JPS5928822B2 - Control circuit for heating and cooling equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides an air-conditioning and heating system that includes a refrigerant heater equipped with a heating element and selectively performs gasification and evaporation of refrigerant between an outdoor heat exchanger and a refrigerant heater depending on the outside temperature. This provides an operation control circuit for the

In other words, when the outside temperature is high during heating, it is necessary to operate the heat pump using an air heat source, that is, to operate the outdoor blower, and cut off the power to the refrigerant heater. It is necessary to stop the operation of the blower and energize the heater for heating the refrigerant, and also to stop the outdoor blower when the heat pump is operating during heating to prevent abnormal rises in high and low pressure due to increases in indoor temperature and decreases in indoor air volume. When using the refrigerant heating heater when the outside temperature drops during heating, it is necessary to control the input to the refrigerant heating heater in stages.

The present invention is a control circuit for a heating and cooling device that satisfies each of the above conditions.

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.

Reference numeral 4 denotes a main pressure reducing mechanism, and 5 indicates an auxiliary pressure reducing mechanism, through which refrigerant flows and the pressure is reduced during operation of the air heat source heat pump when the outside temperature is relatively 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.

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

Reference numeral 8 denotes an on-off valve which is opened when the refrigerant heater acts as an evaporator when the outside temperature is low during heating, allowing the refrigerant to flow.

9 is a check valve. In Fig. 2, 10 is an indoor blower and 11 is an outdoor blower, which stops when the refrigerant heater 7 acts as an evaporator and when the high pressure of the refrigerant circuit reaches 27@/crAO during heat pump operation during heating. .

12 is an operating speed control device for the outdoor blower 11.

13 is an operation switch, 14 is a cooling/heating changeover switch, cooling side contacts 14a, 14'a, and heating side contact 14b.

14b'.

Reference numeral 15 denotes a room thermostat, which is connected to the cooling side contact 14a and the heating side contact 14b of the cooling/heating changeover switch 14.

16 is the first relay coil, which controls the operation of the compressor 1 at 0N-
It has contacts 16a, 16b, and 16c that are turned off.

17 is a second relay coil, and the first relay coil 1
6, in series with the contact 18' of the overcurrent relay 18 of the compressor 1 and the first pressure switch 19 via the room thermostat 15, and in parallel with the power supply.

A second pressure switch 20 has a set value smaller than that of the first pressure switch 19, and has one end connected to the heating side contact 14b of the heating/cooling changeover switch 14, and the other end connected to the third relay coil 21.

One end of the contact 21a of the third relay coil 21 is connected to the contact 2z of the fourth relay coil 22, and the other end is connected to the deice contact 2.
Connect with 3.

Further, the fourth relay coil 22 is connected in series with the outside temperature thermostat 24 via the room thermostat 15, and in parallel with the power supply.

25 is a heater thermometer for heating the refrigerant, and one end is connected to the second relay coil contact 17', and the other end is connected to the fifth relay coil 26.

The fifth relay coil 26 has one end connected to the refrigerant heating heater thermostat 25 and the other end to the outside temperature thermostat 24, and is connected in parallel to the power source.

27 is an operating capacitor for the compressor 1.

28 is a heater for heating the refrigerant, and a contact 26a operated by the fifth relay coil 26.

26b, 26c are connected to the same three-phase power supply as the compressor 1 via a heater temperature fuse 29 for heating the refrigerant, and are connected in a delta connection.

A contact 21b operated by the third relay coil 21 is provided in series with the refrigerant heating heater 28 between the voltages of any two of the three phases.

30 is a temperature fuse for the indoor auxiliary heater.

31 is a temperature relay for indoor auxiliary heater.

32 is an indoor auxiliary heater, and 33 is an important switch for the indoor auxiliary heater 32.

34 is a time switch.

In addition, the temperature fuse 30 for indoor auxiliary heater, the temperature relay 31 for indoor auxiliary heater, the indoor auxiliary heater 32 . The important switch 33 and time switch 34 of the indoor auxiliary heater 32 are each connected in series and connected in parallel to the power source.

35 is a cooling operation lamp, and the cooling/heating changeover switch 14
It is connected in parallel to the power supply via the cooling side contact 14a'.

36 is a heating operation lamp, and the cooling/heating changeover switch 14
It is connected in parallel with the power supply via the heating side contact 14b.

37 is a de-ice lamp, which is connected in parallel to the power source via the indoor blower 10.

Note that the contacts 16a, 16b, and 16c are closed when the first relay coil 16 is energized, and the contact 17' is closed when the second relay coil 17 is energized.

Further, the contacts 21a and 21b are opened when the third relay coil 21 is energized, and the contact 2z is opened when the fourth relay coil 22 is energized.

Contact points 26a, 26b. 26c is the fifth relay coil 26
closes when power is applied.

