JP6650062B2 - Environmental test equipment - Google Patents

Description

  The present invention relates to an environmental test apparatus that can expose a device under test to a predetermined environment.

An environmental test is known as a measure for examining the performance and durability of products and parts. The environmental test is performed using equipment called an environmental test device. The environmental test apparatus artificially creates, for example, a high temperature environment, a low temperature environment, a high humidity environment, and the like.
The environmental test apparatus has, for example, a configuration as shown in FIG. The environmental test apparatus 100 shown in FIG. 13 includes a test chamber 3, a cooling unit 106, a heater 6, a humidifier 7, and a blower 8. The test room 3 is a space covered by the heat insulating material 2. There is an air flow path 10 communicating with the test chamber 3, and the air flow path 10 is provided with the evaporator 107 of the cooling means 106, the heater 6, the humidifier 7, and the blower 8. A temperature sensor 12 and a humidity sensor 13 are provided on the outlet side of the air flow path 10.
In the environmental test apparatus 100, an air conditioner 15 is configured by the members in the air flow path 10, the temperature sensor 12, and the humidity sensor 13.

The cooling means 106 implements a refrigeration cycle using a phase-change heat medium, and is a circulation circuit having a compressor 101, a condenser 102, and an expansion valve 103 in addition to the evaporator 107. Here, the expansion valve 103 is, for example, an electronic expansion valve, and can change the opening degree. The motor that drives the compressor 101 is an induction motor, and cannot change the number of revolutions. That is, the motor that drives the compressor 101 is not controlled by the inverter, and rotates at a constant rotation speed. Note that an inverter-driven compressor may be used.
The compressor 101, the condenser 102, the expansion valve 103, and the evaporator 107 are annularly connected by piping to form a circulation circuit, and a phase-change refrigerant is sealed therein. The refrigerant circulates through the above-mentioned circulation circuit.
The cooling means 106 expands the refrigerant in the evaporator 107 and lowers the surface temperature of the evaporator 107 to remove heat from the environment, similarly to the known means.
In addition, there is a type provided with a small auxiliary cooling means (not shown) in addition to the cooling means 106. The auxiliary cooling means is used for maintaining the temperature in the test chamber 3 at a set temperature after the temperature in the test chamber 3 is stabilized.

  The heater 6 is a known electric heater.

  The humidifying device 7 is a combination of the humidifying heater 25 and the water plate 26, and heats the water in the water plate 26 with the humidifying heater 25 to evaporate.

  The humidity sensor 13 is not particularly limited as long as it can detect humidity. For example, a dry and wet bulb hygrometer can be used.

The environmental test apparatus 100 is for creating a desired temperature / humidity environment in the test room 3 by the built-in air conditioner 15.
That is, the blower 8 is driven to introduce the air in the test chamber 3 into the air flow path 10, and if necessary, heat, cool, humidify, and dehumidify the test chamber 3 to a desired temperature and humidity environment. .
For example, when the same environment as the outside air is set as the starting environment and a high-temperature and high-humidity environment is created, the heater 6 and the humidifier 7 are driven to heat and humidify the inside of the test chamber 3.
Conversely, when creating a low-temperature and low-humidity environment, the cooling unit 106 is driven to lower the temperature and humidity in the test chamber 3, and the heater 6 and the humidifier 7 are driven to lower the temperature in the test chamber 3. And fine tune the humidity.

When a low-temperature and high-humidity environment is created, the cooling unit 106 is driven to lower the temperature in the test chamber 3, and the humidifier 7 is driven to increase the humidity in the test chamber 3.
Even when a low-temperature and high-humidity environment is created, the heater 6 and the like are also operated to finely adjust the temperature and humidity.

  In any case, after the test room 3 has reached the desired environment, the cooling means 106, the heater 6 and the humidifier 7 are appropriately operated to maintain the desired environment.

The cooling means 106 mounted on the conventional environmental test apparatus 100 is additionally described. The cooling means 106 has a capacity (rated output) sufficient to create an environment in a temperature range indicated in a catalog or the like within a certain period of time. ing.
Further, in the case of the environmental test apparatus 100 on the premise that the DUT generates heat, the cooling means 106 has a capacity capable of allowing a heat load.
For example, if the environment test apparatus 100 is displayed to be able to create an environment of 100 degrees Celsius to minus 40 degrees Celsius, the compressor 101 of the mounted cooling means 106 has the test room 3 in a normal temperature state. Has the capacity to drop the temperature of the device to minus 40 degrees Celsius within a predetermined time. Further, the mounted compressor 101 has a capacity enough to maintain the temperature of the test chamber 3 at a set temperature (for example, minus 40 degrees Celsius) even if there is some disturbance.
That is, the compressor 101 of the conventional environmental test apparatus 100 has a capacity enough to cope with the expected maximum cooling load.
Hereinafter, for the sake of explanation, the conventional environmental test apparatus 100 equipped with a compressor 101 having a capacity sufficient to cope with the expected maximum cooling load will be referred to as “standard configuration environmental test apparatus 100” or “conventional environmental test apparatus”. Device 100 ".

Japanese Patent Publication No. 5-60614

The environmental test apparatus 100 has built-in electric equipment and naturally consumes power. The environmental test may be performed for a long time. Therefore, it can be said that the environmental test apparatus 100 is an apparatus that consumes considerable power.
Further, in order to precisely control the temperature in the test chamber 3, the environmental test apparatus 100 may simultaneously drive the cooling means 106 and the heater 6 as described above. That is, the responsiveness of the cooling means 106 is inferior. Therefore, in the environmental test apparatus 100, the cooling unit 106 is driven so that the temperature in the test chamber 3 tends to be slightly low, and the heater 6 is simultaneously driven to finely adjust the temperature.
Here, in the environmental test apparatus 100 of the related art (standard configuration), since the compressor 101 having a capacity capable of coping with the expected maximum cooling load is mounted, the temperature in the test chamber 3 is stable. In this case, the refrigeration output of the cooling means 106 becomes excessive, and it is necessary to increase the output of the heater 6 or the like to offset this. Therefore, the environmental test apparatus 100 of the related art (standard configuration) has a dissatisfaction that the power consumption is large.

Under these circumstances, there is a demand in the market for the development of a so-called energy-saving type environmental test apparatus that consumes less power.
The present inventors have repeated studies to meet this demand, and have investigated the ratio of power consumed by devices constituting the environmental test apparatus 100. As a result, it was found that the power consumption of the cooling unit 106 was the largest among the devices constituting the environmental test apparatus 100.
Therefore, the present inventors prototyped an environmental test apparatus (hereinafter referred to as an improved environmental test apparatus) 200 in which the capacity of the compressor 101 is replaced with a smaller capacity than the current one in order to suppress the power consumption of the cooling means 106. .
That is, most of the power consumption of the cooling means 106 is power required to drive the compressor 101. Therefore, if the capacity of the compressor 101 is made smaller than the current state (standard configuration), the power consumption of the cooling means 106 decreases, and the power consumption of the entire environmental test apparatus 200 also decreases.

Here, even if the capacity of the compressor 101 is replaced with something smaller than the current state (standard configuration), a refrigeration output equivalent to the current state (standard configuration) can be obtained by raising the evaporation temperature of the refrigerant. Therefore, when the temperature in the test chamber 3 is high to some extent, there is no particular problem in performing the environmental test.
Also, as is well known, the actual refrigeration output (the amount of thermal energy taken by the refrigerator) and the motor load of the compressor 101 (the amount of mechanical energy generated by the motor and the power consumption) are not proportional to each other. The cooling means (refrigerator) 106 can exhibit the same refrigeration output as that of the conventional (standard configuration) cooling means 106, and consumes less power than before.

Hereinafter, this principle will be briefly described.
The cooling means 106 is a refrigerator constituting a refrigeration cycle, and compresses a gaseous refrigerant by the compressor 101 to increase the temperature and pressure of the refrigerant gas. Then, the refrigerant gas is cooled and liquefied in the condenser 102 to produce a high-pressure liquid refrigerant. Thereafter, the pressure of the liquid refrigerant is reduced by the expansion valve 103, and the liquid refrigerant is evaporated and vaporized in the evaporator 107. At this time, the refrigerant takes heat of vaporization, and the surface temperature of the evaporator 107 decreases. The cooling means 106 lowers the surface temperature of the evaporator 107 according to the principle described above.

Therefore, the refrigerating output (the amount of heat energy taken by the refrigerating machine) greatly depends on the amount of the refrigerant supplied to the evaporator 107, and the larger the amount of the refrigerant supplied to the evaporator 107, the higher the refrigerating output.
Therefore, the improved environmental test apparatus 200 adopts a method of supplying a larger amount of refrigerant to the evaporator 107 by raising the evaporation temperature of the refrigerant than the conventional (standard configuration).
As a result, the improved environmental test apparatus 200 can exhibit the same refrigeration output as the conventional one despite the fact that the compressor 101 having a smaller rated output (capacity) than the standard configuration is mounted.

Next, the surface temperature of the evaporator 107 will be described.
The surface temperature of the evaporator 107 depends on the evaporation temperature of the refrigerant, and the evaporation temperature of the refrigerant depends on the evaporation pressure of the refrigerant.
Specifically, when the evaporation pressure of the refrigerant is low, the evaporation temperature of the refrigerant decreases, and the surface temperature of the evaporator 107 decreases. Conversely, when the evaporation pressure of the refrigerant is high, the evaporation temperature of the refrigerant increases, and the surface temperature of the evaporator 107 increases.
Further, the evaporation pressure of the refrigerant depends on the opening degree of the expansion valve 103 and the capacity of the compressor 101, and the evaporation temperature of the refrigerant decreases when the opening degree of the expansion valve 103 is reduced or the refrigerant discharge amount from the compressor 101 is small. Then, the surface temperature of the evaporator 107 decreases. Conversely, if the degree of opening of the expansion valve 103 is increased or the amount of refrigerant discharged from the compressor 101 is large, the evaporation temperature of the refrigerant increases, and the surface temperature of the evaporator 107 increases.
Therefore, the improved type environmental test apparatus 200 aims to save energy as described above, and the evaporating temperature of the refrigerant is higher than in the conventional (standard configuration), and the surface temperature of the evaporator 107 is increased. Resulting in.

As described above, the improved environmental test apparatus 200 has a higher evaporating pressure of the refrigerant in the evaporator 107 than the standard environmental test apparatus 100, and the surface temperature of the evaporator 107 is somewhat higher than the conventional one. When the set temperature of the test chamber 3 is high to some extent, no particular problem occurs in performing the environmental test.
However, the improved environmental test apparatus 200 has been difficult to apply to an environmental test that requires an extremely low temperature environment.
That is, in the improved type environmental test apparatus 200, the evaporation pressure of the refrigerant in the evaporator 107 is higher than in the conventional (standard configuration), and the surface temperature of the evaporator 107 has to be somewhat higher than in the conventional.
Even if the surface temperature of the evaporator 107 rises somewhat, the surface temperature of the evaporator 107 drops to a certain temperature. Therefore, when the set temperature of the test chamber 3 is equal to or higher than that temperature, for example, The surface temperature of the evaporator 107 can be reduced with a predetermined temperature range from the actual temperature of the evaporator 107, and the temperature in the test chamber 3 can be lowered to a desired set temperature and maintained.

