JP6296964B2 - Environmental test equipment and cooling equipment - Google Patents

Description

  The present invention relates to an environmental test apparatus. The environmental test apparatus of the present invention is particularly suitable for an environmental test that is performed while maintaining the temperature in the test chamber at or above the freezing point temperature. The present invention also relates to a cooling device.

  As an apparatus for testing the performance and durability of products, materials, etc., an environmental test apparatus as disclosed in Patent Document 1 is known. The environmental test apparatus includes a test chamber on which a test object is placed, and adjusts the temperature and humidity in the test chamber to a desired test environment.

FIG. 1 conceptually shows a typical environmental test apparatus.
The basic configuration of the environmental test apparatus 100 has a heat insulating tank 3 covered with a heat insulating wall 2 as shown in FIG. A test chamber 5 is formed in a part of the heat insulating tank 3. The test chamber 5 is a space in which the device under test 18 is installed.
The environmental test apparatus 100 further includes an air conditioner 17 and a blower 10. The air conditioner 17 includes a humidifier 6, a cooling device 101, and a heater (heating device) 8.
The environmental test apparatus 100 includes an air conditioning ventilation path 15 that communicates with the test chamber 5 in a ring shape, and the air conditioning equipment 17 and the blower 10 described above are incorporated in the air conditioning ventilation path 15.

The air-conditioning ventilation path 15 is formed in a part of the heat insulating tank 3 and communicates with the test chamber 5 at two locations of the air blowing section 16 and the air introducing section 25.
Therefore, when the blower 10 is activated, the air in the test chamber 5 is introduced from the air introduction unit 25 into the air conditioning ventilation path 15. Then, the air conditioning ventilation path 15 enters the ventilation state, air contacts the air conditioning equipment 17 to perform heat exchange and humidity adjustment, and the adjusted air is blown out from the air blowing section 16 into the test chamber 5.
Further, a temperature sensor 12 and a humidity sensor 13 are provided in the vicinity of the air blowing portion 16 of the air conditioning ventilation path 15.
When the environmental test apparatus 100 is used, the air blower 10 is operated to bring the air-conditioning ventilation path 15 into a ventilation state, and air-conditioning is performed so that the detected values of the temperature sensor 12 and the humidity sensor 13 approach the temperature and humidity of the set environment. The device 17 is controlled.

  That is, by operating the blower 10, the air in the test chamber 5 is introduced from the air introduction unit 25 into the air conditioning ventilation path 15, and the temperature and humidity are adjusted by passing through the air conditioning equipment 17 in the air conditioning ventilation path 15. Then, the air whose temperature / humidity is adjusted is returned from the air blowing section 16 to the test chamber 5, and an environment of desired temperature / humidity is created in the test chamber 5.

The environmental test apparatus 100 is also used for food preservation tests and stability tests for pharmaceuticals, cosmetics, and the like. The storage test and the stability test are a kind of environmental test, and are a test in which food, medicine, etc. are left in a certain environment for a long period of time.
In the preservation test of food and the stability test of pharmaceuticals, the inside of the test room 5 is a room temperature and normal humidity area such as 25 ° C / 60% RH (25 ° C / relative humidity 60% environment) Is maintained in a low temperature environment such as 5 ° C. (5 degrees Celsius). Then, food and medicines are kept in the test room 5 for a long time.

The environmental test apparatus 100 includes the humidifier 6, the cooling device 101, and the heater (heating device) 8 as described above in order to maintain the inside of the test chamber 5 at a constant temperature or a temperature / humidity state.
The cooling device 101 is for maintaining the inside of the test chamber 5 at a low temperature or for dehumidifying, and a device that realizes a refrigeration cycle is generally used.
The cooling device 101 has a compressor, a condenser, an expansion means, an evaporator, and a circulation channel that connects these in an annular shape. And the refrigerant | coolant which changes a phase is enclosed with the circulation flow path. The cooling device 101 compresses gaseous refrigerant with a compressor, liquefies the compressed refrigerant with a condenser, introduces the refrigerant into an evaporator through expansion means, vaporizes, takes away heat of vaporization, Reduce the surface temperature.

