JP2003043058A - Method and system for evaluation of ventilation performance - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and a system for the evaluation of a ventilation performance wherein the ventilation performance of an indoor space or the like can be evaluated simply and properly without spending much time and labor. SOLUTION: First, measuring points A in a plurality of places are set mutually at intervals inside an evaluation object space 2 whose ventilation performance is to be evaluated, and wind velocities in the measuring points A are measured three-dimensionally (Fig. a). Then, interpolation points B are set in a plurality of places between the measuring points A or around them, and estimated wind velocities in the interpolation points B are estimated and computed three-dimensionally on the basis of their measured results (Fig. b). The distribution of the ventilation performance inside the space 2 is investigated on the basis of the measured results and their computed results (Fig. c).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and system for evaluating ventilation performance in an indoor space or the like, and more particularly to a technique for properly evaluating ventilation performance with a very simple method.

[0002]

2. Description of the Related Art In recent years, health problems caused by indoor chemical substances such as sick buildings, sick houses, and chemical hypersensitivity have become a problem, and the interest in indoor air quality is increasing. In order to improve the indoor air quality, it is necessary to take measures against pollutant sources such as building materials, finishing materials, interior materials, etc., and to properly understand the proper ventilation performance and appropriately improve indoor ventilation. is important. Conventionally, there have been the following methods for evaluating ventilation performance.

1) Step-up method Ventilation performance is evaluated. A tracer gas having a known concentration is mixed into the space to be evaluated through an air supply port, and the time-dependent change in the tracer gas concentration at the exhaust port is measured to raise the tracer gas concentration. The average ventilation performance in the evaluation target space is evaluated based on the characteristics.

2) Step-down method Ventilation performance is evaluated. When tracer gas is mixed and agitated so as to have a constant known concentration in the space to be evaluated, and when air supply is started, the time-dependent change in tracer gas concentration at the exhaust port. Is measured, and the average ventilation performance in the evaluation target space is evaluated based on the falling characteristics of the tracer gas concentration.

3) Pulse Method Ventilation Performance Evaluation When a tracer gas having a known concentration is mixed in a supply port into a space to be evaluated in a pulsed manner, the time variation of the concentration at the exhaust port is measured to determine the tracer gas concentration. The average ventilation performance in the evaluation target space is evaluated from the rising and falling characteristics.

4) Method using scavenger In the space to be evaluated for evaluating ventilation performance, a known pollution source with a constant amount of generation and a scavenger with known characteristics are installed.
By collecting this after a lapse of a certain time from the start of exposure / collection and analyzing the amount of pollutants collected in the scavenger,
Evaluate the average ventilation performance in the evaluation space during the exposure / collection time.

[0007]

However, these evaluation methods have the following problems. That is, in the method of using the tracer gas of 1) to 3), as the tracer gas, rare gases such as sulfur hexafluoride, nitrous oxide, ethane, and methane, which rarely exist in the natural world, must be used. Since these gases are toxic, suffocative, and flammable, they are very difficult to handle, and various problems occur when they are used in the actual field. In addition, the ventilation / air-conditioning system of a building often adopts a circulation system. Therefore, tracer gas that has been once exhausted may flow into the evaluation space through the circulation system and again through the air supply port. Yes, it was difficult to find out the exact ventilation performance.

In each of the methods 1) to 4), the gas concentration is analyzed by sampling air at regular time intervals, GC (Gas Chromatograph) or IGA (Infrared Gas Analyz).
er) requires analysis by an analyzer, etc., so it takes a great deal of time and cost, and only the average ventilation performance can be evaluated, and even the distribution of ventilation performance (stagnation or short path) It was very difficult to find out. In particular, in the method of 4), since the average characteristics within the exposure / collection time are obtained, it is difficult to accurately evaluate because the influence of the opening / closing of the door and the temperature change is included as an error.

The present invention has been made in view of such circumstances, and an object thereof is to eliminate the use of a tracer gas having various problems, and to save much labor and labor for analysis. In addition, it is another object of the present invention to provide a ventilation performance evaluation method and system capable of appropriately evaluating ventilation performance.

