JP2002098423A - Air conditioner having refrigerant heating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce an electric input during delayed operation of a compressor after a stop of combustion, in an air conditioner having a refrigerant heating device. SOLUTION: By setting the operation frequency of a compressor during delayed operation of the compressor by a state amount of a refrigerant, even in a case of a stop from an any state, reliability of the compressor is not damaged and through exhaust heat by surplus heat exhaust operation, the temperature of a heat exchanger 8a of the refrigerant heating device is increased and compressor delayed operation is practicable at a compressor frequency necessary at a minimum limit to prevention of a refrigerant from superheating, and an electric input during delayed operation of the compressor can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art A conventional control device for an air conditioner equipped with a refrigerant heating device has been disclosed, for example, in JP-A-3-255845.

FIG. 1 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 for heating kerosene by burning kerosene from the space between the indoor heat exchanger 3 and the pressure reducer 4 to the suction side of the compressor 1 via the two-way valve 7. Constitute a refrigeration cycle.

In the heating operation, the four-way valve 2 is set to the heating side and the two-way valve 7
Is opened to operate the compressor 1, whereby 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.

On the other hand, the operation of the refrigerant heating device 8 is to heat a vaporizer (not shown) to an appropriate temperature by a vaporization heater (not shown), and then to operate a blower for supplying combustion air (not shown) to supply fuel. The pump 10 is operated, and fuel is ignited by an igniter (not shown) to start combustion.

By operating the refrigerant heating device 8 while circulating the refrigerant in this way, the heat generated in the combustor (not shown) is absorbed by the refrigerant in the heat exchanger 8a of the refrigerant heating device, and the indoor side is cooled. By radiating heat from the heat exchanger 3, the room can be heated.

[0007] When the heating operation is stopped or when the indoor temperature reaches the set temperature and the outdoor unit is stopped, the temperature of the vaporizer (not shown) is reduced to prevent tarring of unburned fuel. Blower for supplying combustion air even after combustion is stopped (not shown)
The operation of removing residual heat is performed to continue the operation of. On this occasion,
By continuing the operation of the compressor 1 and delaying the circulation of the refrigerant, the compressor 1 performs the compressor delay operation in which the waste heat from the residual heat removal operation is absorbed by the refrigerant. In this way, by stopping the operation of the compressor 1 after the temperature of the heat exchanger 8a of the refrigerant heating device has become sufficiently low, the temperature of the heat exchanger 8a of the refrigerant heating device increases due to exhaust heat, To prevent overheating.

[0008]

However, in the air conditioner equipped with the refrigerant heating device as described above, the compressor frequency in the compressor delay operation is changed from the state in which the refrigerant pressure is high due to the overload operation to the compressor delay operation. In order to ensure that there is no problem in the reliability of the compressor 1 even in the case of shifting, the compressor 1 is operated at the lowest frequency at which the reliability of the compressor 1 can be secured even at the pressure during the overload operation. This frequency is the minimum required for the compressor 1 to prevent the temperature of the heat exchanger 8a of the refrigerant heating device from rising due to the exhaust heat due to the residual heat removal operation and the refrigerant from overheating.
Higher than the operating frequency of

Further, even when the temperature of the heat exchanger 8a of the refrigerant heating device is high, such as when the operation is stopped by the overheat protection control of the heat exchanger 8a of the refrigerant heating device, the residual heat removal operation is performed. In order to prevent the temperature of the heat exchanger 8a of the refrigerant heating device from rising due to the exhaust heat and to prevent the refrigerant from overheating, the compressor frequency in the compressor delay operation is stopped from the normal operation state. When the temperature of the heat exchanger 8a of the refrigerant heating device is not high as in the case of
Is set higher than the operating frequency.

Therefore, when the operation is stopped from a state where the refrigerant pressure is low or a state where the temperature of the heat exchanger 8a of the refrigerant heating device is not high, the compressor delay operation is performed at an unnecessarily high frequency. There is a problem that the electric input of the machine delay operation increases.

The present invention has been made to solve such a conventional problem, and it is an object of the present invention to provide an electric compressor for delay operation of a compressor when the operation is stopped from a state where the refrigerant pressure is low or a state where the temperature of the heat exchanger 8a of the refrigerant heating device is not high. The purpose is to reduce input.

