JP2019082493A - Environmental test device - Google Patents

Abstract

To develop an environmental test device which consumes less electricity than an existing environmental test device does and has a testing room 3, a temperature of which makes the same temperature dropping curve as an existing curve does to reach a desired low level.SOLUTION: The environmental test device includes: a testing room 3; a main freezing circuit 31; a sub freezing circuit 32; a refrigerant cooling circuit 51 branching from the sub freezing circuit 32 for cooling a refrigerant of the main freezing circuit 31; refrigerant control means for intermitting flow of the refrigerant in the refrigerant cooling circuit 51; and switch control means capable of performing a normal operation to circulate the refrigerant in the main freezing circuit 31 and control the temperature in the testing room 3 and performing an excessive cooling operation to circulate the refrigerant in the main freezing circuit 31 and causing the refrigerant to pass through the refrigerant cooling circuit 51, for causing the refrigerant control means to be activated on a certain condition and switching the normal operation and the excessive cooling operation.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an environmental test apparatus capable of exposing a test object to a predetermined environment.

Environmental testing is known as a method for examining the performance and durability of products and parts. Environmental testing is performed using equipment called environmental testing equipment. 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. An 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 described above, the heater 6, the humidifying device 7 and the blower 8. Further, 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-changing 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 for driving the compressor 101 is an induction motor and can not change the rotational speed. That is, the motor for driving the compressor 101 is not inverter-controlled, and rotates at a constant rotational speed. 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 refrigerant that changes phase is sealed therein. The refrigerant circulates in the above-described 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, as in the known one.
In addition to the cooling means 106, a small auxiliary cooling means (not shown) may be provided. The auxiliary cooling means is used for maintaining the temperature in the test chamber 3 at the 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 tray 26, and heats and evaporates the water in the water tray 26 by the humidifying heater 25.

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

The environmental test apparatus 100 creates a desired temperature and 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, the inside of the test chamber 3 is brought to a desired temperature and humidity environment by heating, cooling, humidifying and dehumidifying. .
For example, in the case where the same environment as the outside air is set as the start environment and a high temperature and high humidity environment is to be 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 means 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 further reduce the temperature in the test chamber 3 And fine-tune the humidity.

When a low temperature and high humidity environment is to be created, the cooling means 106 is driven to lower the temperature in the test chamber 3, and the humidifying device 7 is driven to increase the humidity in the test chamber 3.
Even in the case of creating a low temperature and high humidity environment, the heater 6 or the like is also operated to finely adjust the temperature and humidity.

  In any case, after the test chamber 3 reaches a desired environment, the cooling means 106, the heater 6, and the humidifying device 7 are operated appropriately to maintain the desired environment described above.

Regarding the cooling means 106 mounted in the environmental testing apparatus 100 of the prior art, the cooling means 106 has a capacity (rated output) that can create an environment of a temperature range displayed in a catalog etc. within a fixed time. ing.
In the case of the environmental test apparatus 100 on the premise that the test object generates heat, the cooling means 106 has a capacity capable of accepting a heat generation load.
For example, if it is an environmental testing apparatus 100 that can create an environment of 100 degrees Celsius to minus 40 degrees Celsius, the compressor 101 of the cooling means 106 mounted is a test room 3 in a normal temperature state. The capacity of the temperature can be lowered to minus 40 degrees Celsius within a predetermined time. In addition, the mounted compressor 101 has a capacity sufficient to maintain the temperature of the test chamber 3 at the set temperature (for example, minus 40 degrees Celsius) even if there is a slight disturbance.
That is, the compressor 101 of the prior art environmental test apparatus 100 has a capacity sufficient to cope with the expected maximum cooling load.
Hereinafter, for convenience of explanation, the environmental test apparatus 100 of the prior art equipped with the compressor 101 of a capacity sufficient to cope with the expected maximum cooling load is the "environmental test apparatus 100 of standard configuration" or the "environmental test of the prior art" It is referred to as device 100 ".

Japanese Examined Patent Publication No. 5-60614

The environmental test apparatus 100 incorporates an electric device and naturally consumes power. Environmental testing may also take place over extended periods of time. Therefore, it can be said that the environmental test apparatus 100 is an apparatus which consumes a considerable amount of power.
Further, in order to precisely control the temperature in the test chamber 3, the environmental test apparatus 100 may simultaneously drive the cooling unit 106 and the heater 6 as described above. That is, the cooling means 106 has poor responsiveness. Therefore, in the environmental test apparatus 100, the cooling means 106 may be driven so that the inside of the test chamber 3 tends to have a somewhat low temperature, and at the same time, the heater 6 may be driven to finely adjust the temperature.
Here, in the environmental test apparatus 100 according to the prior art (standard configuration), since the compressor 101 having a capacity sufficient to cope with the expected maximum cooling load is mounted, the temperature in the test room 3 is stable. In this case, the frozen output of the cooling means 106 tends to be 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 according to the prior art (standard configuration) is dissatisfied that the power consumption is large.

Under these circumstances, development of a so-called energy saving type environmental testing device with low power consumption is desired in the market.
The present inventors have made studies to meet this requirement, and investigated the proportion of power consumed by the devices constituting the environmental test apparatus 100. As a result, it was found that the power consumption of the cooling means 106 was the largest among the devices constituting the environmental test apparatus 100.
Therefore, for the purpose of suppressing the power consumption of the cooling means 106, the present inventors prototyped an environmental test apparatus (hereinafter, an improved environmental test apparatus) 200 in which the capacity of the compressor 101 was replaced with one smaller than the present one. .
That is, most of the power consumption of the cooling means 106 is the power required to drive the compressor 101. Therefore, if the capacity of the compressor 101 is made smaller than the present (standard configuration), the power consumption of the cooling means 106 is reduced, and the power consumption of the entire environmental test apparatus 200 is also reduced.

Here, even if the capacity of the compressor 101 is replaced with one that is somewhat smaller than the present (standard configuration), a refrigeration output equivalent to the present (standard configuration) can be obtained by raising the evaporation temperature of the refrigerant. Therefore, when the temperature in the test room 3 is high to a certain extent, no particular problem occurs in carrying out the environmental test.
Also, as is 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 and the power consumption generated by the motor) are not proportional. The cooling means (refrigerator) 106 can exhibit the same refrigeration output as that of the conventional (standard configuration) cooling means 106, and the power consumption is smaller than that of the conventional.

The principle will be briefly described below.
The cooling means 106 is a refrigerator that constitutes a refrigeration cycle, and compresses a gaseous refrigerant with the compressor 101 to make the refrigerant gas have a high temperature and pressure. 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 reduces the surface temperature of the evaporator 107 according to the principle described above.

Therefore, the refrigeration output (the amount of heat energy removed by the refrigerator) largely depends on the amount of refrigerant supplied to the evaporator 107, and the larger the amount of refrigerant supplied to the evaporator 107, the larger the refrigeration output.
Therefore, the improved environmental test apparatus 200 employs a method of supplying a larger amount of refrigerant to the evaporator 107 by raising the evaporation temperature of the refrigerant than in the conventional case (standard configuration).
As a result, the improved environmental test apparatus 200 can exhibit the same refrigeration output as that of the related art 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 rises, and the surface temperature of the evaporator 107 rises.
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 if the opening degree of the expansion valve 103 is narrowed or the refrigerant discharge amount from the compressor 101 is small. The surface temperature of the evaporator 107 is lowered. Conversely, if the opening degree of the expansion valve 103 is expanded or the refrigerant discharge amount from the compressor 101 is large, the evaporation temperature of the refrigerant rises, and the surface temperature of the evaporator 107 rises.
Therefore, as described above, the improved environmental testing apparatus 200 aims to save energy, and the evaporation temperature of the refrigerant is higher than that of the conventional (standard configuration), and the surface temperature of the evaporator 107 is increased. Resulting in.

As described above, although the improved environmental test apparatus 200 has a higher evaporation pressure of the refrigerant in the evaporator 107 compared to the environmental test apparatus 100 having the standard configuration, the surface temperature of the evaporator 107 is somewhat higher than that of the conventional one. When the set temperature in the test room 3 is high to a certain extent, no particular problem occurs in performing the environmental test.
However, the improved environmental test apparatus 200 has been difficult to apply to environmental tests that require cryogenic environments.
That is, in the improved 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 must be somewhat higher than in the conventional.
Even though the surface temperature of the evaporator 107 is somewhat high, the surface temperature of the evaporator 107 is lowered to a certain temperature. Therefore, when the set temperature of the test chamber 3 is, for example, equal to or higher than that temperature It is possible to lower the surface temperature of the evaporator 107 with a predetermined temperature range than the actual temperature of the above, and to lower the temperature in the test chamber 3 to a desired set temperature and maintain it.