[0010]

In order to achieve such an object, in the ventilation performance evaluation method according to the present invention, a plurality of locations are provided at intervals in the evaluation target space for evaluating ventilation performance. Set the measurement points, measure the wind speed at each of these measurement points three-dimensionally,
Interpolation points are set over a plurality of locations between or around each of the measurement points, and the expected wind speed at each of these interpolation points is three-dimensionally calculated based on the result of the measurement, and the measurement result at each of these measurement points is set. Data for evaluating ventilation performance is obtained based on the calculation result of each interpolation point (Claim 1).

Further, the ventilation performance evaluation system according to the present invention is a three-dimensional system for three-dimensionally measuring wind velocities at measurement points set at a plurality of points spaced from each other in a space to be evaluated for evaluating ventilation performance. An air velocity measuring device and a computer device that obtains a measurement result from the three-dimensional air velocity measuring device and performs an operation based on the measurement result are provided, and the computer device includes a plurality of computer devices between or around the measurement points. Ventilation performance based on the means for three-dimensionally calculating the expected wind speed at the interpolation points set over the points based on the results of the measurement, and the measurement results of the measurement points and the calculation results of the interpolation points. And means for creating data for evaluating (claim 2).

In these methods and systems, the wind speed at the measurement points set in the space to be evaluated for evaluating the ventilation performance is measured three-dimensionally, and the mutual measurement points are measured based on the measurement results. The predicted wind speed at the interpolation points set between or around the space is calculated three-dimensionally, and the ventilation performance of the evaluation space is evaluated based on these measurement results and prediction results. Since it is not necessary to use it, it is possible to solve the problems such as the difficulty of handling and the difficulty of application to the site, which have occurred in the past. Further, since there is no analysis work as in the past, it is possible to solve the problem that it takes a lot of time for evaluation. Furthermore, in the present invention, the wind speed at each point set in the evaluation target space is measured or calculated, so that the distribution of ventilation performance in the evaluation target space can be known, and stagnation and short path can be investigated. As a result, the evaluation accuracy can be improved as compared with the conventional case.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a ventilation performance evaluation method and system according to the present invention will be described below with reference to the accompanying drawings.

=== Outline of the Invention === FIG. 1 schematically illustrates a ventilation performance evaluation method according to the present invention. In the ventilation performance evaluation method according to the present invention, first, as shown in FIG. 1 (a), measurement points A are set at a plurality of points in the evaluation target space 2 at intervals, and the measurement points A of these measurement points A are set. The wind speed is measured three-dimensionally. The measurement points A are set at equal intervals in the x direction, the y direction, and the z direction, for example, so that measurement can be performed over the entire evaluation target space 2. Thereby, the components of the wind speed in each three-dimensional direction at each measurement point A are obtained. For the measurement at each measurement point A, for example, a three-dimensional wind velocity measuring device such as an ultrasonic type is used. Besides this,
Any measuring device may be used as long as it can measure the wind speed at each measurement point three-dimensionally.

Next, based on the measurement results of these measurement points A, as shown in FIG. 1 (b), the expected wind speed at the interpolation points B set between or around the measurement points A is calculated. . Specifically, each measurement point A
The calculation is performed by setting the conditions that satisfy the continuity of the fluid (air) while reflecting the measurement result of. The detailed method will be described later. By setting the interpolation point B in this way, the continuous wind speed in the evaluation target space 2 can be grasped with a small number of measurement points.

Next, based on the measurement result of each measurement point A and the calculation result of each interpolation point B, data for evaluating the ventilation performance of the evaluation target space is obtained. Specifically, from the velocity field obtained based on the measurement result of each measurement point A and the calculation result of each interpolation point B, for example, by using a known advection-diffusion equation or the like, air is introduced into the evaluation target space 2. The advection distribution state is examined, and for example, a distribution state diagram as shown in FIG. 1C is created so that the age of air in the evaluation target space 2 can be grasped at a glance. As a result, data such as the air advection distribution status of the entire evaluation target space 2 is obtained.

The ventilation performance evaluation system according to the present invention is a system for implementing such a ventilation performance evaluation method, and as shown in FIG. 2, a three-dimensional wind speed for three-dimensionally measuring the wind speed at each measurement point. It is composed of a measuring device 4 and a computer device 6 which performs calculation based on the measurement result from the three-dimensional wind speed measuring device 4.

