JP3267208B2 - Control device for air conditioner equipped with refrigerant heating device having vaporization heater - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a stop of an operation caused by an operation of an overcurrent protector in advance by stopping a supply of electricity to a vaporizing heater for a given time when an operating current exceeds a predetermined value which is set lower than a predetermined current value of the overcurrent protector in an air conditioner having a refrigerant heater. SOLUTION: When a heating operation is started, electricity is supplied to a vaporizing heater 8c to heat a carburetor 8b. Simultaneously, a four-way valve 2 is changed over to the heating side, a two way valve 7 is opened and a compressor 1 is operated. When the temperature of the carburetor 8b reaches a given value, the operation of a blower 8d is started. When a given time passes, an ignitor 11 and a fuel pump 10 are operated to start a combustion. Then, supply of electricity to the vaporizing heater 8c is stopped and the combustion is continued. In the case of starting the heating operation again after stopping the heating operation, when the operating current exceeds a predetermined value which is set lower than a predetermined current value of an overcurrent protector, the supply of electricity to the vaporizing heater 8c is stopped for a given time so that the stop of operation caused by the operation of the overcurrent protector can be avoided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for a vaporization heater of an air conditioner having a refrigerant heating device having a vaporization heater.

[0002]

2. Description of the Related Art A conventional control device for a vaporization heater of an air conditioner equipped with a refrigerant heating device having a vaporization heater includes:
For example, it was as follows.

FIG. 5 is a refrigeration cycle diagram of a conventional example, in which a compressor 1, a four-way valve 2, an indoor heat exchanger 3, a pressure reducer 4, a first check valve 5, and an outdoor cooling heat exchanger 6 are shown. And a refrigerant heating device 8 having a vaporization heater 8c connected between the indoor heat exchanger 3 and the decompressor 4 to the suction side of the compressor 1 via a two-way valve 7 to perform a refrigeration cycle. Make up.

When the heating operation is started, the operation of the refrigeration cycle is as follows. First, the four-way valve 2 is closed on the heating side and the two-way valve 7 is closed in order to always perform the heating operation with a constant refrigerant amount. , A refrigerant recovery operation for recovering the refrigerant in the outdoor-side cooling heat exchanger 6 to the indoor-side heat exchanger 3 is performed, and all the refrigerant is recovered to the heating cycle side. Thereafter, the two-way valve 7 is opened, and the refrigerant is circulated in the order of the compressor 1, the indoor heat exchanger 3, and the heat exchanger 8a of the refrigerant heating device. 2-way valve 7
Open the first check valve 5 and the second
The refrigerant does not return to the outdoor cooling heat exchanger 6 by the check valve 9.

On the other hand, the operation of the refrigerant heating device 8 is to heat the vaporizer 8b to an appropriate temperature by the vaporizing heater 8c, then to operate the combustion air supply blower 8d, to operate the fuel pump 10 and to use the igniter 11 for fuel. It ignites and starts burning.

Here, the vaporizing heater 8c provided in the refrigerant heating device 8 heats the temperature of the vaporizing surface of the vaporizer 8b to an appropriate temperature so that liquid fuel such as kerosene can be easily burned. The energization control of the vaporization heater 8c is performed as follows.

When starting combustion, the vaporization heater 8
c to heat the vaporized surface of the vaporizer 8b to a temperature at which the vaporization of the fuel can be properly performed. Thereafter, in order to maintain the temperature of the vaporized surface at an appropriate temperature, the temperature of the vaporized surface or a portion correlated therewith is determined by the temperature of the vaporized surface. When the temperature reaches the first set temperature, the power supply is stopped,
If the temperature is lower than a second set temperature which is set lower than the first set temperature, a control to energize is performed.

When the combustion is started, the heat of combustion is recovered to the vaporizer 8b by heat transfer or the like. Therefore, the temperature of the vaporizing surface is appropriately maintained, and the power to the vaporizing heater is not usually supplied. However, when the supply air temperature is low and the combustion temperature is low and the heat recovery to the vaporizer 8b cannot be sufficiently performed, the vaporization heater 8c may be energized even during combustion.