On the other hand, when an extremely low temperature environment of, for example, minus 40 degrees Celsius is created in the test chamber 3, the surface temperature of the evaporator 107 must be at least lower than this. Desirably, the surface temperature of the evaporator 107 should be lowered with a predetermined temperature range from the set temperature.
However, in the improved environmental test apparatus 200, the refrigerant evaporation temperature is higher than in the conventional (standard configuration), and the surface temperature of the evaporator 107 is higher than in the conventional (standard configuration). Therefore, in the improved environmental test apparatus 200, it is difficult to lower the surface temperature of the evaporator 107.

Here, even with the improved environmental test apparatus 200, the surface temperature of the evaporator 107 can be lowered below the set temperature if the opening degree of the expansion valve 103 is narrowed down compared to the conventional (standard configuration).
However, since the compressor 101 mounted on the improved environmental test apparatus 200 has a smaller rated output in the first place than the standard configuration, when the surface temperature of the evaporator 107 is lowered below the set temperature, the required refrigeration output is required. (The amount of heat energy taken by the refrigerator) cannot be obtained.
That is, the compressor 101 of the cooling means 106 mounted on the environmental test apparatus 100 having the standard configuration lowers the temperature of the test chamber 3 in a normal temperature state to a set temperature (for example, about minus 40 degrees Celsius) within a predetermined time, and Even if there is some disturbance, the capacity of the test chamber 3 can be maintained at that temperature, but the compressor 101 mounted on the improved environmental test apparatus 200 is different from the conventional one. Small capacity.
Therefore, if the operation is performed with the surface temperature of the evaporator 107 lowered below the set temperature of the extremely low temperature, the required refrigeration output (the amount of heat energy taken by the refrigerator) cannot be obtained, and the temperature of the test chamber 3 is lowered to the set temperature. Takes an excessive amount of time.
That is, a curve (temperature drop curve) showing the relationship between the temperature and time in the test chamber 3 from the room temperature state of the test chamber 3 of the improved environmental test apparatus 200 to the lower limit of the corresponding temperature range is a conventional (standard configuration). Is slower than the environmental test apparatus 100 of FIG.

  Therefore, the present invention further develops the above-described improved environmental test apparatus 200, and consumes less power than before, and the temperature of the test chamber 3 reaches a desired low temperature by drawing a temperature drop curve similar to the conventional one. Development of environmental test equipment capable of

The invention according to claim 1 for solving the above-described problem has a test chamber in which a device under test is arranged, and a cooling unit, wherein the cooling unit has a main refrigeration circuit and an auxiliary refrigeration circuit, Each of the main refrigeration circuit and the auxiliary refrigeration circuit has a compressor, a condenser, an expansion means, and an in-compartment evaporator, and a phase-change refrigerant is circulated therein. The in-compartment evaporator of the auxiliary refrigeration circuit is provided at a position communicating with the test room or the test room, is branched from the auxiliary refrigeration circuit, and extends from a condenser of the main refrigeration circuit to expansion means. A refrigerant cooling circuit that cools the refrigerant passing therethrough; and a refrigerant control unit that controls the flow of the refrigerant flowing through the refrigerant cooling circuit on and off and / or controls the flow rate, and circulates the refrigerant to the main refrigeration circuit and / or the auxiliary refrigeration circuit. And the temperature in the test chamber It is possible to perform a normal operation to control and a supercooling operation to circulate the refrigerant through the main refrigeration circuit and pass the refrigerant through the refrigerant cooling circuit, and to operate the refrigerant control means based on certain conditions, If the difference between the normal has a switching control unit for switching the operation and excessive cooling operation, the surface temperature of the pre-Symbol the internal evaporator belonging to a temperature between the main refrigeration circuit of the test chamber becomes constant less, subcooling operation Is performed.
The invention according to claim 2 includes a test chamber in which a DUT is placed, and a cooling unit, wherein the cooling unit has a main refrigeration circuit and an auxiliary refrigeration circuit, and the main refrigeration circuit and the auxiliary refrigeration circuit. The circuit has a compressor, a condenser, an expansion means, and an in-compartment evaporator, all of which have a phase-change refrigerant circulating therein, and the circuits in the compartments of the main refrigeration circuit and the auxiliary refrigeration circuit are provided. The evaporator is provided at the test chamber or at a position leading to the test chamber, and cools a refrigerant branched from the auxiliary refrigeration circuit and passing from the condenser of the main refrigeration circuit to the expansion means. A refrigerant cooling circuit, and refrigerant control means for intermittently and / or controlling the flow rate of the refrigerant flowing in the refrigerant cooling circuit, and circulating the refrigerant in the main refrigeration circuit and / or the auxiliary refrigeration circuit to reduce the temperature in the test chamber. Controlled normal operation and the main cooling It is possible to perform a supercooling operation that circulates the refrigerant through the circuit and passes the refrigerant through the refrigerant cooling circuit, and operates the refrigerant control unit based on certain conditions to switch between the normal operation and the supercooling operation An environmental test apparatus, comprising switching control means, wherein a supercooling operation is performed when the temperature of the test chamber falls below a certain temperature.

It is desirable that the refrigerant control means can completely shut off the refrigerant flowing in the refrigerant cooling circuit, but it is not necessary that the refrigerant control means be able to completely shut off the refrigerant. If it is not possible to completely shut off the refrigerant flowing through the refrigerant cooling circuit, during normal operation, the amount of refrigerant introduced into the refrigerant cooling circuit is reduced to a small amount, which substantially reduces supercooling of the refrigerant flowing through the main refrigeration circuit. Should not be caused to contribute.
The environmental test apparatus of the present invention has a main refrigeration circuit and an auxiliary refrigeration circuit as cooling means. The in-compartment evaporators of the main refrigeration circuit and the auxiliary refrigeration circuit are provided in a test room or at a position leading to the test room. Therefore, in the environmental test apparatus of the present invention, the temperature and the like in the test chamber can be adjusted by both the main refrigeration circuit and the in-compartment evaporator of the auxiliary refrigeration circuit.
Further, the environmental test apparatus of the present invention includes a refrigerant cooling circuit that cools the refrigerant branched from the auxiliary refrigeration circuit and passing from the condenser of the main refrigeration circuit to the expansion means. Therefore, in the environmental test apparatus of the present invention, the refrigerant in the main refrigeration circuit can be cooled by the auxiliary refrigeration circuit. That is, in the environmental test apparatus of the present invention, the refrigerant flowing through the main refrigeration circuit can be further cooled and sent to the expansion means in a supercooled state.
In the environmental test apparatus of the present invention, the liquid refrigerant that has radiated heat in the condenser and is in a saturated liquid state is cooled by the low-temperature refrigerant in the auxiliary refrigeration circuit and is in a supercooled state. That is, the saturated condensate is deprived of sensible heat (thermal energy required to change the temperature without a phase change) and becomes a supercooled liquid, and the enthalpy of the refrigerant is reduced. When the supercooled liquid refrigerant is adiabatically expanded by the expansion valve, evaporation starts with a small enthalpy even if the evaporation temperature is the same.
As described above, in the environmental test apparatus of the present invention, the supercooling state of the refrigerant is advanced, and the enthalpy is smaller than in the related art. In the environmental test apparatus of the present invention, the enthalpy of the refrigerant is smaller than the enthalpy of the saturated condensate, and the difference in the enthalpy is an increase in the refrigeration output as compared with the conventional case.
Regarding the state of the refrigerant inside the evaporator, the ratio of the liquid is larger when the refrigerant enters the expansion means in a supercooled state than when the refrigerant is expanded without supercooling even at the same evaporation temperature. . Therefore, it can be said that the refrigerating capacity increases.
In the environmental test apparatus of the present invention, the liquid refrigerant having a temperature of, for example, plus 30 degrees Celsius immediately after leaving the condenser is further cooled to a supercooled state, for example, to 20 degrees Celsius. The heat transfer at the time of performing the supercooling process at this time is the amount of heat removed by sensible heat. The refrigeration capacity when the refrigerant is adiabatically expanded to minus 40 degrees Celsius by the expansion means is greater than the refrigeration capacity when the saturated liquid at 30 degrees Celsius is adiabatically expanded to minus 40 degrees Celsius by the amount of supercooling. .
Further, the environmental test apparatus of the present invention includes a normal operation in which the refrigerant is circulated through the main refrigeration circuit and the like to control the temperature in the test chamber, and a supercooling operation in which the refrigerant flowing in the main refrigeration circuit is sent to the expansion means in a supercooled state. Switch based on certain conditions. Therefore, the temperature of the test chamber can reach a desired low temperature by drawing a temperature decrease curve similar to the conventional one.
Further, since the normal operation can be performed using a compressor having a smaller capacity than in the past, power consumption is smaller than in the past. In addition, even when operating in the supercooling operation, the power consumption is smaller than in the conventional case.
Further, in the environmental test apparatus of the present invention, the temperature in the test chamber drops along a temperature drop curve similar to the conventional one, and reaches a desired low temperature.

The invention according to claim 3 for solving the same problem has a test chamber in which a DUT is placed, and a cooling unit, wherein the cooling unit has a main refrigeration circuit and an auxiliary refrigeration circuit, The main refrigeration circuit has a compressor, a condenser, an expansion unit, and an in-compartment evaporator, in which a phase-change refrigerant circulates, and the in-compartment evaporator of the main refrigeration circuit includes: It is provided at a position communicating with the test room or the test room, and cools a refrigerant passing from a condenser of the main refrigeration circuit to expansion means, and is a part of the auxiliary refrigeration circuit. Or a refrigerant cooling circuit configured by a circuit branched from the auxiliary refrigeration circuit, and refrigerant control means for controlling the flow rate of the refrigerant flowing through the refrigerant cooling circuit on and off and / or controlling the flow rate, and supplying the refrigerant to the main refrigeration circuit. Circulation to control the temperature in the test chamber It is possible to perform an operation and a supercooling operation in which the refrigerant is circulated through the main refrigeration circuit and a refrigerant is passed through the refrigerant cooling circuit. has a switching control means for switching over cooling operation, when the difference between the surface temperature before Symbol the internal evaporator belonging to a temperature between the main refrigeration circuit of the test chamber becomes constant less, subcooling operation is performed and An environmental test apparatus characterized in that:
The invention according to claim 4 has a test chamber in which a DUT is placed, and a cooling unit, wherein the cooling unit has a main refrigeration circuit and an auxiliary refrigeration circuit, and the main refrigeration circuit is a compressor. And a condenser, an expansion means, and a refrigerant that changes the phase and has an in-compartment evaporator, wherein the in-compartment evaporator of the main refrigeration circuit is in the test room or the test room. The main refrigeration circuit is provided at a position that communicates with the main refrigeration circuit and cools the refrigerant passing from the condenser to the expansion means, and is branched from a part of the auxiliary refrigeration circuit or the auxiliary refrigeration circuit. Having a refrigerant cooling circuit constituted by a circuit having the above-mentioned circuit, and having refrigerant control means for intermittently controlling the flow of the refrigerant flowing in the refrigerant cooling circuit and / or controlling the flow rate thereof. Control the normal operation and the main refrigeration circuit It is possible to perform a supercooling operation that circulates the medium and passes the refrigerant through the refrigerant cooling circuit, operates the refrigerant control unit based on certain conditions, and controls switching between the normal operation and the supercooling operation. An environmental test apparatus having means, wherein a supercooling operation is performed when the temperature of the test chamber falls below a certain temperature.