On the other hand, when creating a cryogenic environment, such as minus 40 degrees Celsius, in the test chamber 3, the surface temperature of the evaporator 107 must be at least lower than that. Desirably, the surface temperature of the evaporator 107 should be lowered with a predetermined temperature range with respect to the set temperature.
However, in the improved environmental test apparatus 200, the evaporation temperature of the refrigerant rises compared to the conventional (standard configuration), and the surface temperature of the evaporator 107 is higher than the conventional (standard configuration). Therefore, the improved environmental test apparatus 200 does not easily lower the surface temperature of the evaporator 107.

Here, even in the improved environmental testing 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 as compared with the conventional (standard configuration).
However, since the compressor 101 mounted in the improved environmental testing apparatus 200 is originally smaller in rated output than the standard configuration, if the surface temperature of the evaporator 107 is operated lower than the set temperature, the required refrigeration output (The amount of heat energy that the refrigerator takes away) can not be obtained.
That is, the compressor 101 of the cooling means 106 mounted in the environmental testing apparatus 100 of the standard configuration lowers the temperature of the test chamber 3 in the normal temperature state to a set temperature (for example, about -40 degrees Celsius) within a predetermined time, The compressor 101 mounted on the improved environmental testing apparatus 200 has a capacity sufficient to maintain the temperature of the test room 3 at that temperature even if there is a slight disturbance, compared to the conventional one. Capacity is small.
Therefore, if the surface temperature of the evaporator 107 is operated lower than the set temperature of cryogenic temperature, the required refrigeration output (the amount of heat energy which the refrigerator takes away) can not be obtained, and the temperature of the test room 3 is lowered to the set temperature. Takes an excessive amount of time.
That is, the curve (temperature drop curve) showing the relationship between the temperature in the test chamber 3 and the time from the normal 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) In comparison with the environmental test apparatus 100 of

  Therefore, the present invention further develops the above-described improved environmental test apparatus 200, consumes less power than in the conventional case, and the temperature of the test room 3 reaches a desired low temperature by drawing the same temperature drop curve as the conventional. The task is to develop an environmental test device that can

  The invention according to claim 1 for solving the above-mentioned problems has a test chamber in which an object to be tested is placed, and a cooling means, and the cooling means has a main refrigeration circuit and an auxiliary refrigeration circuit. Each of the main refrigeration circuit and the auxiliary refrigeration circuit includes a compressor, a condenser, an expansion means, and an in-compartment evaporator, through which a phase-changing refrigerant circulates, and the main refrigeration circuit and The in-compartment evaporator of the auxiliary refrigeration circuit is provided at the test chamber or at a position communicating with the test chamber, branched from the auxiliary refrigeration circuit, and extending from the condenser of the main refrigeration circuit to the expansion means A refrigerant cooling circuit for cooling the refrigerant passing between the refrigerant and the refrigerant control means for intermittently and / or controlling the flow of the refrigerant flowing in the refrigerant cooling circuit, and circulating the refrigerant to the main refrigeration circuit and / or the auxiliary refrigeration circuit Let the temperature in the test room It is possible to perform a normal operation to control and a supercooling operation to circulate the refrigerant to the main refrigeration circuit and pass the refrigerant to the refrigerant cooling circuit, and operate the refrigerant control means based on certain conditions; It has switching control means for switching between the normal operation and the subcooling operation, and the temperature of the test chamber becomes lower than a predetermined temperature and / or the temperature of the test chamber and the surface of the in-house evaporator belonging to the main refrigeration circuit A subcooling operation is performed when the temperature difference becomes lower than or equal to a certain value.

The refrigerant control means is desirably capable of completely interrupting the refrigerant flowing to the refrigerant cooling circuit, but is not necessarily capable of completely interrupting the refrigerant. When the refrigerant flowing into the refrigerant cooling circuit can not be completely shut off, during normal operation, a small amount of refrigerant introduced into the refrigerant cooling circuit substantially reduces the amount of refrigerant substantially flowing through the main refrigeration circuit. If you do not want to contribute to
The environmental test apparatus of the present invention has a main refrigeration circuit and an auxiliary refrigeration circuit as cooling means. And the storage evaporator of the main refrigeration circuit and the auxiliary refrigeration circuit is provided at a position communicating with the test chamber or the test chamber. 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-storage evaporator of the auxiliary refrigeration circuit.
Further, the environmental test apparatus of the present invention is provided with a refrigerant cooling circuit which 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 device of the present invention, the refrigerant of 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 cooled further and sent out to the expansion means in a subcooled state.
In the environmental test apparatus of the present invention, the liquid refrigerant that has dissipated heat in the condenser and is in a saturated liquid state is cooled by the low temperature refrigerant of the auxiliary refrigeration circuit to be in a subcooled state. That is, the saturated condensate is deprived of sensible heat (heat energy required to change the temperature without phase change) to form a supercooled liquid, which reduces the enthalpy of the refrigerant. When the subcooled 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 subcooling state of the refrigerant is progressing, and the enthalpy is smaller than that of the prior 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 between the enthalpies is the increase of the refrigeration output relative to the conventional one.
With regard to the state of the refrigerant inside the evaporator, the proportion of the liquid is higher in the case where the refrigerant enters the expansion means in the subcooled state than in the case where the refrigerant is expanded without subcooling even at the same evaporation temperature. . Therefore, it can be said that the refrigeration capacity is increased.
In the environmental test apparatus of the present invention, the liquid refrigerant having a temperature of, for example, + 30 ° C. immediately after leaving the condenser is further cooled to a subcooled state, for example, 20 ° C. The heat transfer at the time of the supercooling treatment at this time is the amount of heat removed by sensible heat. The refrigeration capacity when the refrigerant is adiabatically expanded to -40 degrees Celsius by the expansion means is larger than the refrigeration capacity when the saturated liquid of 30 degrees Celsius is adiabatically expanded to -40 degrees Celsius by the amount of supercooling .
Further, the environmental test apparatus of the present invention includes a normal operation of controlling the temperature in the test chamber by circulating the refrigerant in the main refrigeration circuit etc., and a supercooling operation of delivering the refrigerant flowing in the main refrigeration circuit to the expansion means as a supercooling state. Switch based on certain conditions. As a result, the temperature of the test chamber can reach a desired low temperature by drawing a conventional temperature drop curve.
In addition, since the normal operation can be performed using a compressor having a smaller capacity than the conventional one, the power consumption is smaller than that of the conventional one. In addition, even when operating in the subcooling operation, power consumption is reduced compared to the prior art.
Further, in the environmental test apparatus of the present invention, the temperature in the test chamber decreases in the same manner as in the conventional temperature decrease curve, and the desired low temperature is reached.

  In order to solve the same problem, the invention according to claim 2 has a test chamber in which an object to be tested is placed, and cooling means, and the cooling means has a main refrigeration circuit and an auxiliary refrigeration circuit. The main refrigeration circuit includes a compressor, a condenser, an expansion means, and an in-compartment evaporator to circulate a phase-changing refrigerant, and the in-compartment evaporator of the main refrigeration circuit is: The test chamber or a position communicating with the test chamber, for cooling the refrigerant passing from the condenser of the main refrigeration circuit to the expansion means, which is a part of the auxiliary refrigeration circuit Or a refrigerant control circuit constituted by a circuit branched from the auxiliary refrigeration circuit, for controlling or interrupting the flow of the refrigerant flowing in the refrigerant cooling circuit, and / or controlling the flow rate of the refrigerant; It is circulated to control the temperature in the test chamber. It is possible to perform an operation and perform a supercooling operation to circulate the refrigerant to the main refrigeration circuit and pass the refrigerant to the refrigerant cooling circuit, operate the refrigerant control means based on certain conditions, and perform the normal operation And switching control means for switching between the subcooling operation and the difference between the temperature of the test chamber and the surface temperature of the in-house evaporator belonging to the main refrigeration circuit when the temperature of the test chamber becomes lower than a predetermined temperature Is an environmental test device characterized in that a subcooling operation is performed when

  The invention according to claim 3 is the environmental test device according to claim 1 or 2, 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. It is.