Further, the first pressure switch 19 opens its contacts when the pressure exceeds a set pressure, and closes its contacts when the pressure drops to a certain set pressure.

The second pressure switch 20 is the first pressure switch 19
The set pressure is lower, and when the set pressure is exceeded, the contacts are closed, and when the pressure drops to a certain level, the contacts are opened.

The de-ice contact 23 opens the contact when de-ice is activated.

The outside temperature thermostat 24 closes when the outside temperature falls below a set value.

The refrigerant heating heater thermometer 25 opens its contacts when the outside temperature exceeds a set value.

The operation of the above configuration will be explained.

First, when cooling, turn the cooling/heating switch 14 to the cooling side contact 14a.
.

14, connect to i'.

Next, when the operation switch 13 is turned on, the indoor blower 10 is activated.

Also, the first relay coil 16 is connected via the room thermostat 15.
is energized to close the contacts 16 a t 16 b and 16 c, and the compressor 1 is driven.

Furthermore, since the third relay coil 21 and the fourth relay coil 22 are not energized, the contacts 21a and 2z are closed, and the outdoor blower 11 rotates.

And since the four-way valve 2 is not energized, it does not operate.

Further, the cooling/heating operation lamp 35 is lit.

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 pressure is reduced by the auxiliary pressure reducing mechanism 5 and the main pressure reducing mechanism 4, and it flows into the indoor heat exchanger 3, where it absorbs heat through the action of the indoor blower 10, gasifies and evaporates, passes through the refrigerant heater 7 through the four-way valve 2, and is transferred to the compressor. Return to 1.

Next, the operation during heating will be explained.

First, a case where the outside temperature is relatively high will be explained.

The cooling/heating changeover switch 14 is connected to the heating side contacts 14 b, 14
b' and turn on the operation switch 13, the indoor blower 10 will operate.

Also, the first relay coil 16 is connected via the room thermostat 15.
is energized, the contacts 16a and 16bt16c are closed, and the compressor 1 is driven.

Furthermore, the four-way valve 2 is also energized.

When the high pressure is below the set value, the second pressure switch 20 is open, so the third relay coil 21 is not energized and the contact 21a is closed.

Also, since the outside temperature is higher than the set value, the outside temperature thermostat 24 is open, and the fourth relay coil 22 is not energized, so contact 2
z is closed.

Therefore, the outdoor blower 11 rotates and operates. Furthermore, since the outside temperature thermostat 24 is open, the on-off valve 8 and the fifth relay coil 26 are not energized.

Therefore, the contacts 26a, 26b, and 26c are open, and the refrigerant heater 28 is not energized.

The heating operation lamp 36 lights up.

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, liquefies and condenses, and is then depressurized by the main pressure reducing mechanism 4 and the auxiliary pressure reducing mechanism 5, and then released indoors. It flows into the heat exchanger 6, absorbs heat from the outside air by the action of the outdoor blower 11, is gasified and evaporated, passes through the four-way valve 2, the refrigerant heater 7, and returns to the compressor 1.

In this state, when the room temperature rises or the indoor air volume decreases, the condensing capacity of the indoor heat exchanger 3 decreases, causing the high and low pressures to rise abnormally.

However, when the high pressure exceeds a certain set value, the second pressure switch 20 is closed, the third relay coil 21 is energized, the contact 21a is opened, and the outdoor blower 11 stops operating.

Therefore, since the amount of heat absorbed from the outside air by the outdoor heat exchanger 6 decreases, the high and low pressures decrease.

Further, when the high pressure decreases to a certain value, the second pressure switch 20 is opened, the third relay coil 21 is de-energized, the contact 21a is closed, and the outdoor blower 11 starts operating again.

Next, the operation when the outside temperature drops during heating will be explained.

The heating/cooling changeover switch 14 is connected to the heating side contact 14b. 14B and turn on the operation switch 13, the indoor blower 10 will operate.

Also, the first relay coil 16 is connected via the room thermostat 15.
is energized, the contacts 16a, 16b, and 16c are closed, and the compressor 1 is driven.

The four-way valve 2 is also energized. When the high pressure is below the set value, the second pressure switch 20 is open, so the third relay coil 21 is not energized and the contact 21a is closed.

However, because the outside temperature is lower than the set value, the outside temperature thermostat is set to 24.
is closed, and the fourth relay coil 22 is energized, contact 2
2 is open.

Therefore, the outdoor blower 11 is stopped.

On the other hand, since the outside temperature thermostat 24 is closed, the on-off valve 8
, and the fifth relay coil 26 is the second relay coil J'
Since contact 17' of v17 is closed, it is energized and contact 2
6 a = 26 b + 26 c is closed and the refrigerant heating heater 28 is energized.

Also, the heating operation lamp lights up.