  Since the surface of the evaporator is at a low temperature, when the environmental test is performed, frost forms on the surface of the evaporator depending on the test conditions. The same applies when performing a storage test or a stability test using an environmental test apparatus. Depending on the test conditions, frost may form on the surface of the evaporator. For example, the inside of the test chamber 5 is a normal temperature and normal humidity region such as 25 ° C./60% RH (25 ° C./60% relative humidity environment), or the temperature in the test chamber 5 is 5 ° C. (5 ° C.). Even in the case of keeping in such a low temperature environment, the surface temperature of the evaporator is often a temperature below freezing point, and in that case, the evaporator may be frosted. As the frost grows, the amount of heat exchange on the evaporator surface decreases, and there is a problem that the inside of the test chamber 5 may not be maintained at a constant temperature and humidity. It has also been found that the amount of frost on the evaporator increases by opening and closing the door of the test chamber 5 when the test object is taken in and out.

Conventionally, when temperature and humidity cannot be maintained due to such frosting, the following measures have been taken.
(1) The operation of the cooling device 101 is stopped, the temperature in the test chamber is raised to a temperature at which the frost melts, and the frost adhering to the evaporator is naturally thawed.
(2) The cooling device 101 causes the high-temperature refrigerant gas compressed by the compressor to flow into the evaporator without stopping, and raises the surface temperature of the evaporator to forcibly defrost the attached frost (hot gas defrost method).

In addition, as another measure, a measure that prevents the evaporator from frosting in the first place can be considered. Specifically, by the following measures, the evaporation temperature of the refrigerant flowing in the evaporator is set to 0 ° C. or higher so that the surface of the evaporator is not frosted.
(3) An evaporating pressure adjusting valve is provided to control the evaporating pressure of the refrigerant, and the evaporating temperature of the refrigerant flowing in the evaporator is kept at 0 ° C. or higher.
(4) A constant pressure expansion valve is provided to keep the evaporation pressure of the refrigerant constant, and to maintain the evaporation temperature of the refrigerant flowing in the evaporator at 0 ° C. or higher.

JP 2014-20777 A

However, the method (1) of stopping the operation of the cooling device 101 and naturally thawing the frost and the method of (2) forcibly thawing the frost by hot gas defrosting lose the cooling capacity of the cooling device 101 during thawing. Is called. Therefore, during natural thawing or hot gas defrosting, it is difficult to maintain the test chamber 5 at the target temperature and humidity, and the environmental test must be interrupted. It may not be obtained.
Since the storage test and the stability test are environmental tests in which the test object is placed in a certain environment for a long period of time, there is a case where the test interruption in the middle is not allowed. For this reason, a method of performing natural thawing and a method of performing hot gas defrost are not suitable for an environmental test apparatus that performs a storage test or a stability test.

In addition, when adopting a measure for setting the evaporation temperature of the refrigerant flowing in the evaporator to 0 ° C. or higher, it is not necessary to interrupt the environmental test. However, if a measure is taken to increase the evaporation temperature of the refrigerant to 0 ° C. or higher, the difference between the temperature of the air in the test chamber 5 and the surface temperature of the evaporator must be reduced, and the temperature in the test chamber 5 May be difficult to maintain at a predetermined temperature. Moreover, in order to maintain the temperature in the test chamber 5 at a predetermined temperature, it is necessary to employ a large evaporator, which may increase costs. Furthermore, in order to maintain the temperature in the test chamber 5 at a predetermined temperature, it is necessary to increase the circulation amount of the refrigerant, and the power consumption may increase.
Also, if the evaporation temperature is 0 ° C or higher, the evaporation pressure increases, so the suction pressure of the compressor increases, and if a low-temperature refrigerant is used, this pressure rises further, damaging the compressor. May end up.

