JPH01102233A - Defrosting control device for heat pump type air conditioner - Google Patents

Abstract

PURPOSE:To optimize the defrosting control regardless of the ambient temperature of outdoor unit by providing a first control circuit which receives inputs from a logic circuit and a first timer circuit and outputs the defrosting signal, and a second control circuit which receives signals from a second timer circuit and outputs the heating signal. CONSTITUTION:A driver circuit 15 receives the defrosting signal S11 from a first control circuit 12 and the heating signal S13 from a second control circuit 14, and outputs the signal S14 to control a switch valve 16. Upon starting the heating operation, a first timer 10 starts counting time, and a logic circuit 11 is fed with the temperature signal S7 from a temperature sensor 8 that detects the piping temperature of the outdoor unit as well as the voltage signal S8 from a fan motor current sensor 9. The output signal S10 from the logic circuit 11 and the output signal S9 from the first timer circuit 10 are then inputted to the first control circuit 12. If the cumulative time count by the timer circuit 10 is over the defrosting time interval at this time, the defrosting signal S11 is outputted to a second timer circuit 13 and to the driver circuit 15 to turn off the switch valve 16, whereupon the second timer circuit 13 starts time counting.

Description

DETAILED DESCRIPTION OF THE INVENTION 2. Field of Industrial Application The present invention relates to a defrosting control device that performs defrosting control of an outdoor unit of a heat pump air conditioner.

BACKGROUND OF THE INVENTION In recent years, electronic control of heat pump air conditioners has been rapidly progressing, and electronic control is often used in outdoor units to defrost defrost efficiently and optimally.

An example of the conventional heat pump air conditioner mentioned above will be described below with reference to the drawings.

FIG. 4 shows a block diagram of a conventional defrosting control device for a heat pump air conditioner, FIG. 6 is an operation flowchart thereof, and FIG. 6 is a configuration diagram of the heat pump air conditioner.

In FIG. 4, numeral 1 is a temperature detector that detects the temperature of the pipes of the outdoor unit of the heat pump air conditioner and outputs a temperature signal S1. 2 is a first timer circuit that starts integration at the same time as heating operation starts, and outputs an output signal S2. 3 is a first control circuit which inputs the temperature signal S1 of the temperature detector 1 and the output signal 3A-782 of the first timer circuit 2, and outputs a defrosting signal S3. 4 is a second timer circuit which inputs the defrosting signal S3 from the first control circuit 3 and outputs an output signal S4. 5 is a second control circuit which receives the temperature signal S1 from the temperature detector 1 and the output signal S4 from the second timer circuit 4 and outputs a heating signal S5. 6 is a driver circuit which inputs the defrosting signal S3 of the first control circuit 3 and the heating signal S of the second control circuit 5, and outputs the output signal S6.
output and control the switching valve 7.

In FIG. 6, 17 is a compressor, and 18 is an accumulator, which are connected via a switching valve 7 to an annular circuit including an indoor heat exchanger 19, a capillary 23, and an outdoor heat exchanger 21.

2o is an indoor fan motor, and 22 is an outdoor fan motor.

The operation of the defrosting control device for a heat pump air conditioner configured as described above will be explained below using the operation flowchart shown in FIG.

First, when the power is turned on, in step 1, the heating signal S6 is output from the driver circuit 6, and the switching valve 7 is turned on and the heating operation is started. Next, in step 2,
The first timer circuit 2 starts integration. Next, the temperature signal S1 of the temperature detector 1 and the output signal S2 of the first timer circuit 2 are inputted to the first control circuit 3, and in step 3, the first timer circuit 2 starts the integration for a predetermined time T1. Check whether the defrost cycle time (hereinafter referred to as the defrost cycle time) has elapsed.

In step 4, the temperature signal S1 of the temperature detector 1 is
Checks whether the temperature is below 1℃ (hereinafter referred to as the defrost start temperature), and if the defrost start temperature is below 1℃.
℃ or less, the first control circuit 3 outputs the defrosting signal S3 to the driver circuit 6, turns off the switching valve 7, and starts the L defrosting operation, and then proceeds to the next step. If the temperature is K1°C or higher, the heating operation is continued until the temperature reaches the defrosting start temperature by 1°C or lower.

In step 6, the defrosting signal 83 of the first control circuit 3 is inputted to the second timer circuit 4, the second timer circuit 4 starts integration, and the process proceeds to step 7. In step 7,
The temperature signal S1 from the temperature detector 5 and the output unit 1 is input to the second control circuit 5, and the temperature signal S1 from the temperature detector 1 reaches an arbitrarily specified temperature by 2°C (hereinafter referred to as the defrosting end temperature) or more. Check whether if,
If the defrosting end temperature is 2°C or higher, proceed to step 8 and step 2.
At the same time, the timer circuit 4 is reset, the heating signal S5 is output to the driver circuit 6, the logic is returned to step 1, the switching valve 7 is turned ON, and the heating operation is restarted. Further, if the defrosting end temperature is 2° C. or lower, the logic advances to step 9.