[0012]

According to a first aspect of the present invention, at least two or more types of operating frequencies of a compressor during a delayed compressor operation are set in accordance with a state quantity of a refrigerant. .

Accordingly, even if the compressor is stopped from any state, the reliability of the compressor is not impaired, and the temperature of the heat exchanger 8a of the refrigerant heater rises due to the exhaust heat due to the residual heat removal operation, and the refrigerant is discharged. The compressor delay operation can be performed at the minimum necessary compressor frequency to prevent overheating.

According to a second aspect of the present invention, at least two types of operating frequencies of the compressor 1 during the delay operation are set according to the pressure of the refrigerant. Thus, the compressor delay operation can be performed at the lowest frequency at which the reliability of the compressor 1 can be ensured.

According to a third aspect of the present invention, at least two or more types are set according to the temperature of the heat exchanger 8a of the refrigerant heating device during the delay operation. As a result, the compressor delay operation can be performed at the lowest frequency that prevents the temperature of the heat exchanger 8a of the refrigerant heating device from rising and the refrigerant from being overheated.

[0016]

Embodiments of the present invention will be described below with reference to the drawings.

The refrigeration cycle and the cooling operation are the same as those in the prior art, and therefore the description is omitted. Also, the heating operation and the case where the heating operation is stopped to stop the refrigerant heating device 8 are the same as those of the prior art except for the setting of the frequency of the compressor delay operation, and thus the description thereof is omitted.

In this embodiment, the compressor operation frequency during the compressor delay operation is set as follows.

When the operation shifts to the compressor delay operation, the discharge pressure of the compressor 1 is detected by the discharge saturation temperature sensor 11 as the discharge saturation temperature Ta, and the temperature Tb of the heat exchanger 8a of the refrigerant heating device is detected by the heat exchanger temperature sensor 12. To detect. Here, as shown in FIGS. 2 and 3, the operating frequency of the compressor 1 is set based on the discharge saturation temperature Ta and the temperature Tb of the heat exchanger 8a of the refrigerant heating device. The compressor 1 is operated at the higher one of the operating frequencies set from the temperature Tb of the heat exchanger 8a of the refrigerant heating device. When the operation shifts to the compressor delay operation, the discharge saturation temperature Ta becomes T1 and T.
2 and between T3 and T4, the operating frequency of the compressor 1 is set to N1 and N2, respectively.
Further, the temperature Tb of the heat exchanger 8a of the refrigerant heating device is T5
If it is between T6 and T6, the operating frequency of the compressor 1 is set to N4.

FIG. 4 is a chart showing the compressor frequency during the compressor delay operation of this embodiment. The heat exchanger 8a of the refrigerant heating device when the combustion stops and the compressor shifts to the delay operation.
Is between T5 and T6, the compressor operating frequency set from the temperature Tb of the heat exchanger 8a of the refrigerant heating device is N4. On the other hand, when the operation shifts to the compressor delay operation, the discharge saturation temperature Ta is higher than T1.
The compressor operating frequency set from a is N1. Here, since N1> N4, the compressor 1 is operated at the frequency of N1. When the discharge saturation temperature Ta decreases and becomes lower than T2, the compressor operating frequency set from the discharge saturation temperature Ta becomes N2. However, while the temperature Tb of the heat exchanger 8a of the refrigerant heating device is higher than T6, the heat exchanger 8
The compressor operating frequency set from the temperature Tb of a remains at N4, and since N4> N2, the compressor 1 is operated at the frequency of N4. Further, the heat exchanger 8 of the refrigerant heating device
When the temperature Tb of a decreases and becomes lower than T6, the compressor operating frequency set from the temperature Tb of the heat exchanger 8a of the refrigerant heating device becomes N5, but the discharge saturation temperature is higher while the discharge saturation temperature Ta is higher than T4. The compressor operating frequency set from Ta remains N2, and since N2> N5, the compressor 1 is operated at the frequency of N2. Further, when the discharge saturation temperature Ta decreases and becomes lower than T4, the discharge saturation temperature T
The compressor operating frequency set from a is N3 and N5
Since> N3, the compressor 1 is operated at the frequency of N5. When a certain time has elapsed after the shift to the compressor delay operation, the compressor 1 is stopped and the compressor delay operation is terminated.

In this way, the compressor operating frequency setting is changed in accordance with the change in the discharge saturation temperature Ta during the compressor delay operation and the temperature Tb of the heat exchanger 8a of the refrigerant heating device.