The invention described in claim 5, the capacity of the compressor belonging to the auxiliary refrigeration circuit according to any one of claims 1 to 4, characterized in that less than the capacity of the compressor belonging to the main refrigeration circuit Environmental test equipment.

  The main use of the auxiliary refrigeration circuit is to send refrigerant to the refrigerant cooling circuit, and to cool the refrigerant flowing through the main refrigeration circuit. Therefore, the capacity of the compressor belonging to the auxiliary refrigeration circuit is smaller than the capacity of the compressor belonging to the main refrigeration circuit.

In the invention according to claim 6 , the main refrigeration circuit is capable of adjusting the evaporation temperature of the refrigerant, and reduces the evaporation temperature in accordance with the decrease in the temperature of the test chamber, so that the temperature of the test chamber is equal to or lower than a certain temperature. The environmental test apparatus according to any one of claims 1 to 5 , wherein the operation is switched from the normal operation to the supercooling operation on the condition that the operation has been completed.

  In the environmental test apparatus according to the present invention, the temperature in the test chamber drops along a temperature drop curve similar to the conventional one, and reaches a desired low temperature.

The invention according to claim 7 , wherein the auxiliary refrigeration circuit has a compressor, a condenser, an expansion means, and an in-compartment evaporator, and circulates a phase-change refrigerant, and the test chamber When the temperature of the test room is equal to or higher than a certain middle temperature and the set temperature of the test chamber is equal to or lower than a certain low temperature, the main refrigeration circuit and the auxiliary refrigeration circuit are driven to drive the main refrigeration circuit and the auxiliary refrigeration circuit. A quenching operation for passing a refrigerant through the in-compartment evaporator is performed, and the evaporation temperature in both of the in-compartment evaporators is decreased according to the temperature decrease in the test chamber. by stopping the supply of the coolant for the switch to the over-cooling operation, according to any one of claims 1 to 6 temperature of the test chamber and performing only in normal operation the main refrigeration circuit to reach the set temperature Environmental test equipment.

Here, “medium temperature” is a temperature near or slightly lower than normal temperature, and causes a considerable temperature difference between the temperature in the test chamber and the surface temperature of the evaporator without performing the supercooling operation. Temperature that can be used.
In the environmental test apparatus of the present invention, when the temperature in the test chamber before the start of the test is equal to or higher than a certain middle temperature, the main refrigeration circuit and the auxiliary refrigeration circuit are driven to perform a quenching operation to reduce the temperature in the test chamber. Can be lowered in time.
Further, in the environmental test apparatus of the present invention, the evaporation temperature in both of the in-compartment evaporators is reduced in accordance with the temperature decrease in the test chamber. The surface temperature can be kept below that.

The invention according to claim 8 is characterized in that the auxiliary refrigeration circuit has a bypass circuit for returning the refrigerant discharged from the condenser to the compressor, and the refrigerant discharged from the condenser of the auxiliary refrigeration circuit in the bypass circuit. The environmental test apparatus according to any one of claims 1 to 7 , wherein heat is exchanged with a refrigerant discharged from a compressor of the circuit, and the heat is returned to the compressor as a superheated gas.

  When switching from the supercooling operation to the normal operation, it is desirable to provide a bypass circuit in the auxiliary refrigeration circuit in order to gradually reduce the amount of refrigerant in the auxiliary refrigeration circuit that cools the main refrigeration circuit. Thereby, the refrigeration capacity of the main refrigeration circuit can be continuously varied.

According to a ninth aspect of the present invention, the main refrigeration circuit has a bypass circuit that returns a refrigerant discharged from a condenser of the main refrigeration circuit to a compressor of the main refrigeration circuit, and the main refrigeration circuit in the bypass circuit. refrigerant exiting the condenser with the refrigerant heat exchanger exiting from the compressor of the main refrigeration circuit, according to any one of claims 1 to 8 in a superheated gas, characterized in that is returned to the compressor Environmental test equipment.

In the present invention, since the bypass circuit is provided in the main refrigeration circuit, the amount of refrigerant flowing through the evaporator can be further reduced.
Desirably, the capacity of the bypass circuit is such that the entire amount of the refrigerant discharged from the compressor can be passed through and returned to the compressor. That is, it is desirable that the main refrigeration circuit can be operated without stopping the compressor even if the refrigerant flowing to the evaporator is stopped.
It is desirable that the bypass circuit has a flow rate adjusting means such as an expansion valve. By providing a flow control means such as an expansion valve in the bypass circuit, the amount of refrigerant bypassing the evaporator can be arbitrarily adjusted, and as a result, the refrigerant flowing to the evaporator can be adjusted.

The invention according to claim 10, in any one of claims 1 to 9, characterized in that the switching means and / or over-cooling operation shifts from the normal operation to the over-cooling operation having a switching means to shift to the normal operation It is an environmental test apparatus described.

  According to the present invention, the operation method can be switched without stopping the environmental test apparatus, and the temperature in the test chamber can be smoothly controlled.

The invention according to claim 11 is characterized in that a set temperature of the test chamber can be set, and normal operation and supercooling operation are switched according to the set temperature and / or the current temperature of the test chamber. The environmental test apparatus according to any one of claims 1 to 10 , wherein

  According to the present invention, the operation method can be automatically selected.

The invention according to claim 12 is the environmental test apparatus according to any one of claims 1 to 11 , wherein the operation of the auxiliary refrigeration circuit can be stopped.

  According to the invention, the operating method can be changed.

  The environmental test apparatus of the present invention consumes less power than the conventional one. Further, in the environmental test apparatus of the present invention, the temperature of the test chamber can reach a desired low temperature by drawing a temperature decrease curve similar to the conventional one.

It is a lineblock diagram of an environmental test device of an embodiment of the present invention. FIG. 2 is a configuration diagram of the environmental test apparatus of FIG. 1, showing a flow of a refrigerant when performing an intermediate cooling operation (normal operation). FIG. 2 is a configuration diagram of the environmental test apparatus of FIG. 1, showing a flow of a refrigerant when performing a slow cooling operation (normal operation). FIG. 2 is a configuration diagram of the environmental test apparatus of FIG. 1, showing a flow of a refrigerant when performing a quenching operation (normal operation). FIG. 2 is a configuration diagram of the environmental test apparatus of FIG. 1, showing a flow of a refrigerant when performing a supercooling operation. 5 is a flowchart illustrating an example of a switching state of a driving method. It is a lineblock diagram of an environmental test device of yet another embodiment of the present invention. It is a lineblock diagram of an environmental test device of yet another embodiment of the present invention. FIG. 9 is a configuration diagram of an expansion means used in still another embodiment of the present invention. 9 is a graph showing the relationship between temperature and time in the test chamber (temperature drop curve) from the normal temperature state of the environmental test apparatus of Comparative Example 1 (standard configuration) to the lower limit of the corresponding temperature range. 9 is a graph showing a relationship (temperature drop curve) between temperature and time in a test chamber from a normal temperature state of Comparative Example 2 (improved environmental test apparatus) to a lower limit of a corresponding temperature range. 4 is a graph showing a relationship (temperature drop curve) between temperature and time in a test chamber from a normal temperature state to a lower limit of a corresponding temperature range of the environmental test apparatus according to the embodiment of the present invention. It is a block diagram of a prior art and the improved type environmental test apparatus.

Hereinafter, embodiments of the present invention will be further described. Note that the same members as those of the environmental test apparatus 100 of the conventional technology (standard configuration) are assigned the same numbers, and duplicate descriptions are omitted.
The mechanical configuration of the environmental test apparatus 1 according to the embodiment of the present invention is the same as that of the conventional environmental test apparatus 100 except for the structure of the cooling means 30.
That is, the environmental test apparatus 1 includes a test chamber 3, a cooling unit 30, a heater 6, a humidifier 7, and a blower 8, as shown in FIG. The test room 3 is a space covered by the heat insulating material 2. There is an air flow passage 10 communicating with the test chamber 3, and the air flow passage 10 is provided with the two internal evaporators 38 and 48 of the cooling means 30, the heater 6, the humidifier 7, and the blower 8. Have been. The humidifying device 7 is a combination of the humidifying heater 25 and the water plate 26, and heats the water in the water plate 26 with the humidifying heater 25 to evaporate.
A temperature sensor 12 and a humidity sensor 13 are provided on the outlet side of the air flow path 10. In the environmental test apparatus 1, an air conditioner 15 is configured by the members in the air flow path 10, the temperature sensor 12 and the humidity sensor 13.

The cooling means 30 is a characteristic configuration of the present embodiment, and will be described in detail. The cooling means 30 employed in the present embodiment has two refrigeration circuits 31, 32. One of the refrigeration circuits 31 is the main refrigeration circuit 31. The other is an auxiliary refrigeration circuit 32.
The main refrigeration circuit 31 is a circuit drawn by a thick line in FIG. The main refrigeration circuit 31 includes a compressor 35, a condenser 36, an expansion means 37, and an evaporator 38, which are connected in a ring shape by pipes, similarly to the known refrigeration circuit, and constitutes a circulation circuit. Is enclosed.
Hereinafter, in order to distinguish the equipment on the main refrigeration circuit 31 side from the equipment on the auxiliary refrigeration circuit 32 side, the components of the main refrigeration circuit 31 are divided into a main compressor 35, a main condenser 36, a main expansion means 37 and a main side. This is referred to as an in-store evaporator 38.
Further, in the present embodiment, on the main refrigeration circuit 31, there are a primary flow path of the return refrigerant heating heat exchanger 63 and a secondary flow path of the supercooling heat exchanger 50. Therefore, in the present embodiment, the main refrigeration circuit 31 is connected to the primary side passage of the return refrigerant heating heat exchanger 63 from the main side compressor 35, the main side condenser 36, and the secondary side of the subcooling heat exchanger 50. It is an annular flow path that returns to the main compressor 35 around the flow path, the main expansion means 37 and the evaporator 38 inside the main storage.

On the other hand, the auxiliary refrigeration circuit 32 is a circuit drawn by a thick line in FIG. Similarly to the known auxiliary refrigeration circuit 32, a compressor 45, a condenser 46, an expansion means 47, an evaporator 48, and a check valve 49 are connected in a ring shape by piping to form a circulation circuit. A refrigerant that changes phase is enclosed.
Hereinafter, in order to distinguish the equipment on the auxiliary refrigeration circuit 32 side from the equipment on the main refrigeration circuit 31 side, the components of the auxiliary refrigeration circuit 32 are divided into an auxiliary compressor 45, an auxiliary condenser 46, an auxiliary expansion means 47 and an auxiliary expansion means 47. This is referred to as a side-chamber evaporator 48.
Further, in the present embodiment, the primary flow path of the heat exchanger 65 for heating the return refrigerant is interposed on the auxiliary refrigeration circuit 32.
Therefore, in the present embodiment, the auxiliary refrigeration circuit 32 supplies the primary side flow path of the heat exchanger 65 for returning refrigerant from the auxiliary side compressor 45, the auxiliary side condenser 46, the auxiliary side expansion means 47, and the auxiliary side internal evaporation. It is an annular flow path that returns to the auxiliary compressor 45 around the device 48 and the check valve 49.

