JPH02143054A - Controlling method for compressor in refrigerator - Google Patents

Abstract

PURPOSE:To prevent a trouble and a damage of a compressor in a freezing cycle of a freezer by a method wherein the first and second temperatures are set lower than an operating temperature of a prior art motor protector, an abnormal state is displayed after elapsing of a first setting time at a first setting temperature, an abnormal state is displayed after elapsing the second setting time at the second setting time and a compressor is stopped. CONSTITUTION:When a temperature of a condensor 7 is increased due to a certain cause, a first predetermined temperature T3, for example, 60 deg.C is attained, and a first predetermined time (t1), for example, 60 minutes, elapses, an abnormal state is displayed through an alarm and the like. In addition, a temperature of a condensor 7 is increased, a second temperature T4, for example, 70 deg.C, reaches and a second predetermined time (t2), for example, 10 minutes elapses, resulting in that an abnormal state is displayed and at the same time an operation of a compressor 6 is stopped. Since a temperature T4, is lower than a prior art protector operating temperature T5, a damage of the compressor can be avoided.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for protecting and controlling a compressor, which is a component of a refrigeration cycle of various cold storages such as freezers and refrigerators.

(Prior art) Conventionally, a motor protector is installed on the compressor to protect the compressor in the refrigeration cycle of a cold storage warehouse, and a temperature sensor is attached to the condenser associated with the motor protector. Since the temperature of the condenser also rises as the temperature of the compressor increases, the compressor is configured to stop operating when the temperature of the condenser becomes abnormally high. In other words, when the power is turned on and the compressor starts,
The refrigerant becomes hot and flows into the condenser where it is cooled and introduced into the cooler. The temperature of the condenser, which was T at startup, rises to T1, for example 40°C, and stabilizes at that temperature, but if the condenser is heated due to some abnormality, T in Figure 2 (a) As shown in Figure 2 (d), when the temperature reaches a much higher temperature T than the stable temperature 2, the temperature sensor senses this and the motor protector is activated via the controller, causing the compressor to shut down as shown in Figure 2 (d). It is supposed to stop.

(Problem to be solved by the invention) Therefore, in the conventional protection control method, the control system does not operate unless the compressor reaches a reasonably high temperature. There were problems such as damage to the compressor if the condition continued for a long time.

An object of the present invention is to solve the above problems, and therefore, to provide a compressor control method that can prevent damage to a compressor installed in a cold storage.

(Means for Solving Problem 1111) A feature of the compressor control method according to the present invention for protecting the compressor in the refrigeration cycle of a cold storage is that the temperature of the condenser associated with the compressor is such that the temperature of the condenser during normal operation is Temperature of the vessel (T2
) when a preset first temperature (T3) or higher exceeds a preset first time (tl), an abnormality display is displayed, and the condenser is further heated to a second temperature higher than the first temperature. When the temperature reaches (C4) and exceeds that temperature, the preset second
When the time (t8) has elapsed, an abnormality display is displayed and the operation of the compressor is stopped.

(Function) The first and second temperatures T, , T, preset by the method of the present invention are set lower than the temperature T at which a conventional motor protector operates, as shown in Fig. fjS2 (a). Therefore, since a compressor abnormality indication is issued at a temperature lower than that temperature, appropriate measures can be taken at a temperature lower than that temperature.

Furthermore, even if it is left unattended, the abnormality display will be issued again and the compressor will be stopped after a certain period of time rIIJct, > has elapsed at the second set temperature, so damage to the compressor can be avoided.

(Example) Next, an example of the present invention will be described with reference to the drawings. FIG. 3 and FIG. 4 show an example of a cold storage cabinet in which the present invention is implemented, and in the illustrated example, the cold storage box main body (1)
In the front opening of! (2), the doors of which are opened and closed by a handle (3).A machine room (5) is installed in the upper part of the main body (1), which is closed with an inspection lid (4).
A compressor (6) and a condenser (7) constituting a refrigeration cycle are arranged within the machine room. This compressor (6) is equipped with a motor protector (8) and is equipped with a condenser III (
A temperature sensor (9) for detecting the temperature is attached to 7), and they are connected to a controller (lO).

FIG. 1 is a flowchart showing the control method according to the present invention. First, when the refrigerator body (1) is connected to the power source by an appropriate switch, the compressor m (6) is started and the temperature is changed to that of the condenser. The temperature in (7) increases until it becomes stable. During normal operation, the temperature before startup should be set to T□ (for example, 20℃).
), set the temperature of the condenser (7) during stable operation to T2 (for example, 4
0℃), in this flowchart, ■→■→■
--- Perform the operation 1-.

Next, the temperature of the condenser (7) rises due to some reason, reaches a preset first temperature T□1, for example, 60°C, and remains at or above that temperature for a preset first time, for example, 60°C. After minutes have elapsed, an abnormality display such as an alarm will be displayed.The operation in this case is as follows in the flow chart:
It is expressed as ■→■−−−−−−−−−. Note that the abnormality indication is performed by sound, light, or both, or other appropriate means.

Furthermore, the temperature of the condenser (7) increases until it reaches a preset second temperature T41, e.g. 70°C, and remains above that temperature for a preset second period of time 7, e.g. 10 minutes.
When this period has elapsed, an error message is displayed and the operation of the compressor (6) is stopped. In the flowchart, ■→■→■→■→
■ Follow the route. In this way, the temperature of the condenser (7) changes as shown in Figure 2 (a) until the compressor stops operating, and the operating status of the compressor and the abnormality display (alarm) status in that case change. - In the OFF operation, as shown in Figure 2 (b) and (c), the compressor stops at a temperature T,' slightly higher than the second set temperature T4, so the temperature does not rise any higher. Moreover, since the temperature T4 is lower than the conventional protector operating temperature T, damage to the compressor can be avoided.

(Effects of the Invention) Therefore, according to the present invention, the first and second temperatures are set lower than the operating temperature of a conventional motor protector, and the first stage (first set temperature and first set time) is set lower than the operating temperature of a conventional motor protector. At the same time, an error message is displayed at the second stage (the second set time has elapsed at the second set temperature), and the compressor operation is stopped, so the compressor is damaged at each stage. It is possible to protect compressors before they reach such high temperatures as to prevent malfunctions and damage to the compressor in the refrigeration cycle of the cold storage.

[Brief explanation of the drawing]

Fig. 1 is a flowchart showing the compressor control method for a cold storage warehouse according to the present invention, and Fig. 2 (a), (b), and (c) show condenser temperature, compressor on/off, and abnormalities in the method of the present invention. A graph showing the on-off state of the display in relation to time, f
Figure (d) is a graph showing the on-off state of the compressor in relation to time in the conventional control method, Figure 3 is a front view of an example of a cold storage box, and Figure 4 is a machine installed in the cold storage box. It is a perspective view showing the inside of a room. In the figure, 6: Compressor 57: Condenser, T: First set hot water temperature, T4: Second set temperature, t: First set time, Shi2
:Second setting time

Claims (1)

[Claims] In a control method for protecting a compressor forming part of a refrigeration cycle of a cold storage, the temperature of a condenser forming a refrigeration cycle together with the compressor is lower than the temperature of the condenser during normal operation. If the temperature exceeds a high preset first temperature for a preset first time period, an abnormality indication is displayed; 2. A compressor control method for a refrigerated vehicle, comprising: displaying an abnormality display and stopping operation of the compressor when the time period 2 has elapsed.