimental porosity equivalent area.

[0021] Preferably, the step of obtaining a second corresponding relationship between a normal pressure experimental porosity equivalent area and a normal pressure experimental air exchange rate determined in a preliminary experiment under a normal pressure environment comprises:

[0022] The atmospheric pressure experimental porosity equivalent area of ​​each group is tested by the missing gas attenuation method to obtain the slope of different test points of each group; the test point is the test time point corresponding to the gas concentration data of the gas concentration gradually decreasing over time;

[0023] The slopes of each test point are summed and the average value is obtained to determine the group normal pressure experimental air exchange rate of each group;

[0024] According to the group normal pressure experimental air exchange rate of each group and the normal pressure experimental porosity equivalent area of ​​the corresponding group, a second corresponding relationship between the normal pressure experimental porosity equivalent area and the normal pressure experimental air exchange rate is established.

[0025] Preferably, it also includes:

[0026] Obtain the residual ratios of different test points of each group, sum the residual ratios of each test point and obtain the average value to determine the group residual ratio of each group;

[0027] The group residual ratios for each group are summed to obtain the maximum residual ratio for the test;

[0028] The maximum residual ratio is compared with a preset threshold value. If the maximum residual ratio is less than the preset threshold value, a second corresponding relationship between the porosity equivalent area of ​​the normal pressure experiment and the air exchange rate of the normal pressure experiment is established.

[0029] Preferably, the preset relationship between the porosity equivalent area of ​​the normal pressure experiment under the normal pressure environment and the porosity equivalent area of ​​the normal pressure experiment is specifically:

[0030] Under normal pressure environment, the porosity equivalent area of ​​the extraordinary pressure experiment is equal to the porosity equivalent area of ​​the normal pressure experiment.

[0031] Preferably, obtaining the first volume of the tested confined space and the second volume of the experimental confined space, and obtaining the actual air exchange rate of the tested confined space according to the first volume, the second volume and the normal pressure experimental air exchange rate, comprises:

[0032] A calculation formula is established based on the first volume, the second volume, the normal pressure experimental air exchange rate, and the actual air exchange rate, and the calculation formula is:

[0033]

[0034] Among them, E h Indicates the air exchange rate of the tested confined space, E s Indicates the air exchange rate of the experimental enclosed space measured under the experimental environment; V h Represents the first volume of the tested confined space; V s Represents the second volume of the experimental confined space under the experimental environment.

[0035] Preferably, the pressure under the extraordinary pressure environment is 50Pa.

[0036] The present application also provides an air exchange rate testing device, including:

[0037] An air flow test unit, used to set an abnormal pressure environment for the tested confined space through a fan device, and test the air flow generated by the fan device under the abnormal pressure environment;

[0038] The abnormal pressure experiment porosity equivalent area obtaining unit is used to obtain a first corresponding relationship between the abnormal pressure experiment porosity equivalent area determined in a previous experiment under an abnormal pressure environment and the abnormal pressure experiment air flow rate, and obtain the abnormal pressure experiment porosity equivalent area corresponding to the air flow rate according to the air flow rate and the first corresponding relationship;

[0039] A normal pressure experiment air exchange rate obtaining unit is used to obtain a second corresponding relationship between a normal pressure experiment porosity equivalent area determined in a normal pressure environment in advance and the normal pressure experiment air exchange rate; and according to a preset relationship between an extraordinary pressure experiment porosity equivalent area and a normal pressure experiment porosity equivalent area under normal pressure environment, and the extraordinary pressure experiment porosity equivalent area and the second corresponding relationship, obtain the normal pressure experiment air exchange rate corresponding to the extraordinary pressure experiment porosity equivalent area;

[0040] The actual air exchange rate obtaining unit is used to obtain the first volume of the tested enclosed space and the second volume of the experimental enclosed space, and obtain the actual air exchange rate of the tested enclosed space based on the first volume, the second volume and the normal pressure experimental air exchange rate; wherein the actual air exchange rate of the tested enclosed space is the air exchange rate under normal pressure.

[0041] Compared with the prior art, this application has the following advantages:

[0042] The present application provides an air exchange rate testing method, comprising:

[0043] Setting an extraordinary pressure environment for the tested confined space by means of a fan device, and testing the air flow rate generated by the fan device under the extraordinary pressure environment;

[0044] Obtaining a first correspondence between an extraordinary pressure experimental porosity equivalent area and an extraordinary pressure experimental air flow rate determined in a pre-experiment under an extraordinary pressure environment, and obtaining an extraordinary pressure experimental porosity equivalent area corresponding to the air flow rate based on the air flow rate and the first correspondence;

[0045] A second corresponding relationship between a normal pressure experimental porosity equivalent area and a normal pressure experimental air exchange rate determined in a pre-experiment under a normal pressure environment is obtained; and based on a preset relationship between an extraordinary pressure experimental porosity equivalent area and a normal pressure experimental porosity equivalent area under a normal pressure environment, and the extraordinary pressure experimental porosity equivalent area and the second corresponding relationship, the normal pressure experimental air exchange rate corresponding to the extraordinary pressure experimental porosity equivalent area is obtained;

[0046] Obtain a first volume of the tested enclosed space and a second volume of the experimental enclosed space, and obtain an actual air exchange rate of the tested enclosed space based on the first volume, the second volume and the normal pressure experimental air exchange rate; wherein the actual air exchange rate of the tested enclosed space is the air exchange rate under normal pressure.

