JPS6334435A - Control method of refrigerating machine for constant temperature facilities - Google Patents

Abstract

PURPOSE:To make it possible to reach a set value of room temperature in a short time without turning ON or OFF of a refrigerating machine by starting the operation of the refrigerating machine before the room temp. reaches the proportional control area of a heater for heating and controlling the operations of both heater and refrigerating machine. CONSTITUTION:In a laboratory 1 refrigerating machines 6-1, 6-2 and a heater 5 for heating and a blower 4 are provided, and in the outdoor a compressors 7-1, 7-2, condensers 8-1, 8-2 and expansion valves 90 and 91 are provided and they are connected by a piping to form a refrigerating cycle and refrigerating machines are controlled for its operation by a dry-bulb sensor 9. Then based on a set temperature in the room 1 a proportional control range is set up. The heater 5 is controlled by the signal from the sensor 9. Before the temperature in the room 1 reaches the above-mentioned proportional control area the refrigerating machines are operated and the temperature is controlled while both heater 5 and refrigerating machines are operated. As a result it is possible to reach a set value of room temperature in a short time without the refrigerating machine being turned ON or OFF.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to constant temperature equipment used for aging tests of articles.

[Conventional technology]

In the conventional device, when the indoor temperature rises due to the indoor dry bulb temperature characteristic A as shown in Fig. 8, the refrigerators R1 and R227 operate at 0N10.
As FIP was repeated and multiple refrigerators R+ and R2 were started at the same time at the point where the heater control entered the proportional band just before the set value, the room temperature suddenly decreased, and as a result,
Moreover, the operation of the refrigerator stops in a short period of time. In this way, the room temperature is brought close to the set value by repeatedly starting and stopping the refrigerator in a short period of time. Therefore, it takes a long time to reach the set temperature, and no consideration has been given to shortening the time until the set temperature is reached. An example of a related device of this type is Japanese Patent Application No. 60-228628.

(Problem to be Solved by the Invention) The above-mentioned conventional technology does not take into consideration the point of shortening the time until the set temperature is reached, and the problem is that the operation of the refrigerator frequently turns on/off. was there.

An object of the present invention is to provide a method for controlling a refrigerator in a constant temperature facility in which the refrigerator reaches a room temperature setting value in a short time without causing the refrigerator to turn 0N10FF.

[Means for solving problems]

The above purpose is to increase the temperature in the υ test chamber using the thermal heater (in this process, the refrigerator is operated before entering the proportional control region of the heater, and both the heater and the refrigerator are connected simultaneously). This is achieved by controlling rotation.

[Effect]

The control method according to the present invention operates the refrigerator before the temperature in the test chamber approaches the set point and enters the proportional control range of the heater during the operation process of the heating heater, and then stops the operation of the refrigerator. The temperature is controlled so that it approaches the set temperature while operating both the heater and the heater.
The time it takes to reach the set temperature in the test chamber is shorter than when turning the refrigerator on and off, and the temperature can be stably maintained.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 and 2. This figure 1 shows the change in dry bulb temperature and operating status of the refrigerator due to the refrigerator control method of the present invention. A represents the actual indoor dry bulb temperature characteristics, and the horizontal axis is time and the vertical axis is The temperature is measured on the shaft. 211th cs? 1 is in the exam room,
The room temperature is controlled by a refrigerator. Reference numeral 2 denotes a heat insulating material, which constitutes the test chamber 1. 3 is a temperature control unit,
A blower 4 is disposed within the tin conditioning unit 8 so as to blow air into the test chamber 1 through an air outlet 41. A heater 6 is arranged on the suction side of the blower 4. 6-1.6-2 is a cooler, which is arranged upstream of the heater 5, and is connected to a compressor 7-1.7-2 of outdoor equipment installed outdoors through a pipe 60. There is. 8-1.8-2 is a condenser, and the compressor 7-1.7-
It is connected to the discharge side of No.2. In addition, the condenser 8-1.8
-2 are connected to the coolers 6-1 and 6-2 in the temperature control unit 8 through expansion valves 90 and 91, respectively, forming a refrigeration cycle. 9 is a dry bulb sensor, which is installed in the test chamber 1.

Next, its effect will be explained. By operating the refrigerator, when a temperature difference of Δt +' from the set m degree in the test chamber 1 is reached, the signal from the dry bulb sensor 9 causes the temperature to rise from P to 〃Ω thermal heater 5. The temperature of the test chamber 1 was increased by operating the cooler 6-1 from the refrigerator RICI chamber 1 and cooling the test chamber 1. As a result, the dry-bulb temperature property A' temporarily decreases by Δl'' in the test chamber 1. At this point, the temperature heater 5 is still in the proportional band region P, so the
JO Netsu is working at 100% capacity. The cooling capacity of the thermal heater 6 has a relatively sufficient capacity compared to the cooling capacity of the cooler 1. Therefore, refrigerator R
The temperature drop ΔKame' in the test chamber 1 due to operation 1 is relatively small and the relationship Δ1'<Δ1 is maintained with respect to the temperature difference Δ1 due to the ON-1?10 F F of the refrigerator R1. During operation, the temperature inside the test chamber 1 will be raised. When the temperature in the test chamber 1 reaches a temperature difference of Δt2 from the set temperature,
Next, refrigerator R2 starts ONL operation. In this case as well, the temporary drop in m degree due to the operation of refrigerator R2 is Δ2', and the relationship of Δ2゛<Δ2 is maintained, and the temperature rises even while refrigerators R1 and R2 are operating and reaches the target set temperature. to enter a constant temperature state. The time it takes to shift to this constant temperature state E is 8T', and since the operation of cooling rlL@R1 and R2 is controlled without stopping, it takes O time Δ to reach the conventional set temperature 1.
Shorter than T. The temperature to start the refrigeration mR1% R2 is a Milliport sensor that converts the temperature and operates the relay by comparing the set voltage for the set temperature and the input voltage for the current m degree). It can be detected by a dry bulb sensor 9. Since the refrigerators R1 and R2 are activated in sequence, the valley t of the heater 6 may be relatively small.

(Effects of the Invention) According to the present invention, since the refrigerator can be transferred to a constant temperature incubation state without repeating 0ON10FFf, the set temperature in the test chamber can be reached in a short time.

[Brief explanation of drawings]

FIG. 1 shows a change diagram of the dry bulb temperature and the start/stop state of the refrigerator according to the control method of the present invention. Figure 2 is an equipment configuration diagram of the constant temperature equipment, and Figure 8 is a graph of changes in dry bulb temperature and the start/stop status of the refrigerator using the conventional control method. 1...Test room 2...Insulation material 3. ...vI4a unit 4...Blower 5
...Heater 6-1...Refrigerating machine RI' fog...6
-2... Refrigerator R27-1, 7-2... Compressor 8
-1.8-2...Condenser 9...Rolling ball sensor shore 3 group Y1 sight judge 2 concave

Claims (1)

[Claims] 1. A cooler, a heater, and a blower are installed in the test chamber, a compressor, a condensation valve, and an expansion valve are installed outside the room, and these are connected with piping to form a refrigeration cycle, and a dry bulb sensor is installed in the test chamber. In the method for controlling a refrigerator in a constant temperature facility, the operation of the refrigerator is controlled by a signal from the dry bulb sensor, wherein a proportional control range is set based on the equipment temperature in the test chamber, and the heater is controlled by the signal from the dry bulb sensor. Refrigerating machine control for constant temperature equipment, characterized in that the refrigerator is operated before the temperature in the test chamber enters the proportional control range, and the temperature is controlled while operating both the heater and the refrigerator. Method.