In step 9, the output signal S4 of the second timer circuit 4 is input to the second control circuit 6, and the cumulative time of the second timer circuit 4 is set to an arbitrarily specified time T2 (hereinafter referred to as defrosting time). ) to check if it has elapsed. If the defrost time T2 has elapsed, return to step 1, defrost time T
If 2 has not yet passed, the logic returns to step 7.

Problems to be Solved by the Invention However, in the various configurations described above, the temporary drop in power pipe temperature when the outdoor fan motor stops, which occurs when the ambient temperature of the outdoor unit becomes relatively high, can be reduced by 67, -1. This has the problem of erroneously detecting the frost mode and performing unnecessary defrosting operations, resulting in poor heating efficiency and discomfort.

In view of the above problems, the present invention provides a defrosting control device for a heat pump air conditioner that can perform optimal defrosting control regardless of the ambient temperature of the outdoor unit.

Means for Solving the Problems In order to solve the above-mentioned problems, the defrosting control device for a heat pump air conditioner according to the present invention includes a first temperature detector for detecting the pipe temperature of the outdoor unit, and a temperature sensor located inside the outdoor unit. A current detector detects the current flowing in a certain fan motor, a temperature signal from the temperature detector and a voltage signal from the current detector are input, and the temperature of the temperature detector is determined according to the voltage signal from the current detector. a logic circuit that controls the signal, a first timer circuit that starts integration at the same time as heating operation starts, and a first timer circuit that receives the output of the logic circuit and the output of the first timer circuit and outputs a defrosting signal. a second timer circuit that receives the output of the first control circuit and integrates the defrosting time for seven pages, and inputs the temperature signal of the temperature detector and the output signal of the second timer circuit. and a second control circuit that outputs a heating signal.

Effect: With the above-described configuration, the present invention controls the temperature signal of the pipe temperature detected by the temperature detector according to the current flowing through the fan motor detected by the current detector, and inputs the temperature signal to the first control circuit. I will do it.

EXAMPLE Hereinafter, a defrosting control device for a heat pump air conditioner according to an example of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram of a defrosting control device for a heat pump air conditioner according to an embodiment of the present invention, FIG. 2 is an operation flowchart thereof, and FIG. 3 is a circuit diagram.

In FIG. 1, 8 is a temperature detector that detects the pipe temperature of the outdoor unit of the heat pump air conditioner and outputs a temperature signal S7. Reference numeral 9 denotes a current detector that detects the current flowing to the fan motor inside the outdoor unit of the heat pump air conditioner, and outputs a voltage signal S8.

10 is a first timer circuit that starts integration at the same time as the heating operation starts, and outputs an output signal S9. 11 is a logic circuit,
The temperature signal S7 from the temperature detector 8 and the voltage signal S8 from the current detector 9 are input, and an output signal S1° is output. 12 is the first
, the output signal S1° of the logic circuit 11 and the first
The output signal S9 of the timer circuit 10 is inputted to generate the defrosting signal S1.
．． Output.

13 is a second timer circuit which inputs the defrosting signal S11 from the first control circuit 12 and outputs an output signal S1□. 1
4 is a second control circuit which inputs the temperature signal S7 of the temperature detector 8 and the output signal S1 of the second timer circuit 13, and outputs the heating signal "13"; 15 is a driver circuit which is the first control circuit; It inputs the defrosting signal S of 12 and the heating signal S13 of the second control circuit 14, outputs the output signal S14, and controls the switching valves of 16.

In FIG. 3, 27 is an AC power source. A thermostat 26 opens and closes contacts depending on temperature, and the compressor 17 is connected in series between the AC power source 27.

9A-ji 24 is a temperature detector 8 that detects the pipe temperature in the defrosting control device.
The defrosting control is performed by inputting the signals from the current detector 9 and the current detector 9.

16 is an output contact of the defrosting control device 24, which forms a closed circuit between the switching valve 7 and the AC power source 27 via an NC contact.

22 is an outdoor fan motor, 25 is an outdoor fan motor 22
It is connected in series with the thermostat 26 with a 0N10FF switch, and the NC of the output contact 15 of the defrosting control device 24 is
It penetrates through the opening 28 of the current detector 9 via the contact and forms a closed circuit with the AC power supply.

The operation of the defrosting control device for a heat pump air conditioner according to an embodiment of the present invention constructed as described above will be described below with reference to FIGS. 1 and 2.

First, when the power is turned on, in step 10, the driver circuit 16 first outputs the heating signal 14, and the switching valve 16 turns on and starts the heating operation.

