KR100211719B1 - Automatic control apparatus and method of low temperature warehouse refrigerator - Google Patents

Abstract

The present invention efficiently controls the temperature in a warehouse by applying a microprocessor, and provides a function such as a full automatic control over a set temperature and time, a communication control function for military management, and a variety of defrosting methods. The present invention relates to an automatic control device for a cold storage freezer for low temperature warehouses, the sensor for measuring a temperature inside a warehouse, a sensor for measuring a printed circuit board (PCB) temperature, A microprocessor incorporating an A / D converter for converting analog values to digital values, a display unit for displaying a status according to the control of the microprocessor, a reference time generator used as a reference time and a nonvolatile memory of the system, Keyboard for inputting user command signals to the microprocessor It is composed of I / O device for controlling device and status of external device, AC / DC converter for supplying power to controller, and communication driver of RS232C and RS485 / 422 standard for military management and communication. .

Description

Cold storage freezer automatic control device and method

The present invention relates to an automatic temperature control device for a low temperature warehouse freezer, and in particular, by controlling the application of a microprocessor to efficiently control the temperature in the warehouse, the automatic control according to the set temperature and time, the communication control function and sex for military management The present invention relates to a cold storage freezer automatic control device and method characterized in that to provide a more convenient function for the refrigerator user by providing a function such as diversification of the removal method.

In general, the cold storage freezer is an artificial freezing apparatus that stores various agricultural products, aquatic products, and blood to be transfused at a sub-zero temperature to prevent the decay of contents and freeze fresher. The compression is mainly used for freezing. In principle, the refrigerator compresses a gas (refrigerant) that is easy to liquefy and vaporizes it, and vaporizes the liquid refrigerant instantaneously as described above to take the heat of vaporization around, thereby keeping the temperature inside the cold store below a certain temperature.

On the other hand, since the above-mentioned freezer rapidly drops the air in the ambient temperature at a low temperature to a low temperature, frost is formed in the freezer after a certain time to prevent freezing. Therefore, when using the freezer, the frost must be fixed at regular time intervals. It should be removed.

However, in the related art, a simple relay control method in which a high temperature mechanical defrosting timer is attached together with a separate temperature sensor unit in controlling such a low temperature warehouse refrigerator is mainstream. It is troublesome to purchase and configure it, and it is difficult to cope with various functions and user requirements because of the mechanical control method, it is impossible to check the temperature value and operation status in the freezer, difficult to manage group and precise temperature control. There is.

The present invention is to solve the above problems, using a one-chip microprocessor integrated control elements for precise automatic control and temperature control and low-cost warehouse refrigerator control apparatus and method of low cost with a simple hardware configuration To provide.

As a means for solving the above object,

The present invention provides a microprocessor including a sensor for measuring the temperature inside the warehouse, a sensor for measuring the PCB (Printed Circuit Board) temperature, and an A / D converter for converting an analog value into a digital value. A display unit for displaying a state according to the control of the microprocessor, a reference time generation unit borrowed as a reference time and a nonvolatile memory of the system, a keyboard for inputting a user command signal to the microprocessor, and control of an external device And an input / output device for knowing the external device status, an AC / DC converter for supplying power to the control device, and a communication driver for RS232C and RS485 / 422 standards for military management and communication.

1 is a refrigerator automatic control apparatus of the present invention.

2 to 5 is a refrigerator automatic control flow chart of the present invention.

* Explanation of symbols for main parts of the drawings

1 warehouse temperature sensor 2 PCB temperature measurement sensor

3: microprocessor unit 4: display unit

5: reference time generator 6: keyboard

7: AC / DC converter 8: input / output terminal

9: RS-232C RS485

Hereinafter, described in detail with reference to the drawings.