The computer device 6 three-dimensionally calculates the expected wind speed at the interpolation points set at a plurality of points around the measurement point based on the measurement result, the measurement result of each measurement point and each interpolation point. And means for creating data for evaluating ventilation performance based on the prediction result of. These means are realized as programs in the computer device 6. That is, the computer device is a program for calculating the expected wind speed of each interpolation point based on the measurement result of the three-dimensional wind speed measuring device, and based on the measurement result of each measurement point and the calculation result of each interpolation point. It is provided with a program for creating an air advection distribution map or the like as shown in FIG. 1C and displaying it on a screen or the like.

=== Example of Calculation of Predicted Wind Speed === An example of a method of calculating the predicted wind speed at each interpolation point in the ventilation performance evaluation method according to the present invention will be described.

<< Concept of Continuity >> This calculation method is shown in FIG.
As shown in (a), the evaluation target space is divided into a grid shape, a large number of rectangular parallelepiped minute spaces are virtually set, and attention is paid to the relationship between the inflow and outflow amounts of fluid (air) in each minute space. . In each minute space, the continuity of fluid (air) must balance the inflow of fluid (air) into each minute space and the outflow of fluid from each minute space. That is, the inflow amount of the fluid (air) flowing into each minute space and the outflow amount of the fluid (air) flowing out from each minute space must be exactly the same. If this condition is not satisfied, the concentration will be unduly increased or attenuated. That is, in the case of FIG. 4A, the inflow amount of the fluid (air) from the minute space is estimated to be large, and the fluid concentration C _{i, j, k} in the minute space becomes higher than it actually is. . In the case shown in FIG. 4B, the outflow amount of the fluid (air) from the minute space is estimated to be large, and the fluid concentration C _{i, j, k} in the minute space becomes lower than it actually is.

The wind speed at the center of each minute space is calculated using such conditions. The length of one side corresponding to each of the x, y, and z directions of the minute space is Δx, Δy, and Δz, respectively. In addition, the flux of the fluid at each interface of the minute space is expressed by u, x, y, and z, respectively.
v and w, and the flux of the fluid at each interface of this minute space is set as shown in FIG. If the balance of the inflow and outflow amount of fluid in this minute space is satisfied,
The following relational expression (1) is established.

[Equation 1] In addition, the left side of the relational expression (1) is described as a reciprocal rule, and the index i is described as a promise to take the sum in the x, y, and z directions.

Further, the following relational expression (2) is established in each lattice.

[Equation 2]

<< Method for Satisfying Continuity >> Next, in order to satisfy such a relational expression and reflect the measurement result by the three-dimensional wind speed measuring device, the following processing is performed. Here, HSMAC (Highly Simplified), which is generally well known in fluid simulation, is used.
A velocity / pressure mutual correction algorithm called Marker and Cell) is used in a modified form for this purpose. That is, here, it is assumed that the right side of Expression (1) is not set to “0” but is set to the residual ε, which is generally performed in the fluid simulation.

That is, the following equation (3) is used.

[Equation 3]

The velocity correction amount of this residual error ε is a function of pressure, and when this pressure correction amount δp is obtained, the following formula (4) is obtained.

[Equation 4]

In this equation (4), D is defined by the following equation (5).

[Equation 5]

In order to satisfy the continuity in each minute space, the speed correction amount δ obtained by the following equation (6)
It suffices to add u, δv, and δw to the tentatively obtained velocity components in each direction as shown in the following mathematical expression (7).

[Equation 6]

[Equation 7]

In the minute space in each lattice, since the lattice-divided minute regions are adjacent to the adjacent minute spaces, the following calculation is repeated for all the minute regions, and the space to be evaluated is repeated. The residual is converged to “0” as expressed by the following formula (8) in the entire area. In addition, in fact,
The residual ε is converged so as to be about 10 ⁻³ to 10 ⁻⁵ .