As described above, regardless of the state in which the compressor is stopped and the operation is shifted to the compressor delay operation, the refrigerant pressure, that is, the discharge saturation temperature Ta, the heat exchanger of the refrigerant heating device, or the like during the compressor delay. Even if the temperature Tb of the compressor 8a changes, the reliability of the compressor 1 is not impaired, and the temperature Tb of the heat exchanger 8a of the refrigerant heating device rises due to exhaust heat due to the residual heat removal operation, and the refrigerant is overheated. Therefore, the compressor delay operation can be performed at the minimum compressor frequency required to prevent the occurrence of the power failure, so that the electric input during the compressor delay operation can be reduced.

In this embodiment, the pressure of the refrigerant is detected as the discharge saturation temperature Ta, but the pressure of the refrigerant may be directly detected by a pressure sensor. Further, even if the compressor operating frequency is set at the temperature of the indoor heat exchanger 3, the same effect can be obtained. Further, the same effect can be obtained by setting the compressor operating frequency by the outlet pipe temperature of the refrigerant heating device 8 instead of the temperature Tb of the heat exchanger 8a of the refrigerant heating device.

[0024]

According to the first aspect of the present invention, at least two types of operating frequencies of the compressor during the compressor delay operation are set according to the state quantity of the refrigerant. Accordingly, even when the compressor is stopped from any state, the reliability of the compressor is not impaired, and the temperature of the heat exchanger 8a of the refrigerant heating device rises due to the exhaust heat due to the residual heat removal operation, and the refrigerant is overheated. Thus, the compressor delay operation can be performed at the minimum necessary compressor frequency to prevent the operation.

Further, the invention according to claim 2 is to set at least two or more types of operating frequencies of the compressor 1 during the delayed operation by the pressure of the refrigerant. And this gives
The compressor delay operation can be performed at the lowest frequency at which the reliability of the compressor 1 can be ensured, and the electric input of the compressor delay operation during the compressor delay operation can be reduced.

According to a third aspect of the present invention, at least two or more types are set according to the temperature of the heat exchanger 8a of the refrigerant heating device during the delayed operation. As a result, the temperature of the heat exchanger 8a of the refrigerant heating device rises, and the compressor delay operation can be performed at the lowest frequency that can prevent the refrigerant from overheating. Can reduce electric input.

[Brief description of the drawings]

FIG. 1 is a refrigeration cycle diagram of a prior art and an embodiment of the present invention.

FIG. 2 is a compressor operating frequency setting diagram based on a discharge saturation temperature according to the embodiment of the present invention.

FIG. 3 is a compressor operating frequency setting diagram based on a heat exchanger temperature of the refrigerant heating device according to the embodiment of the present invention.

FIG. 4 is a compressor delay operation chart according to the embodiment of the present invention.

[Description of Signs] 1 Compressor 2 4-way valve 3 Indoor heat exchanger 4 Pressure reducer 5 First check valve 6 Heat exchanger for outdoor cooling 7 2-way valve 8 Refrigerant heating device 8a Heat of refrigerant heating device Exchanger 9 Second check valve 10 Fuel pump 11 Discharge saturation temperature sensor 12 Heat exchanger temperature sensor

Claims (4)

[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 having a refrigeration cycle in which a refrigerant heating device is connected through a two-way valve to a suction side of the compressor from between the pressure reducers, a residual heat elimination operation is performed by a delayed operation of a combustion air supply blower after stopping combustion. And a delayed operation of the compressor is performed, and the operating frequency of the compressor during the delayed operation is set to at least 2 by the state quantity of the refrigerant.
An air conditioner equipped with a refrigerant heating device that sets more than one type. 2. An air conditioner equipped with a refrigerant heating device according to claim 1, wherein at least two types of operating frequencies of the compressor during the delayed operation are set according to the pressure of the refrigerant. 3. The operating frequency of the compressor during the delayed operation is set to at least two times according to the temperature of the heat exchanger of the refrigerant heating device.
An air conditioner comprising the refrigerant heating device according to claim 1, wherein the air conditioner is set to at least one type. 4. The refrigerant heating device according to claim 1, wherein at least two types of operating frequencies of the compressor during the delayed operation are set according to the pressure of the refrigerant and the temperature of the heat exchanger of the refrigerant heating device. Air conditioner.