[0047] The air exchange rate testing method provided in the embodiment of the present application establishes a corresponding relationship between the porosity equivalent area of ​​an extraordinary pressure experiment under an extraordinary pressure environment and the air flow rate of an extraordinary pressure experiment, and establishes a corresponding relationship between the porosity equivalent area of ​​a normal pressure experiment under a normal pressure environment and the air exchange rate of a normal pressure experiment, thereby forming a relationship between the air flow rate of an extraordinary pressure experiment under an extraordinary pressure environment and the air exchange rate of a normal pressure experiment under a normal pressure environment, so as to solve the problem that the pressure testing method cannot measure the air exchange rate under normal pressure. The pressure testing method is successfully applied to the air exchange rate under normal pressure, and the air exchange rate in a complex house can be accurately obtained. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present application. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0049] Figure 1 A flow chart of an air exchange rate testing method provided in an embodiment of the present application.

[0050] Figure 2A schematic diagram of the fitting results of the extraordinary pressure porosity equivalent area and the extraordinary pressure experimental air flow test data provided in the embodiments of the present application.

[0051] Figure 3 A schematic diagram of a pore area and flow rate relationship curve provided in an embodiment of the present application.

[0052] Figure 4 A schematic diagram of the residual distribution of pore area and flow fitting provided in the embodiments of the present application.

[0053] Figure 5 A schematic diagram of the fitting results of equivalent pore area and air exchange rate provided for the examples of the present application.

[0054] Figure 6 A schematic diagram of the residuals of the pore area and air exchange rate test fitting results provided in the embodiments of the present application.

[0055] Figure 7 A schematic diagram of an air exchange rate testing device provided in an embodiment of the present application.

[0056] Figure 8 A schematic diagram of actual house air exchange rate provided in an embodiment of the present application. DETAILED DESCRIPTION

[0057] Many specific details are described in the following description to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar generalizations without violating the connotation of the present application. Therefore, the present application is not limited to the specific embodiments disclosed below.

[0058] Therefore, how to conduct shelter research and implementation has become a hot topic of concern for technicians in this field. In this regard, the prior art proposes two methods for detecting the air tightness of shelters. One is the pressure method, that is, a method of testing the air tightness of a closed container, which uses a compressor to pressurize to a specified pressure and analyzes the flow rate under the pressure through a flowmeter, and judges the air tightness of the closed container based on this flow rate. One is the concentration decay method, that is, a method of judging the air exchange rate of a space by injecting a space tracer gas and measuring the concentration of the tracer gas as the leakage decays. However, the pressure method can only detect the airtightness of a pressurized shelter room, and the concentration decay method is subject to specific environmental restrictions. For example, the structure of the house to be tested must be simple and it must be an independent house. It is greatly affected by the house structure and is difficult to promote and apply. In this regard, the embodiment of the present application provides an air exchange rate test method to solve the problem of how the prior art can achieve accurate air exchange rate acquisition under normal pressure.

[0059] The present application embodiment provides a method for testing air exchange rate. Figure 1 As shown, Figure 1 This is a flow chart of an embodiment of an air exchange rate testing method provided in an embodiment of the present application, wherein the method comprises the following steps:

[0060] Step S101, setting an extraordinary pressure environment for the tested enclosed space by using a fan device, and testing the air flow generated by the fan device in the extraordinary pressure environment.

[0061] In this step, the tested confined space refers to a confined space that may be used as a shelter, and this confined space has been conventionally sealed according to the general sealing requirements for shelters. The tested confined space is a non-independent space, and its spatial structure is similar to the complex structure of a real house. However, although the tested confined space is sealed, it still has a gap with the outside world, and there is gas exchange, that is, the so-called "sealed" of the tested confined space is relative, that is, conventional sealing measures such as closing windows and doors are taken, rather than being absolutely sealed from the outside world. The shelter after taking the above-mentioned conventional sealing measures is the object of the air exchange rate test of this method.

[0062] The air exchange rate is a measure of the amount of air added to or removed from a space (usually a room or house) per unit time divided by the volume of the space.

[0063] The air flow rate refers to the mass of air flowing out of the house or in from the outside to the inside per unit time, converted into the volume under the normal pressure of the house (i.e., normal pressure). The air flow rate in this embodiment is usually tested under pressure, so the volume needs to be converted to normal pressure (i.e., normal pressure).

[0064] In order to test and obtain the air exchange rate of the tested confined space, this embodiment needs to set a non-normal pressure environment for the tested confined space through a fan device, and test the air flow rate generated by the fan device under the non-normal pressure environment. Wherein, in this embodiment, the pressure under the non-normal pressure environment is 50Pa. Setting a non-normal pressure environment for the tested confined space through a fan device includes: sucking or injecting air into the tested confined space through a fan device, causing an air pressure difference inside and outside the confined space. In this embodiment, it specifically refers to using a fan device to first increase the pressure of the tested confined space to a certain value, so that the pressure difference between the tested confined space and the outside world reaches the pressure difference value required for the test, and then testing the corresponding air flow rate generated by the fan device.