By operating the refrigerant heating device 8 while circulating the refrigerant in this manner, the heat generated in the combustor 8e is absorbed by the refrigerant in the heat exchanger 8a of the refrigerant heating device, and the indoor heat exchanger 3 By radiating heat from the room, the room can be heated.

[0010]

However, in the control of the vaporization heater 8c of the refrigerant heating device 8 as described above, the heating operation is continued, the heating operation is temporarily stopped from a state where the pressure of the refrigeration cycle is high, and immediately thereafter, the heating operation is stopped again. When heating operation,
There is a problem that the current value increases while the refrigerant recovery operation and the energization of the vaporization heater 8c are performed at the same time, an overcurrent protection device (not shown) operates, and the heating operation cannot be restarted. I was

Next, the reason why such a problem occurs will be described. Since the compressor 1 during the normal heating operation does not have a throttling mechanism in the heating cycle, it operates at a compression ratio of about 1.1 to 1.3, and operates as a positive displacement pump for circulating refrigerant. I have. Therefore, since the load on the compressor 1 is light and the operating current is low, the total current value does not exceed the current set value of the overcurrent protection device even when the vaporizing heater 8c is energized at the same time.

However, during the refrigerant recovery operation, the refrigerant is pumped down from the outdoor cooling heat exchanger 6 to the heating cycle side. Therefore, while the refrigerant remains in the outdoor cooling heat exchanger 6, compression is performed. The compressor 1 is operated at the ratio of about 2 to 4, the operation load becomes heavy, and the operation current becomes higher than in the normal heating operation.

As shown in FIG. 6, the pressure on the suction side of the compressor 1 during the recovery of the refrigerant is substantially the same as the outdoor temperature when the refrigerant in the outdoor cooling heat exchanger 6 is recovered in the heating cycle. After the pressure drops to the saturation temperature, the pressure becomes constant until the liquid refrigerant in the outdoor-side cooling heat exchanger 6 runs out, and when the liquid refrigerant runs out, the pressure gradually drops and changes to almost 0 MPa (gauge pressure). The pressure on the discharge side temporarily increases from the refrigeration cycle pressure at the start of operation due to the recovery of refrigerant,
After that, the temperature is reduced to a pressure at a saturation temperature substantially equal to the room temperature due to heat radiation from the indoor side heat exchanger 3. At this time, the operating current of the compressor 1 changes as shown in FIG. The reason why the operating current is reduced even if the compression ratio is large in the latter half of the refrigerant recovery operation is that the suction pressure is reduced, so that the amount of circulating refrigerant is reduced and the load on the compressor 1 is reduced.

Therefore, as the pressure of the refrigeration cycle at the start of operation increases, the compression ratio of the compressor 1 during refrigerant recovery increases, and the load increases, so that the operation current value increases. For this reason,
When the heating operation is performed again from a state in which the pressure of the refrigeration cycle is high immediately after the stop of the heating operation, the operating current of the compressor 1 during the refrigerant recovery operation increases, and the sum of the current of the vaporizing heater 8c and the current setting of the overcurrent protection device is set. If the value is exceeded, the operation of the air conditioner will stop.

[0015]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a method in which an operating current exceeds a set value which is lower than a current set value of an overcurrent protection device. This stops the energization.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, when the operating current exceeds a set value lower than a current set value of an overcurrent protection device (not shown), energization to the vaporizing heater is stopped for a certain time. Therefore, even if the heating operation is performed again from the state where the pressure of the refrigeration cycle is high immediately after the heating operation is stopped and the refrigerant recovery operation and the energization of the vaporization heater are simultaneously performed, the energization of the vaporization heater is performed before the overcurrent protection device operates. Is stopped, and after a certain period of time, the operating current of the compressor 1 becomes low, and the current is again supplied to the vaporizing heater, so that it is possible to prevent the overcurrent protection device from operating and stopping the operation.