  An object of the present invention is to provide an environmental test apparatus that can carry out continuously for a long time without interrupting the environmental test, paying attention to the above-mentioned problems of the prior art. It is another object of the present invention to provide a cooling device that can be continuously operated for a long time.

The invention according to claim 1 for solving the above-described problem has a test chamber in which the object to be tested is installed, and temperature adjusting means for adjusting the temperature of the test chamber, and the temperature adjusting means is at least a cooling device. The cooling device includes a compressor, a condenser, an expansion means, an evaporator, and a circulation channel that connects these in a ring shape, and a refrigerant that changes phase in the circulation channel. Is packed, and the gaseous refrigerant is compressed by a compressor, the compressed refrigerant is liquefied by a condenser, the refrigerant is introduced into an evaporator through expansion means, vaporized, and returned to the compressor. The expansion means has a first expansion means and a second expansion means, and the evaporator has two openings A and B, and allows the refrigerant to pass between the two openings A and B. , guiding the refrigerant from one opening a through a first expansion means from said condenser And discharging the forward passage connected back to the compressor to drain refrigerant from the other opening B, and the refrigerant of the refrigerant from the inlet to one opening A from the other opening B through the second expansion means from said condenser And a flow path switching means for switching the reverse passage connection to be returned to the compressor. The flow path switching means has a flow path between the condenser and the expansion means on the first expansion means side and the second expansion means side. And the flow path for returning the refrigerant from the evaporator to the compressor is switched to either the flow path for returning the refrigerant from the opening B to the compressor or the flow path for returning the refrigerant from the opening A to the compressor. It is an environmental test apparatus characterized by being.

The environmental test apparatus of the present invention suppresses frost growth while maintaining necessary cooling capacity and dehumidifying capacity by switching the path between the inlet and outlet of the evaporator.
The evaporator employed in the present invention is the same as a known one, and has two openings A and B, and allows the refrigerant to pass between the two openings A and B. Here, the environmental test apparatus of the present invention has a forward passage connection for introducing the refrigerant from one opening A and discharging the refrigerant from the other opening B, and introducing the refrigerant from the other opening B and supplying the refrigerant from one opening A. The reverse pass connection for discharging can be switched.
If the environmental test apparatus is operated in a forward-pass connection state in which the refrigerant is introduced from the opening A and discharged from the other opening B, the refrigerant enters the evaporator from the opening A and the surface temperature of the evaporator decreases. The surface of the evaporator is in contact with external air for heat exchange. The refrigerant introduced from the opening A undergoes heat exchange with the external air on the surface of the evaporator, proceeds to evaporate, becomes superheated gas, and is discharged from the opening B of the evaporator.
Here, paying attention to the temperature distribution on the surface of the evaporator, in the vicinity of the opening A on the inlet side where the liquid refrigerant exists, the cooling capacity is large and the temperature of the refrigerant is low, and the surface temperature of the evaporator is low. Therefore, frost is generated and grows from the vicinity of the opening A on the inlet side. When frost grows, heat exchange between the surface of the evaporator and the outside air becomes worse near the opening A, and the cooling capacity of the cooling device decreases near the opening A.
Here, the environmental test apparatus of the present invention includes a flow path switching means, and can switch the path between the inlet and the outlet of the evaporator. If it demonstrates in a previous example, a refrigerant | coolant can be introduce | transduced from the other opening B and a refrigerant | coolant can be discharged | emitted from one opening A by switching a flow-path switching means.
Therefore, the refrigerant is introduced from the side where frost is not attached, and heat exchange is actively performed in the vicinity of the other opening B, so that the cooling capacity of the cooling device is maintained.

  When frost adheres to the surface of the evaporator during the test, the flow path switching means is switched until the thickness of the frost reaches a state where the heat exchange efficiency is excessively reduced on the entire surface of the evaporator. (Claim 2).

  It is desirable that the test be performed while maintaining the temperature in the test chamber at or above the freezing point temperature.