Although the refrigerant in the main refrigeration circuit 31 and the refrigerant in the auxiliary refrigeration circuit 32 are not mixed, the refrigerant between the main refrigeration circuit 31 and the auxiliary refrigeration circuit 32 is thermally connected via the supercooling heat exchanger 50. Are linked. This will be described below.
In the present embodiment, a supercooling heat exchanger 50 is provided on the main refrigeration circuit 31. The mounting position of the subcooling heat exchanger 50 is on the main refrigeration circuit 31 and between the main condenser 36 and the main expansion means 37.
In the present embodiment, the secondary flow path of the subcooling heat exchanger 50 is connected to the main refrigeration circuit 31, and the refrigerant that has passed through the main condenser 36 and liquefied passes through the subcooling heat exchanger 50. And reaches the main-side expansion means 37.

Further, the primary flow path of the subcooling heat exchanger 50 has a relatively large space, and substantially functions as an evaporator.
The primary flow path of the subcooling heat exchanger 50 constitutes a part of the refrigerant cooling circuit 51 branched from the auxiliary refrigeration circuit 32.
The refrigerant cooling circuit 51 is a flow path branched from between the auxiliary condenser 46 and the auxiliary expansion means 47 of the auxiliary refrigeration circuit 32 and reaching the suction side of the auxiliary compressor 45. The expansion means 52 and the primary flow path of the supercooling heat exchanger 50 described above are interposed.

As an auxiliary circuit, a main refrigeration circuit side bypass circuit 60 is provided on the main refrigeration circuit 31 side, and an auxiliary refrigeration circuit side bypass circuit 61 is provided on the auxiliary refrigeration circuit 32 side.
The main refrigeration circuit side bypass circuit 60 is a flow path branched from between the subcooling heat exchanger 50 of the main refrigeration circuit 31 and the main expansion means 37 and reaching the suction side of the main compressor 35. In the middle of the main refrigeration circuit side bypass circuit 60, there is a bypass side expansion means 53 and a secondary side flow path of the return refrigerant heating heat exchanger 63.
The auxiliary refrigeration circuit side bypass circuit 61 is a flow path branched from between the auxiliary side condenser 46 and the auxiliary side expansion means 47 of the auxiliary refrigeration circuit 32 and reaching the suction side of the auxiliary side compressor 45. There is a secondary side flow path of the expansion means 66 for heat and the heat exchanger 65 for heating the return refrigerant.

In the present embodiment, the compressors (the main compressor 35 and the auxiliary compressor 45) of the cooling means 30 are all driven by the induction motor, and the rotation speed is constant and cannot be changed. That is, in the present embodiment, none of the compressors of the cooling means 30 (the main compressor 35 and the auxiliary compressor 45) has the inverter control function.
The capacities of the main compressor 35 and the auxiliary compressor 45 are different. Specifically, the capacity of the auxiliary compressor 45 is smaller than the capacity of the main compressor 35.
The ratio between the capacity of the main compressor 35 and the capacity of the auxiliary compressor 45 is determined by the balance between the target refrigeration capacity and the energy saving effect. In the present embodiment, the capacity of the auxiliary compressor 45 is 20 to 35% of the capacity of the main compressor 35.

That is, the capacity of the auxiliary compressor 45 is preferably 50% or less of the capacity of the main compressor 35, more preferably 35% or less. It is desirable that the capacity of the auxiliary compressor 45 be 20% or more of the capacity of the main compressor 35.
The most recommended capacity of the auxiliary compressor 45 is 20 to 35% of the capacity of the main compressor 35.

  The main use of the auxiliary refrigeration circuit 32 is to bring the refrigerant flowing through the main refrigeration circuit 31 into a supercooled state. Therefore, the auxiliary compressor 45 does not need to have a large capacity. Would be contrary. On the other hand, if the capacity of the auxiliary compressor 45 is excessively small, the refrigerant flowing through the main refrigeration circuit 31 cannot be sufficiently supercooled.

The capacity of the main compressor 35 is smaller than that of the conventional compressor (standard configuration). If only the main compressor 35 is used, any of the following situations may occur.
(1) When the test chamber 3 is cooled using only the main compressor 35, the temperature does not reach the lowest temperature in the temperature application range described in the catalog.
(2) When the test room 3 at room temperature is cooled using only the main compressor 35, it takes more time to reach the lowest temperature in the temperature application range described in the catalog than in the conventional (standard configuration). For example, it takes 90 minutes or more.

  In the present embodiment, the expansion means of the cooling means 30 are all electronic expansion valves, and can change the opening degree. Any expansion means of the cooling means 30 can be in a fully closed state. That is, the main expansion means 37, the auxiliary expansion means 47, the refrigerant cooling expansion means 52, the bypass expansion means 53, and the bypass expansion means 66 are all electronic expansion valves and can change the opening degree, and It can be in a fully closed state.

In the present embodiment, the auxiliary expansion means 47 of the auxiliary refrigeration circuit 32 and the refrigerant cooling expansion means 52 of the refrigerant cooling circuit 51 function as refrigerant control means for interrupting the refrigerant flowing through the refrigerant cooling circuit 51. In the present embodiment, the refrigerant cooling circuit 51 is intermittently opened and closed by opening and closing the auxiliary expansion means 47 and the refrigerant cooling expansion means 52.
That is, by closing the auxiliary expansion means 47 and opening the refrigerant cooling expansion means 52, the refrigerant cooling circuit 51 is opened, and the flow path to the auxiliary side internal evaporator 48 is shut off. As a result, the refrigerant is supplied to the primary passage of the subcooling heat exchanger 50.
Conversely, by opening the auxiliary expansion means 47 and closing the refrigerant cooling expansion means 52, the refrigerant cooling circuit 51 is closed, and the flow path to the auxiliary internal storage evaporator 48 is opened. As a result, the refrigerant is supplied to the auxiliary side internal evaporator 48.

In the environmental test apparatus 1 of the present embodiment, the cooling means 30 can be operated in four operation modes.
More specifically, an intermediate cooling operation (normal operation) in which the refrigerant is circulated through the main refrigeration circuit 31 indicated by a thick line in FIG. 2 and a slow cooling operation (normal operation) in which the refrigerant is circulated through the auxiliary refrigeration circuit 32 indicated by a thick line in FIG. Operation), a quenching operation (normal operation) in which the refrigerant is circulated through both the main refrigeration circuit 31 and the auxiliary refrigeration circuit 32 as shown by a bold line in FIG. A supercooling operation that circulates through the cooling circuit 51 can be performed.

In the middle cooling operation (FIG. 2), only the main compressor 35 belonging to the main refrigeration circuit 31 is driven, and the auxiliary compressor 45 belonging to the auxiliary refrigeration circuit 32 is stopped.
The medium cooling operation (FIG. 2) is performed by circulating the refrigerant only in the main refrigeration circuit 31.
In the intermediate cooling operation, the gaseous refrigerant is compressed by the main compressor 35, and the compressed refrigerant passes through the primary flow path of the heat exchanger 63 for returning refrigerant heating, enters the main condenser 36, and liquefies. Is done. The liquefied refrigerant passes through the secondary flow path of the subcooling heat exchanger 50 (no heat exchange), is decompressed by the main expansion means 37, enters the main storage evaporator 38, and evaporates. Then, the process returns to the main compressor 35.
In the present embodiment, the temperature of the test chamber 3 is monitored, and when the temperature of the test chamber 3 decreases, the opening degree of the main-side expansion means 37 is reduced in order to lower the surface temperature of the main-side internal evaporator 38. Can be

That is, when the temperature of the test chamber 3 decreases to some extent, the temperature difference between the main-side in-store evaporator 38 and the test chamber 3 decreases, and the heat exchange efficiency decreases, so that the opening degree of the main-side expansion means 37 is reduced.
When the temperature difference between the main side evaporator 38 and the test chamber 3 becomes small, the opening degree of the main side expansion means 37 is gradually reduced as described above, and the temperature of the main side evaporator 38 decreases. A certain temperature difference is ensured between the surface temperature of the evaporator 38 in the main storage and the temperature in the test chamber 3.

After the temperature in the test chamber 3 reaches the set temperature, the opening degree of the main expansion means 37 is further reduced to save energy. The opening can be reduced only until the suction pressure of the machine 35 reaches the lower limit.
However, by opening the main refrigeration circuit side bypass circuit 60, the amount of refrigerant flowing through the main expansion means 37 and flowing to the main side internal evaporator 38 can be further reduced.
That is, even if the opening degree of the main-side expansion means 37 is constant, the main-side expansion means 37 is opened by opening the bypass-use expansion means 53 from a closed state or by further increasing the opening degree of the bypass-use expansion means 53. The amount of the refrigerant flowing through can be reduced.
In the present embodiment, the opening degree of the bypass expansion means 53 is mainly adjusted, and the main refrigeration circuit side bypass circuit 60 is opened, so as to flow through the main expansion means 37 and flow into the main storage evaporator 38. The control for decreasing the refrigerant amount is referred to as “main refrigeration circuit side bypass control”.
Further, control for mainly reducing the opening degree of the main-side expansion means 37 to reduce the amount of refrigerant flowing to the main-side internal evaporator 38 is referred to as “normal control”, and is distinguished from “main refrigeration circuit-side bypass control”.

  Further, in the present embodiment, the thickness of the main refrigeration circuit side bypass circuit 60 and the diameter of the bypass expansion means 53 are considerably large, and the main compressor 35 is kept driven and passes through the main expansion means 37. Thus, the refrigerant flowing to the main-side internal evaporator 38 can be reduced to zero. That is, the entire amount of the refrigerant flowing out of the main compressor 35 can be flown to the main refrigeration circuit side bypass circuit 60 and returned to the main compressor 35.

When the opening degree of the main-side expansion means 37 is reduced, the amount of the refrigerant passing through the main-side internal evaporator 38 is reduced. It is returned to the suction side of the main compressor 35.
When the bypass expansion means 53 is opened, part or all of the refrigerant flows into the main refrigeration circuit side bypass circuit 60. Then, the refrigerant flows into the secondary flow path of the return refrigerant heating heat exchanger 63, is exchanged with the high-temperature refrigerant flowing through the primary flow path of the refrigerant heating heat exchanger 63, is vaporized, and becomes superheated gas. Then, it returns to the suction side of the main compressor 35.
In the environmental test apparatus 1 of the present embodiment, since the capacity of the main compressor 35 of the main refrigeration circuit 31 is smaller than that of the conventional (standard configuration), the medium cooling operation performed by driving only the main compressor 35 is performed. Consumes less power than before.