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 refrigerant passes through the valve 9, the outdoor heat exchanger 6, and the four-way valve 2, flows into the refrigerant heater 1, is heated by the refrigerant heater 28, gasifies and evaporates, and returns to the compressor 1.

In this state, when the room temperature rises or the indoor air volume decreases, the condensing capacity of the indoor heat exchanger 3 decreases, causing the high and low pressures to rise abnormally.

However, when the high pressure exceeds a certain set value, the second pressure switch 20 closes, the third relay coil 21 is energized, the contact 21b opens, and the input to the refrigerant heater 28 is reduced to approximately 67 points. Ru.

Therefore, since the amount of heat absorbed by the refrigerant heater I decreases, the high and low pressures decrease.

When the input high pressure decreases to a certain value, the second pressure switch 20 is opened and the third relay coil 21 is no longer energized, and the contact 2.1b is closed and the refrigerant heater heater 2
The 8 input is again rated.

In addition, in order to prevent the refrigerant heater 28 from overheating, which occurs when the amount of refrigerant circulating in the refrigerant circuit abnormally decreases, the heater thermometer 25 opens and the fifth relay coil 26 opens when the temperature exceeds a certain set value. Contact 26 is no longer energized
a, 26b.

26c is open and the refrigerant heating heater 28 is not energized.

Then, when the temperature drops below a certain set value, the heater thermometer 25 is closed and the heater 28 is energized.

Furthermore, when the heater thermometer 25 malfunctions and the heater overheats and the temperature rises further, the refrigerant heating heater temperature fuse 29 operates and cuts off two of the three phases, so the refrigerant heating heater 28 is not energized and the heater 28 is overheated. can be prevented.

As explained above, the present invention provides heating: heating/cooling changeover switch 1.
When the outside temperature is high, the outside temperature thermostat 24 is connected in parallel to the power supply through the heating side contacts 14b and 141 (of 4). and operating the outdoor blower 11 connected in parallel to the power source via the room thermostat 15 by the fourth relay coil 22 connected in parallel to the power source;
ON The fifth relay coil 26 connected in parallel with the fourth relay coil 22 turns off the input of the refrigerant heating heater 2B, and the input of the first relay coil 26 connected in parallel with the power supply via the room thermostat 15 is turned off. The compressor 1 is turned on by the relay coil 16 when energized.

Also, when the indoor temperature rises and the indoor air volume decreases.

In case of low pressure abnormality, the heating side contact 14b is connected to prevent the pressure from rising.
, 14b', the third relay coil 21, which is connected in series with the second pressure switch 17, is energized and connected to the outdoor blower 11. The outdoor blower 1 is activated by the contact 21a of the third relay coil 21 connected in series.
1 is stopped and the high and low pressures are lowered by reducing the amount of heat absorbed by the refrigerant.

Further, when the outside temperature is low, the outside temperature thermostat 24 activates the fourth relay coil 22, the on-off valve 8, and the fifth
The relay coil 26 is energized, the contact 22 of the fourth relay coil 22 is used to stop the outdoor blower, and the fifth relay coil 26 is energized to the refrigerant heating heater 28, and the room thermostat 15 is energized. The compressor 1 is driven by the first relay coil 16 connected in parallel with the power supply via the contact point.

In addition, in order to prevent abnormal increases in high and low pressures when the room temperature rises or when the indoor air volume decreases, a second pressure switch 20 is connected in parallel to the power supply via the heating side contacts i 4b and 11.
As a result, the third relay coil 21 connected in series with the second pressure switch 20 is energized to connect either two phases of the three-phase power supply of the refrigerant heating heater 28 to the Δ-connected refrigerant heating heater 28. The contact 21b of the third relay coil 21 provided in series with the heater is opened to reduce the input to the refrigerant heating heater 28 to about 67 degrees, and the high and low pressures are lowered by reducing the amount of heat absorbed by the refrigerant.

In addition, when the heat pump is operated when the outside temperature is high or when the outside temperature is low and the refrigerant heater I is used to heat the refrigerant, if the mechanism that deals with the previous pressure increase fails and the high and low pressures further increase, the above-mentioned A first pressure switch 19 having a higher pressure setting value than the second pressure switch 20 is connected in series with the first relay coil 16 and second relay coil 17 via the room thermostat 15, and connected in parallel with the power source. When the high pressure reaches the set value by the first pressure switch 19, the first relay coil 16 and the second relay coil L/17 are de-energized, and the first relay coil contact 16a, 16b, 16c are opened to stop the compressor 1, and the contact 17' of the second relay coil 17 is used to stop the energization of the fifth relay coil 26, and the fifth relay coil contacts 26a, 26b, 25c are opened. It is opened and the input to the refrigerant heating heater 28 is stopped.

