JPS62217079A - Controller for refrigerator - 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 [Field of Industrial Application] The present invention relates to a method for controlling a refrigerator, and more particularly to defrosting control for a refrigerator that can change speed and drive a compressor motor for compressing refrigerant.

[Prior art]

A conventional defrosting system has been proposed for a compressor in which the rotational speed is constant, as described in JP-A No. 1@60-30975. In this case, when the cooling load is light, the continuous operation time of the compressor is short and the amount of frost formed on the cooler is also small. For this reason, the compressor is operated until the cumulative time reaches a predetermined value, and defrosting is performed after the cumulative time reaches the predetermined value.

Also, when the cooling load becomes heavier, the continuous operation time of the compressor becomes longer.

Moreover, the amount of frost on the cooler increases rapidly. Therefore, when the cooling load is heavy, that is, when the compressor runs continuously for a long time, defrosting is performed even if the cumulative time of the predetermined value is not reached when the cooling load is light. It had become.

Problems to be solved by invention C] Conventional defrosting methods do not take into consideration defrosting when the rotation speed of the compressor motor changes depending on the temperature conditions inside the refrigerator, and *iC1 cooling load When the compressor is operated at a low speed when the
No consideration was given to ll m.

The purpose of the present invention is to set the interval before defrosting according to the rotation speed of the compressor motor, to eliminate unnecessary electric frost during low-speed operation when the amount of frost on the cooler is small, and to achieve efficient defrosting. The purpose is to perform frost control.

[Means for resolving misunderstandings]

In a refrigerator equipped with a drive circuit that continuously controls the speed of a compressor motor for compressing refrigerant, the rotation speed of the compressor motor is determined based on the a degree difference between the internal temperature and the target temperature.
This is achieved by comparing the predetermined rotation speed with the integrated value of the operating time at or above the rotation speed and the integrated value of the operating time unrelated to the rotation speed and varying the interval until defrosting.

[Effect]

Defrosting is performed by setting the time interval until defrosting according to the operating state of the compressor using means for calculating the cumulative operating time t1 of the compressor and means for calculating the cumulative operating time t2. Operate. by this,? @The control device in the warehouse will take a longer time to defrost when the compressor rotates at low speed, where there is little frost formation, so it will no longer perform defrosting operation when defrosting is unnecessary.

〔Example〕

Hereinafter, one embodiment of the invention will be explained with reference to Figure t-41 and Figure 2. In FIG. 1, numeral 1 is a freezer temperature detector that detects the temperature inside the freezer compartment, and 2 is a freezer temperature regulator that changes the temperature inside the freezer compartment to a target temperature. Reference numeral 6 denotes a cooler temperature detector that detects when the temperature of the cooler reaches a predetermined value or higher during defrosting and defrosting is completed. Reference numeral 4 denotes an outside temperature detector that detects the ambient temperature of the refrigerator. Reference numeral 5 denotes a voltage comparator that compares the input signals ft, l) of the freezer compartment 1 degree detector 1, freezer compartment temperature controller 2, cooler temperature detector 6, and outside altitude detector 4 with the voltage of the human converter 6. The data are compared and input to a control circuit 7, which will be described later. 7 is a control circuit consisting of a microcomputer, and has input terminals I+, I2. Is, I4 output terminal 01.02. It has Os. The temperature detected by the freezer compartment temperature detector 1 is input to the input end check 1, and the target temperature of the freezer compartment temperature regulator 2 is input to the input terminal check 2, and the rotation speed of the compressor motor 9 is determined based on the temperature deviation between the two. do. 8
is a drive circuit connected to the output terminal 01 of the control circuit 7, and rotates c! determined by the control circuit 7. 1 signal and drives the compressor electric motor 9 at variable speed. 10 is a triac, which is connected to the output terminal 02 of the control circuit 7. This triac 10 operates when performing defrosting control, and is turned ON by the weight removal start signal from the control circuit 7.
L, the defrosting heater 11 is energized to start defrosting. Reference numeral 12 denotes a first timer, which integrates the operating time of the compressor IIm machine 9 during which the rotation speed of the compressor electric motor 9 determined by the control circuit 7 is equal to or higher than a predetermined rotation speed (for example, 250 Orpm). It is something. 15 is a straw 2 timer,
The operation time of the compressor electric motor 9 is accumulated regardless of the rotation speed.

Next, the Eri control operation will be explained with reference to Figure 2. FIG. 2 is a flowchart showing the operation of the defrosting control system in this embodiment. In FIG. 2, step S1 calculates a temperature deviation between the temperature detected by the freezer compartment temperature detector 1 and the target temperature set by the freezer compartment controller 2, and based on the temperature deviation, the compressor '1 drive 9 The rotational speed N is determined.