Next, the slow cooling operation (FIG. 3) will be described.
The slow cooling operation (FIG. 3) is performed by circulating the refrigerant through the auxiliary refrigeration circuit 32 as described above. In the slow cooling operation, only the auxiliary compressor 45 belonging to the auxiliary refrigeration circuit 32 is driven, and the main compressor 35 belonging to the main refrigeration circuit 31 is stopped.
Further, when performing the slow cooling operation, the refrigerant cooling expansion means 52 is closed, and the supply of the refrigerant to the refrigerant cooling circuit 51 is blocked.
In the slow cooling operation, the gaseous refrigerant is compressed by the auxiliary compressor 45, and the compressed refrigerant passes through the primary flow path of the return refrigerant heating heat exchanger 65, enters the auxiliary condenser 46, and liquefies. Is done. The liquefied refrigerant is decompressed by the auxiliary expansion means 47, enters the auxiliary internal evaporator 48, evaporates, and returns to the auxiliary compressor 45.
As described above, in the present embodiment, the temperature of the test chamber 3 is monitored, and when the temperature of the test chamber 3 decreases, the auxiliary expansion means 47 is opened to lower the surface temperature of the auxiliary internal evaporator 48 accordingly. The degree is narrowed down.

Even during the slow cooling operation, the amount of refrigerant flowing through the auxiliary-side expansion means 47 and flowing to the auxiliary-side in-compartment evaporator 48 by opening the bypass expansion means 66 and allowing the refrigerant to pass through the auxiliary refrigeration circuit-side bypass circuit 61. Can be further reduced.
In the present embodiment, by controlling the auxiliary refrigeration circuit side bypass circuit 61 to open, the control to reduce the amount of refrigerant flowing through the auxiliary side expansion means 47 and flowing to the auxiliary side internal evaporator 48 is referred to as “auxiliary refrigeration circuit”. Side bypass control. "
Also, control for mainly reducing the opening degree of the auxiliary side expansion means 47 to reduce the amount of refrigerant flowing to the auxiliary side internal evaporator 48 is referred to as “normal control” and is distinguished from “auxiliary refrigeration circuit side bypass control”.

  In the present embodiment, the thickness of the auxiliary refrigeration circuit side bypass circuit 61 and the diameter of the bypass expansion means 66 are considerably large, and the state in which the auxiliary compressor 45 is driven is maintained while passing through the auxiliary side expansion means 47. The refrigerant flowing to the auxiliary side internal evaporator 48 can be reduced to zero. That is, the entire amount of the refrigerant that has flowed out of the auxiliary condenser 46 flows into the auxiliary refrigeration circuit side bypass circuit 61, is heated by the refrigerant heating heat exchanger 65, and is returned to the auxiliary compressor 45 in a state of being superheated gas.

  In the slow cooling operation, the auxiliary compressor 45 having a small capacity is driven to cool, and thus the refrigeration capacity is small.

Next, the rapid cooling operation (FIG. 5) will be described.
The rapid cooling operation (FIG. 5) is an operation method in which both the main refrigeration circuit 31 and the auxiliary refrigeration circuit 32 are driven to perform cooling. That is, in the rapid cooling operation, the main compressor 35 belonging to the main refrigeration circuit 31 and the auxiliary compressor 45 belonging to the auxiliary refrigeration circuit 32 are driven, and the operation corresponding to the above-mentioned medium cooling operation and the operation corresponding to the slow cooling operation are performed. Are performed simultaneously.
In the rapid cooling operation, the two compressors (the main compressor 35 and the auxiliary compressor 45) are simultaneously driven to perform cooling, so that the refrigerating capacity is large.
If the temperature in the test chamber 3 is high to some extent, the surface temperature of the main-side internal evaporator 38 and the surface temperature of the auxiliary-side internal evaporator 48 are generally lower than those in the test chamber 3. There may be a difference between the temperature of the vessel 38 and the temperature of the auxiliary side internal evaporator 48.
On the other hand, when the temperature in the test chamber 3 is considerably low, the temperature of the main-side internal evaporator 38 and the temperature of the auxiliary-side internal evaporator 48 are both controlled to be lower than the temperature in the test chamber 3. Is done.

Even during the rapid cooling operation, the “main refrigeration circuit side bypass control” and the “auxiliary refrigeration circuit side bypass control” can be performed. In addition, the state in which the main compressor 35 is driven during the rapid cooling operation can be maintained, and the refrigerant flowing through the main expansion means 37 and flowing to the main evaporator 38 can be reduced to zero. Similarly, the state in which the auxiliary side compressor 45 is driven during the rapid cooling operation can be maintained, and the refrigerant flowing through the auxiliary side expansion means 47 and flowing to the auxiliary side internal evaporator 48 can be made zero.
In the environmental test apparatus 1 of the present embodiment, since the capacity of the main compressor 35 of the main refrigeration circuit 31 is smaller than that of the conventional (standard configuration), the consumption of the rapid cooling operation performed by driving the main compressor 35 is reduced. The power is lower compared to prior art environmental test equipment of the type having auxiliary cooling means.

Next, the supercooling operation will be described. The supercooling operation is performed by circulating the refrigerant through the main refrigeration circuit 31 and the refrigerant cooling circuit 51 as shown in FIG.
When performing the supercooling operation, the auxiliary side expansion means 47 as the refrigerant control means is closed, the flow path to the auxiliary side internal evaporator 48 is shut off, and the refrigerant cooling expansion means 52 is opened.
During the supercooling operation, both the main compressor 35 and the auxiliary compressor 45 are driven. During the supercooling operation, the auxiliary compressor 45 belonging to the auxiliary refrigeration circuit 32 is driven, but no refrigerant flows through the auxiliary-side internal evaporator 48 of the auxiliary refrigeration circuit 32. Specifically, the auxiliary expansion means 47 connected to the auxiliary internal evaporator 48 is closed, and the auxiliary internal evaporator 48 is not used.
Instead, in the auxiliary refrigeration circuit 32, the refrigerant cooling expansion means 52 is opened, and the refrigerant is supplied to the refrigerant cooling circuit 51.

  During the supercooling operation, the auxiliary-side compressor 45 is driven, compresses the gaseous refrigerant by the auxiliary-side compressor 45, and the compressed refrigerant flows to the primary side of the heat exchanger 65 for returning refrigerant heating. After passing through the passage, it enters the auxiliary condenser 46 and is liquefied. The liquefied refrigerant is decompressed by the refrigerant cooling expansion means 52 and enters the primary flow path of the supercooling heat exchanger 50. As described above, the primary flow path of the subcooling heat exchanger 50 substantially functions as an evaporator. As a result, the refrigerant is vaporized in the primary flow path of the subcooling heat exchanger 50, and the temperature of the primary flow path decreases. The vaporized refrigerant returns to the auxiliary compressor 45.

On the other hand, in the main refrigeration circuit 31, the refrigerant circulates in the same flow path as in the above-described medium cooling operation (FIG. 2). That is, in the main refrigeration circuit 31, the gaseous refrigerant is compressed by the main compressor 35, and the compressed refrigerant passes through the primary flow path of the return refrigerant heating heat exchanger 63 and enters the main condenser 36. Liquefied. Then, the liquefied refrigerant passes through the secondary flow path of the subcooling heat exchanger 50.
Here, during the supercooling operation, the auxiliary compressor 45 is driven, and the refrigerant liquefied in the auxiliary condenser 46 flows through the refrigerant cooling circuit 51 and flows through the primary side flow path of the subcooling heat exchanger 50. It evaporates, and the temperature of the primary flow path has dropped.
Therefore, the refrigerant flowing through the main refrigeration circuit 31 and liquefied by the main condenser 36 is further cooled by the supercooling heat exchanger 50 and is strongly supercooled. That is, the refrigerant liquefied in the main condenser 36 is often in a slightly supercooled state, but the degree of subcooling is further increased by being further cooled in the subcooling heat exchanger 50.

The amount of cooling by the subcooling heat exchanger 50, in other words, the degree of supercooling, is adjusted by increasing or decreasing the amount of refrigerant passing through the refrigerant cooling circuit 51.
In the present embodiment, by adjusting the opening degree of the bypass expansion means 66, the amount of refrigerant passing through the refrigerant cooling circuit 51 can be increased or decreased, and the amount of cooling by the supercooling heat exchanger 50 can be changed.
Also in the supercooling operation, the refrigerant flows through the refrigerant cooling expansion unit 52 and flows into the supercooling heat exchanger 50 by opening the bypass expansion unit 66 and passing the refrigerant through the auxiliary refrigeration circuit side bypass circuit 61. The amount of refrigerant can be further reduced.
That is, in this embodiment, the auxiliary refrigeration circuit side bypass circuit 61 is provided on the auxiliary refrigeration circuit 32 side, and the auxiliary refrigeration circuit side bypass circuit 61 is provided with the bypass expansion means 66. The opening degree of the bypass expansion means 66 can be changed.
In the present embodiment, by adjusting the opening degree of the refrigerant cooling expansion means 52 on the refrigerant cooling circuit 51 side and the opening degree of the bypass expansion means 66 provided in the auxiliary refrigeration circuit side bypass circuit 61, the supercooling operation is performed. By adjusting the amount of the refrigerant flowing through the heat exchanger 50, the degree of supercooling of the refrigerant flowing through the main refrigeration circuit 31 can be adjusted.

As described above, since the thickness of the auxiliary refrigeration circuit side bypass circuit 61 and the diameter of the bypass expansion means 66 are considerably large, the state where the auxiliary side compressor 45 is driven is maintained, and the auxiliary refrigerant 45 passes through the refrigerant cooling expansion means 52. Thus, the refrigerant flowing through the subcooling heat exchanger 50 can be reduced to zero.
In the present embodiment, the control of reducing the amount of refrigerant flowing through the refrigerant cooling expansion means 52 and flowing into the supercooling heat exchanger 50 by opening the auxiliary refrigeration circuit side bypass circuit 61 is referred to as “refrigerant cooling circuit”. This is referred to as “bypass control”. Further, control for mainly reducing the opening degree of the refrigerant cooling expansion means 52 to reduce the amount of refrigerant flowing to the supercooling heat exchanger 50 is referred to as “normal control” and is distinguished from “refrigerant cooling circuit bypass control”.

  In the supercooling heat exchanger 50, it is desirable to advance the supercooling by 10 degrees Celsius or more, and more desirably to advance the supercooling by 15 degrees Celsius or more.

  The supercooled refrigerant is depressurized by the main expansion means 37, enters the main evaporator 38, evaporates, and returns to the main compressor 35.

When the supercooling operation is compared with the above-mentioned medium cooling operation, in both cases, the liquid refrigerant is vaporized in the main-side internal evaporator 38 and deprives heat of evaporation (latent heat) to lower the surface temperature of the main-side internal evaporator 38. They are common in that
In the supercooling operation, the surface temperature of the main-side internal evaporator 38 decreases due to the decrease in the enthalpy due to the supercooling, in addition to the decrease in the temperature of the main-side internal evaporator 38 due to the evaporation heat (latent heat). Therefore, by performing the supercooling operation, the refrigerating capacity (the amount of heat energy taken by the refrigerator) is increased as compared with the medium cooling operation.
As a result, even if the surface temperature of the main-side internal evaporator 38 is lower than the surface temperature of the main-side internal evaporator 38 during the medium cooling operation, the required refrigeration output can be exhibited. it can.
In other words, in the supercooling operation, even if the surface temperature of the main-side internal evaporator 38 is set to the same temperature as that of the conventional environmental test device, the same refrigeration output as that of the conventional environmental test device can be obtained.