1 is a block diagram of the present invention, the storage temperature sensor unit 1 for measuring the temperature in the low temperature warehouse with a platinum resistance thermometer, the sensor unit 2 of the PCB circuit board for measuring the main PCB temperature with a dummy; A keyboard 6 for inputting a control signal such as defrost time to the microprocessor, a one-chip processor, a 10-bit A / D converter and an internal RAM, and temperature data provided from the sensor units 1 and 2. And the microprocessor unit 3 for controlling the operation mode and the defrost operation mode of the air conditioner compressor according to the control signal provided from the keyboard 6, the present operation state and various kinds of control under the control of the microprocessor unit 3; The display unit 4 which displays an error state, and outputs the reference time of the system used for various controls, and also used as a non-volatile memory to store the current work status and various information Interfacing with microprocessor for control and output by reference time generator (5), AC / DC converter (7) which combines DC power and power stabilization according to system power by receiving external AC power And an RS232C and RS485 / 422 driver 9 for inducing communication with the outside for group management.

In the present invention configured as described above, the temperature in the warehouse is measured by the warehouse temperature sensor unit 1 and input to the microprocessor 3, and the temperature data of the PCB circuit board by the temperature sensor unit 2 of the PCB circuit board. Input to microprocessor 3.

The reason for detecting the temperature of the PCB circuit board is that the stable operating temperature of the chip installed on the PCB board is generally between 25 degrees and 75 degrees, and it may cause a malfunction when the refrigerator is operated below 0 degrees.

Therefore, after initializing the system, the microprocessor checks the temperature of the PCB board and starts the heater so that it can always maintain the temperature above 25 degrees.

After that, by analyzing the signals output from the components of the various refrigeration system to determine whether there is an abnormality, mainly check the overheat state of the motor and the pressure holding state of the compressor when it is determined that it is not normal through the display unit (4) To prompt the user to take appropriate action.

When the microprocessor 3 receives the defrost time from the keyboard 6 and the operation time exceeds the set time, the microprocessor 3 operates the external devices, that is, the compressor and the solenoid valve, to execute the defrost mode through the input / output terminal 8. Here, defrosting apparatus using water, defrosting apparatus using water and defrosting apparatus using air and defrosting apparatus using air are mainly used. The microprocessor 3 uses the water, heater, and air. It is possible to implement mutual interfacing suitable for the defroster by incorporating all operation modes.

After the defrosting is completed for the set defrosting time, the microprocessor 3 turns off the water supply solenoid valve, sets the drain time to the timer for the reserved time, and discharges the water.

At this time, the reference time of the system used for various control is based on the output signal of the reference time generator 5, and the reference time generator 5 is also used as a nonvolatile memory to store the current work status and various information. Can be.

Referring to the operation mode of the present invention having the configuration and operation characteristics as described above using a flow chart as follows.

Here, the drawing uses a method of dividing into 2-5 degrees for convenience of description, which shows one operation mode, which will be described sequentially below.

First, when power is supplied to the PCB, the microprocessor 3 initializes the system and at the same time checks whether there is an abnormality of each system, and if there is no abnormality, the first step S1 for displaying the logo screen for about 2 seconds and the sensor unit 2 A second step (S2) of checking the temperature of the PCB circuit board, and if the checked temperature is 0 degrees or less, a third step of turning on the internal heater, stopping all functions, and displaying it on the display device (4). And a fourth step S4 of turning on only the internal heater when the checked temperature is between 0 degrees and 25 degrees, and a fifth step S5 of turning off the internal heater when the checked temperature is 25 degrees or higher. The operation proceeds to perform the operation of keeping the temperature of the first PCB circuit board constant.

Thereafter, the sixth step S6 of checking whether there is an abnormality due to the overheating of the motor or the pressure of the compressor, and the seventh step of stopping all functions of the refrigerator and outputting the abnormal state through the display device when it is determined that the abnormality has occurred. S7) and the eighth step S8 of checking whether the compressor is in operation by turning on or off the low pressure relay if no abnormality occurs in the sixth step S6, and the low pressure relay in the eighth step S8. If it is turned on, the compressor is stopped and the automatic stop is displayed through the display device. In operation S9, if the low voltage relay is turned off in operation S8, the compressor is started and operated through the display device. In operation 10, the compressor is configured to control the operation of the compressor.

