JPH02237648A - Constant temperature and humidity device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to the operation control of a refrigerator in a constant temperature and humidity apparatus during a test room temperature rise operation. [Conventional technology] In order to prevent frequent starting and stopping of refrigerator operation in conventional constant temperature and humidity equipment, a time guard is installed that limits the minimum time during which the refrigerator can be restarted after it has been stopped. Related to this type of equipment is the Hitachi Environmental Testing Equipment Cosmopier C sales technical data (issued in March/April S 6) constant temperature chamber and constant temperature and humidity chamber.

[Problem to be solved by the invention]

Conventional constant temperature and humidity equipment, when raising the temperature in the test room to a predetermined temperature in a short period of time, stops the refrigerator and increases the output of the heater to approach the predetermined temperature. An example of the structure of a constant temperature and humidity device, as shown in Fig. 1, consists of a test chamber 1, an air conditioned room 2 in which a refrigerator evaporator 12, a heater 7, and a humidifier 8 are arranged, and a blower is connected between the two rooms. 6 to control the predetermined temperature and humidity by circulating air. Here, the operation of the compressor 9 of the refrigerator is shown in the flowchart shown in Fig. 2, and in order to prevent frequent starts and stops, a time guard is provided to limit the shortest time in which it can be restarted after it has been stopped. As shown in Figure 3, when the test room temperature is raised from the current set temperature T m t to the next set temperature T m Even if Hg is reached, the compressor 9 will not restart, and the temperature in the test room will continue to rise until the time guard time Hg has passed, resulting in an overshoot state and destroying the samples installed in the test room. There may be cases where this happens. The purpose of the present invention is to prevent the temperature from rising too high (overshoot) from the set temperature when the temperature in the test room increases. [Means for solving the problem] In order to solve the above-mentioned problem, the time guard that restricts the restart of the refrigerator after it has been stopped is ignored only when the temperature in the test room rises, and the time guard is set at the same time as or before the set temperature is reached. Added control to enable restart. [Operation] By controlling the restart time guard after stopping the refrigerator only when the temperature in the test room rises, the refrigerator can be operated at the same time as the temperature in the test room rises and reaches the set temperature, or even before it reaches the set temperature. This makes it possible to prevent the temperature in the test room from rising too high (overshooting) relative to the set temperature. [Example] Figure 4 shows a control flow chart of a constant temperature and humidity device to which the present invention is applied. This diagram is a version of the conventional control flowchart shown in Figure 2, with the restart time guard after the compressor stopped only when the temperature in the test room rises removed. In other words, the current test chamber temperature T is the set temperature Tmt and shifts to the next step's set temperature Tmx, so the device enters temperature rising operation, the refrigerator stops, and the heater output increases, and then the test room temperature increases. Since there is no time guard, the refrigerator, which had stopped at the same time as T reached the set temperature Tmz, immediately started up and resumed cooling operation, and the test room temperature T reached the set temperature Tmz
This prevents excessive rise (overshoot). Figure 5 shows the changes in the test room temperature T and the operating conditions of the refrigerator and heating system according to the present invention. Furthermore, in the above invention, by restarting the refrigerator after stopping it at a temperature slightly lower than the set temperature Tmx, when the test room temperature T approaches the set temperature Tmx to a certain temperature, the refrigerator starts operating. Similarly, a method of restarting the test chamber and slowing down the temperature rise speed in the test room to prevent the temperature from rising too high (overshoot) above the set temperature Tyax is also considered. [Effects of the Invention] According to the present invention, when the temperature in the test room is rising, the refrigerator is operated at the same time as the set temperature is reached, or immediately before reaching the set temperature, and the temperature in the test room is prevented from rising too much (overshoot) with respect to the set temperature. It is possible to prevent this from happening.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram of the structure and equipment arrangement of a constant temperature and humidity device according to an embodiment of the present invention, Fig. 2 is a control flowchart during temperature rise operation showing a conventional example, and Fig. 3 is a temperature rise of a conventional example. FIG. 4 is a control flowchart during temperature increase operation according to the present invention, and FIG. 5 is a temperature change diagram during temperature increase operation according to the present invention. 1...Test room, 2...Air conditioning room, 6...Blower. 7
... Heater, 9 ... Compressor, 12 ... Evaporator. ■ 2nd meeting

Claims (1)

[Claims] 1. Of the constant temperature and humidity devices that control the temperature and humidity in the test chamber to a specified level by circulating air through the test chamber and the air control unit consisting of the refrigerator's evaporator, heater, humidifier, and blower, the refrigerator is In order to prevent frequent starts and stops, only when the refrigerator is stopped when the temperature in the test room rises and the temperature is raised in a short time using a heater in the case where the refrigerator is equipped with a time guard that limits the shortest time that it can be restarted after it has been stopped. . A constant temperature and humidity device, characterized in that the time guard is ignored and the refrigerator can be restarted at the same time as the set temperature is reached after the temperature rises.