JPH09318107A - Environmental testing device with water surface area variable type humidifier - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the amount of natural evaporation of water during low temperature operation, to diminish the dehumidifying load, to save energy and to reduce the capacities of a refrigerating machine and dehumidifier. SOLUTION: When a low humidity operating condition at relative a humidity of 40% or lower is set, for example, a surface area controller 23 automatically opens a solenoid valve 32c and closes a solenoid valve 32b simultaneously. Thereby, water in a second humidifying pan 32 is drained and supply of makeup water is stopped. As a result, water remains only in a first humidifying pan 31 and the surface area of water in a humidifier 3 is cut by half. Therefore, steam generation rate due to natural evaporation can be remarkably diminished, resulting in a decrease in dehumidifying load and in operating load of the dehumidifier and an evaporator. Then, a considerable energy saving can be accomplished because of a decrease in the dehumidifying load itself and operation of the small-sized dehumidifier and a refrigerating machine.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is equipped with a humidifier that heats water contained in a container by heating means to generate steam from the surface thereof, and operates under operating conditions including low-humidity operating conditions. The present invention relates to an environmental test device, and particularly to a technique for improving a low humidity operation state.

[0002]

2. Description of the Related Art As an environmental test device, a cooler consisting of a heater and an evaporator of a refrigerator or a regenerative dehumidifier in addition to this, and a pan-and-plate humidifier with a built-in heater are circulated. Generally, the temperature and humidity of the air are adjusted to maintain the desired temperature and humidity conditions in the test chamber. Many of such environmental testing devices are operated under a wide range of temperature and humidity conditions from low temperature low humidity conditions to high temperature high humidity conditions.
Under the low-humidity operating condition, there is a problem that the water in the humidifier spontaneously evaporates even if the output of the heater becomes 0, which causes an extra dehumidification load.

In order to prevent this, conventionally, during low-humidity operation, a punching plate is placed on the surface of the humidifier to reduce the amount of natural evaporation, or a refrigerator having a large dehumidifying capacity including a dehumidifying load due to natural evaporation. A dehumidifier was installed. However, in such a conventional apparatus, since a person has to perform an operation of placing a punching plate, the continuity of the test state and control is lost. Therefore, labor saving in the test cannot be achieved and the test efficiency decreases. thing,
Energy is wasted because it causes an increase in the capacity of the refrigerator and dehumidifier, and the operation of a refrigerator or the like that has an excessively large capacity to handle the water load that is originally unnecessary. Had a problem with.

As a conventional humidifier having a variable humidifying capacity, porous humidifying elements capable of containing water are arranged in parallel, and air is flowed between them to generate a suction force of water and a natural evaporation force. In a humidifier that can be humidified by utilizing it, a device has been proposed in which the number of humidifying elements containing water is variable (see Japanese Patent Laid-Open No. 192527/1990). However, such a humidifier is completely different in performance and the like from the humidifier used in the environmental test apparatus of the type in which the amount of humidification is controlled by controlling the heater. Further, it cannot be applied to an environmental test device that controls the temperature and humidity with high accuracy or has a low humidity operating condition.

[0005]

SUMMARY OF THE INVENTION The present invention solves the above problems in the prior art and enables energy saving under low humidity operating conditions while maintaining the continuity of operating conditions, and improves the capacity of refrigerators and dehumidifiers. An object of the present invention is to provide an environmental test device that can reduce the number of environmental tests.

[0006]

In order to solve the above-mentioned problems, the present invention according to claim 1 heats water contained in a container by heating means to generate steam from the surface thereof. An environmental test apparatus including the above humidifier is characterized by including surface area varying means for changing the surface area and actuating means for operating the surface area varying means. In addition to the above, the invention according to claim 2 is characterized in that the operating means is a control means for automatically operating the surface area varying means so as to reduce the area of the surface under a predetermined low humidity operation condition. To do.

Here, the "predetermined low humidity operation condition" means that the output of the heating means of the humidifier becomes 0, and the output of the heating means becomes 0 even after the control means controls to reduce the surface area of water. Or, the humidity condition is such that the condition is close to this. Such conditions vary depending on the control range of temperature and humidity, the size of the surface area of water in the humidifier container, the installation location of the humidifier, the amount of circulating air, the degree to which the surface area of water is reduced, etc.
It is specifically determined for each actual environment test device.