[Equation 8]

<< Spatial Interpolation Satisfying Continuity >> In the fluid simulation, the above-mentioned processing is executed for the entire evaluation target space, but in this embodiment, this processing is applied as a spatial interpolation algorithm. That is, in ordinary fluid simulation, the calculation of the momentum equation proceeds in the form of obtaining a temporary value of the velocity field of the entire space using an unknown pressure, so naturally, the velocity and pressure in all minute regions are corrected. Need to go. In this embodiment, since the method based on actual measurement is used, the true value is already determined by the actual measured value in some small spaces. Therefore, the velocity value is obtained so that continuity can be obtained in a minute space without an actual measurement value. This makes it possible to obtain a spatial interpolation value that satisfies continuity in the entire evaluation target space.

The specific method is as follows. That is, the measurement result at each measurement point is obtained as a three-dimensional velocity vector with the measurement point as the base point. On the other hand, the concept of continuity as described above is based on the flux of the velocity vector passing through each interface in the minute space in the lattice. This is the same as what is called staggered variable arrangement in fluid simulation.

In a sparsely-spaced grid space, it is not possible to find the flux of the velocity vector passing through the interfaces of all the minute spaces. Therefore, the temporary velocity at the center of the minute space where there is no measurement point is first calculated by linear interpolation or the like. I'll do it. Then, if the velocities of the fluid (air) at all the lattice points (including the true value and the tentative interpolation value) are obtained, the flux of the velocity vector at each interface can be tentatively obtained, and the velocity correction described above can be performed. It can be carried out.

The concept of this calculation method is illustrated in FIGS. First, it is assumed that each measurement point A is set as shown in FIG. The measurement value at this measurement point A becomes a true value. In the form including this measurement point A,
A lattice-shaped minute space C is set (FIG. 6). Here, a minute space C including the measurement point (true value) A and a minute space C not including the measurement point A are formed. Measurement point (true value) A
For a small space C that does not include the
(Mark) is set (FIG. 7). Flux can be obtained by creating data with temporary interpolation values. As a result, the flux (arrow in the figure) can be obtained as shown in FIG. 7 for the interfaces of all minute spaces (FIG. 8).

Then, the flux at each interface is corrected by the formula (6) so that the continuity is satisfied in all the minute spaces (FIG. 9). Further, the value of the center point (marked in the figure) is obtained from the flux of each interface obtained by this correction (FIG. 10). At this time, when the velocity at the center of the lattice is reproduced using the obtained interface flux, the velocity at the measurement point where the true value should have been obtained changes due to correction,
It will not be a true value. Therefore, the original measurement value is substituted again for the measurement point. Then, the flux at each interface of each micro space is calculated from the value of the center point of each micro space (including the true value and the other value). And again,
A process of correcting the flux at each interface is performed by the mathematical expression (6) so that the continuity is satisfied in all the small spaces, and this process is repeated, so that the amount of change in the value in all the small spaces has a predetermined convergence condition (for example, Residual error ε 10 ^-3 to 10
^-5 ) is satisfied.

By carrying out such a series of iterative processes, the spatially interpolated value of the velocity field that finally satisfies the continuity while reflecting the measured value can be obtained.

=== Evaluation Example of Ventilation Performance Using Spatial Interpolation Value of Velocity Field === The spatial interpolation value of the velocity field obtained by the above processing satisfies continuity, and based on this, Concentration calculations can be performed. The advection-diffusion equation of concentration is expressed by the following equation (9).
Represented by

[Equation 9]

Here, the velocity field u _i is obtained by spatial interpolation. If this equation is discretized and brought into a non-steady state analysis method, the same situation as the ordinary tracer gas method can be reproduced, and the ventilation performance of each part can be evaluated by aggregating the time-series changes in concentration for each minute region. It will be possible.

In addition, steady analysis was performed under the assumption of arbitrary uniform generation at all points, and the obtained concentration distribution was instantaneously uniformly diffused (if the substance generated in the target region was instantaneously and uniformly diffused). Normalized by the theoretical solution of the average concentration), the air age used in the ventilation performance evaluation (an index that indicates how many seconds have elapsed since the air was supplied) is the nominal ventilation time (of the ventilation frequency). Matches the value normalized by the reciprocal). Utilizing this property, it is also possible to obtain the distribution of ventilation performance from the steady-state analysis result of concentration. Generally, the latter method is preferable because the calculation time of the steady analysis is shorter than that of the unsteady analysis.

FIG. 11 is a flow chart showing the flow of a series of processes from setting of actual measurement values at measurement points to evaluation of ventilation performance. All such processing is executed by a computer program installed in the computer device according to the present invention.