Thereafter, in step 11 (S11) of checking the on-off operation of the pump down switch, which is a manual switch that temporarily suspends the operation of the refrigerator, and when it is determined that the pump down switch is in the on state (11) (S11), the flow of the refrigerant A twelfth step (S12) of completely shutting off the solenoid valve controlling the solenoid valve (solenoid off), a thirteenth step (S13) of judging whether the low pressure relay is in operation or not; When the low pressure switch is turned on in step S13, that is, when the compressor does not operate, the process proceeds to the fourteenth step (S14) of proceeding to the stop mode to determine whether the pump down switch is pressed, and to go to the stop mode from the pump down mode. Proceed.

When it is determined that the pump down switch is turned on in the eleventh step S11, a fifteenth step S15 of comparing the current operation time with a set time input by the keyboard and an operation time are set in the fifteenth step S15. If the time exceeds the defrost mode, and proceeds to the defrost mode consisting of the sixteenth step (S16) to display the defrost time through the display device.

When the operation time does not exceed the set time in the fifteenth step (S15), by checking the temperature in the freezer to compare the set temperature set by the keyboard with the current temperature in the freezer (S17), and the 17th When the internal temperature of the refrigerator is lower than the set temperature in step S17, the solenoid valve is turned off to induce the operation of the compressor to stop the compressor operation (S18), and in the 17th step (S17), the internal temperature of the freezer is set temperature + dead. If higher than the dead band (dead band) is made of the nineteenth step (S19) to induce the compressor operation by turning on the solenoid valve proceeds to maintain the internal temperature of the freezer to the set temperature.

After the eighteenth step (S18), it is determined whether the cooler fan switch is turned on. If the cooler fan switch is turned on, the cooler fan switch is turned off in steps 20 and 21 (S20 and S21) for operating the cooler fan motor. When the low pressure switch is turned on, that is, when the operation of the compressor is stopped, the 22nd and 23rd steps (S22, S23) of stopping the operation of the cooler fan motor are performed. The process of determining whether the motor is operating is performed.

After turning on the solenoid valve in the 19th step (S19), if the restart prevention time is not exceeded and the set restart prevention time is not exceeded, the flow returns to the system start-up flow and if the exceeded steps 24, 25 (S24, S25) and the 26th and 27th steps (S26, S27) of operating the fan motor when the low pressure switch is turned off after the step (S25), that is, the compressor is in operation, when the temperature inside the freezer is higher than the set temperature. Proceed to the step of determining whether the motor operation.

In step 16 (S16), after deciding on the defrost mode, it is determined which operation mode is the defrost mode, and if the water defrost mode, the water defrost operation mode, and if the heater defrost mode, the heater defrost operation mode. Step 28 (S28) to proceed to the air defrost operation mode if the air defrost mode, and the 29th step to stop the compressor operation by turning off the solenoid valve in the heater defrost operation mode in the 28 (S28) ( S29), and after the low pressure switch is checked, the fan motors are turned off, the defrosting heaters are turned on, and the defrosting heaters are turned on (S30, S31). When it is turned on, the defrosting is completed in the 32nd and 34th steps (S32 and S34) for switching to the drain mode, and when the low voltage switch is turned off in the 30th step (S30) and in the 32nd step (S32). If not, check the defrost timer to enter the drain mode when the defrost time is finished, or if the drainage step of discharging the melted water by the heating device in the defrost step of the 33rd step (S33) to continue the defrost mode Proceed.

When removing the frost using water in the 28th step (S28) and the 35th step (S35) for turning off the solenoid valve, and it is determined whether the low-pressure switch is on, if the low-pressure switch on the fan motor is turned off and the water supply relay 36, 37 to turn on (S36, S37), and when the frost is removed using air in the 28th step (S28) consists of a 38th step (S38) to turn off the solenoid valve and turn on the fan motor. Proceed with the step of removing the frost using water or air.