[0065] Step S101, obtain a first correspondence between an extraordinary pressure experimental porosity equivalent area and an extraordinary pressure experimental air flow determined in a preliminary experiment under an extraordinary pressure environment, and obtain an extraordinary pressure experimental porosity equivalent area corresponding to the air flow based on the air flow and the first correspondence.

[0066] After obtaining the air flow rate of the tested confined space in the extraordinary pressure environment, the extraordinary pressure experimental porosity equivalent area corresponding to the air flow rate in the extraordinary pressure environment can be further obtained. In this embodiment, in order to obtain the extraordinary pressure experimental porosity equivalent area corresponding to the air flow rate in the extraordinary pressure environment, a first correspondence between the extraordinary pressure experimental porosity equivalent area determined in a pre-experiment under the extraordinary pressure environment and the extraordinary pressure experimental air flow rate is obtained, and according to the air flow rate and the first correspondence, the extraordinary pressure experimental porosity equivalent area corresponding to the air flow rate is obtained.

[0067] Among them, obtaining the first corresponding relationship between the porosity equivalent area of ​​the extraordinary pressure experiment determined in the extraordinary pressure environment in advance and the air flow of the extraordinary pressure experiment includes: first, setting a test box, one of the side panels of the test box is set as a detachable side panel, and a plurality of openings of different specifications are set on the detachable side panel, and different groups of openings on the test box can be set by blocking the openings or replacing the detachable side panels, that is, setting different groups of openings on the test box, and selecting the number of openings in each group; wherein, the openings on the test box are used to simulate the pores existing in the house in the real world. The test box can flexibly install the opening sizes of different detachable side panels to achieve the corresponding functions of different opening sizes. For example, the openings with a diameter of 6.6mm are used to measure the internal air pressure and can complete the pressurization experiment. In addition, the functions of openings of different sizes are also different. Specifically, there are 1-12 openings with a diameter of 4mm, which can respectively simulate the air tightness of houses with an area of ​​1 times, 2 times, 3 times...12 times the area of ​​4mm openings. The number of 10mm diameter openings is 1-7, which can simulate the air tightness of a house with an area of ​​10mm openings 1, 2, 3, ... 7 times the area of ​​10mm openings. The number of 20mm diameter openings is 1-6, which can simulate the air tightness of a house with an area of ​​20mm openings 1, 2, 3, ... 6 times the area of ​​20mm openings. The number of 40mm diameter openings is 1-5, which can simulate the air tightness of a house with an area of ​​40mm openings 1, 2, 3, ... 5 times the area of ​​40mm openings.

[0068] In addition, in this embodiment, different groups of openings are set on the experimental box, and the number of openings in each group is selected, including: at the same temperature, different groups of openings are set on the experimental box, and the number of openings in each group is selected; or at different temperatures, different groups of openings are set on the experimental box, and the number of openings in each group is selected.

[0069] After obtaining the number of openings in each group, the normal pressure experimental porosity equivalent area of ​​the openings under the number of openings in each group can be obtained, and the normal pressure experimental air flow corresponding to the normal pressure experimental porosity equivalent area can be obtained. Among them, the normal pressure experimental porosity equivalent area can be obtained by direct measurement, and the normal pressure experimental air flow can be measured by fan equipment. Please refer to the corresponding measurement results of openings in different groups under normal pressure environment in Table 1 below.

[0070] Temperature Opening Total opening area flow 25.5 Containment 0 0.1043 24.1 1 row 1 1262.917499 26.41 23.6 1 row 2 2510.558121 53.64 23.7 1 row 3 3751.323268 82.14 24 1 row 4 4977.566962 110.5 23.9 1 row 4; 2 rows 1 5288.643134 118.1868 23.9 1st column 4; 2nd column 3 5893.626533 132.1014 24.5 1st column 4; 2nd column 5 6520.580581 146.5214 24.7 1st column 4; 2nd column 6; 3rd column 3 7065.605479 159.0569 25 1st column 4; 2nd column 6; 3rd column 7; 4th column 5 7407.434811 166.919 25.1 3 columns 6; 2 columns 2 1055.206289 26.22 25.4 3 columns 6; 2 columns 4 1669.11301 39.91 25.3 3 columns 6; 2 columns 6 2299.945857 56.07 25.3 2 columns 1; 3 columns 2 467.3695494 10.17 25.6 2 columns 1; 3 columns 4 608.6738233 13.82 25.6 2 columns 1; 3 columns 7 828.2680225 19.42 25.9 3 columns 1 80.13071539 2.896 25.9 3 columns 1; 4 columns 12 206.5622746 6.57

[0071] Table 1

[0072] It should be noted that, in actual situations, even if the airtightness of the house is very high, there are still gaps that are invisible to the naked eye, that is, when the extraordinary-pressure experimental porosity equivalent area is zero, there is still an extraordinary-pressure experimental air flow. In this embodiment, no openings are set on the test box or the openings are closed, and the corresponding extraordinary-pressure experimental porosity equivalent area is zero, and the extraordinary-pressure experimental air flow corresponding to the extraordinary-pressure experimental porosity equivalent area of ​​zero is the background extraordinary-pressure experimental air flow, and the background extraordinary-pressure porosity equivalent area is obtained based on the background extraordinary-pressure experimental air flow. Figure 2 As shown, Figure 2 This is a schematic diagram of the fitting results of the extraordinary pressure porosity equivalent area and the extraordinary pressure experimental air flow test data. Figure 2 The fitting results shown in the figure show that the background pore area is 4.646mm after back-calculating the air flow rate in the non-normal pressure experiment. 2 .