In the environmental test apparatus 1 of the present embodiment, the operation method and the control method are switched based on certain conditions. Specifically, rapid cooling operation, medium cooling operation, slow cooling operation, and supercooling operation are switched based on the set temperature and the actual temperature in the test chamber 3.
In addition, normal control and bypass control (main refrigeration circuit side bypass control, auxiliary refrigeration circuit side bypass control, refrigerant cooling circuit bypass control) are switched based on certain conditions.

In the present embodiment, the rapid cooling operation, the intermediate cooling operation, and the slow cooling operation are collectively referred to as a normal operation.
In the present embodiment, the normal operation includes a rapid cooling operation, a medium cooling operation, and a slow cooling operation, and an operation method is automatically selected according to a situation.
The rapid cooling operation, the medium cooling operation, and the slow cooling operation only differ in cooling capacity, and are simply selected according to the cooling load.
That is, when the cooling load is large and it is necessary to rapidly lower the temperature in the test chamber 3, the rapid cooling operation is executed.
If the cooling load is moderate and the rapid cooling operation is performed, the temperature in the test chamber 3 may suddenly change. Although the temperature in the test chamber 3 has reached the set temperature, the temperature in the test chamber 3 is extremely low. Cold operation is selected.
When the cooling load is small, for example, when the temperature in the test chamber 3 is relatively high and stable, the slow cooling operation is selected.

  As a method of controlling the amount of refrigerant supplied to the evaporators 38 and 48 and the supercooling heat exchanger 50, normal control and bypass control (main refrigeration circuit side bypass control, auxiliary refrigeration circuit side bypass control, refrigerant cooling circuit Bypass control). The bypass control is selected when it is desired to reduce the amount of the refrigerant supplied to the evaporators 38 and 48 and the subcooling heat exchanger 50.

  In the present embodiment, there are cases where the supercooling operation is performed depending on the set temperature and cases where the supercooling operation is not performed. That is, the operation method shifts in accordance with the two types of flows depending on the set temperature. For example, it is selected whether or not the supercooling operation is performed at a temperature of A degrees Celsius. A degree Celsius is a temperature lower than room temperature, for example, about 0 degree Celsius to about 10 degree Celsius.

  FIG. 6 is a flowchart showing a transition process of the driving method. In the present embodiment, when the set temperature is equal to or higher than A degree Celsius, a full operation rapid cooling operation is performed at the start. That is, the operation method is a rapid cooling operation, and the control method is an ordinary control operation.

When the temperature in the test chamber 3 approaches the set temperature, the control method is switched, and the cooling output is reduced for energy saving. Specifically, the cooling output is reduced by performing the auxiliary refrigeration circuit side bypass control while performing the rapid cooling operation.
Then, the state in which the auxiliary side compressor 45 is driven is maintained, the refrigerant flowing through the auxiliary side expansion means 47 and flowing to the auxiliary side internal evaporator 48 is set to zero, and the operation is substantially switched to the medium cooling operation. That is, although the auxiliary compressor 45 is driven, the operation method is substantially the medium cooling operation, and the control method of the main refrigeration circuit 31 is the normal control.
Thereafter, the control method of the main refrigeration circuit 31 is automatically switched to the main refrigeration circuit side bypass control, and the refrigeration output is reduced.
Thereafter, the slow cooling operation is restored. Specifically, the opening degree of the auxiliary expansion means 47 is increased. That is, although the middle-cooling operation is substantially being performed at present, the auxiliary-side compressor 45 maintains the driven state. Therefore, when the opening degree of the auxiliary side expansion means 47 is increased, the refrigerant flows into the auxiliary side internal evaporator 48, and the slow cooling operation is restored. The control method of the auxiliary refrigeration circuit 32 at this time is normal control.
When the slow cooling operation is restored, the main compressor 35 is stopped. That is, the rapid cooling operation is practically stopped, and the slow cooling operation is performed.

When the temperature in the test chamber 3 further decreases, the control method of the auxiliary refrigeration circuit 32 is switched to the auxiliary refrigeration circuit side bypass control, and the cooling output is further reduced. Finally, the auxiliary compressor 45 also stops.
In the flowchart of FIG. 6, an example in which the rapid cooling operation is performed first and the slow cooling operation is performed last is shown. However, the first operation method may be the medium cooling operation, or may end with the medium cooling operation.

On the other hand, when the set temperature is less than A degree Celsius, the supercooling operation is performed at the start. The control method at the start is normal control.
Then, the control method is switched according to the temperature drop in the test chamber 3. That is, the refrigerant cooling circuit bypass control is performed while performing the supercooling operation.
When the temperature in the test chamber 3 further decreases, the auxiliary compressor 45 is stopped and the operation shifts to the medium cooling operation. The control method of the main refrigeration circuit 31 at this time is normal control.
When the temperature in the test chamber 3 further decreases and reaches the set temperature, the control method is switched, the main refrigeration circuit side bypass control is performed, and the temperature in the test chamber 3 is maintained at the set temperature.

Next, the operation methods when the set temperature is equal to or higher than A degree Celsius and when it is lower than A degree Celsius will be specifically described.
When the set temperature is equal to or higher than A degree Celsius, the rapid cooling operation is performed first as described above in principle.

In the rapid cooling operation, both the main refrigeration circuit 31 and the auxiliary refrigeration circuit 32 are driven to lower the temperature in the test chamber 3. Then, when the temperature in the test chamber 3 approaches the set temperature, the refrigeration output is gradually reduced.
At the beginning of the rapid cooling operation, the main refrigeration circuit 31 and the auxiliary refrigeration circuit 32 are fully operated. When the temperature of the test chamber 3 is reduced to some extent, the temperature difference between the main chamber internal evaporator 38 and the auxiliary side internal evaporator 48 and the test chamber 3 is reduced, and the heat exchange efficiency is reduced. The opening degree of the 37 and the auxiliary expansion means 47 is reduced (normal control).

By performing the quenching operation, the temperature in the test chamber 3 decreases, and when the temperature approaches the set temperature, the required amount of cooling heat gradually decreases. Therefore, the refrigeration output is gradually reduced for energy saving. .
That is, if the DUT does not generate heat, the cooling required after the temperature in the test chamber 3 reaches the target temperature suppresses the heat generated by the blower 8 stirring the internal air. And the amount of heat required to suppress heat entering from the external environment is less than that required at startup. Therefore, the amount of cold required for the cooling means 30 in order to maintain the temperature in the test chamber 3 at the target temperature is small enough to meet these requirements. Therefore, the control method and the operation method are changed, and the refrigeration output is gradually reduced.

The transition of the operation method and the control method is performed with reference to the output of the heating heater 6 or the humidification heater 25 or both.
In this measure, the quenching operation is performed first, and the outputs of the heater 6 and the like are monitored. Then, the operation method or the control method is shifted so that the output of the heater 6 or the like is minimized.
That is, in the environmental test apparatus 1 of the present embodiment, the heater 6 and the like are operated to finely adjust the temperature in the test chamber 3. Therefore, when the heating value of the heater 6 or the like is large, it can be said that the refrigeration output is excessive.
Therefore, in the present embodiment, the output of the heating heater 6 and / or the humidification heater 25 is monitored, and the operation method or the control method is changed so as to minimize the output.
The order of changing the operation method or the control method is as shown in FIG. 6 described above. When the temperature in the test chamber 3 approaches the set temperature, the cooling output is performed by performing the auxiliary refrigeration circuit side bypass control while performing the rapid cooling operation. To decrease.
If the heating value of the heater 6 or the like is still large, the state in which the auxiliary compressor 45 is driven is maintained, and the refrigerant flowing through the auxiliary expansion means 47 and flowing to the auxiliary internal evaporator 48 is reduced to zero. Then, the operation is substantially switched to the medium cooling operation, and the main refrigeration circuit 31 is normally controlled.
If the heating value of the heater 6 or the like is still large, the main refrigeration circuit 31 is subjected to main refrigeration circuit side bypass control to lower the refrigeration output.

When the amount of the refrigerant passing through the main-side internal evaporator 38 is continuously reduced and the amount of the refrigerant flowing through the main-side internal evaporator 38 of the main refrigeration circuit 31 reaches the lower limit, the operation of the main refrigeration circuit 31 is performed by a control device (not shown). Is to be stopped. Specifically, when the heating value of the heater 6 or the like is large, the operation of the main refrigeration circuit 31 is stopped, and the operation is switched to the slow cooling operation.
As described above, although the middle-cooling operation is currently being performed substantially, the auxiliary-side compressor 45 remains driven. Therefore, when the opening degree of the auxiliary-side expansion means 47 is increased, the refrigerant flows to the auxiliary-side internal evaporator 48, and the slow cooling operation is restored.
When the slow cooling operation is restored, the main compressor 35 is stopped. That is, the rapid cooling operation is practically stopped, and the slow cooling operation is performed.
If the heating value of the heater 6 or the like is still large, the auxiliary refrigeration circuit 32 is subjected to the auxiliary refrigeration circuit side bypass control to further reduce the cooling output. Finally, the auxiliary compressor 45 also stops.

Next, a description will be given of an operation method in a case where the temperature is extremely low as compared with the normal temperature, such as a case where the set temperature is minus 40 degrees Celsius.
In this embodiment, since the set temperature is minus 40 degrees Celsius and the set temperature is less than A degree Celsius, the supercooling operation is performed at the start.
During the supercooling operation, both the main compressor 35 and the auxiliary compressor 45 are driven.
Then, when the temperature of the test chamber 3 decreases to some extent and the difference between the surface temperature of the main-side internal evaporator 38 and the temperature in the test chamber 3 becomes less than a certain value, the opening degree of the main-side expansion means 37 is gradually reduced. By lowering the temperature of the main-side internal evaporator 38, a certain temperature difference is secured between the surface temperature of the main-side internal evaporator 38 and the temperature in the test chamber 3.

Here, in the supercooling operation, the surface temperature of the main-side internal evaporator 38 decreases due to the decrease in the enthalpy due to the supercooling, in addition to the decrease in the temperature of the main-side internal evaporator 38 due to the heat of evaporation (latent heat). The refrigerating capacity (the amount of heat energy taken by the refrigerator) is large.
Therefore, even if the surface temperature of the main-side internal evaporator 38 is considerably reduced, a necessary refrigeration output can be exhibited.
Therefore, the temperature in the test chamber 3 can be reduced to the set temperature.

By performing the supercooling operation, the temperature in the test chamber 3 decreases, and when the temperature approaches the set temperature, the required amount of cooling heat gradually decreases. Therefore, the refrigeration output is gradually reduced for energy saving. Go.
That is, the control method and the operation method are changed, and the refrigeration output is gradually reduced.