  The main application of the auxiliary refrigeration circuit is to deliver the 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 may be smaller than the capacity of the compressor belonging to the main refrigeration circuit.

  In the invention according to claim 4, the main refrigeration circuit is capable of adjusting the evaporation temperature of the refrigerant, and the evaporation temperature is decreased according to the temperature decrease of the test chamber, and the temperature of the test chamber is equal to or lower than a predetermined temperature. The environmental test device according to any one of claims 1 to 3, characterized in that the normal operation is switched to the subcooling operation on condition that it becomes the condition.

  In the environmental test apparatus of the present invention, the temperature in the test chamber is lowered in the same manner as in the conventional temperature drop curve, and the desired low temperature is reached.

  In the invention according to claim 5, the auxiliary refrigeration circuit includes a compressor, a condenser, an expansion means, and an in-compartment evaporator, and a phase-changing refrigerant circulates, and the test chamber The main refrigeration circuit and the auxiliary refrigeration circuit are driven to drive the main refrigeration circuit and the auxiliary refrigeration circuit when the temperature of the test room is above a certain medium temperature and the set temperature of the test room is below a certain low temperature. The quenching operation is performed to pass the refrigerant to the in-compartment evaporator, and the evaporation temperature in both of the in-compartment evaporators is lowered according to the temperature drop in the test chamber, and thereafter the in-compartment evaporator of the auxiliary refrigeration circuit 5. The system according to any one of claims 1 to 4, wherein the supply of the refrigerant to the engine is stopped and the operation is switched to the subcooling operation, and the normal operation is performed only by the main refrigeration circuit when the temperature in the test chamber reaches the set temperature. Environmental testing equipment.

Here, the "medium temperature" is a temperature near or slightly lower than the normal temperature, and causes a considerable temperature difference between the temperature in the test chamber and the surface temperature of the evaporator even without performing the subcooling operation. It is the temperature that can be done.
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 the quenching operation to shorten the temperature in the test chamber. It can be lowered in time.
Further, in the environmental test apparatus of the present invention, the evaporation temperature in both the storage evaporators is lowered according to the temperature drop in the test chamber, so even if the temperature in the test chamber is lowered, The surface temperature can be maintained below that.

  In the invention according to claim 6, 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 is the auxiliary refrigeration The environmental test apparatus according to any one of claims 1 to 5, wherein the environmental test device is heat-exchanged with the refrigerant that has exited from the compressor of the circuit and 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 reduce the amount of refrigerant in the auxiliary refrigeration circuit that gradually cools the main refrigeration circuit. Thereby, the refrigeration capacity of the main refrigeration circuit can be varied continuously.

  The invention described in claim 7 is that the main refrigeration circuit has a bypass circuit that returns the refrigerant coming from the condenser of the main refrigeration circuit to the compressor of the main refrigeration circuit, and the main refrigeration circuit in the bypass circuit The refrigerant according to any one of claims 1 to 6, wherein the refrigerant coming out of the condenser is heat-exchanged with the refrigerant coming out of the compressor of the main refrigeration circuit, and is returned to the compressor as a superheated gas. Environmental testing equipment.

In the present invention, since the main refrigeration circuit is provided with the bypass circuit, the amount of refrigerant flowing to the evaporator can be reduced.
The capacity of the bypass circuit is preferably such that the entire amount of refrigerant coming out of the compressor can pass through and be 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.
Further, it is desirable that the bypass circuit has a flow rate adjusting means such as an expansion valve. By providing 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 8 has switching means for shifting from normal operation to supercooling operation and / or switching means for shifting from supercooling operation to normal operation. It is an environmental test apparatus as 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 controlled smoothly.

  The invention according to claim 9 is characterized in that the set temperature of the test chamber can be set, and the normal operation and the 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 8, wherein

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

  The invention according to claim 10 is the environmental test apparatus according to any one of claims 1 to 9, characterized in that the operation of the auxiliary refrigeration circuit can be stopped.

  According to the invention, the method of operation can be changed.

  The environmental test apparatus of the present invention consumes less power than before. Also, in the environmental testing device of the present invention, the temperature of the test room can reach a desired low temperature by drawing a temperature drop curve similar to the conventional one.

It is a block diagram of the environmental test apparatus of embodiment of this invention. It is a block diagram of the environmental test apparatus of FIG. 1, Comprising: The flow of a refrigerant | coolant at the time of implementing middle cooling operation (normal operation) is shown. It is a block diagram of the environmental test apparatus of FIG. 1, Comprising: The flow of a refrigerant | coolant at the time of implementing a slow cooling operation (normal operation) is shown. It is a block diagram of the environmental test apparatus of FIG. 1, Comprising: The flow of a refrigerant | coolant at the time of implementing quenching operation (normal operation) is shown. It is a block diagram of the environmental test apparatus of FIG. 1, Comprising: The flow of the refrigerant | coolant at the time of implementing a subcooling operation is shown. It is a flow chart which shows an example of the change situation of a driving method. It is a block diagram of the environmental test apparatus of other embodiment of this invention. It is a block diagram of the environmental test apparatus of other embodiment of this invention. It is a block diagram of the expansion means employ | adopted by the further another embodiment of this invention. It is a graph which shows the relationship (temperature fall curve) between the temperature in a test chamber from the normal temperature state of the environmental test apparatus of Comparative example 1 (standard composition) to the lower limit of a corresponding temperature range (temperature fall curve). It is a graph which shows the relationship (temperature fall curve) of the temperature in a test chamber and time to the lower limit of a corresponding temperature range from the normal temperature state of comparative example 2 (improved type environmental testing apparatus). It is a graph which shows the relationship (temperature fall curve) between the temperature in a test chamber from the normal temperature state of the environmental test apparatus of the Example of this invention to the lower limit of a corresponding temperature range, and time. It is a block diagram of a prior art and an improved environmental test apparatus.

Hereinafter, embodiments of the present invention will be further described. In addition, about the member same as the environmental test apparatus 100 of a prior art (standard structure), the same number is attached | subjected and the duplicate description is abbreviate | omitted.
The mechanical configuration of the environmental test apparatus 1 according to the embodiment of the present invention is the same as the environmental test apparatus 100 according to the prior art except for the structure of the cooling means 30.
That is, as shown in FIG. 1, the environmental test apparatus 1 includes a test chamber 3, a cooling unit 30, 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 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 described above, the heater 6, the humidifier 7 and the blower 8. It is done. The humidifying device 7 is a combination of the humidifying heater 25 and the water tray 26, and heats and evaporates the water in the water tray 26 by the humidifying heater 25.
Further, 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 described above, 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 systems of refrigeration circuits 31 and 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 thick lines in FIG. The main refrigeration circuit 31 has a compressor 35, a condenser 36, an expansion means 37 and an evaporator 38 annularly connected by piping to form a circulation circuit, similarly to known ones, and forms a circulation circuit inside which a phase change occurs 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 constituent members of the main refrigeration circuit 31 are the main compressor 35, the main condenser 36, the main expansion means 37 and the main side It is called an in-compartment evaporator 38.
Further, in the present embodiment, on the main refrigeration circuit 31, there are the primary side flow path of the return refrigerant heating heat exchanger 63 and the secondary side flow path of the supercooling heat exchanger 50. Therefore, in the present embodiment, the main refrigeration circuit 31 is connected from the main compressor 35 to the primary flow path of the return refrigerant heating heat exchanger 63, the main condenser 36, and the secondary side of the supercooling 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 main storage evaporator 38.