[0073] Correspondingly, the obtaining of the extraordinary pressure experimental porosity equivalent area of ​​the openings under the number of openings in each group, and the obtaining of the extraordinary pressure experimental air flow corresponding to the extraordinary pressure experimental porosity equivalent area, include: obtaining the extraordinary pressure experimental porosity equivalent area of ​​the openings under the number of openings in each group as the sum of the background extraordinary pressure porosity equivalent area and the extraordinary pressure experimental porosity equivalent area of ​​the openings under the number of openings. Obtaining the extraordinary pressure experimental air flow corresponding to the extraordinary pressure experimental porosity equivalent area as the sum of the background extraordinary pressure experimental air flow and the extraordinary pressure experimental air flow corresponding to the extraordinary pressure experimental porosity equivalent area. In this regard, the data in the above Table 1 can be adjusted as shown in Table 2.

[0074]

[0075]

[0076] Table 2

[0077] Finally, according to the normal pressure experimental porosity equivalent area and the corresponding normal pressure experimental air flow rate under each group, the first corresponding relationship between the normal pressure experimental porosity equivalent area and the normal pressure experimental air flow rate is established.

[0078] Specifically, in this embodiment, considering that the air velocity at 50 Pa is much lower than the speed of sound, it can be considered as a gap in the wall of an incompressible fluid. There are three types of openings. When the ratio of the length l to the diameter d of the opening is less than or equal to 0.5, it is called a thin-walled opening; when the ratio of the length l to the diameter d is greater than 4, it is called a slender hole; when 0.5 is less than l / d and less than or equal to 4, it is called a short hole (or thick-walled hole). These opening flow formulas can be used to derive a general formula using the Bernoulli equation: q v =KAΔp m ; Where K represents the coefficient determined by the shape, size and liquid properties of the hole; for elongated holes For short holes and thin-walled holes, A represents the cross-sectional area of ​​the hole; m represents the pressure difference at both ends of the hole; m represents the index determined by the aspect ratio of the hole: for slender holes: m = 1, for thin-walled small holes: m = 0.5, for short holes: m = 0.5-1.

[0079] When the pressure difference remains unchanged, the average velocity in the pore remains unchanged. Therefore, the air flow rate (normal pressure experiment) is linearly related to the pore equivalent area (normal pressure experiment). The experimental data are as follows: Figure 3 As shown, Figure 3 It is a schematic diagram of the relationship between the pore equivalent area and the air flow rate, such as Figure 3 As shown in the figure, it is the fitting result of pore equivalent area and air flow rate at 50Pa. The fitting formula is as follows: Q = 0.02243 × A; A refers to the pore equivalent area; Q refers to the air flow rate (m 3 / h). Perform statistical analysis on the fitting results and test values ​​to determine whether the experimental results are correct. Figure 4 As shown, Figure 4 This is a schematic diagram of the residual distribution of the pore equivalent area and air flow fitting. The fitting results are compared with the measured results. The significant P value is: 0, and the correlation coefficient R 2 :0.99957, since its P value <<0.01, the test results show that the model results are significantly correlated with the test results. Measurement result correlation coefficient R 2 >99.9%, indicating that the result has a confidence level of more than 99.9%, thus establishing the first corresponding relationship between the porosity equivalent area of ​​the extraordinary pressure experiment and the air flow rate of the extraordinary pressure experiment.

[0080] It should be noted that for the equivalent pore area A, since all holes are circular in laboratory environment, its K value remains a constant. A can be used to represent the relationship between flow rate and area, and the K value is omitted. For example, in the actual process, K1A1 is measured to represent the relationship between pressure and flow rate. Under laboratory conditions, kA represents the pressure-flow relationship. When the pressure and flow are equal, K1A1=KA. Since K is a constant here, A is used to represent K1A1 as an equivalent pore area.

[0081] Step S103, obtaining a second corresponding relationship between the normal pressure experimental porosity equivalent area determined in advance in a normal pressure environment and the normal pressure experimental air exchange rate; and according to the preset relationship between the extraordinary pressure experimental porosity equivalent area and the normal pressure experimental porosity equivalent area under normal pressure environment, as well as the extraordinary pressure experimental porosity equivalent area and the second corresponding relationship, obtaining the normal pressure experimental air exchange rate corresponding to the extraordinary pressure experimental porosity equivalent area.