As described above, the storage test and the stability test are performed at room temperature and normal humidity regions such as 25 ° C / 60% RH (25 ° C / 60% relative humidity environment) and 5 ° C in the test chamber. It is carried out in a low temperature environment such as C (5 degrees Celsius), and the set temperature of the test chamber is above the freezing point temperature. As described above, the refrigerant enters the evaporator through the opening A, and the surface of the evaporator in the vicinity of the opening A comes into contact with external air for heat exchange. Then, evaporation of the refrigerant in the evaporator proceeds and is discharged as superheated gas from the opening B of the evaporator. Therefore, frost forms on the surface of the evaporator and in the vicinity of the opening A.
On the other hand, after switching the path between the inlet and outlet of the evaporator by the flow path switching means, frost is attached to the surface at the position near the outlet of the evaporator (near the opening A), The refrigerant has become a superheated gas after heat exchange with the outside air, and the cooling capacity of the refrigerant itself is low.
On the other hand, the surface of the evaporator is in contact with the air in the test chamber, and the temperature of the air is equal to or higher than the freezing point temperature. Therefore, frost adhering to the surface in the vicinity of the outlet of the evaporator (near the opening A) is melted by exposure to air having a temperature equal to or higher than the freezing point temperature.

The invention according to claim 4 is the environmental test apparatus according to any one of claims 1 to 3, wherein the forward pass connection and the reverse pass connection are switched at regular intervals.
The invention according to claim 5 includes a compressor, a condenser, an expansion means, an evaporator, and a circulation channel that connects these in an annular shape, and a refrigerant that changes phase is enclosed in the circulation channel. by which, the gaseous refrigerant compressed by the compressor, the compressed refrigerant liquefied in the condenser, vaporized and introduced into the evaporator the refrigerant through the expansion means, the cooling system to return to the compressor, the expansion has a first expansion means and second expansion means as a means, the evaporator is intended to pass two openings a, the two openings a have B, and the refrigerant between the B, the condensing A forward passage connection through which the refrigerant is introduced from one opening A through the first expansion means, discharged from the other opening B and returned to the compressor, and the other through the second expansion means from the condenser. Conversely refrigerant refrigerant from the introduction to one opening a from the opening B is discharged back into the compressor Comprising a flow path switching means for switching the direction passing connection, the flow path switching unit switches the flow path between the expansion means and the condenser to one of the first expansion means side and the second expansion means side, and The flow path for returning the refrigerant from the evaporator to the compressor is switched to either a flow path for returning the refrigerant from the opening B to the compressor or a flow path for returning the refrigerant from the opening A to the compressor. It is a cooling device.

  The cooling device of the present invention also employs a structure that can switch the path between the inlet and outlet of the evaporator. Therefore, the cooling capacity can be maintained.

  The environmental test apparatus of the present invention can be continuously performed for a long time without interrupting the test. Further, the cooling device of the present invention can be operated continuously for a long time.

1 is a cross-sectional view conceptually showing an embodiment of the present invention and a conventional environmental testing apparatus. It is a piping system diagram of a cooling device of an embodiment of the present invention. FIG. 3 is a piping system diagram of FIG. 2, showing a refrigerant flow when operated in a forward-pass connected state. FIG. 3 is a piping system diagram of FIG. 2, showing the flow of refrigerant when operated in a reverse-direction connected state. It is sectional drawing which represented notionally the environmental test apparatus of other embodiment of this invention conceptually.

Embodiments of the present invention will be further described below. The environmental test apparatus 1 according to the present embodiment is capable of performing a food preservation test and a stability test for pharmaceuticals, cosmetics, and the like. The structure of the environmental test apparatus 1 of the present embodiment is substantially the same as that of the environmental test apparatus 100 of the prior art.
That is, as shown in FIG. 1, the environmental test apparatus 1 has a heat insulating tank 3 covered with a heat insulating wall 2. A test chamber 5 is formed in a part of the heat insulating tank 3. The test chamber 5 is a space in which the device under test 18 is installed.
The environmental test apparatus 1 further includes a humidifying device 6, a cooling device 7, a heater (heating device) 8, and a blower 10. In the present embodiment, an air conditioning device 17 is configured by the humidifying device 6, the cooling device 7, and the heater 8.