In the next step 1C8, the rotation speed N is compared with a predetermined rotation speed (for example, 2500 rpm). Rotation speed N is 250Orp
If it is more than 2500 rpm, proceed to Ss, operate the first timer 12, and calculate the cumulative operating time t of 2500 rpm or more S4
Proceed to. Also, in S2, the rotation speed N is 250Orpm.
If it is less than sls, it is determined whether N==Qrpm, that is, the compressor is stopped, and if it is stopped, the process returns to step 81. If the vehicle is in operation, the process advances to step S4. Next, in step S4, the timer 16 is operated to obtain the cumulative operating time t2 of the compressor motor 9 regardless of the rotation speed. Next, in step S5, the cumulative operating time t2 is compared with a defrosting interval setting value A+ (for example, 15 hours). If tz<I5, step 81
Return to If tz=7.5, the process proceeds to step S6, where the cumulative operating time t1 of 2500 rpm or more is compared with a predetermined value Ba (for example, 4 hours). If tl<4, return to step S1 (n, t+)4, proceed to step SIO. Also, in step S5 tz)7.
If it is 5, the process proceeds to step S7, where the timer t2 is compared with the defrosting interval setting value A2 (for example, 26.5 hours). If tz(23,5), proceed to step S6 and set t2=2
If it is 3.5, the process proceeds to step S8, where the outside temperature T detected by the outside temperature detector 4 is compared with a predetermined value To (for example, 17° C.). If T is 17°C, proceed to S4, and if T is 1217°C, proceed to S1o. Also tz) 23
．． If it is 5, step S! Then, the timer t2 is compared with the defrosting interval setting value As (for example, 415 hours). If tz<47.5, proceed to step S8, and t,=
If it is 47.5, the process advances to step S10.

Next, at S+o, the input terminal of the control circuit 7 outputs an operation command signal from the output terminal 01 regardless of the temperature of the human power source from h, and the drive circuit 8 forcibly operates the compressor motor 9. 30 for a certain period of time, for example 0.5 hours.
It operates at 0 rpm and proceeds to step S11. Step S1
1, the output of the output terminal 01 of the control circuit 7 is canceled to stop the operation, and a defrosting signal is output from the output terminal 02, and the triac 10 is set to (1)NL, the defrosting heater 11. Turn on the power and start defrosting. Next step 8B
The temperature detected by the cooler temperature detector 6 is inputted to the input terminal checker 3 of the control circuit 7, and the defrosting end temperature is determined by the temperature detected by the cooler temperature detector 6.
For example, it is determined whether the temperature is 12°C or higher, and if it is lower than 12°C, repeat step 812; if it is 12°C or higher, proceed to step 51sVC, and read the above-mentioned try book 10 (J F
P l, the power supply to the defrosting heater 11 is stopped, defrosting is completed, the first timer and the second timer are cleared in step S's, and the process returns to step S1. In addition,
If the power is temporarily cut off due to a momentary power outage, etc., and the power is turned on again after the control circuit loses power, the first timer 12 and second timer 16 are cleared, so the power is turned on. The initial defrosting start time is determined based on the temperature of the cooler detected by the cooler temperature detector 6 at the time. That is, the temperature of the cooler is a predetermined value +i (for example, 10°C)
In the above case, defrosting is performed based on FIG.
Defrosting is performed at a smaller value, for example, 4 hours.

As described above, according to this embodiment, the compressor tfJ: J machine 9
By selecting the defrost interval based on the cumulative operating time based on the rotation speed of the engine and the outside air temperature, it is possible to set an appropriate defrost interval according to the cooling load, eliminating unnecessary defrosting and eliminating unnecessary defrosting. This prevents the temperature inside the refrigerator from rising.

〔Effect of the invention〕

According to the present invention, the defrosting interval can be set according to the operating state of the compressor by calculating the operating time based on the rotation speed of the compressor, and defrosting can be performed in accordance with the amount of frost formed on the cooler 1. So,
This eliminates unnecessary defrosting, improves operating efficiency, and
It suppresses unnecessary temperature rise inside the refrigerator and has the effect of saving power.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an overview of a control device according to an embodiment of the present invention, and FIG. 2 is a flowchart showing the operation of a defrosting control system according to the present invention. 1... Freezer room temperature sensor, 2... Freezer room temperature regulator, 6... Cooler altitude sensor, 4... Outside air temperature sensor, 5... Voltage comparator, 6... L) /A converter, 7... Control circuit, 8... Drive circuit, 9... Compressor motor, 10... Triac, 11... Defrost heater, 12... First timer, 13 ...Second timer. /” Patent attorney Katsuo Ogawa ~ Kyo 1 (2) Ryo z (2)

Claims (1)

[Claims] 1. A drive means for controlling the rotation speed of a compressor for compressing refrigerant;
In a refrigerator control device equipped with temperature detection means for detecting an outside temperature of the refrigerator, the cumulative operating time t_1 of the compressor when the rotation speed of the compressor is at a rotation speed equal to or higher than a predetermined value.
means for calculating the total operating time t_2 of all the compressors, and the cumulative time 2 is within a predetermined defrosting interval setting value, and the cumulative time 1 is greater than or equal to a predetermined time. and a control means for maintaining the compressor at a predetermined rotation speed when the temperature is above a predetermined temperature, and defrosting is performed in response to the control means. Device.