According to a third aspect of the present invention, in addition to the features of the first aspect of the invention, the container is a surface area variable type container having a shape in which the surface area of water changes depending on the water level, and the surface area varying means includes the It is characterized by comprising a variable surface area container and water level control means capable of controlling the water level at a plurality of different positions.

[0009]

FIG. 1 shows an example of a schematic configuration of an environmental test apparatus to which the present invention is applied. As shown in FIG. 1A, the environmental test apparatus includes a test chamber 1 surrounded by a heat insulating wall (not shown) as a main body part, an air-conditioning chamber 2 partitioned from the test chamber 1, and a humidifier 3 arranged in the air-conditioning chamber 2. An evaporator 4 to which a refrigerant is sent from a refrigerator (not shown), a heater 5, a blower 6 for circulating air between the two chambers, a temperature sensor 7 and a humidity sensor 8 provided at the inlet of the test chamber 1, and the outside of the main body part. , A rotary regeneration type dehumidifier 9 for bypassing and dehumidifying a part of the air in the test chamber 1, a machine room in which the refrigerator and the like are provided, an operation control panel (not shown), and a temperature provided in the operation control panel. The device includes a control unit 10, a humidity control unit 20, and the like, and is operated under a wide range of operating conditions including low-humidity operating conditions, from low-temperature low-humidity to high-temperature high-humidity.

FIG. 1B shows a humidifier 3 and a humidity controller 20.
An example of the configuration will be described. The humidifier 3 includes a first humidifying tray 31 and a second humidifying tray 32, which are containers partitioned by the partition 3a.
Heater 31 as heating means provided on each plate
a and 32a, solenoid valves 31b and 32b and 31 for supplying and draining water in the respective dishes 31 and 32
c and 32c, float tank 33 communicating with the humidifying dish
And a float switch 33a for opening and closing the solenoid valves 31b and 32b provided therein.

The humidity control section 20 is integrally formed in the entire operation control panel of the environmental test apparatus (not shown), and the humidity setting section 21 for setting the humidity in the test chamber 1 and the humidity setting set by the humidity setting section 21. The value and the measured humidity H of the humidity sensor 7 are received, and the heater 31 is detected by these values and the deviation between them.
a, 32a for controlling the outputs of the heater control portion 22 and the humidity setting portion 21, and when the value is equal to or less than a constant value corresponding to the low humidity operating condition, the solenoid valve 32c is opened to open the second humidifying tray. A surface area for controlling the surface area of water in the humidifier by draining the water in 32 and forcibly closing the solenoid valve 32b via the signal converter 34 when the water in the second humidifying tray 32 is drained. The control part 23 etc. are provided.

Due to the above-described configurations of the humidifier 3 and the humidity controller 20, in the present example, the second humidifying tray 32 and the solenoid valve 3 are provided.
Reference numeral 2c corresponds to a surface area changing means capable of changing the surface area of the water of the humidifier 3, and the surface area control portion 23 reduces the surface area of the humidifier 3 under the low humidity operation condition.
It is an operating means for automatically operating 2c and corresponds to a control means. Although the humidity set value is used for the control by the surface area control section 23 in the above, the humidity measured value H may be used instead, or the humidity and temperature set values or measured values may be used. . Further, instead of the surface area control portion 23 that automatically changes the surface area, a surface area changeover switch or the like for manually operating the solenoid valve 32c or the signal converter 34 may be provided.

The above-mentioned environmental test apparatus is operated as follows. When the set humidity is equal to or higher than a certain value that is not low humidity, each device except the dehumidifier 9 is operated, and the temperature control unit 10 and the humidity control unit 20 control the temperature and humidity inside the test chamber 1 to be the set temperature and humidity. It This allows
A target temperature / humidity environment can be applied to a sample (not shown) placed in the test chamber 1. In the humidifier 3,
The water inside is heated by the heaters 31a and 32a, and steam is generated from the surface of the water, and this is sent to the test chamber. The water in the humidifier 3 is used to make up for various types of water loss.
In addition, a solenoid valve 31 is used to prevent scale adhesion due to concentration.
In order to replenish the water discharged by the c and 32c, it is replenished via the solenoid valves 31b and 32b operated by the float switch 33a and a timer or the like.

