Environmental test apparatus with bypass flow path with flow rate control portion controlled according to temperature of compressor
There is provided an environmental test apparatus that can create a predetermined environment inside a test chamber, the environmental test apparatus including: the test chamber for placing a test target object; a heating portion; and a cooling portion. The cooling portion has a refrigeration circuit having a compressor, a condenser, an expansion portion, and an evaporator and in which a phase-changing refrigerant is to be circulated. The refrigeration circuit has a first bypass flow path connecting a discharge side of the condenser and a suction side of the compressor and the first bypass flow path is provided with a first flow rate control portion. A temperature measurement portion for measuring a temperature of the compressor and a controller are provided. The controller is configured to control a substantial degree of opening of the first flow rate control portion according to a detection value of the temperature measurement portion.
1 . An environmental test apparatus that can create a predetermined environment inside a test chamber, the environmental test apparatus comprising:
the test chamber configured such that a test target object is placed inside the test chamber;
a heating portion configured to heat an inside of the test chamber; and
a cooling portion configured to cool the inside of the test chamber, wherein
the cooling portion has a refrigeration circuit in which a phase-changing refrigerant is circulated, the refrigeration circuit having a compressor, a condenser configured to receive compressed refrigerant from the compressor, an expansion portion configured to receive condensed refrigerant from the condenser, and an evaporator configured to receive expanded refrigerant from the expansion portion and to return vaporized refrigerant to the compressor,
the refrigeration circuit has a first bypass flow path connecting a discharge side of the condenser and a suction side of the compressor and the first bypass flow path is provided with a first flow rate control portion,
a temperature measurement portion is configured to measure a temperature of the compressor, and
a controller is configured to control the inside of the test chamber to the predetermined environment and to control a degree of opening of the first flow rate control portion according to a detection value of the temperature measurement portion.
2 . The environmental test apparatus according to claim 1 , wherein
the compressor is an enclosed compressor in which a motor and a compression portion are built in a closed container, the closed container is configured to contain a lubricating oil, and the temperature measurement portion is attached on an outer surface of the closed container at a position corresponding to an area where the lubricating oil is contained.
3 . The environmental test apparatus according to claim 1 , wherein
the compressor is an enclosed compressor in which a motor and a compression portion are built in a closed container, the closed container is configured to contain a lubricating oil, and the compressor has a refrigerant suction port into which the refrigerant is to be introduced, and
the temperature measurement portion is attached on an outer surface of the closed container in an area on a side opposite to the refrigerant suction port with respect to an imaginary plane containing a center of the closed container that is parallel to an imaginary plane containing a vertical cross section of the refrigerant suction port.
4 . The environmental test apparatus according to claim 1 , wherein
the refrigeration circuit has a second bypass flow path connecting the discharge side of the condenser and the suction side of the compressor, and the second bypass flow path is provided with a second flow rate control portion and a temperature sensing element configured to sense a temperature of the refrigerant introduced into the compressor,
and a degree of opening of the second flow rate control portion is to be controlled according to the temperature of the refrigerant introduced into the compressor which is sensed by the temperature sensing element.
5 . The environmental test apparatus according to claim 1 , wherein
the refrigeration circuit has a cascade cooling structure including a primary refrigeration circuit and a secondary refrigeration circuit, and in the primary refrigeration circuit, a high temperature side compressor, a high temperature side condenser, a high temperature side expansion portion, and a primary side of a cascade condenser are sequentially connected in a circulation loop, in which the phase-changing refrigerant is to be circulated, and
in the secondary refrigeration circuit, a low temperature side compressor, a secondary side of the cascade condenser, a low temperature side expansion portion, and a low temperature side evaporator are sequentially connected in a circulation loop, in which the phase-changing refrigerant is to be circulated.