JPS594615B2 - Control circuit for heating and cooling equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is equipped with a refrigerant heater equipped with a power heating element, and selectively performs gasification and evaporation of the refrigerant between an outdoor heat exchanger and a refrigerant heater depending on the outside temperature. Regarding the control circuit of heating and cooling equipment,
When the outside temperature is low during heating, the heat input to the refrigerant heater is controlled in stages to prevent abnormal increases in high and low pressures due to increases in indoor air temperature and decreases in indoor air volume.
This is to ensure equipment reliability and safe operation.

An embodiment of the present invention will be described below based on the drawings.

In FIG. 1, 1 is a compressor, 2 is a four-way valve, and 3 is an indoor heat exchanger, which functions as an evaporator during cooling and a condenser during heating.

4 is a main pressure reducing mechanism, and 5 is an auxiliary pressure reducing mechanism that reduces the pressure of the refrigerant flowing during operation of the air heat source heat pump when the outside temperature is high during cooling and heating.

6 is an outdoor heat exchanger which acts as a condenser during cooling and as an evaporator during heat pump operation during heating.

7 is a refrigerant heater which acts as an evaporator when the outside temperature is low during heating.

Reference numeral 8 denotes an on-off valve that is opened when the outside temperature is low and the refrigerant heater is used as an evaporator to allow the refrigerant to flow.

9 is a check valve. In Fig. 2, 10 is an indoor blower;
Reference numeral 11 denotes an outdoor blower which is stopped when the refrigerant heater 7 is used as an evaporator.

12 is an operation switch, and 13 is a heating/cooling changeover switch, which has cooling side contacts 13a, 13a' and heating side contacts 13b, 13b'.

14 is a room thermo switch, which is the cooling/heating changeover switch 1.
Connect to the cooling side contact 13a and the heating side contact 13b of No.3.

room thermo switch 14 with isH i-th relay coil
It is connected to the power supply in parallel with the compressor 1 via.

The contact 15' closes when the relay coil 15 is energized.

16 is an overcurrent relay for the compressor 1, and 17 is an operating capacitor.

The outdoor blower 11 is connected in parallel to the first relay coil 15 of the compressor 11 via a contact 18a operated by the second relay coil 18.

When the relay coil 18 is energized, the contact 18a
is opened, and the contact 18b is closed.

19 is a speed control device for the outdoor blower 11, and 20 is an operating capacitor.

21 is an outside temperature thermoswitch, one end of which is connected to the heating side contact 13b' of the cooling/heating changeover switch 13 via a contact 15' activated by the first relay coil 15;
Connect to the relay coil 18 of.

Then, the outside temperature thermoswitch 21 is at or above the set temperature,
Open contact 21a.

Reference numeral 8 denotes an on-off valve, which is connected to the heating side contact 13b' of the cooling/heating changeover switch 13 via a contact 18b that operates multiple times with the second relay coil 18 and a contact 15' that operates multiple times with the first relay coil 15. .

22 is the third relay coil and overheat prevention thermo switch 2
3,24. It is connected to the heating side contact 13b' of the cooling/heating changeover switch 13 via the contacts 18b and 15'.

25 is a heater for heating the refrigerant, and contacts 22a and 22b are operated by the third V-coil 22.

It is connected to the power supply for the refrigerant heater via 22c.

The heater 25 is equipped with a low pressure switch 26 in the phase having the contact point 22a among the three phases.

Further, the low pressure switch 26 is provided with a diode 27 and a high pressure switch 28 connected in parallel in series to control the heater 25 of the refrigerant heater 7 in stages.

29 is a cooling operation lamp, and 30 is a heating operation lamp.

Note that the low pressure switch 26 and the high pressure switch 28 open their respective contacts when the pressure exceeds a set value.

Further, the low pressure switch 26 detects the pressure on the suction side of the compressor 1, and the high pressure switch 28 detects the pressure on the discharge side.

The operation of the above configuration will be explained.