In the present invention, when the operating current exceeds a first set value lower than the current set value of the overcurrent protection device, the current value flowing to the vaporizing heater is subtracted from the first set value. By stopping the power supply to the vaporization heater until the pressure falls below a second set value set to a value lower than the value, the heating operation is performed again from the state in which the pressure of the refrigeration cycle immediately after the heating operation is stopped is high, and the refrigerant recovery operation is performed. Even if the energization of the vaporization heater is performed at the same time, the energization of the vaporization heater is stopped before the overcurrent protection device operates, and the operation current obtained by summing the operation current of the compressor 1 and the current flowing to the vaporization heater becomes an overcurrent. Since the current is supplied to the vaporization heater again after the current value does not exceed the current set value of the protection device, it is possible to prevent the overcurrent protection device from operating and stopping operation.

Further, in the present invention, when the operation current exceeds a set value lower than the current set value of the overcurrent protection device during the refrigerant recovery operation, the power supply to the vaporization heater is stopped until the refrigerant recovery operation is completed. Thereby, even if the heating operation is performed again from the state where the pressure of the refrigeration cycle is high immediately after the heating operation is stopped and the refrigerant recovery operation and the energization of the vaporization heater are performed at the same time,
The energization of the vaporization heater is stopped before the overcurrent protection device operates, and the energization of the vaporization heater is performed again after the refrigerant recovery operation is completed.This prevents the overcurrent protection device from operating and stopping operation. Can be prevented.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings.

First, a first embodiment of the present invention will be described. The refrigeration cycle is the same as that of the conventional example, and the description is omitted.

FIG. 1 is a timing chart in the case where the heating operation is performed from a state where the pressure of the refrigeration cycle is low after a sufficient time has elapsed since the end of the previous heating operation.

When the heating operation is started, the vaporizing heater 8c is first energized to heat the vaporizer 8b to a temperature T1 sufficient to vaporize kerosene as fuel. Vaporizer 8b
Is detected by a temperature sensor (not shown) attached to the vaporizer 8b. At this time, the refrigerant recovery operation of operating the compressor 1 with the four-way valve 2 on the heating side and closing the two-way valve 7 to recover the refrigerant in the outdoor cooling heat exchanger 6 to the indoor heat exchanger 3 is performed. Do.

Here, the energization of the vaporization heater 8c and the operation of the compressor 1 are performed simultaneously, but the load on the compressor 1 is low and the operating current is low because the refrigeration cycle pressure at the start of operation is low. Therefore, the operating current does not become higher than A1, and naturally does not become higher than the current set value A2 of the overload protection device (not shown).

When the temperature of the vaporizer 8b reaches T1, the blower 8 for supplying the combustion air is kept energized to the vaporizer heater 8c.
The operation of d is started, and after a certain period of time, the igniter 11 and the fuel pump 10 are operated. If the flame is started by ignition and combustion is detected by a flame monitoring device (not shown), power supply to the igniter 11 is stopped after a predetermined time.

When the combustion is started and the temperature of the vaporizer 8b reaches T2, the power supply to the vaporizer heater 8c is stopped. However, even if the power supply to the vaporizer heater 8c is stopped, the vaporization of the vaporizer 8b is performed by recovering the combustion heat. The temperature is kept at a proper temperature.

Next, FIG. 2 is a timing chart when the heating operation is performed again from the state where the pressure of the refrigeration cycle is high immediately after the heating operation is stopped.

When the heating operation is started, a sufficient time elapses from the end of the heating operation, and the vaporizing heater 8c and the compressor 1 are simultaneously operated as in the case of performing the heating operation from a state where the pressure of the refrigeration cycle is low. Since the operating load of the compressor 1 is heavy and the operating current is high due to the high pressure of the refrigeration cycle, the operating current exceeds A1, which is set lower than the current set value A2 of the overload protection device. Is stopped for a certain time T1, and therefore does not become higher than the current set value A2 of the overload protection device.

Therefore, even if the heating operation is performed again from the state where the pressure of the refrigeration cycle is high immediately after the stop of the heating operation, it is possible to prevent the overcurrent protection device from operating and stopping the operation.

When the compressor 1 and the vaporizing heater 8c are simultaneously operated during the heating operation after the end of the refrigerant recovery operation, the same control is performed when the operation current exceeds A1, and the operation current becomes A2. It is possible to prevent the overcurrent protection device from operating and stopping the operation due to the increase.