On the other hand, the auxiliary refrigeration circuit 32 is a circuit drawn by thick lines in FIG. The auxiliary refrigeration circuit 32 also has a compressor 45, a condenser 46, an expansion means 47, an evaporator 48, and a check valve 49, which are annularly connected by piping to form a circulation circuit, similarly to known ones. A phase change refrigerant is sealed.
Hereinafter, in order to distinguish the apparatus on the auxiliary refrigeration circuit 32 side from the apparatus on the main refrigeration circuit 31 side, the constituent members of the auxiliary refrigeration circuit 32 are the auxiliary compressor 45, the auxiliary condenser 46, the auxiliary expansion means 47 and the auxiliary It is called an in-compartment evaporator 48.
Further, in the present embodiment, on the auxiliary refrigeration circuit 32, the primary side flow passage of the return refrigerant heating heat exchanger 65 is interposed.
Therefore, in the present embodiment, the auxiliary refrigeration circuit 32 includes the primary side flow passage of the heat exchanger 65 for heating the return refrigerant, the auxiliary side condenser 46, the auxiliary side expansion means 47, and the auxiliary side internal evaporation from the auxiliary compressor 45. It is an annular channel that returns to the auxiliary compressor 45 around the vessel 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 space between the main refrigeration circuit 31 and the auxiliary refrigeration circuit 32 is thermally coupled via the supercooling heat exchanger 50. It is coordinated. This will be described below.
In the present embodiment, the subcooling heat exchanger 50 is provided on the main refrigeration circuit 31. The mounting position of the supercooling 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 side flow passage of the subcooling heat exchanger 50 is connected to the main refrigeration circuit 31, and the refrigerant liquefied by passing through the main side condenser 36 is the supercooling heat exchanger 50. Leading to the main side expansion means 37 through the secondary side flow path.

Further, the primary side flow passage of the subcooling heat exchanger 50 has a relatively large space, and substantially functions as an evaporator.
The primary side flow passage 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 passage branched from between the auxiliary condenser 46 and the auxiliary expansion means 47 of the auxiliary refrigeration circuit 32 and leading to the suction side of the auxiliary compressor 45. The expansion means 52 and the primary side flow path of the above-described heat exchanger for supercooling 50 are interposed.

Further, as an auxiliary circuit, there is a main refrigeration circuit side bypass circuit 60 on the main refrigeration circuit 31 side, and an auxiliary refrigeration circuit side bypass circuit 61 on the auxiliary refrigeration circuit 32 side.
The main refrigeration circuit side bypass circuit 60 is a flow path branched from between the supercooling heat exchanger 50 of the main refrigeration circuit 31 and the main side expansion means 37 and leading to the suction side of the main side compressor 35. In the middle of the main refrigeration circuit side bypass circuit 60, there are secondary side flow paths of the bypass expansion means 53 and 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 leading to the suction side of the auxiliary side compressor 45 and bypassing in the middle thereof There are secondary side flow paths of the expansion means 66 and the heat exchanger 65 for heating the return refrigerant.

In the present embodiment, the compressors of the cooling means 30 (the main compressor 35 and the auxiliary compressor 45) are all driven by the induction motor, and the number of rotations is constant and can not 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 an 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 percent of the capacity of the main compressor 35.

That is, the capacity of the auxiliary compressor 45 is desirably 50% or less of the capacity of the main compressor 35, and more desirably 35% or less. The capacity of the auxiliary compressor 45 is preferably at least 20 percent of the capacity of the main compressor 35.
The capacity of the auxiliary compressor 45 most recommended is 20 to 35 percent of the capacity of the main compressor 35.

  Since the main application of the auxiliary refrigeration circuit 32 is to supercool the refrigerant flowing through the main refrigeration circuit 31, the auxiliary compressor 45 does not need a large capacity, and if the capacity is large, for the purpose of energy saving It will be against. On the other hand, when the capacity of the auxiliary compressor 45 is excessively small, the refrigerant flowing through the main refrigeration circuit 31 can not be sufficiently subcooled.

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

  Further, in the present embodiment, the expansion means of the cooling means 30 are all electronic expansion valves, and the opening degree can be changed. Any expansion means of the cooling means 30 can be fully closed. That is, the main side expansion means 37, the auxiliary side 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 degree of opening, 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 to the refrigerant cooling circuit 51. In the present embodiment, the refrigerant cooling circuit 51 is interrupted by opening and closing the auxiliary expansion means 47 and the refrigerant cooling expansion means 52.
That is, by closing the auxiliary side expansion means 47 and opening the refrigerant cooling expansion means 52, the refrigerant cooling circuit 51 is opened, and the flow path leading to the auxiliary side internal evaporator 48 is shut off. As a result, the refrigerant is supplied to the primary side flow passage of the supercooling heat exchanger 50.
Conversely, by opening the auxiliary side expansion means 47 and closing the refrigerant cooling expansion means 52, the refrigerant cooling circuit 51 is closed, and the flow path leading to the auxiliary in-house evaporator 48 is opened. As a result, the refrigerant is supplied to the auxiliary in-compartment evaporator 48.

In the environmental test apparatus 1 of this embodiment, the cooling means 30 can be operated by four operation methods.
More specifically, the medium cooling operation (normal operation) in which the refrigerant is circulated in the main refrigeration circuit 31 shown by a thick line in FIG. 2 and the slow cooling operation (normal operation) in which the refrigerant is circulated in the auxiliary refrigeration circuit 32 shown by a thick line in FIG. 4) and a rapid cooling operation (normal operation) in which the refrigerant is circulated to both the main refrigeration circuit 31 and the auxiliary refrigeration circuit 32 as shown by thick lines in FIG. 4; and the refrigerant as the main refrigeration circuit 31 and the refrigerant as shown in FIG. A supercooling operation can be performed to circulate the cooling circuit 51.

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 to the main refrigeration circuit 31.
In the middle cooling operation, the gaseous refrigerant is compressed by the main side compressor 35, and the compressed refrigerant is returned through the primary side flow path of the refrigerant heating heat exchanger 63 and enters the main side condenser 36 and is liquefied Be done. The liquefied refrigerant passes through the secondary flow path of the supercooling heat exchanger 50 (is not heat exchanged), is decompressed by the main expansion means 37, enters the main in-house evaporator 38 and evaporates. , Return to the main compressor 35.
Further, 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 expansion means 37 is narrowed in order to lower the surface temperature of the main chamber internal evaporator 38 accordingly. Be

That is, when the temperature of the test chamber 3 is lowered to a certain extent, the temperature difference between the main in-compartment evaporator 38 and the test chamber 3 becomes small and the heat exchange efficiency decreases, so the opening degree of the main expansion means 37 is narrowed.
When the temperature difference between the main storage evaporator 38 and the test chamber 3 decreases, the opening degree of the main expansion means 37 is gradually narrowed as described above, and the temperature of the main storage evaporator 38 decreases. A constant temperature difference is secured between the surface temperature of the main-side storage evaporator 38 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 narrowed to save energy, but the main side compression means 37 allows the refrigerant to pass through the main expansion means 37. The opening degree can only be reduced until the suction pressure of the machine 35 reaches the lower limit.
However, by opening the main refrigeration circuit side bypass circuit 60, it is possible to further reduce the amount of refrigerant which is allowed to pass through the main expansion means 37 and flow to the main storage internal evaporator 38.
That is, even if the opening degree of the main side expansion means 37 is constant, the main side expansion means 37 can be opened by opening the bypass expansion means 53 from the closed state or by expanding the opening degree of the bypass expansion means 53 more. The amount of 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 to flow through the main side expansion means 37 and flow into the main side internal evaporator 38. Control for reducing the amount of refrigerant is referred to as "main refrigeration circuit side bypass control".
Also, control for reducing the opening amount of the main expansion means 37 to reduce the amount of refrigerant flowing to the main storage in-chamber 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 maintained while passing through the main expansion means 37. Thus, the refrigerant flowing to the main-in-compartment evaporator 38 can be made zero. That is, the entire amount of the refrigerant that has exited from the main compressor 35 can be flowed to the main refrigeration circuit bypass circuit 60 and returned to the main compressor 35.

If the opening degree of the main expansion means 37 is narrowed, the amount of refrigerant passing through the main storage internal evaporator 38 is reduced, so even when there is an excess of refrigerant, the main refrigeration circuit side bypass circuit 60 is used. 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 to the main refrigeration circuit side bypass circuit 60. Then, the refrigerant flows into the secondary flow passage of the return refrigerant heating heat exchanger 63, is heat-exchanged with the high temperature refrigerant flowing in the primary flow passage of the refrigerant heating heat exchanger 63, and is vaporized to form the overheated gas. It returns to the suction side of the main side compressor 35 in the state which became.
In the environmental test apparatus 1 of the present embodiment, the capacity of the main compressor 35 of the main refrigeration circuit 31 is smaller than that of the conventional (standard configuration), so an intermediate cooling operation performed by driving only the main compressor 35 is performed. Power consumption is less than before.

