JP2603519B2 - Air conditioning equipment odor evaluation method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for evaluating odor of an air conditioner, and more particularly to a method suitable for evaluating putrefaction odor generated from an air conditioner for an automobile.

(Prior art)

Conventionally, it has been known that putrefaction odor is generated from an air conditioner of an automobile, but it has not been sufficiently clarified what is the cause component of the putrefaction odor and from which part of the air conditioner.

Therefore, it was not possible to evaluate the reproduction of putrefaction odor,
It has been studied using old air-conditioning equipment collected from the market, but it was difficult to properly evaluate it because the odor of putrefaction could not be reproduced in the ventilation test and the level of putrefaction odor was different.

[Problems to be solved by the invention]

As described above, the generation mechanism and location of putrefactive odor generated from the air conditioner of the automobile have not been clarified at all. However, as a result of various studies, the present inventor has found that the above-mentioned unpleasant odor (putrefactive odor) is of various low-grade originating from the human body. It was found that fatty acids were the cause, and the evaporator of the air conditioner was a source of unpleasant odor.

However, the type of lower fatty acid is also unknown, and it is unknown what mechanism these lower fatty acids adsorb to the evaporator and how they emit odor.

Therefore, as a result of further research, it was found that lower fatty acids were adsorbed and desorbed from the surface-treated film (sodium silicate or silica gel) of the evaporator due to the interposition of dew condensation moisture, generating an unpleasant odor.

However, in order to experimentally reproduce the generation of unpleasant odors, a method of supplying the evaporator of the lower fatty acid to the evaporator, a method of fixing the lower fatty acid adsorbed on the evaporator, and evaporating only the fixed lower fatty acid are evaluated. Difficult issues such as methods were left.

The aim of the present invention is to use simple devices and simple procedures,
An object of the present invention is to provide a method for evaluating the odor of an air conditioner that can reproduce the generation of the odor of the air conditioner and evaluate the odor.

[Means for solving the problem]

The method for evaluating the odor of an air conditioner according to claim 1 is characterized in that the evaporator of the air conditioner is cooled in a state in which the evaporator is housed in a container so that the surface of the evaporator is condensed or condensed, and then the lower fatty acid is evaporated in the container. A gas is supplied to adsorb the condensate on the surface of the evaporator, and then the evaporator is cooled and the condensate is frozen, and the evaporated gas of the lower fatty acid in the container is discharged out of the container. The purpose is to evaluate the odor of lower fatty acids that evaporate together with water vapor from the surface while absorbing heat.

The odor evaluation method for an air conditioner according to claim 2 is based on claim 1.
In the invention, a surface-treated film of a substance exhibiting alkalinity by hydrolysis is previously formed on the surface of the evaporator.

[Action]

In the odor evaluation method for an air conditioner according to claim 1,
A surface treatment film such as sodium silicate (water glass) or colloidal silica is formed on the surface of the evaporator of the air conditioner to prevent water droplets from being released during operation of the air conditioner and to promote drying when the air conditioner is turned off. When the evaporator is cooled and dew forms on its surface, the evaporator is hydrolyzed to form an alkaline dew solution.

Accordingly, when the evaporator is cooled in the state where the evaporator is housed in the container and the surface of the evaporator is condensed or condensed and then the evaporating gas of lower fatty acid is supplied into the container, the evaporating gas is adsorbed on the condensate.

Next, the evaporator is cooled to freeze the above-mentioned condensate, and the vapor of the lower fatty acid in the container is discharged out of the container while the lower fatty acid is fixed on the surface of the evaporator. This is because only lower fatty acids adsorbed on the evaporator are to be evaluated.

Next, when the evaporator absorbs heat, the lower fatty acid evaporates together with the water vapor from the surface thereof, so that the odor emitted from the evaporator can be evaluated while absorbing the heat of the evaporator.

In the odor evaluation method for an air conditioner according to claim 2,
The same function as in claim 1 is obtained, but a surface treatment film of a substance exhibiting alkalinity by hydrolysis (for example, water glass, colloidal silica, etc.) is previously formed on the surface of the evaporator. As described in the section of action, when dew forms on the surface of the evaporator, an alkaline dew solution is surely formed by hydrolysis. Other operations are the same as those of the first aspect.

〔The invention's effect〕

According to the odor evaluation method for an air conditioner according to the first aspect, as described above, the generation of the odor from the evaporator of the air conditioner can be reliably reproduced. Therefore, the odor evaluation can be performed according to the actual use state of the air conditioner.

Moreover, the odor generation can be reproduced and the odor can be evaluated with a very simple device and in a simple procedure.

According to the odor evaluation method for an air conditioner according to the second aspect, the same effect as the first aspect is obtained, but a surface treatment film of a substance exhibiting alkalinity by hydrolysis is formed on the surface of the evaporator in advance. As described in the section of the operation, when dew is condensed on the surface of the evaporator, an alkaline condensate is surely formed by hydrolysis, so that the vapor of the lower fatty acid is adsorbed on the condensate of the alkali. The odor evaluation can be performed in the same manner as described above.