The environmental test apparatus 1 includes an air conditioning ventilation path 15 that communicates with the test chamber 5, and an air conditioning device 17 and a blower 10 are provided in the air conditioning ventilation path 15. The cooling device 7 realizes a refrigeration cycle, and an evaporator 33 is installed in the air conditioning ventilation path 15.
A temperature sensor 12 and a humidity sensor 13 are provided in the vicinity of the air blowing portion 16 of the air conditioning ventilation path 15.
The temperature sensor 12 is provided in the vicinity of the air blowing portion 16 of the air conditioning ventilation path 15 and can detect the temperature of the air immediately after being adjusted by the air conditioning equipment 17.
The humidity sensor 13 can detect the relative humidity of the air immediately after being adjusted by the air conditioner 17.

The cooling device 7 employed in the environmental test apparatus 1 of the present embodiment is unique to the present embodiment, and will be described in detail below.
The cooling device 7 employed in the present embodiment is as shown in FIG. 2, and includes a compressor 30, a condenser 31, a first expansion means 32a, a second expansion means 32b, and an evaporator 33. Yes. The first expansion means 32a and the second expansion means 32b are capillary tubes. The evaporator 33 has a well-known structure, has two openings A and B, and allows the refrigerant to pass between the two openings A and B.
The cooling device 7 further includes a first on-off valve 40, a second on-off valve 41, a third on-off valve 45, and a fourth on-off valve 46 as flow path switching means. These on-off valves are all electromagnetic valves.

Although the cooling device 7 employed in the present embodiment has an annular flow path that connects the above-described devices in a ring shape, the circulation flow path has a branch portion and a merge portion, and the first system circulation flow path And the second system circulation channel.
In other words, the circulation passage of the first system constitutes a forward passage connecting passage for allowing the refrigerant to pass from the opening A to the opening B of the evaporator 33, and the discharge side of the compressor 30 and the condenser 31. The first on-off valve 40, the first expansion means 32a, and the opening A of the evaporator 33 are connected in order by pipes, and the opening B of the evaporator 33, the third on-off valve 45, and the suction side of the compressor 30 are connected. It is a circulation flow path constructed by sequentially connecting pipes. Hereinafter, this series of channels is referred to as a main channel 47. The circulation channel of the first system is a channel that allows the refrigerant to pass through only the main channel 47, and the refrigerant enters the condenser 31 from the discharge side of the compressor 30, and further from the condenser 31 to the first on-off valve 40. And enters the opening A of the evaporator 33 via the first expansion means 32a. Further, the refrigerant is discharged from the opening B of the evaporator 33 and returns to the suction side of the compressor 30 via the third opening / closing valve 45.

  In the cooling device 7 employed in the present embodiment, the first branch portion 50 is provided between the condenser 31 of the main flow path 47 and the first on-off valve 40. A second branch 51 is provided between the opening B of the evaporator 33 and the third on-off valve 45. And between the 1st branch part 50 and the 2nd branch part 51 is connected by the auxiliary forward flow path 52, and the 2nd on-off valve 41 and the 2nd expansion means 32b are connected to the said auxiliary forward flow path 52 in this order. .

  A third branch 53 is provided between the first expansion means 32 a of the main flow path 47 and the opening A of the evaporator 33, and a junction 55 is provided between the third on-off valve 45 and the suction side of the compressor 30. The third branch portion 53 and the merging portion 55 are connected by an auxiliary return flow path 56, and the fourth open / close valve 46 is connected to the auxiliary return flow path 56.