When the set humidity is less than a certain value, the target humidity condition cannot be achieved by only dehumidifying the evaporator of the refrigerator, so the dehumidifier 9 is operated. The dehumidifier 9 may be operated by a person's judgment based on the temperature and humidity conditions set based on an operation manual or the like, but it is preferable that the dehumidifier 9 is automatically operated by zone control or another control method.
Under such operating conditions, for example, when the low humidity operating condition of relative humidity of 40% or less is set, the surface control control portion 23 automatically opens the solenoid valve 32c and closes the solenoid valve 32b. As a result, the water in the second humidifying tray 32 is drained and the replenishment is interrupted. As a result, the water remains only in the first humidifying dish 31, and the surface area of the water in the humidifier is halved.

In the above operation, in the humidifier 3, water vapor of W (kg / h) evaporates from the surface of water as shown in the following equation. W = C ・ A ・ (Pws-Pw) C: Constant determined by the wind speed passing over the humidifying dish surface (kg /
mmHg · m ² · h) A: Surface area of water in the humidifying dish (evaporation area) (m ² ) Pws: Saturated water vapor pressure (m) at the temperature of the water in the humidifying dish
mHg) Pw: Water vapor partial pressure of passing air (mmHg)

According to this equation, the amount of evaporation is proportional to the difference in water vapor pressure and the surface area of water. In this case, the humidification output becomes 0 under the low-humidity operating condition, and the temperature of the water in the humidifier 3 becomes almost the same as the temperature of the circulating air, but the natural evaporation action occurs due to the difference in the water vapor pressure. As the humidity decreases, the partial pressure of water vapor in the circulating air decreases, the pressure difference increases, and the amount of evaporation increases. However, according to the present invention, under the low-humidity operating condition, the water in the second humidifying dish 32 is automatically drained and the surface area A of the water is halved, so that the amount of water vapor generated by natural evaporation can be greatly reduced. As a result, the dehumidifying load is reduced, and the load during operation of the dehumidifier and the evaporator is reduced.
Further, since the refrigerator including the dehumidifier and the evaporator may have a dehumidifying capacity that does not include the dehumidifying load of the natural evaporation in the second humidifying tray, the capacity thereof can be reduced. Then, a large energy saving effect can be obtained by reducing the dehumidifying load itself and operating the downsized dehumidifier and refrigerator.

In the above example, the surface area of water in the humidifier is halved under the low humidity operation condition where the relative humidity is about 40% or less. Even if the amount of natural evaporation decreases, the output of the heater 31a of the humidifier is maintained at or near 0, and does not increase so much.

On the other hand, when the operating conditions are other than low humidity, the first
Also, since the second humidifying dish is filled with water, a sufficient evaporation area is secured. As a result, evaporation from the humidifier is promoted, and particularly during high-humidity operation, a large amount of evaporation is obtained relative to the outputs of the heaters 31a and 32a, resulting in an energy saving effect.

2 to 4 show another example of the humidifier. Although FIG. 2 is provided with a partition 3a similar to that shown in FIG. 1 (b), by changing the position of the partition, the first humidifying tray 3
That of the second humidifying dish 32 is made larger than the surface area of water of 1. By doing so, the amount of spontaneous evaporation under low-humidity operating conditions can be further reduced. Then, FIG.
By doing so, it is possible to change only the surface area without changing the amount of water held between the first and second humidifying dishes.

FIG. 3 shows an example of a humidifying tray in which the surface area of water changes depending on the depth of water, instead of the humidifying tray having a rectangular cross section, and the bottom and side surfaces of which are continuously inclined. Shows dish 31 '. In the humidifier having such a humidifying plate, the float switch 3 of the float tank 33
3b is a second on / off contact for turning on / off at a position within a certain range above and below the depth of 1/2 of the water, in addition to the first on / off contact for detecting the upper position for normal water surface control. Is equipped with. Then, at the time of low humidity operation, a signal for reducing the surface area is sent from the surface control section 23 to the signal converter 34 ′, and the second ON-OFF contact is replaced with the second ON-OFF contact.
Switch to using the on / off contact of. As a result, during low-humidity operation, the electromagnetic valve 31b is opened / closed to control the makeup water so that the water depth is about ½, and the surface area of water can be maintained to about ½ of the normal operation.