The transition of the operation method and the control method is performed with reference to the output of the heating heater 6 and / or the humidification heater 25 as in the case described above.
The order of changing the operation method or the control method is as shown in FIG. 6 described above. When the temperature in the test chamber 3 approaches the set temperature, the refrigerant cooling circuit bypass control is performed while performing the supercooling operation, and the refrigerant cooling is performed. The amount of refrigerant flowing to the subcooling heat exchanger 50 after passing through the expansion means 52 is reduced. Specifically, in the present embodiment, the amount of refrigerant flowing to the subcooling heat exchanger 50 is reduced by opening the auxiliary refrigeration circuit side bypass circuit 61.
As a result, the degree of supercooling of the refrigerant flowing through the main refrigeration circuit 31 decreases, the enthalpy of the refrigerant increases, and the refrigeration output decreases.
Finally, the amount of refrigerant flowing to the subcooling heat exchanger 50 becomes zero.
Then, a control device (not shown) determines whether or not the operation of the auxiliary refrigeration circuit 32 should be stopped. Specifically, when the amount of heat generated by the heater 6 or the like is large, the operation of the auxiliary refrigeration circuit 32 is stopped. That is, the operation method is switched from the supercooling operation to the medium cooling operation.
If the heating value of the heater 6 or the like is still large even after the operation of the auxiliary refrigeration circuit 32 is stopped and switched to the medium cooling operation, the main refrigeration circuit 31 is normally controlled to reduce the refrigeration output. If the heating value of the heater 6 or the like is still large, the control method is switched, and the main refrigeration circuit 31 is subjected to the main refrigeration circuit side bypass control to lower the refrigeration output.

In the above-described embodiment, when the set temperature is lower than A degree Celsius, the supercooling operation is performed at the start. However, the present invention is not limited to this configuration. When the set temperature is lower than A degree Celsius, the medium cooling operation or the rapid cooling operation may be performed first, and the process may be shifted to the supercooling operation halfway.
Hereinafter, this method will be described.

For example, if the medium cooling operation is performed, the auxiliary side expansion means 47 as the refrigerant control means is opened, the refrigerant cooling expansion means 52 is closed, the refrigerant cooling circuit 51 is closed, and the flow path to the auxiliary side internal evaporator 48 is established. open. Then, only the main-side compressor 35 belonging to the main refrigeration circuit 31 is driven, and the temperature of the main-side internal evaporator 38 decreases. In the initial stage of operation, the main refrigeration circuit 31 is operated under normal control.
Therefore, the opening degree of the main-side expansion means 37 is fully opened, and a large amount of refrigerant is sent to the main-side in-store evaporator 38 to generate a lot of cold heat, thereby rapidly lowering the temperature in the test chamber 3.
When the temperature of the test chamber 3 drops to some extent, the difference between the surface temperature of the main-side internal evaporator 38 and the temperature in the test chamber 3 decreases, and the heat exchange efficiency decreases. Squeezed.

  That is, when the temperature difference between the surface temperature of the main-side internal evaporator 38 and the temperature in the test chamber 3 becomes less than a certain value, the opening degree of the main-side expansion means 37 is gradually reduced, and the temperature of the main-side internal evaporator 38 is reduced. And a constant temperature difference is secured between the surface temperature of the main-side internal evaporator 38 and the temperature in the test chamber 3.

  When the temperature of the test chamber 3 decreases, the main-side expansion means 37 is also gradually narrowed. However, as described above, in the present embodiment, the evaporation temperature of the refrigerant is high. In some cases, a constant temperature difference between the surface temperature and the temperature in the test chamber 3 cannot be secured. Even if a certain temperature difference can be secured between the surface temperature of the evaporator 38 in the main storage and the temperature in the test chamber 3, the refrigeration output is extremely reduced and the temperature of the test chamber 3 is substantially lowered. May not be possible.

In the present embodiment, a temperature at which a certain temperature difference between the surface temperature of the main-side internal evaporator 38 and the temperature in the test chamber 3 is not expected to be secured, or a temperature slightly higher than that is stored in advance as a threshold value. are doing.
When the temperature of the test chamber 3 decreases and the current temperature of the test chamber 3 becomes lower than a predetermined threshold value (for example, 0 degree Celsius), the operation method is switched, and the operation shifts to the supercooling operation.
As a result, the auxiliary compressor 45 on the auxiliary refrigeration circuit 32 side is started, and the operation of the auxiliary refrigeration circuit 32 is started. Then, the auxiliary expansion means 47 as the refrigerant control means is closed, the expansion means 52 for cooling the refrigerant is opened, the refrigerant cooling circuit 51 is opened, and the flow path to the auxiliary evaporator 48 is shut off.
The refrigerant liquefied in the main condenser 36 is further cooled in the supercooling heat exchanger 50, and is strongly supercooled. As a result, the surface temperature of the main-side internal evaporator 38 can be made lower than the surface temperature of the main-side internal evaporator 38 during the middle cooling operation. A constant temperature difference between the surface temperature of the test chamber 3 and the temperature in the test chamber 3 is secured, and the temperature of the test chamber 3 further decreases.

  The operation after the temperature of the test chamber 3 reaches the vicinity of the set temperature is the same as that described above. The amount of heat generated by the heater 6 and the like is monitored, and the control method or the operation method is changed.

In the present embodiment, when the set temperature is extremely low, as described above, the normal operation (medium cooling operation) is performed until the temperature in the test chamber 3 reaches the threshold, and the temperature in the test chamber 3 is increased. When the pressure becomes equal to or less than the threshold, the operation is switched to the supercooling operation.
Here, in the present embodiment, the main compressor 35 has a smaller capacity than the conventional compressor (standard configuration), and is driven until the temperature in the test chamber 3 becomes lower than the threshold. The power consumption by the compressor 35 is small. Also, regarding the power consumption after switching to the supercooling operation, the environmental test apparatus 1 consumes less power than the conventional one.

  In the embodiment described above, as a test method when the set temperature is extremely low, the medium cooling operation is first performed, and the operation is switched to the supercooling operation on condition that the temperature in the test chamber 3 becomes equal to or lower than the threshold. Alternatively, a rapid cooling operation may be performed first to rapidly lower the temperature in the test chamber 3. Even when the rapid cooling operation is performed first, the operation is switched to the supercooling operation on condition that the temperature in the test chamber 3 becomes equal to or lower than the threshold value.

When the rapid cooling operation is performed first and then the operation is switched to the supercooling operation, the two compressors (the main compressor 35 and the auxiliary compressor 45) are simultaneously driven to perform cooling. In the rapid cooling operation, in principle, when the temperature of the test chamber 3 changes, only the surface temperature of the main side evaporator 38 is reduced. However, in this operation method, since the set temperature is extremely low, The evaporator 48 in the side cabinet is also controlled to be lower than the temperature in the test chamber 3.
When the temperature in the test chamber 3 becomes equal to or lower than the threshold, the operation is switched to the supercooling operation.
In the case of the operation method in which the quenching operation is performed first, since the auxiliary side compressor 45 has already been started, the auxiliary side expansion means 47 as the refrigerant control means is closed, and the refrigerant cooling expansion means 52 is opened, so that the refrigerant cooling circuit is opened. 51 is opened to shift to the supercooling operation.

  In the embodiment described above, none of the compressors of the cooling means 30 (the main compressor 35 and the auxiliary compressor 45) has the inverter control function, but may have the inverter control function.

  In the embodiment described above, the threshold value is determined in advance, and the operation mode is switched from the normal operation to the supercooling operation on the condition that the temperature in the test chamber 3 falls below the threshold. Here, it is recommended that the threshold value be about 10 degrees Celsius to about minus 10 degrees Celsius. A more recommended range is from 10 degrees Celsius to 0 degrees Celsius.

  Instead of the threshold value, the temperature in the test chamber 3 is compared with the surface temperature (evaporation temperature) of the main side evaporator 38, and the operation system is supercooled from the normal operation on condition that both are within a certain range. You may switch to driving.

  In the embodiment described above, the main refrigeration circuit-side bypass circuit 60 is branched from between the supercooling heat exchanger 50 of the main refrigeration circuit 31 and the main expansion means 37, but may be branched from another portion. For example, as shown in an environmental test device 72 in FIG. 7, a branch may be made between the main condenser 36 and the supercooling heat exchanger 50.

  In the embodiment described above, the auxiliary refrigeration circuit 32 is a circulation circuit including the auxiliary-side internal evaporator 48, but a circuit leading to the auxiliary-side internal evaporator 48 like an environmental test device 75 shown in FIG. It may be omitted.

In the embodiment described above, the electronic expansion valve is used as the expansion means, but may have another configuration.
For example, like an expansion means 80 shown in FIG. 9, a capillary tube 81 and an electromagnetic valve 82 are connected in series to form a capillary tube 83 with an on-off valve, and a plurality of these may be piped in parallel. .

  In the embodiment described above, the heat exchangers 63 and 65 for returning the refrigerant are provided in the bypass circuits 60 and 61, and the refrigerant flowing in the bypass circuits 60 and 61 and the high-temperature gas refrigerant on the discharge side of the compressors 35 and 45 are connected. Although the heat was exchanged between the condensers 36 and 46, the heat exchange may be performed with the liquid refrigerant flowing through the pipes on the outlet side of the condensers 36 and 46.

Hereinafter, examples of the present invention will be described.
The system diagram of the environmental test apparatus 1 of the present embodiment is the same as FIG.
In the environmental test apparatus 1, a compressor having a rated output of 1.2 kW was employed as the main compressor 35. A compressor having a rated output of 0.4 kW was employed as the auxiliary compressor 45.
Comparative Example (standard configuration) 1 is an environmental test apparatus 100 shown in the system diagram of FIG. 13, and a commercially available environmental test apparatus 100 was used. The environmental test apparatus 100 has a compressor with a rated output of 1.5 kW as the compressor 101.
Comparative Example 1 is a commercially available environmental test apparatus 100, and the cooling means 106 has a capacity (rated output) that can arbitrarily create an environment in a temperature range indicated in a catalog or the like.
Comparative Example 2 is an improved environmental test apparatus described above, which is an environmental test apparatus 200 shown in the system diagram of FIG. It was replaced on the machine.
The compressor 101 mounted on the improved environmental test apparatus of Comparative Example 2 has a smaller capacity than that of Comparative Example 1 (standard configuration), and when the test chamber 3 is cooled, the compressor 101 has the lowest temperature applicable range described in the catalog. It takes longer than Comparative Example 1 to reach the temperature.

The indoor temperature was set to 20 degrees Celsius, the set temperature was set to minus 40 degrees Celsius, and the environmental test apparatus 100 of Comparative Example (standard configuration) 1 was started. The relationship between the surface temperature of the evaporator 107 and the temperature change of the test chamber 3 after starting the environmental test apparatus 100 of the comparative example (standard configuration) 1 is as shown in the graph of FIG.
The environmental test apparatus 100 of the comparative example (standard configuration) 1 is equipped with a compressor 101 having a capacity (rated output) capable of arbitrarily creating an environment in a temperature range indicated in a catalog or the like. In the test, the temperature of the test chamber 3 dropped to the set temperature and then stabilized.