Next, in step 11, the first timer circuit 10 starts integration. Next, the temperature signal S7 of the temperature detector 8 and the voltage signal S8 of the current detector 9 are input to the logic circuit 11, and in step 12, the voltage signal S of the current detector 9 is input.
Step 8 checks whether or not the fan motor is energized. If energized, the process goes to step 13; if not, step 12 is repeated. Next step 13
Then, it is checked whether the temperature signal S7 of the temperature detector 8 is below the arbitrarily specified temperature by 3°C (hereinafter referred to as the defrosting start temperature), and if it is below the defrosting starting temperature by 3°C. If the defrosting start temperature is 4° C. or higher, the logic advances to step 12 by outputting the output signal S1° to the first control circuit 12 and proceeding to step 14. In step 14, logic circuit 1
1 and the output signal S9 of the first timer circuit 1o are input to the first control circuit 12, and at the time when the output signal S9 of the logic circuit 10 is input to the first control circuit 12, Check whether the accumulated time of the timer circuit 1o has passed an arbitrary prescribed time T3 (hereinafter referred to as the defrosting cycle time), and if the defrosting cycle time T3 has not elapsed, the logic goes to step 12. Return, progress 11-,
- If so, output the defrost signal S, 1 to the second timer circuit 13 and driver circuit 16, and turn off the switching valve 16.
At the same time as starting the L defrosting operation (step 15), the integration of the second timer circuit 13 is started.

In step 17, the temperature signal S7 of the temperature detector 8 is input to the second control circuit 14, and the temperature signal S7 of the temperature detector 8 is increased to an arbitrarily specified temperature of 4°C (hereinafter referred to as the defrosting end temperature). ) or more. If the defrosting end temperature is 4℃ or higher, proceed to step 18 and step 2.
The timer circuit 13 is output to the driver circuit 16, the logic is returned to step 10, the switching valve 16 is turned ON, and the heating operation is restarted. Also, if the defrosting end temperature is 4℃ or less, step 1
Proceed with logic to 9. In step 19, the output signal S12 of the second timer circuit 13 is input to the second control circuit 14, and the cumulative time of the second timer circuit 13 is set to an arbitrarily specified time T4 (hereinafter referred to as defrosting time). ) has elapsed, and if the defrosting time T2 has elapsed, the process returns to step 1o, and if the defrosting time T2 has elapsed, the logic returns to step 17.

As described above, according to this embodiment, the temperature detector 8 detects the piping temperature of the heat pump air conditioner, the current detector 9 detects the current flowing to the fan motor inside the outdoor unit,
The temperature signal S7 of the temperature detector 8 and the voltage signal S8 of the current detector 9 are input, and when the voltage signal S8 of the current detector 9 is not energized to the fan motor, the temperature signal S7 of the temperature detector 8 is output. By providing the logic circuit 11 that controls the temperature so as not to occur, a temporary rise in the ambient temperature of the outdoor unit will not be detected when the fan motor inside the outdoor unit stops.
Therefore, unnecessary defrosting operations due to erroneous detection at high outside temperatures can be eliminated.

Effects of the Invention As described above, the present invention provides a temperature detector for detecting the piping temperature of an outdoor unit of a heat pump air conditioner, a current detector for detecting a current flowing to a fan motor inside the outdoor unit, and a temperature detector for detecting the temperature of a fan motor disposed inside the outdoor unit. A logic circuit for controlling the temperature signal of the heavy equipment and a logic circuit for controlling the temperature signal of the heavy equipment and for starting the heating operation. a first timer circuit that simultaneously starts integration; a first control circuit that receives the output of the logic circuit and the output of the first timer circuit and outputs a defrosting signal; A second timer circuit that takes the output as input and integrates the defrosting time, and a second control circuit that takes the temperature signal of the temperature detector and the output signal of the second timer circuit as input and outputs a heating signal. This eliminates unnecessary defrosting operations due to erroneous detection of the defrosting mode when the temperature around the outdoor unit is relatively high, thereby increasing heating efficiency and performing optimal defrosting control.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of a defrosting control device for a heat pump air conditioner according to an embodiment of the present invention, Fig. 2 is an operation flowchart of Fig. 1, Fig. 3 is a circuit diagram of the same, and Fig. 4 is a conventional heat pump air conditioner. FIG. 6 is an operation flowchart of FIG. 4, and FIG. 6 is a block diagram of the defrosting control device. 8...Temperature detector, 9...Current detector, 10...14/, -5...First timer circuit, 11...Logic circuit,
12...First control circuit, 13...Second timer circuit, 14...Second control circuit, 1
7...Compressor, 18...Accumulator, 19...Indoor heat exchanger, 2゜...Indoor fan motor, 21...Outdoor heat exchanger, 22
...Outdoor fan motor, 23...Capillary. Name of agent: Patent attorney Toshio Nakao and 1 other person 2nd
Figure 3 Figure 5 Figure 6 Figure 3

Claims (1)

[Claims] a temperature detector that detects the pipe temperature of the outdoor unit; a current detector located inside the outdoor unit that detects the current flowing to the fan motor; a temperature signal from the temperature sensor; a logic circuit that receives a voltage signal as an input and controls the temperature signal of the temperature detector according to the voltage signal from the current detector; a first timer circuit that starts integration at the same time as heating operation starts; and the logic circuit. and the output of the first
The first circuit takes the output of the timer circuit as input and outputs the defrosting signal.
and the output of the first control circuit as inputs,
A heat pump air conditioner comprising a second timer circuit that integrates defrosting time, and a second control circuit that receives a temperature signal from the temperature detector and an output signal from the second timer circuit and outputs a heating signal. Defrost control device.