Next, the slow cooling operation (FIG. 3) will be described.
The slow cooling operation (FIG. 3) is performed by circulating the refrigerant in 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 refrigerant supply to the refrigerant cooling circuit 51 is prevented.
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 is liquefied Be done. Then, the liquefied refrigerant is depressurized by the auxiliary expansion means 47, enters the auxiliary in-house 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 storage evaporator 48 accordingly. The degree is narrowed.

Even in the slow cooling operation, the amount of refrigerant flowing through the auxiliary expansion means 47 by passing through the auxiliary expansion means 47 by opening the bypass expansion means 66 and letting the refrigerant pass through the auxiliary refrigeration circuit side bypass circuit 61 Can be further reduced.
In the present embodiment, the auxiliary refrigeration circuit side bypass circuit 61 is opened to reduce the amount of refrigerant flowing through the auxiliary side expansion means 47 and flowing to the auxiliary side in-house evaporator 48. It is called "side bypass control".
Also, control for reducing the opening amount of the auxiliary expansion means 47 to decrease the amount of refrigerant flowing to the auxiliary storage 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 auxiliary compressor 45 is maintained in a driven state and passes through the auxiliary expansion means 47. The refrigerant flowing to the auxiliary side in-house evaporator 48 can be made zero. That is, the entire amount of the refrigerant coming out of the auxiliary side condenser 46 can be supplied to the auxiliary refrigeration circuit side bypass circuit 61, and can be returned to the auxiliary side compressor 45 in a state of being heated by the refrigerant heating heat exchanger 65 to be an overheated gas.

  In the slow cooling operation, since the auxiliary compressor 45 with a small capacity is driven to cool, the refrigeration capacity is small.

Next, the quenching operation (FIG. 5) will be described.
The rapid cooling operation (FIG. 5) is an operation method of driving and cooling both the main refrigeration circuit 31 and the auxiliary refrigeration circuit 32. 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 an operation corresponding to the above-mentioned middle cooling operation and an operation corresponding to the slow cooling operation Takes place simultaneously.
In the rapid cooling operation, since the two compressors (the main compressor 35 and the auxiliary compressor 45) are simultaneously driven to perform cooling, the refrigeration capacity is large.
When the temperature in the test chamber 3 is high to a certain extent, the surface temperature of the main-in-room evaporator 38 and the surface temperature of the auxiliary-in-room evaporator 48 are generally lower than that of the test chamber 3. There may be a difference between the temperature of the vessel 38 and the temperature of the auxiliary in-compartment evaporator 48.
On the other hand, when the temperature in the test chamber 3 is considerably low, control is performed so that the temperature of the main in-chamber evaporator 38 and the temperature of the auxiliary in-chamber evaporator 48 become lower than the temperature in the test chamber 3 Be done.

Also in the rapid cooling operation, "main refrigeration circuit side bypass control" and "auxiliary refrigeration circuit side bypass control" can be performed. Further, it is possible to keep the refrigerant flowing through the main expansion means 37 and flowing to the main storage evaporator 38 zero while maintaining the driving state of the main compressor 35 during the quenching operation. Similarly, the state in which the auxiliary compressor 45 is driven during the quenching operation can be maintained, and the refrigerant flowing through the auxiliary expansion means 47 and flowing to the auxiliary in-house 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), consumption of the quenching operation performed by driving the main compressor 35 The power is less compared to prior art environmental test equipment of the type having auxiliary cooling means.

Next, the subcooling operation will be described. The subcooling operation is performed by circulating the refrigerant between the main refrigeration circuit 31 and the refrigerant cooling circuit 51 as shown in FIG.
When performing the supercooling operation, the auxiliary expansion means 47 serving as the refrigerant control means is closed to shut off the flow path leading to the auxiliary side storage evaporator 48, and the refrigerant cooling expansion means 52 is opened.
In the subcooling operation, both the main compressor 35 and the auxiliary compressor 45 are driven. In the case of the supercooling operation, the auxiliary compressor 45 belonging to the auxiliary refrigeration circuit 32 is driven, but the refrigerant does not flow to the auxiliary in-storage evaporator 48 of the auxiliary refrigeration circuit 32. Specifically, the auxiliary expansion means 47 connected to the auxiliary in-storage evaporator 48 is closed, and the auxiliary in-storage 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 subcooling operation, the auxiliary compressor 45 is driven, and the gaseous refrigerant is compressed by the auxiliary compressor 45, and the compressed refrigerant is returned to the primary side flow of the heat exchanger 65 for heating the refrigerant. It passes through the path, enters the auxiliary condenser 46 and is liquefied. Then, the liquefied refrigerant is decompressed by the refrigerant cooling expansion means 52 and enters the primary side flow passage of the supercooling heat exchanger 50. As described above, the primary side flow passage of the subcooling heat exchanger 50 substantially functions as an evaporator. As a result, the refrigerant is vaporized in the primary side flow passage of the supercooling heat exchanger 50, and the temperature of the primary side flow passage is lowered. 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 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 is returned, passes through the primary flow path of the refrigerant heating heat exchanger 63, and enters the main condenser 36. And liquefied. Then, the liquefied refrigerant passes through the secondary flow passage of the subcooling heat exchanger 50.
Here, during the subcooling operation, the auxiliary compressor 45 is driven, and the refrigerant liquefied in the auxiliary condenser 46 flows through the refrigerant cooling circuit 51, and in the primary flow path of the supercooling heat exchanger 50. It evaporates and the temperature of the primary side flow path is falling.
Therefore, the refrigerant flowing through the main refrigeration circuit 31 and liquefied by the main-side condenser 36 is further cooled by the supercooling heat exchanger 50, and the refrigerant is strongly subcooled. That is, in many cases, the refrigerant liquefied in the main side condenser 36 is also somewhat subcooled in some cases, but the degree of subcooling advances by further cooling by the subcooling heat exchanger 50.

The amount of cooling by the supercooling 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.
Further, even during the supercooling operation, the bypass expansion means 66 is opened to allow the refrigerant to pass through the auxiliary refrigeration circuit side bypass circuit 61, thereby passing through the refrigerant cooling expansion means 52 and flowing to the supercooling heat exchanger 50. The amount of refrigerant can be further reduced.
That is, in the present 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 bypass expansion means 66. The bypass expansion means 66 can change the opening degree.
In the present embodiment, for supercooling 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 amount of refrigerant flowing into the heat exchanger 50 can be adjusted to adjust the degree of subcooling of the refrigerant flowing through the main refrigeration circuit 31.

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 relatively large, the auxiliary compressor 45 is maintained in the driven state and passes through the refrigerant cooling expansion means 52. Thus, the refrigerant flowing to the supercooling heat exchanger 50 can be made zero.
In the present embodiment, by opening the auxiliary refrigeration circuit side bypass circuit 61, control for reducing the amount of refrigerant flowing through the refrigerant cooling expansion means 52 to the supercooling heat exchanger 50 is referred to as “refrigerant cooling circuit It is called "bypass control". Also, control for reducing the opening amount of the refrigerant cooling expansion means 52 to reduce the amount of refrigerant flowing to the subcooling heat exchanger 50 is referred to as "normal control" and is distinguished from "refrigerant cooling circuit bypass control".

  In the subcooling heat exchanger 50, it is desirable to proceed with subcooling at 10 degrees Celsius or more, and more desirably, to proceed with supercooling at 15 degrees Celsius or more.

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

When the supercooling operation and the above-mentioned middle cooling operation are compared, the liquid refrigerant is vaporized in the main storage internal evaporator 38 in both of them, and the heat of evaporation (latent heat) is taken away to lower the surface temperature of the main storage internal evaporator 38 It is common in the point which
In the subcooling operation, the surface temperature of the main in-compartment evaporator 38 is also lowered due to the decrease in enthalpy due to the subcooling, in addition to the temperature decrease of the main in-compartment evaporator 38 due to the heat of evaporation (latent heat). Therefore, by performing the subcooling operation, the refrigeration capacity (the amount of heat energy taken by the refrigerator) is increased compared to the middle cooling operation.
As a result, even if the surface temperature of the main-in-compartment evaporator 38 is lower than the surface temperature of the main-in-compartment evaporator 38 when performing the middle cooling operation, the required refrigeration output can be expressed it can.
In other words, in the supercooling operation, even when the surface temperature of the main-side in-compartment evaporator 38 is made equal to that of the conventional environmental test device, it is possible to obtain the same refrigeration output as the conventional environmental test device.