First, when cooling, turn the cooling/heating switch 13 to the cooling side contact 13a.
.

13a' and then turn on the operation switch 12, the cooling operation lamp 29 lights up and the indoor blower 10 starts operating.

Further, the compressor 1 is driven via the room thermoswitch 14.

Furthermore, since the second relay coil 18 is not energized, the contact 18a is closed and the outdoor blower 11 starts operating.

Also, since the contact point 18b is open, the on-off valve 8. and the third relay coil is not energized.

Therefore, the refrigerant compressed by the compressor 1 flows into the outdoor heat exchanger 6 through the four-way valve 2, radiates heat through the action of the outdoor blower 11, and is condensed and liquefied.

Next, the auxiliary pressure reducing mechanism 5. The pressure is reduced by the main pressure reducing mechanism 4 and flows into the indoor heat exchanger 3vC, which absorbs heat through the action of the indoor blower 10 and is gasified and evaporated to the four-way valve 2. 'Z medium heater 7
and returns to compressor 1.

Next, the operation during heating will be explained.

When the cooling/heating changeover switch 13 is connected to the heating side contacts 13b, 13b' and the operation switch 12 is turned on, the heating operation lamp 30 lights up and the indoor fan 10 is turned on.
= move.

Further, the first relay coil 151 is energized through the room thermoswitch 14 to the compressor 1, and the compressor 1 is driven.

Further, since the contact 15' is closed, the four-way valve 2 is energized and switched to the heating side.

When the outside temperature is high, the outside temperature thermoswitch 21 is in an open state, so the second relay coil 18vc is not energized and the contact 18a is closed and the outdoor blower 11 is operated.

Further, since the contact point 18b is open, the third relay coil 22 is not energized and the refrigerant heating heater 25 is not operated.

Also, the on-off valve 8 is not energized, so the refrigerant compressed by the compressor 1 flows into the indoor heat exchanger 3 through the four-way valve 2, radiates heat through the action of the indoor blower 10, condenses, and liquefies the main Decompression mechanism 4. It is auxiliary depressurized and flows into the outdoor heat exchanger 6, where it absorbs heat (through the action of the outdoor blower 11), is gasified and evaporated, passes through the four-way valve 2, the 16-medium heater 7, and returns to the compressor 1.

Next, when the outside temperature is low, the outside temperature thermos switch 21 is closed and the second relay coil 18 is energized, and the contact 18a is opened and the multi-room blower 11 does not operate.

Further, the contact 18b is closed, the on-off valve 8 is energized and opened, the third relay coil 22 is also energized, and the contacts 22a and 22b are energized.
, 22c are closed and the refrigerant heating heater 25 is energized.

Therefore, the refrigerant compressed by the compressor 1 flows into the indoor heat exchanger 3 through the four-way valve 2, radiates heat through the action of the indoor blower 10, condenses and liquefies, and is depressurized by the main pressure reducing mechanism 4.
The check valve 91 and the outdoor heat exchanger 6 are energized, and the refrigerant flows through the four-way valve 2 into the refrigerant heater 7, is heated by the refrigerant heating heater 25, is gasified and evaporated, and returns to the compressor 1.

Also, when the room temperature rises or when the indoor air volume is low, the condenser capacity decreases.

Low pressure increases.

However, when the low pressure exceeds a certain set value, the low pressure switch 26 opens and one phase of the three-phase power supply of the n-medium heating heater 25 is half-waved by the diode 27, so the refrigerant heating heater input becomes the initial input. On the other hand, it decreases to about 67 sections.

Therefore, the amount of heat absorbed on the low pressure side decreases, so the high and low pressures decrease.

However, when the pressure rises further, the high pressure switch 28 changes the three phases of the refrigerant heating heater 25 to a single phase state, reducing the initial heater input to 50%, thereby reducing the high and low pressures. do.

In this way, in order to prevent an abnormal pressure rise when the room temperature rises or the indoor air volume is low, the first step is to use the low pressure filter 26 and half-wave one phase of the three phases using the diode 27 to reduce the heater input to approximately 67, and as a second step, the high pressure switch 28 reduces the heater input to 50.
Reduce to %.