[0082] Among them, in this step, the second corresponding relationship between the normal pressure experimental porosity equivalent area determined in the previous experiment under normal pressure environment and the normal pressure experimental air exchange rate is obtained, including: the normal pressure experimental porosity equivalent area of ​​each group is tested by the missing gas attenuation method to obtain the slope of different test points of each group. Among them, the test point is the gas concentration data corresponding to the test time point of the gas concentration of the detection gas decreasing over time. Then, the slopes of each test point are summed and the average value is obtained to determine the group normal pressure experimental air exchange rate of each group. The test results are shown in Table 3:

[0083]

[0084]

[0085] Table 3

[0086] Furthermore, in order to verify the credibility of the results, it also includes: obtaining the residual ratio of different test points in each group, summing the residual ratios of each test point and obtaining the average value to determine the group residual ratio of each group. Then, summing the group residual ratios of each group to obtain the maximum residual ratio of the test, and finally, comparing the maximum residual ratio with a preset threshold value. If the maximum residual ratio is less than the preset threshold value, a second corresponding relationship between the porosity equivalent area of ​​the normal pressure experiment and the air exchange rate of the normal pressure experiment is established. Among them, the residual ratios of the air exchange rate measurement points are shown in Table 4.

[0087]

[0088]

[0089] Table 4

[0090] As shown in Table 4, the maximum residual ratio of the test results is 4.77%, which means that all the calculated results are above the 95% confidence interval and the experimental results are credible.

[0091] In this embodiment, the second corresponding relationship between the porosity equivalent area of ​​the normal pressure experiment and the air exchange rate of the normal pressure experiment is established specifically by establishing the second corresponding relationship between the porosity equivalent area of ​​the normal pressure experiment and the air exchange rate of the normal pressure experiment according to the group normal pressure experiment air exchange rate of each group and the porosity equivalent area of ​​the corresponding group. Wherein, when the opening area and the house volume remain unchanged, under the same pressure difference, the house volume, p, p 0 are constants, so the atmospheric pressure test air exchange rate is proportional to the atmospheric pressure test porosity equivalent area. Therefore, the experimental results can be linearly fitted to find out their relationship. The fitting results are as follows: Figure 5 As shown, Figure 5 This is a schematic diagram of the fitting results of pore equivalent area and air exchange rate. According to the fitting results, we obtained the fitting results of air exchange rate and pore equivalent area according to the theoretical model as follows: E = 4.49372 × 10 -6 A, where A is the equivalent pore area. It should be noted that under normal pressure in the refuge room environment, there will be a pressure difference of ±xPa, and it cannot be guaranteed to be 0Pa (balance), so the relationship between its flow rate and pressure is equal to that under 50Pa, that is, there is a K1A1 relationship, which has a corresponding KA value in the laboratory. Since the K value in the laboratory is a constant, the A value is the same, and the corresponding air exchange rate is also the same, which explains the corresponding relationship between the laboratory air exchange rate and the actual air exchange rate at normal pressure.

[0092] Furthermore, the fitting results and the test values ​​were statistically analyzed to analyze their correlation. The results are as follows: Figure 6 As shown; Figure 6 This is a schematic diagram of the residual error of the pore equivalent area and air exchange rate test fitting results. The fitting results are compared with the measured results, and the significant P value is: 0, the correlation coefficient R 2 :0.99102, since its P value <<0.01, the test results show that the model results are significantly correlated with the test results. Measurement result correlation coefficient R 2 >99%, indicating that the result has a confidence level of more than 99%, thus establishing a second corresponding relationship between the porosity equivalent area of ​​the normal pressure experiment and the air exchange rate of the normal pressure experiment.

[0093] After obtaining the second corresponding relationship between the normal pressure experimental porosity equivalent area and the normal pressure experimental air exchange rate determined in the pre-experiment under normal pressure environment, it is also necessary to obtain the preset relationship between the normal pressure experimental porosity equivalent area and the normal pressure experimental porosity equivalent area under normal pressure environment, wherein the preset relationship between the normal pressure experimental porosity equivalent area and the normal pressure experimental porosity equivalent area under normal pressure environment is specifically: under the experimental environment, the normal pressure experimental porosity equivalent area is equal to the normal pressure experimental porosity equivalent area. Finally, according to the preset relationship between the normal pressure experimental porosity equivalent area and the normal pressure experimental porosity equivalent area under normal pressure environment, as well as the normal pressure experimental porosity equivalent area and the second corresponding relationship, the normal pressure experimental air exchange rate corresponding to the normal pressure experimental porosity equivalent area is obtained.

[0094] Step S104, obtaining the first volume of the tested enclosed space and the second volume of the experimental enclosed space, and obtaining the actual air exchange rate of the tested enclosed space based on the first volume, the second volume and the normal pressure experimental air exchange rate; wherein the actual air exchange rate of the tested enclosed space is the air exchange rate under normal pressure.

[0095] After obtaining the normal-pressure experimental air exchange rate corresponding to the normal-pressure experimental porosity equivalent area, the first volume of the tested confined space and the second volume of the experimental confined space can be obtained, and based on the first volume, the second volume and the normal-pressure experimental air exchange rate, the actual air exchange rate of the tested confined space can be obtained.