In the environmental test apparatus 1 of the present embodiment, the operation method and the control method are switched based on certain conditions. Specifically, the quenching operation, the medium cooling operation, the slow cooling operation, and the supercooling operation are switched based on the set temperature and the actual temperature in the test chamber 3.
Further, 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 medium cooling operation, and the slow cooling operation are collectively referred to as a normal operation.
In the present embodiment, there are a rapid cooling operation, an intermediate cooling operation, and a slow cooling operation as the normal operation, and the operation method is automatically selected according to the situation.
The quenching 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 the temperature in the test chamber 3 needs to be rapidly reduced, the quenching operation is performed.
Also, if the cooling load is medium and there is a possibility that the temperature in the test chamber 3 may suddenly change when the quenching operation is performed, the medium cooling operation is selected. Although the temperature in the test chamber 3 has reached the set temperature, the set temperature is extremely low, and the freezing output is insufficient in the slow cooling operation, and the temperature in the test chamber 3 can not be stabilized. Cold driving is selected.
The slow cooling operation is selected when the cooling load is small, such as when the temperature in the test chamber 3 is relatively high and stable.

  Further, 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 There is bypass control). The bypass control is selected when it is desired to reduce the amount of refrigerant supplied to the evaporators 38 and 48 and the subcooling heat exchanger 50.

  In the present embodiment, the subcooling operation may be performed depending on the set temperature, and the subcooling operation may not be performed. That is, depending on the set temperature, the operation method shifts in two large flows. For example, it is selected whether or not the supercooling operation is performed at a temperature of a degree Celsius. In addition, A degree C is a temperature lower than normal temperature, for example, is about 0 degree C to about 10 degree C.

  FIG. 6 is a flowchart showing the transition process of the driving method. In the present embodiment, when the set temperature is A degrees Celsius or more, the quenching operation of the full operation is performed at the start. That is, the operation method is a quenching operation, and the control method is usually operated under control.

Then, when the temperature in the test room 3 reaches the vicinity of the set temperature, the control method is switched, and the cooling output is reduced for energy saving. Specifically, the auxiliary refrigeration circuit side bypass control is performed while the rapid cooling operation is performed to reduce the cooling output.
Then, maintaining the state where the auxiliary compressor 45 is driven, the refrigerant flowing through the auxiliary expansion means 47 and flowing to the auxiliary in-house evaporator 48 is made zero, and the mode is switched to the substantially middle cooling operation. That is, although the auxiliary compressor 45 is driven, the operation method is substantially medium cooling operation, and the control method of the main refrigeration circuit 31 is normal control.
Thereafter, the control method of the main refrigeration circuit 31 is automatically switched to the main refrigeration circuit side bypass control to lower the refrigeration output.
After that, the slow cooling operation is restored. Specifically, the opening degree of the auxiliary side expansion means 47 is opened. That is, although the intermediate cooling operation is currently performed, the auxiliary compressor 45 is maintained in the driven state. Therefore, when the opening degree of the auxiliary side expansion means 47 is opened, the refrigerant flows to the auxiliary side in-house evaporator 48, and the slow cooling operation is restored. The control method of the auxiliary refrigeration circuit 32 at this time is normal control.
The main compressor 35 is stopped when the slow cooling operation is restored. That is, the quenching 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 to further reduce the cooling output. Finally, the auxiliary compressor 45 is also stopped.
The flowchart of FIG. 6 shows an example in which the quenching operation is performed first and the slow cooling operation is performed last, but the first operation method may be the medium cooling operation, and the medium cooling operation may finally be finished.

On the other hand, if the set temperature is less than A degrees Celsius, the subcooling 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 decrease in the test chamber 3. That is, the refrigerant cooling circuit bypass control is performed while performing the subcooling operation.
When the temperature in the test chamber 3 further decreases, the auxiliary compressor 45 is stopped to shift to the middle 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, an operation method in the case where the set temperature is A degree C or more and the case where the set temperature is less than A degree C will be specifically described.
In the case where the set temperature is A ° C. or higher, the quenching operation is basically performed first as described above.

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. When the temperature in the test chamber 3 approaches the set temperature, the refrigeration output is gradually reduced.
At the initial stage of the rapid cooling operation, the main refrigeration circuit 31 and the auxiliary refrigeration circuit 32 are fully operated. When the temperature in the test chamber 3 is lowered to some extent, the temperature difference between the main in-compartment evaporator 38 and the auxiliary in-compartment evaporator 48 and the test chamber 3 becomes small, and the heat exchange efficiency is lowered. The opening degree of the auxiliary expansion means 47 is reduced (normal control).

By performing the quenching operation, the temperature in the test room 3 is lowered, and when it reaches the set temperature, the required amount of cold heat gradually decreases, so the refrigeration output is gradually reduced for energy saving .
That is, if the object under test does not generate heat, the cold heat necessary after the temperature in the test chamber 3 reaches the target temperature suppresses the heat generation generated by the blower 8 stirring the air inside. It is limited to the cold heat required for cooling and the cold heat required to suppress heat entering from the external environment, and is smaller than at startup. Therefore, the amount of cold heat required of the cooling means 30 in order for the temperature in the test chamber 3 to maintain the target temperature is sufficient for these, and is small. Therefore, the control method and the operation method are changed, and the refrigeration output is gradually reduced.

The transition of the operation method and control method is performed with reference to the output of the heater 6 and / or the humidification heater 25 or both.
In this measure, the quenching operation is first performed to monitor the output of the heater 6 or the like. Then, the operation method or control method is shifted so as to minimize the output of the heater 6 or the like.
That is, in the environmental test apparatus 1 of the present embodiment, the heater 6 or the like is operated to finely adjust the temperature in the test chamber 3. Therefore, when the calorific 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 heater 6 and / or the humidifying heater 25 is monitored, and the operation method or control method is changed so as to minimize this.
The order of changing the operation method or control method is as shown in FIG. 6 described above, and when the temperature in the test chamber 3 reaches near the set temperature, the auxiliary refrigeration circuit side bypass control is performed while performing the quenching operation, and the cooling output To reduce
If the calorific value of the heater 6 or the like is still large, the auxiliary compressor 45 is maintained and the refrigerant flowing through the auxiliary expansion means 47 and flowing to the auxiliary in-house evaporator 48 is made zero. Substantially switching to the middle cooling operation to control the main refrigeration circuit 31 normally.
If the calorific value of the heater 6 or the like is still large, the main refrigeration circuit side bypass control is performed on the main refrigeration circuit 31 to lower the refrigeration output.

When the amount of refrigerant passing through the main side in-house evaporator 38 continues to be reduced and the amount of refrigerant flowing to the main side in-house evaporator 38 of the main refrigeration circuit 31 reaches the lower limit, the control device (not shown) operates the main refrigeration circuit 31 It is determined whether or not to stop. Specifically, when the calorific value of the heater 6 or the like is large, the operation of the main refrigeration circuit 31 is stopped to switch to the slow cooling operation.
As described above, although the intermediate cooling operation is currently performed, the auxiliary compressor 45 is maintained in the driven state. Therefore, when the opening degree of the auxiliary side expansion means 47 is opened, the refrigerant flows to the auxiliary side internal evaporator 48, and the slow cooling operation is restored.
The main compressor 35 is stopped when the slow cooling operation is restored. That is, the quenching 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 side bypass control is performed on the auxiliary refrigeration circuit 32 to further reduce the cooling output. Finally, the auxiliary compressor 45 is also stopped.

Next, an operation method in the case of extremely low temperature, which is extremely low compared to normal temperature, such as set temperature of minus 40 degrees Celsius, will be described.
In the present 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.
In the subcooling operation, both the main compressor 35 and the auxiliary compressor 45 are driven.
When the temperature of the test chamber 3 drops to some extent and the surface temperature of the main chamber internal evaporator 38 and the temperature difference in the test chamber 3 become less than a certain level, the opening degree of the main expansion means 37 is gradually narrowed. The temperature of the main in-compartment evaporator 38 is lowered to ensure a constant temperature difference between the surface temperature of the main in-compartment evaporator 38 and the temperature in the test chamber 3.