Next, a second embodiment of the present invention will be described. The case where the heating operation is performed from a state where the pressure of the refrigeration cycle is low after a sufficient time has elapsed since the end of the heating operation is the same as that of the first embodiment, and thus the description is omitted.

FIG. 3 is a timing chart when the heating operation is performed again from the state where the pressure of the refrigeration cycle is high immediately after the heating operation is stopped.

When the heating operation is started, a sufficient time has elapsed since the end of the heating operation, and the vaporizing heater 8c and the compressor 1 are simultaneously operated, as in the case where the heating operation is performed from a state where the pressure of the refrigeration cycle is low. Since the operating load of the compressor 1 is heavy and the operating current is high due to the high pressure of the refrigeration cycle, the operating current exceeds A1, which is set lower than the current set value A2 of the overload protection device. Is stopped, and when the operation current becomes less than A3, the supply of electricity to the vaporization heater 8c is restarted. Here, A3 is set to a value obtained by subtracting a value obtained by multiplying the current value flowing through the vaporization heater 8c by 1.15 times from A2. Therefore, the operating current does not become higher than the current set value A2 of the overload protection device.

Therefore, even if the heating operation is performed again from the state where the pressure of the refrigeration cycle is high immediately after the stop of the heating operation, it is possible to prevent the overcurrent protection device from operating and stopping the operation.

Further, when the compressor 1 and the vaporizing heater 8c are simultaneously operated during the heating operation after the refrigerant recovery operation is completed and the operating current exceeds A1, the same control is performed, and the operating current becomes A2. It is possible to prevent the overcurrent protection device from operating and stopping the operation due to the increase.

Next, a third embodiment of the present invention will be described. The case where the heating operation is performed from a state where the pressure of the refrigeration cycle is low after a sufficient time has elapsed since the end of the heating operation is the same as that of the first embodiment, and thus the description is omitted.

FIG. 4 is a timing chart when the heating operation is performed again from the state where the pressure of the refrigeration cycle is high immediately after the heating operation is stopped.

When the heating operation is started, a sufficient time has elapsed from the end of the heating operation, and the vaporizing heater 8c and the compressor 1 are simultaneously operated, similarly to the case where the heating operation is performed from a state where the pressure of the refrigeration cycle is low. Since the operating load of the compressor 1 is heavy and the operating current is high due to the high pressure of the refrigeration cycle, the operating current exceeds A1, which is set lower than the current set value A2 of the overload protection device. Is stopped until the refrigerant recovery operation is completed, and therefore does not become higher than the current set value A2 of the overload protection device.

Therefore, even if the heating operation is performed again from the state where the pressure of the refrigeration cycle is high immediately after the heating operation is stopped, it is possible to prevent the overcurrent protection device from operating and stopping the operation.

[0039]

The effects of the present invention are as follows.

According to the present invention, when the operating current exceeds a set value lower than the current set value of the overcurrent protection device, energization to the vaporizing heater is stopped for a certain period of time. Therefore, even if the heating operation is performed again from the state where the pressure of the refrigeration cycle is high immediately after the stop of the heating operation and the refrigerant recovery operation and the energization of the vaporization heater are simultaneously performed, the energization of the vaporization heater is performed before the overcurrent protection device operates. The compressor is stopped, and after a certain period of time, the operating current of the compressor becomes low, and then the heater is energized again, so that it is possible to prevent the overcurrent protection device from operating and stopping the operation. Further, when the compressor and the vaporizing heater are simultaneously operated during the heating operation after the refrigerant recovery operation is completed, the same control is performed when the operation current exceeds A1. It is possible to prevent the operation of the protection device from stopping due to operation.