[0096] Specifically, under normal pressure, when the pore area A in the laboratory is the same as the pore area A in the actual house, their Q is equal. s , the second volume V of the experimental confined space s , the first volume V of the tested confined space h , then the actual air exchange rate E of the tested enclosed space can be established h The calculation formula between:

[0097]

[0098] Among them, E h Indicates the air exchange rate of the tested confined space, E s Indicates the air exchange rate of the experimental enclosed space measured under the experimental environment; V h Represents the first volume of the tested confined space; V s Represents the second volume of the experimental confined space under the experimental environment.

[0099] The air exchange rate testing method provided in the present application establishes a corresponding relationship between the porosity equivalent area of ​​an extraordinary pressure experiment under an extraordinary pressure environment and the air flow rate of an extraordinary pressure experiment, and establishes a corresponding relationship between the porosity equivalent area of ​​a normal pressure experiment under a normal pressure environment and the air exchange rate of a normal pressure experiment, thereby forming a relationship between the air flow rate of an extraordinary pressure experiment under an extraordinary pressure environment and the air exchange rate of a normal pressure experiment under a normal pressure environment, so as to solve the problem that the pressure testing method cannot measure the air exchange rate under normal pressure. The pressure testing method is successfully applied to the air exchange rate under normal pressure, and the air exchange rate in a complex house can be accurately obtained.

[0100] The present application also provides a specific example, which is as follows:

[0101] A house was taken on site to verify the results. The embodiment of the present application provides a schematic diagram of the flow test results of the house under various pressures (not shown). During the test, multiple pressure results were tested around 50Pa, and finally fitted by fitting results. For example, the test results are shown in Table 5.

[0102]

[0103] Table 5

[0104] The test results were fitted, and the correlation was 0.99866, with a confidence level of >99%, indicating the feasibility of the test results. The final results obtained based on the fitting are shown in Table 6:

[0105]

[0106] Table 6

[0107] As shown in the table, the flow rate at 50PA is 185.27M 3 / H, based on this result, combined with the formula Q = 0.02243 × A, it can be calculated that the pore area is: 8259MM 2 , combined with the formula E = 4.49372 × 10 -6 A concluded that the laboratory air exchange rate under normal pressure is 0.0371MIN -1 , since the flow rate in the laboratory is equal to the actual flow rate in the house, then: Q s =E s V s ×60=Q h =E h V h ×60; where Q s Indicates the laboratory flow rate M 3 / H;E s Indicates the laboratory air exchange rate MIN-1; V s represents the volume of the laboratory refuge room; Q hIndicates the actual house flow M 3 / H;E h Indicates the actual room air exchange rate MIN -1 V h ; The actual house volume is 131.8M 3 ; The volume of the laboratory house is 2.2897M 3 According to the formula Q = 0.02243 × A, it can be calculated That is, the air exchange rate of the house when it is still and windless is 0.0645%.

[0108] However, in reality, it is difficult for a house to have a windless environment. Using the dynamic wind speed model, the air exchange rate result at a wind speed of 1 meter / s is calculated. The calculation method is as follows:

[0109] According to the wind speed model:

[0110] Where E represents the air exchange rate, k represents the comparison between the atmospheric wind speed and the wind speed in the gap, k = 2.53, A represents the porosity equivalent area, v 0 represents the positive atmospheric wind speed, v f Indicates the wind speed of molecular motion. The air exchange rate at a wind speed of 1m / s is compared to the air exchange rate at 0m / s: ΔE=60A / V×V 0 =1.4832×10 -3 ; then the actual room air exchange rate at 1m / s is: E = E h +ΔE=0.21282%min -1 For comparison, the house was monitored for a week, with a total of 59 attenuation tests, each lasting 2 hours and covering approximately 120 points. The test results are as follows: Figure 8 shown.

[0111] from Figure 8 However, it was learned that the actual air exchange rate monitored was between 0.05-0.35%. Due to the unstable wind speed outside the house, the average wind speed measured was around 1m / s, and the average of these 59 attenuation methods was 0.19%. These values ​​are basically consistent with the pressure method calculation this time.

[0112] Corresponding to the above method embodiment, the present application also provides an air exchange rate testing device embodiment corresponding to the air exchange rate testing method embodiment, such as Figure 7 As shown, Figure 7 This is a schematic diagram of an air exchange rate test device provided in an embodiment of the present application. Since the device embodiment is basically similar to the method embodiment, the description is relatively simple. For relevant parts, please refer to the partial description of the method embodiment. The device embodiment described below is only illustrative.