〔Example〕

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

This embodiment is an embodiment in which the present invention is applied to an air conditioner for a vehicle, and first, a mechanism of generating odor from the air conditioner will be described.

In order to investigate the cause of the unpleasant odor generated from the air conditioner, the acidic gas generated from the air conditioner of the actual vehicle actually used (hereinafter referred to as air conditioner) was filtered using alkaline filter paper at a flow rate of 500 / min. Sampled below.
The analysis results were as shown in FIG. 1 and Table 1.

In FIG. 1, the temporal odor is an unpleasant odor generated at a specific timing in relation to the operating state of the air conditioner, and the non-temporal odor is an unpleasant odor generated when the air conditioner is ON. These were detected by sensory evaluation. Then, it was found that the timed odor was generated at a predetermined timing after the air conditioner was turned off.

Table 1 is a result obtained by analyzing the lower fatty acids listed in Table 1 which cause unpleasant odors emitted from the human body. Similar tendencies are observed for the actual vehicles A and B. It is considered to be the main cause of odor generation.

Next, in order to examine whether or not the above-mentioned lower fatty acids produce the same odor as that generated from an air conditioner, a mixture of these lower fatty acids was applied to a test piece cut from an evaporator of a new air conditioner, and an experiment was performed. The result as shown in FIG. 2 was obtained.

On the other hand, when an experiment was conducted on an old air conditioner collected from the market, the results shown in FIG. 3 were obtained. The odor intensity of the temporal odor shown in FIG. 2 is generated at exactly the same timing as that of FIG. 3 and shows the same tendency, so that the reproducibility of the odor generation by the lower fatty acid is clear. Then, as can be seen from FIG. 3, after the air conditioner was turned off, the fin temperature of the evaporator became the dew point, and it was found that odor was generated when the condensate was evaporated from the evaporator.

Next, in order to examine the reproducibility of the odor generation due to the lower fatty acid, the test pieces shown in Table 2 were tested for the reproducibility of the odor generation by the lower fatty acid, and the results shown in Table 2 were obtained. Was.

As can be seen from Table 2, when a substance exhibiting alkalinity by hydrolysis, such as silicate, sodium metasilicate, or silica gel, is present on the surface of the evaporator, there is reproducibility of odor generation due to lower fatty acids.

Considering the mechanism of the odor generation,
It is considered that an odor is generated from the evaporator by the mechanism as shown in FIGS.

FIG. 4 shows a case where a silicate surface treatment film composed of colloidal silica and water glass is formed on the surface of the evaporator. When dew is formed on the evaporator, the silicate is hydrolyzed and dissolved in dew water. It becomes an alkaline solution, and the evaporated gas of lower fatty acids dissolves in the alkaline solution to form a salt, and a part of the salt flows out of the evaporator as a salt. Decomposes into fatty acids and emits into the air together with water vapor to generate odor.

Fig. 5 to Fig. 7 show the case where a surface-treated film of silica gel is formed on the surface of the evaporator. When dew forms on the surface of silica gel, lower fatty acids are adsorbed and bonded to the surface, and it takes about 2 minutes after the air conditioner is turned off. During this time, when the surface of the evaporator dries, a vapor of lower fatty acid is generated together with water vapor. FIG. 6 schematically shows a state in which the lower fatty acid is bonded to silica gel containing water, and FIG. 7 schematically shows a state in which the vapor of the lower fatty acid evaporates alone or in combination with H ₂ O. This is shown in FIG.

As described above, the substance causing the odor from the air conditioner is a lower fatty acid, and the lower fatty acid is bonded to and absorbed by the alkaline substance generated by hydrolysis from the surface treatment film when the evaporator is dewed. It was clarified that when the condensed water on the evaporator surface dries for about two minutes after the air conditioner was turned off, evaporative gas of lower fatty acids was generated together with water vapor to generate an unpleasant odor.

Next, an odor generation reproduction device which is the subject of the present application and is provided for an odor evaluation method of an air conditioner will be briefly described, and then the odor evaluation method will be described.

The odor generation reproduction device 1 is configured as shown in FIG. 8, and a storage chamber 3 is formed on the upper side of a metal double-bottomed box-shaped container 2. An evaporator 4 with a treatment film is provided, and an upstream end of a refrigerant passage in the evaporator 4 is connected to an external liquid nitrogen container 8 by a pipe 7 having a pump 5 and an on-off valve 6 interposed therebetween. The discharge pipe 9 opens to the outside atmosphere.