Further, according to the present invention, when the operating current exceeds a first set value lower than the current set value of the overcurrent protection device, the current value flowing to the vaporizing heater is subtracted from the first set value. The power supply to the vaporization heater is stopped until the value falls below a second set value set to a value lower than the set value. Therefore, even if the heating operation is performed again from the state where the pressure of the refrigeration cycle is high immediately after the heating operation is stopped and the refrigerant recovery operation and the energization of the vaporization heater are performed at the same time, the energization of the vaporization heater is performed before the overcurrent protection device operates. The overheat protection device is stopped because the operating current of the compressor and the sum of the current flowing through the vaporization heater, etc., fall to a current value that does not exceed the current setting value of the overcurrent protection device, and then the vaporization heater is energized again. Can be prevented from operating and stopping the operation. Also, when operating the compressor and the vaporization heater simultaneously during the heating operation after the end of the refrigerant recovery operation,
The same control is performed when the operating current exceeds A1, and it is possible to prevent the operating current from becoming higher than A2, causing the overcurrent protection device to operate and stopping the operation.

Further, according to the present invention, when the operating current exceeds the set value lower than the current set value of the overcurrent protection device during the refrigerant recovery operation, the power supply to the vaporization heater is stopped until the refrigerant recovery operation is completed. Things. Therefore, even if the heating operation is performed again from the state where the pressure of the refrigeration cycle is high immediately after the stop of the heating operation and the refrigerant recovery operation and the energization of the vaporization heater are simultaneously performed, the energization of the vaporization heater is performed before the overcurrent protection device operates. Since the operation is stopped and the vaporization heater is energized again after the refrigerant recovery operation is completed, it is possible to prevent the overcurrent protection device from operating and stopping the operation.

[Brief description of the drawings]

FIG. 1 is a timing chart of a first embodiment of the present invention.

FIG. 2 is a timing chart of the first embodiment of the present invention.

FIG. 3 is a timing chart of a second embodiment of the present invention.

FIG. 4 is a timing chart of a third embodiment of the present invention.

FIG. 5 is a refrigeration cycle diagram of a conventional example.

FIG. 6 is a diagram showing changes in compressor discharge pressure and suction pressure during a refrigerant recovery operation of a conventional example.

FIG. 7 is a diagram showing a change in compressor operating current during a refrigerant recovery operation according to a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Compressor 2 4-way valve 3 Indoor heat exchanger 4 Pressure reducer 5 1st check valve 6 Heat exchanger for outdoor cooling 7 2-way valve 8 Refrigerant heating device 8a Heat exchanger of refrigerant heating device 8b Vaporizer 8c Vaporization heater 8d Blower for supplying combustion air 8e Combustor 9 Second check valve 10 Fuel pump 11 Ignition device

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-59-60142 (JP, A) JP-A-2-157559 (JP, A) JP-A-5-215387 (JP, A) JP-A-9-99 152168 (JP, A) JP-A-2-143050 (JP, A) JP-A-7-294054 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) F24F 11/02 102 F25B 49/02

Claims (3)

(57) [Claims] 1. An annular connection of a compressor, a four-way valve, an indoor heat exchanger, a pressure reducer, a first check valve, an outdoor cooling heat exchanger, and the like. In an air conditioner configured as a refrigeration cycle by connecting a refrigerant heating device having a vaporization heater via a two-way valve from between a pressure reducer to the suction side of the compressor, the vaporizer is heated by the vaporization heater. When the operating current of the air conditioner exceeds a set value lower than the current set value of the overcurrent protection device, a refrigerant heating device having a vaporizing heater that stops energizing the vaporizing heater for a certain period of time. A control device for an air conditioner comprising: 2. When the operating current of the air conditioner exceeds a first set value lower than the current set value of the overcurrent protection device while the evaporator is being heated by the evaporator heater,
The power supply to the vaporization heater is stopped until the current falls below a second set value which is lower than a value obtained by subtracting a current value flowing through the vaporization heater from a first set value.
A control device for an air conditioner, comprising a refrigerant heating device having the vaporization heater according to the above. 3. When the refrigerant recovery operation for operating the compressor with the four-way valve closed on the heating side and the two-way valve closed at the same time while the vaporizer is being heated by the vaporization heater, When the operating current of the machine exceeds a set value lower than the current set value of the overcurrent protection device, the power supply to the vaporizing heater is stopped until the refrigerant recovery operation is completed. A control device for an air conditioner equipped with a refrigerant heating device.