In the humidifier of this example, the humidifying tray 31 'and the float switch 33b having multiple contacts correspond to a surface area variable type container and a water level control means capable of controlling the water level at a plurality of different positions, respectively. Make up. When such a humidifier is used, the humidifying tray 31 'and the float switch 33b are special, but the number of parts can be reduced as compared with the examples of FIGS. 1 and 2.

FIG. 4 shows a humidifying tray 31.sub.3 having a stepped cross section and capable of changing the surface area of water by forming three types of water surfaces depending on the water depth. With this humidifier,
The float switch 33c of the float tank 33 has second and third on / off switches that sequentially turn on and off at shallow water depths, in addition to the first on / off contact at the uppermost position for normal water surface control. It has an off contact. Then, during the low humidity operation, a signal for reducing the surface area is sent from the surface control section 23 to the signal converter 34 depending on the degree of the low humidity condition, and the second or third contact is used instead of the first on / off contact. Switch to using on / off contacts. As a result, during low-humidity operation, the electromagnetic valve 31b is opened / closed to control the makeup water so that the surface of the water becomes S ₂ or S ₃ .

Also in the humidifier of this example, the humidifying tray 31 and the float switch 33c having multiple contacts constitute the surface area varying means. When such a humidifier is used, the humidifying tray 31 and the float switch 33c are special as in the case of FIG. 3, but compared to the examples of FIGS. 1 and 2,
The number of parts can be reduced, and the water surface can be controlled to have different surface areas for a plurality of low humidity conditions.

[0024]

As described above, according to the present invention, in the first aspect of the invention, the surface area varying means for changing the surface area of the water in the container forming the humidifier and the operating means for activating the surface area changing means are provided. Therefore, it is possible to reduce the surface area of water by operating the surface area varying means under the low humidity operation condition. As a result, it is possible to reduce the amount of natural evaporation of water during low-humidity operation, reduce the dehumidifying load, save energy, and reduce the capacity of the refrigerator, dehumidifier, and the like.

According to the second aspect of the present invention, the operating means is used as the control means, and the surface area varying means is automatically operated so as to reduce the surface area of the water under low humidity operating conditions. Environmental conditions and control continuity can be maintained. Then, it is possible to easily control the low humidity in the environment test device having a wide humidity control range.

According to the third aspect of the present invention, the surface area variable means is composed of the surface area variable type container and the water level control means capable of controlling the water level at a plurality of different positions. It is not necessary to add parts such as valves, and an effect such as energy saving can be obtained with a simple and inexpensive structure.

[Brief description of drawings]

FIG. 1 shows an example of an environmental test apparatus to which the present invention is applied;
(A) is explanatory drawing of the whole structure, (b) is explanatory drawing of the structure of a humidifier and a humidity control part.

2 (a) and 2 (b) are explanatory views showing another example of a humidifier applicable to the environment test apparatus of the present invention.

FIG. 3 is an explanatory view showing another example of the humidifier.

FIG. 4 is an explanatory view showing another example of the humidifier.

[Explanation of symbols]

3 Humidifier 23 Surface Area Control Part (Actuating Means, Control Means) 31 First Humidification Dish (Container) 31 'Humidification Dish (Container, Surface Area Variable Type Container, Water Level Surface Area Variable Means) 31 ¨ Humidification Dish (Container, Surface Area Variable Type Container) , Surface area varying means) 32 second humidifying tray (container, surface area varying means) 32c solenoid valve (surface area varying means) 33b float switch (water level controlling means, surface area varying means) 33c float switch (water level controlling means, surface area varying means)

Claims (3)

[Claims] 1. An environmental test apparatus comprising a humidifier configured to heat water contained in a container by heating means to generate water vapor from the surface of the container, and a surface area varying means capable of changing the area of the surface. And an actuating means for actuating the surface area varying means. 2. The operating means is a control means for automatically operating the surface area varying means so as to reduce the area of the surface under a predetermined low humidity operation condition. Environmental test equipment. 3. The surface area variable container having a shape in which the surface area of water changes depending on the water level, and the surface area variable means can control the water level at a plurality of different positions from the variable surface area container. The environment test apparatus according to claim 1, wherein the environment test apparatus comprises a water level control means.