Outside the opening 10 of the front wall 2a of the container 2, an electric fan
An opening 10 is opened and closed by a sliding first shutter 12 and closed by the first shutter 12 in an airtight manner via a sealing material 12a. It is possible. Further, the opening 13 of the rear wall 2b of the container 2 is opened and closed by a hinged door 14, and the door 14 is closed and hooked.
The opening 13 is closed in an airtight manner through the sealing material 14a by applying the pressure. The opening 10, the evaporator 4, and the opening 13 are arranged in series.

The opening 16 at the center of the inner bottom wall 2c in the container 2 is opened and closed by a slide-type second shutter 17 provided below the inner bottom wall 2c, and is airtightly sealed by the second shutter 17 via a sealing material 17a. It can be closed. In the drawings, reference numerals 18 and 19 denote rubber sealing materials, and reference numerals 20 and 21 denote pipe joints. Therefore,
When the first shutter 12, the second shutter 17, and the door 14 are closed, the housing chamber 3 is airtightly partitioned from the outside.

Below the inner bottom wall 2c in the container 2, there is provided a bottom housing chamber 22 having a low height, and the lower fatty acid shown in Table 1 is introduced into the bottom housing chamber 22 from the openings 13 and 16. A flask 24 containing a mixed solution of a predetermined concentration can be accommodated.

Next, a method for evaluating the odor generated from the evaporator 4 of the air conditioner using the odor generation reproduction device 1 will be described.

First, the flask 24 containing the lower fatty acid solution is set in the bottom accommodation chamber 22 and the second shutter 17 is closed. Then, the pump 5 is operated with the first shutter 12 and the door 14 opened, and the evaporator 4 is opened. Supply liquid nitrogen to cool,
Dew is formed on the surface of the evaporator 4.

Next, while closing the first shutter 12 and the door 14,
The pump 5 is stopped.

Next, the first shutter 12 and the door 14 are closed, and the second shutter 17 is opened to supply the evaporated gas of the lower fatty acid generated from the lower fatty acid solution in the flask 24 into the storage chamber 3 for a predetermined time. .

Next, the second shutter 17 is closed, the pump 5 is operated to cool the evaporator 4, and the dew condensation water on its surface is frozen.

Next, the first shutter 12 and the door 14 are opened, and the evaporated gas of the lower fatty acid filled in the storage chamber 3 is discharged without operating the fan 11. However, in this case, if the fan 11 is operated for a very short time, the fan 11 can be discharged effectively.

Next, the pump 5 is stopped, the fan 11 is operated, and the evaporator 4 absorbs heat to dry the dew condensation water frozen on the surface thereof, and the lower fatty acid evaporating gas generated together with the water vapor is removed at the point A in the figure. Evaluate by nose near.

When the dew is condensed on the evaporator 4, the first shutter 12 and the door 14 may be closed and the second shutter 17 may be opened, and the vaporized gas of the lower fatty acid may be adsorbed on the dew water while the dew is formed.

Alternatively, when dew is condensed on the evaporator 4, the first shutter 12 and the door 14 are opened and the evaporative gas of the lower fatty acid is supplied from the outside to the fan 11 while the fan 11 is operated, and the evaporative gas of the lower fatty acid is condensed on the evaporator 4. May be adsorbed. Also, without performing odor evaluation with the nose,
It is also possible to perform quantitatively using a chemical analyzer.

As described above, the odor evaluation method of the present embodiment can reproduce the odor using the odor generation reproducing device 1 having a very simple structure, and can evaluate the odor generated from the evaporator 4 by a simple procedure. .

[Brief description of the drawings]

The drawings relate to an embodiment of the present invention. FIG. 1 is an explanatory diagram of an odor generation characteristic in an actual vehicle, FIG. 2 is an explanatory diagram of an odor generation characteristic by a lower fatty acid performed on a test piece, FIG.
Fig. 4 is an explanatory view of an odor generation characteristic obtained by an air conditioner of a product collected from the market, Figs. 4 and 5 are explanatory views each illustrating an odor generating mechanism of the air conditioner, and Figs. FIG. 8 is an enlarged explanatory view in which each state is modeled, and FIG. 8 is a sectional view of an odor generation reproduction device. 2 ... container, 4 ... evaporator, 8 ... liquid nitrogen container, 24 ... flask containing lower fatty acid solution.

Claims (2)

(57) [Claims] An evaporator for an air conditioner is cooled in a state in which the evaporator is housed in a container and dew condensation is caused on the surface of the evaporator or after the surface of the evaporator is supplied with an evaporating gas of lower fatty acid in the container. In the state where the evaporator is cooled and the above-mentioned condensate is frozen, the evaporating gas of the lower fatty acid in the container is discharged out of the container, and then the heat is absorbed by the evaporator from the surface thereof. An odor evaluation method for an air conditioner, wherein the odor of a lower fatty acid evaporating with water vapor is evaluated. 2. The method for evaluating an odor of an air conditioner according to claim 1, wherein a surface treatment film of a substance exhibiting alkalinity by hydrolysis is previously formed on the surface of the evaporator.