In addition, in order to prevent the refrigerant heating heater from overheating, the heater thermometer 25 connected in series with the fifth relay coil 26 stops the energization of the fifth relay coil 26, and the three-phase power supply of the refrigerant heating heater 28 is turned off. Open the contacts of the fifth relay coil 26 provided in each phase to turn off the heater input.
Make it.

Further, since heater temperature fuses 29 are provided in two of the three phases of the refrigerant heating heater 28, even if the temperature further increases due to a failure of the heater thermometer 25, the heater input is turned off by the temperature fuses 29. .

Therefore, to prevent overheating of the refrigerant heater 28, the reliability of the equipment is improved by using a double safety structure of a heater thermometer and a temperature fuse.
It measures safety.

Furthermore, when the heat pump is operated when the outside temperature is high, or when the refrigerant heater is used to heat the refrigerant when the outside temperature is low, the mechanism to deal with the rise in pressure may fail and the high and low pressures will increase further. When the pressure rises, the second pressure switch 20
A first pressure switch 19 with a higher pressure setting is connected to the first relay coil 16 via the room thermostat 15.
and a second relay coil 17, and when the first pressure switch 19 causes the high pressure to reach a set value, the first and second relay coils are de-energized and the first relay coil 16 is turned off. Contact points 16a, 16b, 16c
The compressor 1 is stopped by O, and the second relay coil 1 is
The present invention is equipped with a mechanism for stopping the energization of the fifth relay coil 26 through the contact point 17' of the fifth relay coil 26, and stopping the input to the refrigerant heating heater 28 through the contact point of the fifth relay coil 26, thereby improving the reliability and safety of the equipment. This is an even more sophisticated control circuit for the air conditioning system.

In this way, the present invention connects a compressor, a four-way valve, an indoor heat exchanger, a pressure reducing mechanism, an outdoor heat exchanger, and a refrigerant heater having a heater for heating the refrigerant in a ring to form a cooling/heating cycle circuit, and also connects the compressor to the outdoor blower. a fourth relay coil having a normally closed contact connected in series; and a third relay coil having a normally closed contact connected in series to the normally closed contact of the fourth relay coil and a normally closed contact controlling the input of the refrigerant heating heater. , a second pressure switch which is connected in series with the third relay coil and closes when the high or low pressure of the refrigerant cycle circuit rises abnormally, and a fifth pressure switch which energizes the refrigerant heating heater when the outside temperature drops.
Since it is equipped with a device consisting of a relay coil and an outside temperature thermostat connected in series to the fifth relay coil and fourth relay coil connected in parallel, this device gasifies the refrigerant according to the outside temperature during heating. Evaporation can be performed selectively in the outdoor heat exchanger and the refrigerant heater, and the input to the refrigerant heating heater can be controlled according to the high and low pressures of the cooling and heating cycle circuit. This prevents abnormal increases in high and low pressures in the heating and cooling cycle circuit due to increases in indoor temperature and decreases in air volume, and enables efficient heating operation under all conditions.

[Brief explanation of drawings]

FIG. 1 is a cooling/heating cycle circuit diagram according to an embodiment of the present invention, and FIG. 2 is a control circuit diagram thereof. 1... Compressor 2... Four-way valve, 3...
... Indoor heat exchanger, 4... Pressure reduction mechanism, 6.
...Outdoor heat exchanger, 7...Refrigerant heater,
11... Outdoor blower, 20... Second pressure switch, 21... Third relay coil, 21
a... Normally closed contact, 22... 4th relay coin 22'... Normally closed contact, 24...
・Outside temperature thermostat, 26...5th relay coil,
28... Heater for heating refrigerant.

Claims (1)

[Claims] 1 A compressor, a four-way valve, an indoor heat exchanger, a pressure reducing mechanism, an outdoor heat exchanger, and a refrigerant heater having a heater for heating the refrigerant are connected in a ring to form a cooling/warming cycle circuit, and a normally closed circuit is connected in series to an outdoor blower. a fourth relay coil having a contact; a third relay coil having a normally closed contact connected in series to the normally closed contact of the fourth relay coil; and a normally closed contact controlling the input of the refrigerant heating heater; a second pressure switch connected in series with the coil and closed when the high/low pressure of the cooling/heating cycle circuit rises abnormally; and a fifth relay coil connected in parallel to the fifth relay coil that energizes the refrigerant heating heater when the outside temperature drops. Equipped with a device consisting of a coil and an outside temperature thermostat connected in series to the fourth relay coil, during heating, this device selectively gasifies and evaporates the refrigerant between the outdoor heat exchanger and the refrigerant heater depending on the outside temperature. What is claimed is: 1. A control circuit for a heating and cooling device, characterized in that the input to a heater for heating a refrigerant is controlled according to the high and low pressures of a heating and cooling cycle circuit.