[0113] Please refer to Figure 6 The air exchange rate testing device comprises: an air flow testing unit 701, which is used to set a non-normal pressure environment for the tested enclosed space through a fan device, and test the air flow generated by the fan device under the non-normal pressure environment; a non-normal pressure experimental porosity equivalent area obtaining unit 702, which is used to obtain a first corresponding relationship between the non-normal pressure experimental porosity equivalent area determined in a pre-experiment under a non-normal pressure environment and the non-normal pressure experimental air flow, and obtain the non-normal pressure experimental porosity equivalent area corresponding to the air flow according to the air flow and the first corresponding relationship; a normal pressure experimental air exchange rate obtaining unit 703, which is used to obtain the normal pressure experimental porosity equivalent area determined in a pre-experiment under a normal pressure environment and the normal pressure experimental air flow. a second corresponding relationship of the normal-pressure experimental air exchange rate; and according to the preset relationship between the normal-pressure experimental porosity equivalent area and the normal-pressure experimental porosity equivalent area under normal-pressure environment, as well as the normal-pressure experimental porosity equivalent area and the second corresponding relationship, obtain the normal-pressure experimental air exchange rate corresponding to the normal-pressure experimental porosity equivalent area; an actual air exchange rate obtaining unit 704 is used to obtain the first volume of the tested enclosed space and the second volume of the experimental enclosed space, and according to the first volume, the second volume and the normal-pressure experimental air exchange rate, obtain the actual air exchange rate of the tested enclosed space; wherein, the actual air exchange rate of the tested enclosed space is the air exchange rate under normal pressure.

[0114] In summary, the testing method for the porosity equivalent area of ​​a confined space provided in the present application can solve the problem that the pressure testing method cannot be applied to the test of the air exchange rate of the tested confined space in a normal pressure environment. At the same time, it can also avoid the problem that the porosity equivalent area of ​​the actual confined space cannot be accurately and directly tested due to the pores between the building and the outside world cannot be directly observed by the naked eye or have irregular shapes, and the data obtained even after time-consuming and laborious testing is not accurate enough. The testing method for the porosity equivalent area of ​​a confined space provided in the present application can conveniently and accurately obtain the air exchange rate of the tested confined space in a normal pressure environment, thereby providing a data basis for establishing a theoretical data model and evaluation technical method for the confined space.

[0115] The above is a detailed introduction to the embodiment of a method for testing the porosity equivalent area of ​​a confined space provided by the present application. Specific examples are used herein to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method and its core idea of ​​the present application. At the same time, for those skilled in the art, according to the idea of ​​the present application, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be construed as a limitation on the present application. The scope of protection of the present application shall be based on the scope defined by the claims of the present application.

Claims

1. A method for testing air exchange rate, It is characterized in that include: Setting an extraordinary pressure environment for the tested confined space by means of a fan device, and testing the air flow rate generated by the fan device under the extraordinary pressure environment; Obtaining a first correspondence between an extraordinary pressure experimental porosity equivalent area and an extraordinary pressure experimental air flow rate determined in a pre-experiment under an extraordinary pressure environment, and obtaining an extraordinary pressure experimental porosity equivalent area corresponding to the air flow rate based on the air flow rate and the first correspondence; A second corresponding relationship between a normal pressure experimental porosity equivalent area and a normal pressure experimental air exchange rate determined in a pre-experiment under a normal pressure environment is obtained; and based on a preset relationship between an extraordinary pressure experimental porosity equivalent area and a normal pressure experimental porosity equivalent area under a normal pressure environment, and the extraordinary pressure experimental porosity equivalent area and the second corresponding relationship, the normal pressure experimental air exchange rate corresponding to the extraordinary pressure experimental porosity equivalent area is obtained; Obtaining a first volume of the tested enclosed space and a second volume of the experimental enclosed space, and obtaining an actual air exchange rate of the tested enclosed space according to the first volume, the second volume and the normal pressure experimental air exchange rate; wherein the actual air exchange rate of the tested enclosed space is the air exchange rate under normal pressure; The step of obtaining a first volume of the tested enclosed space and a second volume of the experimental enclosed space, and obtaining an actual air exchange rate of the tested enclosed space according to the first volume, the second volume and the normal pressure experimental air exchange rate, comprises: A calculation formula is established based on the first volume, the second volume, the normal pressure experimental air exchange rate, and the actual air exchange rate, and the calculation formula is: ； in, Indicates the air exchange rate of the tested confined space. It indicates the air exchange rate of the experimental enclosed space measured under the experimental environment; Represents the first volume of the tested confined space; Represents the second volume of the experimental confined space under the experimental environment.

2. The air exchange rate testing method according to claim 1, It is characterized in that The step of obtaining a first corresponding relationship between an extraordinary pressure experimental porosity equivalent area and an extraordinary pressure experimental air flow rate determined in a pre-experiment under an extraordinary pressure environment comprises: Setting different groups of openings on the experimental box and selecting the number of openings in each group; the openings on the experimental box are used to simulate the pores existing in houses in the real world; Obtaining the normal pressure experimental porosity equivalent area of ​​the openings under the number of openings in each group, and obtaining the normal pressure experimental air flow corresponding to the normal pressure experimental porosity equivalent area; According to the extraordinary pressure experimental porosity equivalent area and the corresponding extraordinary pressure experimental air flow rate under each group, a first corresponding relationship between the extraordinary pressure experimental porosity equivalent area and the extraordinary pressure experimental air flow rate is established.

3. The air exchange rate testing method according to claim 2, It is characterized in that The setting of different groups of openings on the experimental box and selecting the number of openings in each group include: At the same temperature, set different groups of openings on the test box and select the number of openings in each group; or At different temperatures, different groups of openings are set on the experimental box, and the number of openings in each group is selected.

