US-12625036-B2 - Environmental test apparatus with bypass flow path with flow rate control portion controlled according to temperature of compressor

US12625036B2US 12625036 B2US12625036 B2US 12625036B2US-12625036-B2

Abstract

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.

Inventors

Haruki SETO
Yuta MORIYAMA
Katsuhiko Watabe
Tetsuya Okadome
Masaki Yamamoto
Takumi Usui

Assignees

ESPEC CORP.

Dates

Publication Date: 20260512
Application Date: 20230622
Priority Date: 20220628

Claims (5)

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.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application is based on Japanese Patent Application No. 2022-103245 filed on Jun. 28, 2022, the contents of which are incorporated herein by way of reference. TECHNICAL FIELD The present invention relates to an environmental test apparatus that can create a specific environment within a test chamber and expose a test target object to a desired environment. BACKGROUND An environmental test is known as a test for examining performance and durability of products, parts, and the like. The environmental test is carried out using a facility called an environmental test apparatus. The environmental test apparatus generally has a test chamber and an air conditioning portion. The air conditioning portion includes air conditioning equipment such as a blower, a heating device, and a cooling device. The test chamber and the air conditioning portion, for example, form a series of circulation air paths, and air in the test chamber is introduced into the air conditioning portion, and then a temperature and a humidity of the air are adjusted and the adjusted air is returned into the test chamber, thereby creating a desired temperature environment and humidity environment in the test chamber. Patent Literature 1: JP2014-66593A The environmental test apparatus may be operated continuously for long periods of time. Also, during continuous operation, the cooling device of the environmental test apparatus may temporarily be operated under severe conditions. Therefore, in the environmental test apparatus of the related art, a motor that drives a compressor may generate heat during operation, and thus there is a concern about motor winding burnout, oil viscosity reduction and premature deterioration, and damage to compression parts due to these factors, which are factors that reduce reliability of the environmental test apparatus. The present invention solves the above-described problems of the related art, and an object of the present invention is to provide an environmental test apparatus that can suppress excessive heat generation of a motor of a compressor. SUMMARY An aspect of the present invention is 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, in which 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, and the controller is configured to control an inside of the test chamber to the predetermined environment and 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. In the aspect described above, it is preferable that the compressor be an enclosed compressor in which the motor and a compression portion are built in a closed container, the closed container be configured to contain a lubricating oil, and the temperature measurement portion be attached on an outer surface of the closed container at a position corresponding to an area where the lubricating oil is contained. In the aspect described above, it is preferable that the compressor be an enclosed compressor in which the motor and a compression portion are built in a closed container, the closed container be configured to contain the lubricating oil, and the compressor have a refrigerant suction port into which the refrigerant is to be introduced, and the temperature measurement portion be 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. In the aspect described above, it is preferable that a refrigeration circuit have 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 be provided with a second flow rate control portion of which a substantial degree of opening is to change according to a temperature of a refrigerant introduced into the compressor. In the aspect described above, the refrigeration circuit may have 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 hi