The circulation channel of the second system constitutes a reverse direction passage connecting channel for allowing the refrigerant to pass from the opening B of the evaporator 33 toward the opening A. The circulation path of the second system causes the refrigerant condensed in the condenser 31 to flow through the auxiliary forward flow path 52 to the opening B of the evaporator 33, and the refrigerant discharged from the opening A of the evaporator 33 is auxiliary returned. This is a flow path that returns to the suction side of the compressor 30 via the flow path 56.
That is, when the refrigerant is passed through the second system, the refrigerant enters the condenser 31 from the discharge side of the compressor 30, and further evaporates from the condenser 31 via the second on-off valve 41 and the second expansion means 32b. Enter opening B of vessel 33. Further, the refrigerant is discharged from the opening A of the evaporator 33 and returns to the suction side of the compressor 30 via the fourth on-off valve 46.

Switching between the first system circulation channel and the second system circulation channel is performed by switching the first on-off valve 40, the second on-off valve 41, the third on-off valve 45, and the fourth on-off valve 46, which are the channel switching means. Is done by. That is, as shown in FIG. 3, the auxiliary forward flow path 52 and the auxiliary return flow path 56 are closed by opening the first open / close valve 40 and the third open / close valve 45 and closing the second open / close valve 41 and the fourth open / close valve 46. Only the main channel 47 communicates.
Therefore, when the compressor 30 is driven in this state, the refrigerant is the compressor 30, the condenser 31, the first on-off valve 40, the first expansion means 32a, the opening A of the evaporator 33, the opening B of the evaporator 33, and the third. It flows in the order of the on-off valve 45 and returns to the suction side of the compressor 30.

On the other hand, as shown in FIG. 4, by opening the second on-off valve 41 and the fourth on-off valve 46 and closing the first on-off valve 40 and the third on-off valve 45, the auxiliary forward flow path 52 and the auxiliary return flow path 56 are opened. A part of the main channel 47 is closed.
Therefore, when the compressor 30 is driven in this state, the refrigerant is the compressor 30, the condenser 31, the second on-off valve 41, the second expansion means 32b, the opening B of the evaporator 33, the opening A of the evaporator 33, the fourth. It flows in the order of the on-off valve 46 and returns to the suction side of the compressor 30.

Next, functions of the environmental test apparatus 1 of the present embodiment will be described. For example, when the environmental test apparatus 1 is used to perform a food preservation test or a stability test for pharmaceuticals, cosmetics, etc., the inside of the test chamber 5 is 25 ° C / 60% RH (25 ° C./60% relative humidity environment). The test is continuously performed over a long period of time while maintaining the environment in the normal temperature and normal humidity region such as) and the low temperature environment such as 5 ° C. (5 ° C.).
The environmental test apparatus 1 of the present embodiment has a timer (not shown), and includes a first on-off valve 40, a second on-off valve 41, a third on-off valve 45, and a fourth on-off valve 46 that are flow path switching means at regular intervals. Switching takes place. That is, the refrigerant circulation path is switched between the first system circulation path and the second system circulation path at regular intervals.

In the present embodiment, the refrigerant is circulated in the circulation path of the first system for the first fixed time.
As a result, the refrigerant passes through the condenser 31 in the forward direction. More specifically, the refrigerant passes from the opening A side toward the opening B side.
If it demonstrates from the compressor 30, the refrigerant | coolant gas compressed with the compressor 30 will flow through the main flow path 47, will enter into the condenser 31, and will liquefy. The liquefied refrigerant is expanded via the first expansion means 32 a and enters the opening A of the evaporator 33. The refrigerant enters the evaporator 33 and heat exchanges with the air passing through the air-conditioning ventilation path 15 to evaporate, and is discharged as an overheated gas from the opening B of the evaporator 33. The refrigerant discharged from the opening B is sucked into the compressor 30.