In the drain mode after the step, if the defrosting is completed during the set defrosting time is completed, the 39th step (S39) for turning off the heater / water solenoid valve and the drain time to the timer for a predetermined time 40 and 41 steps (S40 and 41) to set and wait until the water is drained, 42 steps (S42) to operate the fan motor to remove the water droplets of the evaporator for about 5 seconds after the drain time, and all The process of clearing the memory device of the flag of the system and returning to the first operation is performed in step 43 (S43) which repeats sequentially.

Briefly summarizing the flow of the present invention made as described above, the step of checking the system initialization and system abnormality when the power supply and displaying the logo for a few seconds (S1) and by keeping the temperature of the PCB circuit board constant Step (S2-S5) to prevent the temperature of the circuit board from dropping below 0 degrees, checking (steps S6-S10) for checking, treating and displaying the abnormality of the refrigerator, and determining whether the pump down switch is pressed and pumping down. A step (S11-S14) of going from the mode to the stop mode, comparing the set operating time with the currently operating time, determining and processing whether to go to the defrost mode or continuing operation (S15-S16), and Check the temperature to control the temperature equal to the set temperature and determine whether to turn the fan motor (S17-S27), and to determine whether the mode to the frost and the type of frost removal Selecting step (S18), defrosting method using a heater (S30-S34), supplying water (water) to remove the defrosting (S35-S37), and air (air) by continuously blowing the fan Step of removing the defrosting (S38), and checking the time during the defrosting step of switching to the drain mode with the completion of defrosting (S33-S34), and draining step of discharging the melted water in the defrosting step (S39) S40, removing the remaining water droplets after the draining step (S41-S42), and resetting and starting the system (S43) after the operation process of one cycle is completed.

As described above, the present invention provides a function of efficiently controlling the temperature in the warehouse by controlling the application of a microprocessor, fully automatic control according to a set temperature and time, communication control function for military management, and diversification of defrosting method. It is effective.

Claims (2)

Control signals such as a warehouse temperature sensor unit (1) for measuring the temperature in a low temperature warehouse with a platinum resistance thermometer, a sensor unit (2) for a PCB circuit board for measuring the main PCB temperature with a dummyster, and a defrost time for the microprocessor A keyboard 6 for inputting a digital signal, a one-chip processor, a 10-bit A / D converter and an internal RAM, and temperature data provided from the sensor units 1 and 2 and control signals provided from the keyboard 6. The microprocessor unit 3 for controlling the operation mode and the defrost operation mode of the air conditioner compressor, and the display unit for displaying the current operation state and various error conditions under the control of the microprocessor unit 3 A reference time generator (5) for outputting the reference time of the system used for various controls and used as a non-volatile memory to store the current work status and various information, and AC / DC converter (7) that functions as a DC power supply and power stabilization suitable for system power supply by receiving current power, and an input / output terminal part (8) that receives signals from external devices and interfaces with a microprocessor for control and output, and group management Cold storage freezer automatic control device, characterized in that consisting of RS232C and RS485 / 422 driver (9) to induce communication with the outside for. Checking the system initialization and system abnormality when power is supplied and displaying the logo for several seconds (S1), and keeping the temperature of the PCB circuit board constant and preventing the circuit board temperature from dropping below 0 degrees (S2). -S5), checking whether there is an abnormality of the refrigerator, and processing and displaying (S6-S10), determining whether the pump down switch is pressed and going from the pump down mode to the stop mode (S11-S14), and the set operation Determining and processing the defrost mode or continuing operation by comparing the time with the current operating time (S15-S16), by checking the temperature in the freezer to control the temperature to the set temperature and run the fan motor Determining whether it is (S17-S27), determining whether the defrosting mode is selected (S28), and defrosting method using a heater (S30-S34). Step of removing the frost by supplying water (water) (S35-S37), and the step of removing the frost by continuously blowing air (air) with a fan (S38), and checking the time during the frost removal with the completion of the frost removal Switching to the drain mode (S33-S34), draining step of discharging the melted water in the defrosting step (S39-S40), removing the remaining water droplets after the draining step (S41-S42), and Resetting and starting the system after the cycle operation process is finished (S43) consisting of the automatic control of the cold storage freezer, characterized in that repeated in sequence.

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