=== Actual Evaluation Example === A test for evaluating the ventilation performance was conducted by actually applying the ventilation performance evaluation method and system according to the present invention. In this test, a measurement chamber 8 as shown in FIGS. 12 and 13 is manufactured,
The ventilation performance in this measurement room 8 was evaluated. The measuring chamber 8 has a cubic space of 2,500 mm × 2,400 mm × 1,920 mm defined inside, and 200 mm × 200 mm on each of the two opposite wall surfaces.
The air supply port 10 and the 180 mmφ exhaust port 12 are installed. In addition, a louver is installed at the air supply port 10,
In addition to obtaining the rectification effect in the above, it is possible to control the direction of the blown air flow. In addition, outside the measurement room 8,
A fan 14 for sending air to the air supply port 10 was provided near the air supply port 10, and the blowing speed thereof was 5.0 m / s. The exhaust port 12 is of a natural exhaust type.

FIG. 12 shows a measurement room having such a space.
And, as shown in FIG. 13, measurement points A were set at a plurality of points. The measurement points A were grid points, and there were a total of 100 points including 4 points in the x direction (500 mm intervals), 5 points in the y direction (400 mm intervals), and 5 points in the z direction (320 mm intervals).

A three-dimensional wind speed measuring device was installed at each measurement point A, and the three-dimensional wind speed at each measurement point A was measured. An ultrasonic measuring device was used as the three-dimensional wind speed measuring device. At each measurement point, to stabilize the air flow,
An interval of 60 seconds was set after the setting of the anemometer, and after continuous measurement for 30 seconds, an average value of the wind speed component in each axial direction for 30 seconds was obtained.

The measurement results at this time are shown in FIG.
It shows in (b). The measured value of the wind speed in the measurement chamber 8 can be obtained three-dimensionally.

Further, based on this measurement result, the expected wind speed at the interpolation points set around each measurement point A is calculated. Then, based on the measurement result of each measurement point A and the calculation result of each interpolation point, the air advection distribution state in the entire measurement chamber 2 is examined. 15 (a) to 15 (c) show an example of the progress of calculating the expected wind speed at the interpolation point from the measurement result at each measurement point A and examining the air advection distribution situation in the entire measurement chamber.

[0044]

According to the present invention, the wind speed at the measurement points set in the space to be evaluated for evaluating ventilation performance is measured three-dimensionally, and the measurement points are used to measure the wind speed between the measurement points. The tracer gas is used as in the past because the expected wind speed at the interpolation points set around it is calculated three-dimensionally, and data for evaluating ventilation performance is obtained based on these measurement results and prediction results. Therefore, it is possible to solve the problems such as the difficulty of handling and the difficulty of application in the field, which have occurred in the past. Further, since there is no analysis work as in the past, it is possible to solve the problem that it takes a lot of time for evaluation. Further, according to the present invention, since the wind speed at each point set in the evaluation target space is measured or calculated, the ventilation performance distribution in the evaluation target space can be known, and stagnation and short path can be investigated. As a result, the evaluation accuracy can be improved as compared with the conventional case.

[Brief description of drawings]

FIG. 1 is a diagram schematically illustrating a ventilation performance evaluation method according to the present invention.

FIG. 2 is a system configuration diagram schematically showing an embodiment of a ventilation performance evaluation system according to the present invention.

FIG. 3 is a diagram for explaining an example of a method for calculating a predicted wind speed at an interpolation point of the ventilation performance evaluation method and system according to the present invention, in particular, a method of dividing an evaluation target area into minute areas and a minute area interface. FIG. 6 is a diagram showing an index relating to a flux of a velocity vector in FIG.

FIG. 4 is a diagram for explaining an example of a method of calculating an expected wind speed at an interpolation point of the ventilation performance evaluation method and system according to the present invention, in which the flux of the velocity vector at the interface of the minute area is the amount of inflow and outflow. It is the figure which showed the case where the fluid concentration in a region was not correctly evaluated by mismatch.

FIG. 5 is a diagram for explaining an example of a method for calculating an expected wind speed at an interpolation point of the ventilation performance evaluation method and system according to the present invention, showing a three-dimensional wind speed measurement point in the evaluation target region. Is.