Here, the evaporator 33 has a large cooling capacity and a low temperature on the inlet side where the refrigerant exists in a liquid phase state. That is, the surface temperature of the evaporator 33 varies, and the temperature in the vicinity of the opening A side is lower than that of other parts. Therefore, frost is generated from the opening A side which is the inlet side of the refrigerant and grows gradually. When frost grows, heat exchange with circulating air worsens. For this reason, the heat exchange capacity decreases in the vicinity of the opening A, the region where the refrigerant evaporates moves to the opening B side as the outlet of the evaporator 33, and frost spreads and grows from the opening A side to the opening B side. .
Here, in the environmental test apparatus 1 of the present embodiment, the refrigerant circulation path is switched between the first system circulation path and the second system circulation path at regular intervals, and the evaporator inlet and outlet are switched. Is replaced. That is, the flow path switching means is switched until the frost thickness reaches a state where the heat exchange efficiency is excessively lowered on the entire surface of the evaporator 33.

By switching the circulation path to the second system, the flow direction of the refrigerant flowing in the evaporator 33 is reversed. As a result, the refrigerant is introduced from the opening B side where frost has not yet grown, and the cooling capacity in the vicinity of the opening B side is increased. Since the refrigerant evaporates in a region where frost is not formed, the cooling device 7 can maintain the cooling capacity and the dehumidifying capacity. In addition, the refrigerant evaporates on the opening B side and becomes superheated gas and flows to the opening A side with frost.
In many cases, the refrigerant reaching the opening A side no longer loses the cooling capacity. Further, the air passing through the air-conditioning ventilation path 15 also contacts the surface of the evaporator 33 and in the vicinity of the opening A. Here, for example, when the stability test for pharmaceuticals, cosmetics, and the like is performed using the environmental test apparatus 1, the air passing through the air-conditioning ventilation path 15 is in the vicinity of 25 ° C or 5 ° C and higher than the freezing point temperature. Therefore, on the surface of the evaporator 33 and in the vicinity of the opening A, the temperature is raised by taking heat away from the surrounding air. As a result, the frost adhering to the vicinity of the opening A melts.

As time elapses, frost is generated in the vicinity of the opening B. However, as described above, the refrigerant circulation path is replaced at regular intervals, so that the frost in the vicinity of the opening B is also melted.
Therefore, the environmental test apparatus 1 of the present embodiment can perform defrosting without interrupting the test.

  In the above-described embodiment, the first on-off valve 40, the second on-off valve 41, the third on-off valve 45, and the fourth on-off valve 46 are employed as the flow path switching means. However, a valve such as a three-way valve or a four-way valve is used. May be. In the embodiment described above, the electromagnetic valve is employed as the flow path switching means, but it may be of another structure such as a motor valve.

  In the above-described embodiment, the circulation path of the first system and the circulation path of the second system are switched at regular intervals, but a sensor for detecting the frost growth state is provided, and the thickness of the frost is The flow path switching means may be switched before reaching a state where the heat exchange efficiency is excessively lowered on the entire surface.

In the environmental test apparatus 1 described above, the internal layout has an air conditioning ventilation passage 15 that communicates with the test chamber 5 in a ring shape on the back side of the test chamber 5 as shown in FIG. 10 is built-in. An air introduction unit 25 is provided at the lower part of the air conditioning ventilation path 15, and an air blowing part 16 is provided at the upper part of the air conditioning ventilation path 15.
The internal layout is not limited to that shown in FIG. 1. For example, an air conditioner 17 or the like may be arranged below the test chamber 5 as shown in FIG. 5.
The environmental test apparatus 60 shown in FIG. 5 only has a different layout compared to the environmental test apparatus 1 described above, and the other components are the same, so the same numbers are assigned to the same members. Therefore, detailed description is omitted.

Moreover, in the environmental test apparatus 1 and 60, the air conditioning apparatus 17 and the air blower 10 are incorporated in the air-conditioning ventilation path 15, and the arrangement | sequence order is the humidification apparatus 6, the cooling apparatus 7, heater (in order from the air introduction part 25). Although the heating device 8 and the blower 10 are arranged, the arrangement order is arbitrary.
For example, the humidifying device 6, the heater (heating device) 8, the cooling device 7, and the blower 10 may be sequentially from the air introduction unit 25. In addition, when employ | adopting the structure which provides the heater (heating device) 8 in the upstream of the cooling device 7, the air heated up with the heater 8 can be applied to the cooling device (evaporator) 33, and a cooling device ( Evaporator 33 has a high effect of melting frost.