As explained above, in the present invention, during heating, when the first relay coil is not energized, the circuit connected to the power supply via the cooling/heating switch is cut off, and the outside temperature is changed via the contacts of the first relay coil. When the outside temperature is high, the outside temperature thermoswitch cuts off the power to the second link coil, and the contact of this second relay coil operates the outdoor fan, and at the same time turns the power on to the third relay coil of the refrigerant heating heater. Cut off.

Also, when the outside temperature is low, the outside temperature thermoswitch energizes the second relay coil through the contacts of the first relay coil, and the outdoor blower is stopped by the contacts of the second relay coil, and the third relay coil is turned on. energize the heater to heat the refrigerant.

Since the high and low pressures rise when the room temperature rises or when the indoor air volume is low, a low pressure switch is installed in one of the three phases of the power supply for the refrigerant heater, and a diode and high pressure switch are installed in parallel with the switch. When the voltage exceeds the set value, the low pressure switch is opened and the power source is rectified by the diode, thereby reducing the heater input to the refrigerant heating heater and lowering the high and low pressures.

Furthermore, when the pressure rises, the high pressure switch also turns off the diode rectification, allowing the three-phase to be used as a single phase, significantly reducing the heater input compared to the initial level, and lowering the high and low pressures.

Therefore, the heater input for heating the refrigerant can be controlled in stages according to the rate of pressure increase when the room temperature rises or when the indoor air volume decreases, preventing abnormal pressure rises and improving equipment reliability and safety. can be measured.

[Brief explanation of the drawing]

FIG. 1 is a refrigerant circuit diagram showing one embodiment of the present invention, and FIG. 2 is a control circuit diagram thereof. 4... Compressor, 2... Four-way valve, 3...
...Indoor heat exchanger, 4...Main pressure reduction mechanism, 5
...Auxiliary pressure reduction mechanism, 6...Outdoor heat exchanger, 7...Refrigerant heater, 8...Opening/closing valve, 11... Outdoor blower, 12...operation switch, 13...cooling/heating selector switch, 14.
...Room thermo switch, 15...First relay coil, 18...Second glue (7-coil, 21...Outside temperature thermo switch, 22・
...Third relay coil, 22a, 22b, 22
c...Third relay coil contact, 25...
...Refrigerant heating heater, 26...Low pressure switch, 27...Diode, 28...
・High pressure switch.

Claims (1)

[Scope of Claims] 1. A compressor, a four-way valve, an indoor heat exchanger, a pressure reducing mechanism, an outdoor heat exchanger, and a refrigerant heater are provided, and the refrigerant gasification and evaporation are performed between the outdoor heat exchanger and the outdoor heat exchanger according to the outside temperature during heating. In a device that selectively operates with a refrigerant heater, the first relay coil, compressor, and outdoor blower are each connected in parallel with the power supply via the operation switch, cooling/heating changeover switch, and room thermoswitch, and the operation switch and the cooling/heating changeover switch are connected in parallel with the power supply. A four-way valve, an outside temperature thermoswitch, and a second relay coil connected in series with each other are connected in parallel to the power supply via heating side contacts. It is equipped with a circuit having an on-off valve connected in parallel with the pressure reducing mechanism, and a third relay coil that turns on and off the refrigerant heating heater of the three-phase power supply, and the first relay coil turns on the circuit when it is not energized. When the second relay coil is de-energized, the outdoor fan is energized, and the on-off valve and the third relay coil are de-energized.The third relay coil, which has contacts connected to each phase of the refrigerant heating heater, is de-energized. At the same time, the contact is activated to cut off the power supply to the refrigerant heating heater, and the refrigerant heating heater has a low pressure switch provided in one phase thereof, a diode connected in parallel with the low pressure switch, and a high pressure cassette. A control circuit for a heating and cooling device, characterized in that it has a series circuit.