FIG. 6 is a diagram for explaining an example of a method of calculating an expected wind speed at an interpolation point of the ventilation performance evaluation method and system according to the present invention, in which a lattice-shaped minute space C is set so as to include a measurement point A. It is a figure which shows a state.

FIG. 7 is a diagram for explaining an example of a method for calculating an expected wind speed at an interpolation point of the ventilation performance evaluation method and system according to the present invention, which is a measurement point (true value) A (○ in the figure).
Tentative interpolation value (in the figure ×)
It is a figure which shows the state which set the mark.

FIG. 8 is a diagram for explaining an example of a method of calculating an expected wind speed at an interpolation point of the ventilation performance evaluation method and system according to the present invention, which is a measurement point (true value) A (○ in the figure).
It is a diagram of a state in which the flux of the velocity vector (arrow in the figure) at each microregion interface is obtained using the () and the temporary interpolation value (x in the figure).

FIG. 9 is a diagram for explaining an example of a method of calculating an expected wind speed at an interpolation point of the ventilation performance evaluation method and system according to the present invention, in which the velocity vector at each microregion interface is processed by velocity-pressure mutual correction processing. It is a figure which shows the state corrected so that flux (arrow in a figure) may satisfy continuity.

FIG. 10 is a diagram for explaining an example of a calculation method of an expected wind speed at an interpolation point of the ventilation performance evaluation method and system according to the present invention, which is a speed at each micro area interface after speed-pressure mutual correction processing. It is a figure which shows the state which calculated | required the speed | velocity | rate at a microregion center point (mark in a figure) from the flux of a vector (arrow in a figure), and also set true value again about the measurement point A (mark in a figure).

FIG. 11 is a flowchart showing an example of a processing procedure of the ventilation performance evaluation method and system according to the present invention.

FIG. 12 is a transverse cross-sectional view showing the internal structure of a measurement chamber used in an evaluation test to which the ventilation performance evaluation method and system according to the present invention are applied.

FIG. 13 is a vertical cross-sectional view showing the internal structure of a measurement chamber used in an evaluation test to which the ventilation performance evaluation method and system according to the present invention are applied.

FIG. 14 is an explanatory diagram showing three-dimensionally the measurement results of each measurement point in the evaluation example of the ventilation performance evaluation method and system according to the present invention.

FIG. 15 is an explanatory diagram showing an evaluation process in an evaluation example of the ventilation performance evaluation method and system according to the present invention.

[Explanation of symbols]

A measurement point B interpolation point 2 Evaluation target space 4 Three-dimensional wind velocity measuring device 6 Computer equipment 8 measuring room 10 Air supply port 12 exhaust port 14 fans

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Shigeru Sakamoto             4-640 Shimoseido, Kiyose City, Tokyo Stocks             Company Obayashi Technical Research Institute F term (reference) 2F034 AA02 AB01 AB02 AB03 AC03                       AC14 BA20 DA01 DA10 DB01                       DB10                 5B056 BB00 HH00

Claims (2)

[Claims] 1. A measurement point is set at a plurality of points at intervals in an evaluation target space for evaluating ventilation performance, and the wind speed at each of these measurement points is measured three-dimensionally, and the measurement points are mutually measured. Interpolation points are set at multiple locations between or around it, and the expected wind speed at each of these interpolation points is calculated three-dimensionally based on the results of the above-mentioned measurement, and the measurement results of these measurement points and the calculation of each interpolation point are calculated. A ventilation performance evaluation method characterized by obtaining data for evaluating ventilation performance based on the results. 2. A three-dimensional wind speed measuring device for three-dimensionally measuring wind speeds at measurement points set at a plurality of points spaced from each other in a space to be evaluated for evaluating ventilation performance, and this three-dimensional wind speed measurement. A computer device for obtaining a measurement result from a device and performing an operation based on the measurement result, wherein the computer device is an expected wind speed at interpolation points set at a plurality of locations between or around the measurement points. Means for three-dimensionally calculating based on the measurement result, and means for creating data for evaluating ventilation performance based on the measurement result at each measurement point and the calculation result at each interpolation point A ventilation performance evaluation system characterized by being equipped with.