The indoor temperature was set to 20 degrees Celsius and the set temperature was set to minus 40 degrees Celsius, and the environmental test apparatus 200 of Comparative Example 2 was started. The relationship between the surface temperature of the evaporator 107 and the change in the temperature of the test chamber 3 after starting the environmental test apparatus 200 is as shown in the graph of FIG.
In the environmental test apparatus 200 of Comparative Example 2, the temperature of the test room 3 could not reach the set temperature.

The indoor temperature was set to 20 degrees Celsius, the set temperature was set to minus 40 degrees Celsius, and the environmental test apparatus 1 of the embodiment was started. The relationship between the surface temperature of the main-side internal evaporator 38 and the temperature change of the test chamber 3 after starting the environmental test apparatus 1 of the example was as shown in the graph of FIG.
The relationship between the surface temperature of the evaporator 38 in the main storage of the environmental test apparatus 1 of the embodiment and the temperature change of the test chamber 3 (FIG. 12) is that the environmental test apparatus 100 of the comparative example (standard configuration) 1 is started. This was close to that of the later example and was comparable to that of Comparative Example 1.

  Regarding the environmental test apparatus 100 of the comparative example (standard configuration) 1 and the environmental test apparatus 1 of the example, when the maximum refrigeration output is developed, the evaporation temperature of the refrigerant, the supercooling temperature of the refrigerant, and the refrigeration output are as follows: The results are shown in Table 1 below.

  As is clear from the above-mentioned table, the cooling means 30 of the environmental test apparatus 1 of the present embodiment can exhibit the same maximum output although the evaporation temperature of the refrigerant is higher than that of the comparative example (standard configuration) 1. it can.

  For the environmental test apparatus 100 of Comparative Example 1 (standard configuration) and the environmental test apparatus 1 of Example, when the set temperature was set to minus 40 degrees Celsius, the evaporation temperature of the refrigerant, the supercooling temperature of the refrigerant, and the refrigeration output were as follows. Table 2 below.

  As is clear from the above table, the cooling means 30 of the environmental test apparatus 1 of the present embodiment has a higher degree of supercooling than the comparative example (standard configuration) 1 and has the same evaporating temperature under the same conditions. A refrigeration output can be exhibited.

Table 3 shows the relationship between the set temperature and the power consumption of the environmental test apparatus 100 of the comparative example (standard configuration) 1 and the relationship between the set temperature and the power consumption of the environmental test apparatus 1 of the example. .
Comparing the two, the set temperature and the power consumption of the environmental test apparatus 1 of the example were about 30% lower than the set temperature and the power consumption of the environmental test apparatus 100 of the comparative example 1.

DESCRIPTION OF SYMBOLS 1 Environmental test apparatus 30 Cooling means 31 Main refrigeration circuit 32 Auxiliary refrigeration circuit 35 Main-side compressor 36 Main-side condenser 37 Main-side expansion means 38 Main-side internal evaporator 45 Auxiliary-side compressor 46 Auxiliary-side condenser 47 Auxiliary-side Expansion means 48 Auxiliary side evaporator 50 Subcooling heat exchanger 51 Refrigerant cooling circuit 52 Refrigerant cooling expansion means 60 Main refrigeration circuit side bypass circuit 61 Auxiliary refrigeration circuit side bypass circuit 63 Refrigerant heating heat exchanger 70 Environmental test Equipment 72 Environmental test equipment 75 Environmental test equipment

Claims (12)

A test chamber for arranging the device under test, and cooling means, the cooling means has a main refrigeration circuit, an auxiliary refrigeration circuit, the main refrigeration circuit and the auxiliary refrigeration circuit, both compressor, A condenser, expansion means, and a refrigerant having a phase change and having an in-compartment evaporator are circulated,
The in-compartment evaporator of the main refrigeration circuit and the auxiliary refrigeration circuit is provided at a position communicating with the test room or the test room,
A refrigerant cooling circuit that is branched from the auxiliary refrigeration circuit and cools a refrigerant that passes between a condenser of the main refrigeration circuit and expansion means;
Having refrigerant control means for intermittently and / or controlling the flow rate of the refrigerant flowing in the refrigerant cooling circuit,
A normal operation in which a refrigerant is circulated through the main refrigeration circuit and / or the auxiliary refrigeration circuit to control the temperature in the test chamber; and a supercooling that circulates the refrigerant through the main refrigeration circuit and passes the refrigerant through the refrigerant cooling circuit. It is possible to drive,
Operating the refrigerant control means based on certain conditions, having a switching control means to switch between the normal operation and supercooling operation,
If the difference between the surface temperature before Symbol the internal evaporator belonging to a temperature between the main refrigeration circuit of the test chamber becomes constant less, environmental testing apparatus characterized by excessive cooling operation is performed. A test chamber for arranging the device under test, and cooling means, the cooling means has a main refrigeration circuit, an auxiliary refrigeration circuit, the main refrigeration circuit and the auxiliary refrigeration circuit, both compressor, A condenser, expansion means, and a refrigerant having a phase change and having an in-compartment evaporator are circulated,
  The in-compartment evaporator of the main refrigeration circuit and the auxiliary refrigeration circuit is provided at a position communicating with the test room or the test room,
  A refrigerant cooling circuit that is branched from the auxiliary refrigeration circuit and cools a refrigerant that passes between a condenser of the main refrigeration circuit and expansion means;
  Having refrigerant control means for intermittently and / or controlling the flow rate of the refrigerant flowing in the refrigerant cooling circuit,
  Normal operation of circulating a refrigerant through the main refrigeration circuit and / or the auxiliary refrigeration circuit to control the temperature in the test chamber; and supercooling by circulating the refrigerant through the main refrigeration circuit and passing the refrigerant through the refrigerant cooling circuit. It is possible to drive,
  Operating the refrigerant control means based on certain conditions, having a switching control means to switch between the normal operation and supercooling operation,
  An environmental test apparatus wherein a supercooling operation is performed when the temperature of the test chamber falls below a certain temperature. A test chamber for placing the device under test, and cooling means, wherein the cooling means has a main refrigeration circuit and an auxiliary refrigeration circuit, and the main refrigeration circuit has a compressor, a condenser, and expansion means; , Which has an internal evaporator and circulates a phase-change refrigerant,
The in-compartment evaporator of the main refrigeration circuit is provided at a position communicating with the test room or the test room,
It is for cooling the refrigerant passing from the condenser of the main refrigeration circuit to the expansion means, and is formed by a part of the auxiliary refrigeration circuit or a circuit branched from the auxiliary refrigeration circuit. Circuit
Having refrigerant control means for intermittently and / or controlling the flow rate of the refrigerant flowing in the refrigerant cooling circuit,
It is possible to perform a normal operation of circulating a refrigerant through the main refrigeration circuit to control the temperature in the test chamber, and a supercooling operation of circulating the refrigerant through the main refrigeration circuit and passing the refrigerant through the refrigerant cooling circuit. Yes,
Operating the refrigerant control means based on certain conditions, having switching control means to switch between the normal operation and supercooling operation,
If the difference between the surface temperature before Symbol the internal evaporator belonging to a temperature between the main refrigeration circuit of the test chamber becomes constant less, environmental testing apparatus characterized by excessive cooling operation is performed. A test chamber for placing the device under test, and cooling means, wherein the cooling means has a main refrigeration circuit and an auxiliary refrigeration circuit, and the main refrigeration circuit has a compressor, a condenser, and expansion means; , Which has an internal evaporator and circulates a phase-change refrigerant,
  The in-compartment evaporator of the main refrigeration circuit is provided at a position communicating with the test room or the test room,
  It is for cooling the refrigerant passing from the condenser of the main refrigeration circuit to the expansion means, and is configured by a part of the auxiliary refrigeration circuit or a refrigerant branched from the auxiliary refrigeration circuit. Circuit
  Having refrigerant control means for intermittently and / or controlling the flow rate of the refrigerant flowing in the refrigerant cooling circuit,
  It is possible to perform a normal operation of circulating a refrigerant through the main refrigeration circuit to control the temperature in the test chamber, and a supercooling operation of circulating the refrigerant through the main refrigeration circuit and passing the refrigerant through the refrigerant cooling circuit. Yes,
  Operating the refrigerant control means based on certain conditions, having a switching control means to switch between the normal operation and supercooling operation,
  An environmental test apparatus wherein a supercooling operation is performed when the temperature of the test chamber falls below a certain temperature. The environmental test apparatus according to any one of claims 1 to 4 , wherein the capacity of the compressor belonging to the auxiliary refrigeration circuit is smaller than the capacity of the compressor belonging to the main refrigeration circuit. The main refrigeration circuit is capable of adjusting the evaporation temperature of the refrigerant,
Wherein in response to temperature drop of the test chamber to reduce the evaporation temperature, claims 1 to 5 temperature of the test chamber, characterized in that it is switched to the over-cooling operation from the normal operation on condition that a constant temperature or less The environmental test apparatus according to any one of the above. The auxiliary refrigeration circuit has a compressor, a condenser, an expansion means, and an evaporator in the refrigerator, and circulates a phase-change refrigerant,
When the temperature in the test chamber is equal to or higher than a certain middle temperature and the set temperature of the test chamber is equal to or lower than a certain low temperature,
The main refrigeration circuit and the auxiliary refrigeration circuit are driven to perform a quenching operation in which a refrigerant is passed through an in-compartment evaporator of the main refrigeration circuit and the auxiliary refrigeration circuit,
Reduce the evaporation temperature in both the in-house evaporator according to the temperature drop in the test chamber,
After that, the supply of the refrigerant to the in-compartment evaporator of the auxiliary refrigeration circuit is stopped to switch to the supercooling operation,
Environmental testing apparatus according to any one of claims 1 to 6, characterized in that only in normal operation the main refrigeration circuit and a temperature of the test chamber reaches a set temperature. The auxiliary refrigeration circuit has a bypass circuit that returns the refrigerant that has flowed out of the condenser to the compressor, and the refrigerant that has flowed out of the compressor of the auxiliary refrigeration circuit in the bypass circuit has the refrigerant that flowed out of the compressor of the auxiliary refrigeration circuit. The environmental test apparatus according to any one of claims 1 to 7 , wherein heat is exchanged and returned to the compressor as a superheated gas. The main refrigeration circuit has a bypass circuit that returns the refrigerant that has flowed out of the condenser of the main refrigeration circuit to the compressor of the main refrigeration circuit, and the refrigerant that has flowed out of the condenser of the main refrigeration circuit in the bypass circuit. with the refrigerant heat exchanger exiting from the compressor of the main refrigeration circuit, environmental testing apparatus according to any one of claims 1 to 8 in a superheated gas, characterized in that is returned to the compressor. The environmental test apparatus according to any one of claims 1 to 9 , further comprising switching means for shifting from normal operation to supercooling operation and / or switching means for shifting from supercooling operation to normal operation. Any said it is possible to set the set temperature of the test chamber, according to claim 1 to 10, characterized in that switched normal operation and over cooling operation in accordance with the temperature of the current setting temperature and / or the test chamber An environmental test apparatus according to any one of the above. Environmental testing apparatus according to any one of claims 1 to 11, characterized in that it is possible to stop the operation of the auxiliary refrigeration circuit.

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