  In the above-described embodiment, food preservation tests and stability tests for pharmaceuticals, cosmetics, etc. have been disclosed as examples of use of the environmental test apparatus 1, but the test object is not limited, and mechanical parts and resin products Any other object may be tested. Also, the test purpose is not limited to the storage test and the stability test.

  The cooling device of the present invention has been developed for the purpose of being employed in the environmental test apparatus 1, but can also be employed in a refrigerator or a storage.

1,60 Environmental test device 5 Test chamber 6 Humidification device 7 Cooling device 8 Heater (heating device)
DESCRIPTION OF SYMBOLS 10 Blower 30 Compressor 31 Condenser 32a First expansion means 32b Second expansion means 33 Evaporator 40 First on-off valve (flow path switching means)
41 Second on-off valve (channel switching means)
45 Third open / close valve (flow path switching means)
46 Fourth open / close valve (flow path switching means)

Claims (5)

A test chamber in which the DUT is installed; and a temperature adjusting means for adjusting the temperature of the test chamber. The temperature adjusting means includes at least a cooling device.
The cooling device has a compressor, a condenser, an expansion means, an evaporator, and a circulation channel that connects these in an annular shape, and a refrigerant that changes phase in the circulation channel is enclosed. The refrigerant is compressed by a compressor, the compressed refrigerant is liquefied by a condenser, the refrigerant is introduced into an evaporator through an expansion means, vaporized, and returned to the compressor.
The expansion means has a first expansion means and a second expansion means,
The evaporator has two openings A and B, and allows the refrigerant to pass between the two openings A and B. The refrigerant passes through the first expansion means from the condenser and passes through the first opening A. A forward passage connection for introducing and discharging the refrigerant from the other opening B and returning it to the compressor, and introducing the refrigerant from the other opening B through the second expansion means from the condenser and discharging the refrigerant from the one opening A And a flow path switching means for switching the reverse passage connection back to the compressor ,
The flow path switching means switches the flow path between the condenser and the expansion means to either the first expansion means side or the second expansion means side, and flows the refrigerant from the evaporator back to the compressor. An environmental test apparatus , wherein the path is switched to one of a flow path returning from the opening B to the compressor and a flow path returning from the opening A to the compressor .   When frost adheres to the surface of the evaporator during the test, the flow path switching means is switched until the thickness of the frost reaches a state where the heat exchange efficiency is excessively reduced on the entire surface of the evaporator. The environmental test apparatus according to claim 1.   The environmental test apparatus according to claim 1 or 2, wherein the test is performed while maintaining the temperature in the test chamber at or above the freezing point temperature. 4. The environmental test apparatus according to claim 1, wherein the forward pass connection and the reverse pass connection are switched at regular intervals. A compressor, a condenser, an expansion means, an evaporator, and a circulation channel that connects these in an annular shape, and the phase change refrigerant is sealed in the circulation channel, compressing the gaseous refrigerant In the cooling device that is compressed by the machine, the compressed refrigerant is liquefied by the condenser, the refrigerant is introduced into the evaporator through the expansion means, vaporized, and returned to the compressor.
The expansion means has a first expansion means and a second expansion means,
The evaporator has two openings A and B, and allows the refrigerant to pass between the two openings A and B. The refrigerant passes through the first expansion means from the condenser and passes through the first opening A. A forward passage connection for introducing and discharging the refrigerant from the other opening B and returning it to the compressor, and introducing the refrigerant from the other opening B through the second expansion means from the condenser and discharging the refrigerant from the one opening A And a flow path switching means for switching the reverse passage connection back to the compressor ,
The flow path switching means switches the flow path between the condenser and the expansion means to either the first expansion means side or the second expansion means side, and flows the refrigerant from the evaporator back to the compressor. A cooling apparatus , wherein the path is switched to either a flow path for returning the path from the opening B to the compressor or a flow path for returning the path from the opening A to the compressor .

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