Here, in the subcooling operation, in addition to the temperature drop of the main side in-house evaporator 38 due to the heat of evaporation (latent heat), the surface temperature of the main side in-house evaporator 38 also decreases due to the reduction of enthalpy due to the subcooling , The refrigeration capacity (the amount of heat energy that the refrigerator takes away) is large.
Therefore, even if the surface temperature of the main-in-compartment evaporator 38 is considerably lowered, the required refrigeration output can be expressed.
Therefore, the temperature in the test chamber 3 can be lowered to the set temperature.

By performing the supercooling operation, the temperature in the test chamber 3 decreases, and when it reaches the set temperature, the required amount of cold heat gradually decreases, so 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 heater 6 and / or the humidification heater 25 as in the case described above.
The order of changing the operation method or control method is as shown in FIG. 6 described above, and when the temperature in the test chamber 3 reaches the vicinity of the set temperature, the refrigerant cooling circuit bypass control is performed while performing the subcooling operation. The amount of refrigerant passing through the expansion means 52 and flowing to the supercooling heat exchanger 50 is reduced. Specifically, in the present embodiment, the amount of refrigerant flowing to the supercooling heat exchanger 50 is reduced by opening the auxiliary refrigeration circuit side bypass circuit 61.
As a result, the degree of subcooling of the refrigerant flowing through the main refrigeration circuit 31 is reduced, the enthalpy of the refrigerant is increased, and the refrigeration output is reduced.
Finally, the amount of refrigerant flowing to the subcooling heat exchanger 50 becomes zero.
Then, a control device (not shown) determines whether the operation of the auxiliary refrigeration circuit 32 should be stopped. Specifically, when the calorific value of the heater 6 or the like is large, the operation of the auxiliary refrigeration circuit 32 is stopped. That is, the operation method switches from the subcooling operation to the middle cooling operation.
Even when the operation of the auxiliary refrigeration circuit 32 is stopped and switched to the intermediate cooling operation, when the calorific value of the heater 6 or the like is large, the main refrigeration circuit 31 is normally controlled to reduce the refrigeration output. If the calorific value of the heater 6 or the like is still large, the control method is switched, and the main refrigeration circuit side bypass control is performed on the main refrigeration circuit 31 to reduce the refrigeration output.

In the embodiment described above, when the set temperature is less than A degree Celsius, the subcooling operation is performed at the start. However, the present invention is not limited to this configuration, and when the set temperature is less than A degree Celsius, the medium cooling operation or the quenching operation may be performed first, and the operation may be shifted to the supercooling operation halfway.
This method will be described below.

For example, if the medium cooling operation is to be performed, the auxiliary expansion means 47 serving 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 leading to the auxiliary side internal evaporator 48 is open. Then, only the main compressor 35 belonging to the main refrigeration circuit 31 is driven, and the temperature of the main in-compartment evaporator 38 is lowered. At the initial stage of operation, the main refrigeration circuit 31 is operated under normal control.
Therefore, the opening degree of the main expansion means 37 is fully opened, a large amount of refrigerant is sent to the main storage internal evaporator 38, a large amount of cold heat is generated, and the temperature in the test chamber 3 is rapidly reduced.
When the temperature of the test chamber 3 is lowered to a certain extent, the difference between the surface temperature of the main chamber internal evaporator 38 and the temperature in the test chamber 3 becomes small, and the heat exchange efficiency is lowered. Squeezed.

  That is, when the surface temperature of the main side in-house evaporator 38 and the temperature difference in the test chamber 3 become less than a constant, the opening degree of the main side expansion means 37 is gradually narrowed, and the temperature of the main side in-house evaporator 38 To maintain a constant temperature difference between the surface temperature of the main in-compartment 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 squeezed in sequence, but as described above, since the evaporation temperature of the refrigerant is high in the present embodiment, In some cases, a constant temperature difference can not be secured between the surface temperature and the temperature in the test chamber 3. Further, even if a constant temperature difference can be secured between the surface temperature of the main side in-house evaporator 38 and the temperature in the test chamber 3, the refrigeration output is extremely reduced and the temperature of the test chamber 3 is substantially reduced. May not be able to

In the present embodiment, a temperature at which it is predicted that a constant temperature difference can not be secured between the surface temperature of the main-side storage evaporator 38 and the temperature in the test chamber 3 or a temperature slightly higher than that is stored in advance as a threshold. doing.
When the temperature in the test chamber 3 advances and the current temperature in the test chamber 3 becomes lower than a predetermined threshold (for example, 0 degrees Celsius), the operation method is switched to shift to the supercooling operation.
As a result, the auxiliary compressor 45 on the auxiliary refrigeration circuit 32 side is activated, and the operation of the auxiliary refrigeration circuit 32 is started. Then, the auxiliary side expansion means 47 serving as the refrigerant control means is closed, the refrigerant cooling expansion means 52 is opened, the refrigerant cooling circuit 51 is opened, and the flow path leading to the auxiliary side internal evaporator 48 is shut off.
The refrigerant liquefied by the main-side condenser 36 is further cooled by the subcooling heat exchanger 50 and is strongly subcooled. As a result, the surface temperature of the main-side storage evaporator 38 can be made lower than the surface temperature of the main-side storage evaporator 38 during the middle cooling operation, and the main-side storage evaporator 38 A constant temperature difference is secured between the surface temperature of and the temperature in the test chamber 3, 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 generation of the heater 6 or 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 Switches to the subcooling operation when the value becomes below the threshold.
Here, in the present embodiment, the main compressor 35 has a smaller capacity than the compressor of the related art (standard configuration), and is driven before the temperature in the test chamber 3 falls below the threshold. Power consumption by the compressor 35 is low. Further, with regard to the power consumption after the switching to the supercooling operation, the environmental test device 1 consumes less power than in the prior art.

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

In the case of performing the quenching operation first and then switching to the subcooling operation, cooling is performed by simultaneously driving the two compressors (the main compressor 35 and the auxiliary compressor 45). In the quenching operation, in principle, only the surface temperature of the main-compartment internal evaporator 38 is lowered when the temperature of the test chamber 3 changes, but in the present operation method, since the set temperature is extremely low, The in-storage evaporator 48 is also controlled to be lower than the temperature in the test chamber 3.
Then, when the temperature in the test chamber 3 becomes lower than the threshold value, the operation is switched to the subcooling operation.
In the case of the operation method in which the quenching operation is performed first, since the auxiliary compressor 45 is already activated, the auxiliary expansion unit 47 serving as the refrigerant control unit is closed and the refrigerant cooling expansion unit 52 is opened. 51 is opened, and it shifts to supercooling operation.

  In the embodiment described above, although the compressors of the cooling means 30 (the main compressor 35 and the auxiliary compressor 45) do not have the inverter control function, they may have the inverter control function.

  In the embodiment described above, the threshold 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 minus 10 degrees Celsius. A more recommended range is also in the range of 10 degrees Celsius to 0 degrees Celsius.

  Instead of the threshold value, the temperature in the test room 3 is compared with the surface temperature (evaporation temperature) of the evaporator 38 on the main storage side, and the operation method is supercooled from the normal operation on condition that both are within a certain level 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 other parts. For example, as shown in the environmental test apparatus 72 of FIG. 7, a branch may be made from between the main condenser 36 and the subcooling heat exchanger 50.

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

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

  In the embodiment described above, the bypass circuits 60, 61 are provided with the refrigerant heating heat exchangers 63, 65, and the refrigerant flowing in the bypass circuits 60, 61 and the high temperature gaseous refrigerant on the discharge side of the compressors 35, 45 Although the heat exchange is performed between the heat exchangers, 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.
A system diagram of the environmental test apparatus 1 of the present embodiment is the same as that of FIG.
In the environmental test device 1, a compressor with a rated output of 1.2 kw was adopted as the main side compressor 35. In addition, a compressor with a rated output of 0.4 kw was adopted as the auxiliary compressor 45.
The comparative example (standard composition) 1 is the environmental test apparatus 100 of the systematic diagram of FIG. 13, and the commercially available environmental test apparatus 100 was used. The environmental test apparatus 100 is equipped with a compressor having a rated output of 1.5 kw as the compressor 101.
The comparative example 1 is a commercially available environmental test apparatus 100, and the cooling means 106 has a capacity (rated output) which can arbitrarily create an environment of a temperature range displayed in a catalog or the like.
The comparative example 2 is the above-mentioned improved type environmental testing device, which is the environmental testing device 200 of the system diagram of FIG. 13 and is a modification of the above-mentioned commercially available environmental testing device 100 to compress the compressor 101 at the rated power of 1.2 kw. It was replaced by a machine.
The compressor 101 mounted in the improved environmental testing apparatus of Comparative Example 2 has a smaller capacity than that of Comparative Example (standard configuration) 1, and when the test room 3 is cooled, the minimum temperature coverage described in the catalog is obtained. It takes a longer time to reach the temperature than Comparative Example 1.