4. The air exchange rate testing method according to claim 2, It is characterized in that Also includes: No opening is provided on the test box or the opening is closed, the corresponding extraordinary pressure test porosity equivalent area is zero, and the extraordinary pressure test air flow corresponding to the extraordinary pressure test porosity equivalent area being zero is the background extraordinary pressure test air flow, and the background extraordinary pressure porosity equivalent area is obtained according to the background extraordinary pressure test air flow; Accordingly, obtaining the normal pressure experimental porosity equivalent area of ​​the openings under the number of openings in each group, and obtaining the normal pressure experimental air flow corresponding to the normal pressure experimental porosity equivalent area, includes: The normal pressure experimental porosity equivalent area of ​​the openings under the number of openings in each group is obtained by including the sum of the background normal pressure porosity equivalent area and the normal pressure experimental porosity equivalent area of ​​the openings under the number of openings; The extraordinary pressure experimental air flow corresponding to the extraordinary pressure experimental porosity equivalent area is obtained as the sum of the background extraordinary pressure experimental air flow and the extraordinary pressure experimental air flow corresponding to the extraordinary pressure experimental porosity equivalent area.

5. The air exchange rate testing method according to claim 1, It is characterized in that The step of obtaining a second corresponding relationship between a normal pressure experimental porosity equivalent area determined in a pre-experiment under normal pressure and an air exchange rate of a normal pressure experiment comprises: The atmospheric pressure experimental porosity equivalent area of ​​each group is tested by the missing gas attenuation method to obtain the slope of different test points of each group; the test point is the test time point corresponding to the gas concentration data of the gas concentration gradually decreasing over time; The slopes of each test point are summed and the average value is obtained to determine the group normal pressure experimental air exchange rate of each group; According to the group normal pressure experimental air exchange rate of each group and the normal pressure experimental porosity equivalent area of ​​the corresponding group, a second corresponding relationship between the normal pressure experimental porosity equivalent area and the normal pressure experimental air exchange rate is established.

6. The air exchange rate testing method according to claim 5, It is characterized in that Also includes: Obtain the residual ratios of different test points of each group, sum the residual ratios of each test point and obtain the average value to determine the group residual ratio of each group; The group residual ratios for each group are summed to obtain the maximum residual ratio for the test; The maximum residual ratio is compared with a preset threshold value. If the maximum residual ratio is less than the preset threshold value, a second corresponding relationship between the porosity equivalent area of ​​the normal pressure experiment and the air exchange rate of the normal pressure experiment is established.

7. The air exchange rate testing method according to claim 1, It is characterized in that The preset relationship between the porosity equivalent area of ​​the normal pressure experiment and the porosity equivalent area of ​​the normal pressure experiment under the normal pressure environment is specifically: Under normal pressure environment, the porosity equivalent area of ​​the extraordinary pressure experiment is equal to the porosity equivalent area of ​​the normal pressure experiment.

8. The air exchange rate testing method according to claim 1, It is characterized in that The pressure under the extraordinary pressure environment is 50Pa.

9. An air exchange rate testing device, applied to the air exchange rate testing method according to any one of claims 1 to 8. It is characterized in that include: An air flow test unit, used to set an abnormal pressure environment for the tested confined space through a fan device, and test the air flow generated by the fan device under the abnormal pressure environment; The abnormal pressure experiment porosity equivalent area obtaining unit is used to obtain a first corresponding relationship between the abnormal pressure experiment porosity equivalent area determined in a previous experiment under an abnormal pressure environment and the abnormal pressure experiment air flow rate, and obtain the abnormal pressure experiment porosity equivalent area corresponding to the air flow rate according to the air flow rate and the first corresponding relationship; A normal pressure experiment air exchange rate obtaining unit is used to obtain a second corresponding relationship between a normal pressure experiment porosity equivalent area determined in a normal pressure environment in advance and the normal pressure experiment air exchange rate; and according to a preset relationship between an extraordinary pressure experiment porosity equivalent area and a normal pressure experiment porosity equivalent area under normal pressure environment, and the extraordinary pressure experiment porosity equivalent area and the second corresponding relationship, obtain the normal pressure experiment air exchange rate corresponding to the extraordinary pressure experiment porosity equivalent area; An actual air exchange rate obtaining unit is used to obtain a first volume of the tested enclosed space and a second volume of the experimental enclosed space, and obtain an actual air exchange rate of the tested enclosed space according to the first volume, the second volume and the normal pressure experimental air exchange rate; wherein the actual air exchange rate of the tested enclosed space is the air exchange rate under normal pressure; The step of obtaining a first volume of the tested enclosed space and a second volume of the experimental enclosed space, and obtaining an actual air exchange rate of the tested enclosed space according to the first volume, the second volume and the normal pressure experimental air exchange rate, comprises: A calculation formula is established based on the first volume, the second volume, the normal pressure experimental air exchange rate, and the actual air exchange rate, and the calculation formula is: ； in, Indicates the air exchange rate of the tested confined space. It indicates the air exchange rate of the experimental enclosed space measured under the experimental environment; Represents the first volume of the tested confined space; Represents the second volume of the experimental confined space under the experimental environment.

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