The indoor temperature was 20 degrees Celsius, the set temperature was −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 activating the environmental test apparatus 100 of the comparative example (standard configuration) 1 was as shown in the graph of FIG.
The environmental test apparatus 100 of the comparative example (standard configuration) 1 is equipped with the compressor 101 having a capacity (rated output) capable of arbitrarily creating an environment of a temperature range displayed in a catalog etc. The temperature of the test room 3 dropped to the set temperature and then stabilized.

Further, the environmental 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 temperature change of the test chamber 3 after starting the environmental test apparatus 200 was 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 be brought to the set temperature.

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

  Regarding the environmental test apparatus 100 of Comparative Example (standard configuration) 1 and the environmental test apparatus 1 of Example, the evaporation temperature of the refrigerant, the subcooling temperature of the refrigerant, and the refrigeration output when the maximum refrigeration output is expressed respectively are It was as Table 1 below.

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

  With regard to the environmental test apparatus 100 of Comparative Example (standard configuration) 1 and the environmental test apparatus 1 of Example, the evaporation temperature of the refrigerant when the set temperature is set to minus 40 degrees Celsius, the subcooling temperature of the refrigerant, and the refrigeration output Table 2 below.

  As apparent from the above-mentioned table, the cooling means 30 of the environmental test apparatus 1 of the present embodiment has a degree of supercooling higher than that of the comparative example (standard configuration) 1 and is equivalent under the same evaporation temperature. Frozen output can be expressed.

The relationship between the set temperature and power consumption of the environmental test apparatus 100 of the comparative example (standard configuration) 1 and the relationship between the set temperature and power consumption of the environmental test apparatus 1 of the example were as shown in Table 3 below. .
When the two are compared, the set temperature and the power consumption of the environmental test device 1 of the example are about 30 percent lower than the set temperature and the power consumption of the environmental test device 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 in-house evaporator 45 Auxiliary side compressor 46 Auxiliary side condenser 47 Auxiliary side Expansion means 48 Auxiliary side internal evaporator 50 Overcooling 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 (10)

The test room has a test chamber in which the test object is placed, and a cooling means, and the cooling means has a main refrigeration circuit and an auxiliary refrigeration circuit, and both the main refrigeration circuit and the auxiliary refrigeration circuit are compressors, A condenser, an expansion means, and an in-compartment evaporator, through which a phase-changing refrigerant circulates,
The internal evaporator of the main refrigeration circuit and the auxiliary refrigeration circuit is provided at a position communicating with the test chamber or the test chamber,
A refrigerant cooling circuit for cooling a refrigerant branched from the auxiliary refrigeration circuit and passing from the condenser of the main refrigeration circuit to the expansion means;
It has a refrigerant control means for controlling and / or controlling the flow of the refrigerant flowing in the refrigerant cooling circuit.
Normal operation of controlling the temperature in the test chamber by circulating the refrigerant in the main refrigeration circuit and / or the auxiliary refrigeration circuit, and supercooling in which the refrigerant is circulated through the refrigerant cooling circuit while circulating the refrigerant through the main refrigeration circuit It is possible to drive and
It has switching control means for operating the refrigerant control means based on certain conditions and switching between the normal operation and the subcooling operation,
The supercooling operation is performed when the temperature of the test chamber falls below a certain temperature and / or when the difference between the temperature of the test chamber and the surface temperature of the in-house evaporator belonging to the main refrigeration circuit falls below a certain value. An environmental test apparatus characterized in that it is carried out. The test room has a test chamber in which the object to be tested is placed, and cooling means, and the cooling means has a main refrigeration circuit and an auxiliary refrigeration circuit, and the main refrigeration circuit includes a compressor, a condenser, and expansion means. And an in-compartment evaporator, through which a phase-changing refrigerant circulates,
The in-compartment evaporator of the main refrigeration circuit is provided at a position communicating with the test chamber or the test chamber,
A refrigerant cooling system for cooling a refrigerant passing from the condenser of the main refrigeration circuit to the expansion means, the refrigerant cooling system comprising a part of the auxiliary refrigeration circuit or a circuit branched from the auxiliary refrigeration circuit Have a circuit,
It has a refrigerant control means for controlling and / or controlling the flow of the refrigerant flowing in the refrigerant cooling circuit.
It is possible to perform a normal operation in which the refrigerant is circulated in the main refrigeration circuit to control the temperature in the test chamber, and a supercooling operation in which the refrigerant is circulated through the refrigerant cooling circuit while circulating the refrigerant in the main refrigeration circuit. Yes,
It has switching control means for operating the refrigerant control means based on certain conditions and switching between the normal operation and the subcooling operation,
The supercooling operation is performed when the temperature of the test chamber falls below a certain temperature and / or when the difference between the temperature of the test chamber and the surface temperature of the in-house evaporator belonging to the main refrigeration circuit falls below a certain value. An environmental test apparatus characterized in that it is carried out.   The environmental test device according to claim 1 or 2, wherein a capacity of a compressor belonging to the auxiliary refrigeration circuit is smaller than a capacity of a compressor belonging to the main refrigeration circuit. The main refrigeration circuit is capable of adjusting the evaporation temperature of the refrigerant,
4. The method according to claim 1, wherein the evaporation temperature is lowered according to the temperature decrease of the test chamber, and the normal operation is switched to the supercooling operation on condition that the temperature of the test chamber becomes lower than a predetermined temperature. An environmental test apparatus according to any of the above. The auxiliary refrigeration circuit includes a compressor, a condenser, an expansion means, and an in-storage evaporator, through which a phase-changing refrigerant circulates.
If the temperature in the test room is above a certain medium temperature and the set temperature in the test room is below a certain low temperature,
A rapid cooling operation is performed to drive the main refrigeration circuit and the auxiliary refrigeration circuit to pass refrigerant to the in-storage evaporator of the main refrigeration circuit and the auxiliary refrigeration circuit.
In accordance with the temperature drop in the test chamber, the evaporation temperature in the two storage evaporators is decreased,
Thereafter, the supply of the refrigerant to the in-storage evaporator of the auxiliary refrigeration circuit is stopped to switch to the supercooling operation,
The environmental test device according to any one of claims 1 to 4, wherein normal operation is performed only with the main refrigeration circuit when the temperature in the test chamber reaches a set temperature.   The auxiliary refrigeration circuit has a bypass circuit that returns the refrigerant that has exited from the condenser to the compressor, and in the bypass circuit, the refrigerant that has exited from the condenser of the auxiliary refrigeration circuit has exited from the compressor of the auxiliary refrigeration circuit The environmental test apparatus according to any one of claims 1 to 5, wherein the environmental test device is heat-exchanged and returned to the compressor as a superheated gas.   The main refrigeration circuit has a bypass circuit that returns the refrigerant exiting the condenser of the main refrigeration circuit to the compressor of the main refrigeration circuit, and the refrigerant exiting the condenser of the main refrigeration circuit in the bypass circuit is the above-mentioned The environmental test apparatus according to any one of claims 1 to 6, wherein heat is exchanged with the refrigerant that has exited from the compressor of the main refrigeration circuit, and is returned to the compressor as a superheated gas.   The environmental test device according to any one of claims 1 to 7, further comprising switching means for shifting from normal operation to supercooling operation and / or switching means for shifting from supercooling operation to normal operation.   The set temperature of the test room can be set, and the normal operation and the subcooling operation are switched according to the set temperature and / or the current temperature of the test room. Environmental test equipment described in.   The environmental test device according to any one of claims 1 to 9, wherein the operation of the auxiliary refrigeration circuit can be stopped.

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