JP3242214B2 - Refrigerant heating air conditioner - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigerant heating type air conditioner provided with a refrigerant heater, and more particularly to a two-way valve leak detecting structure which is a refrigerant recovery means of an outdoor heat exchanger.

[0002]

2. Description of the Related Art In an air conditioner using a refrigeration cycle, the performance of a heat pump air conditioner has been remarkably improved due to the development of inverter control technology and the like. However, the performance improvement is significant for the cooling capacity and not so much for the heating capacity. This is because the heating effect is affected by the outside air temperature, and the problem that the heating capacity decreases as the outside air temperature becomes lower has not been solved.

Therefore, the heating capacity is not affected by the outside temperature,
In addition, attention has been paid to a refrigerant-heated air conditioner having a space saving equivalent to that of a normal heat pump air conditioner, easy workability and safety.

A refrigeration cycle of this type of air conditioner includes a compressor, a four-way valve, an outdoor heat exchanger, a check valve, a cooling expansion device, an indoor heat exchanger, and a cooling refrigerant circuit for sequentially connecting the compressor. Branching from between the check valve and the indoor heat exchanger,
It includes a refrigerant heater connected to the compressor, and includes a compressor, a four-way valve, an indoor heat exchanger, a refrigerant heater, and a heating refrigerant circuit for sequentially connecting the compressor.

[0005] A two-way valve is provided upstream of the refrigerant heater, and the two-way valve is closed to operate in the heating refrigerant circuit so that the refrigerant in the outdoor heat exchanger is recovered. Has become.

[0006] The refrigerant heater is provided with a refrigerant pipe as a heat exchange pipe along a peripheral surface of the heater main body through which the combustion gas flows. A combustion unit including a gas burner, a proportional control valve, and the like is arranged to face the refrigerant heater.

[0007] During the heating operation, the combustion unit heats the refrigerant heater in a state where combustion control is performed based on a signal from the control circuit. During the cooling operation, the two-way valve is closed to guide the refrigerant to the refrigerant circuit for cooling.

During the heating operation, the refrigerant in the outdoor heat exchanger is recovered, the four-way valve is switched, and the two-way valve is opened to guide the refrigerant to the refrigerant circuit for heating. At this time, gas combustion is performed by the gas burner to heat the refrigerant heater. Therefore, in a state where the gas-burned heat is added to the refrigerant, the refrigerant carries heat to the indoor heat exchanger to perform a heating action.

[0009]

By the way, the refrigerant, which is a heat exchange medium used in the air conditioner, originally has a refrigerating cycle having a hermetic structure, and contaminants such as dust are mixed into the refrigerant from the outside. I can't imagine that.

[0010] However, in actuality, at the stage when a refrigeration cycle component device such as a compressor is manufactured, chips and other impurities tend to adhere to the inside thereof. Naturally, the finished product is obtained through the internal washing step, but may remain as it is under some conditions, and this is mixed into the refrigerant.

In particular, since the two-way valve is closed during the cooling operation, the above-mentioned contaminants in the refrigerant are easily collected and penetrate into the details to be accumulated. If left as it is, impurities that accumulate in the valve portion of the two-way valve cannot maintain a completely closed (water-stopped) state, and a so-called valve leakage phenomenon occurs.

Since the inside of the valve body is not provided with a faucet like a faucet, it cannot be judged from outside. In fact, if there is a valve leak during the cooling operation, the refrigerant is depressurized, becomes low temperature, and is guided to the refrigerant heater, similarly to passing through a very small hole. Since there is no combustion action of the combustion unit, the leaked refrigerant evaporates in the refrigerant heater and is discharged at a lower temperature.

In the refrigerant heater, dew condensation occurs on the surface. When the dew grows, it eventually flows down and leaks from the refrigerant heater, and wets the surrounding components. If valve leakage continues with long-term use, there is a possibility that rust may occur in the components.

The present invention has been made in view of the above circumstances, and a purpose thereof is to determine valve leakage of a two-way valve, and in the case of valve leakage, cause the cause of the leakage from the valve body. The present invention provides an air conditioner capable of improving reliability by providing an aggressive countermeasure against valve leakage, and enabling discrimination between valve leakage and failure of the two-way valve itself.

[0015]

In order to achieve the above object, a refrigerant-heated air conditioner according to a first aspect of the present invention provides an outdoor heat exchanger, a check valve, a four-way valve from a discharge side of a compressor. A valve, a cooling expansion device, an indoor heat exchanger, a cooling refrigerant circuit for sequentially connecting the suction side of the compressor, and a branch from a connection pipe between the check valve and the indoor heat exchanger, and a compressor suction side. A heating refrigerant circuit that sequentially connects the indoor heat exchanger, the refrigerant heater, and the suction side of the compressor from a discharge side of the compressor through a four-way valve, and a refrigerant heater connected to the refrigerant heater. A two-way valve interposed on the upstream side, and a control means for recovering the refrigerant of the outdoor heat exchanger by closing the two-way valve and performing an operation in a heating refrigerant circuit, Upstream and downstream of the refrigerant heater, temperature detecting means provided respectively, during cooling operation Means for determining valve leakage of the two-way valve by comparing the temperature difference detected by the temperature detecting means with the set temperature difference, and means for opening and closing the two-way valve several times based on a signal from the determination means. did.

A refrigerant-heated air conditioner according to a second aspect of the present invention provides an outdoor heat exchanger, a check valve, a throttle device for cooling, an indoor heat exchanger, a compressor from a discharge side of a compressor via a four-way valve. A cooling refrigerant circuit for sequentially connecting the suction sides of the compressor, and a refrigerant heater branched from a connection pipe between the check valve and the indoor heat exchanger and connected to the compressor suction side. From the side, an indoor heat exchanger, a refrigerant heater, a heating refrigerant circuit sequentially connecting the suction side of the compressor via a four-way valve, and a two-way valve interposed on the upstream side of the refrigerant heater, In a refrigerant heating type air conditioner equipped with control means for recovering the refrigerant of the outdoor heat exchanger by closing the two-way valve and operating in the refrigerant circuit for heating, the upstream side of the two-way valve, the refrigerant Temperature detecting means provided respectively on the downstream side of the heater, and the above-mentioned temperature during cooling operation. And detecting the temperature difference by known means, means for determining a valve leakage of the two-way valve by comparing the set temperature difference,
The means for opening and closing the two-way valve several times based on the signal of the determination means and the means for determining the valve leakage of the two-way valve emit a set number of signals within a predetermined time, stop the cooling operation and And means for displaying an abnormality.

[0017]

In the cooling operation, the detected temperature difference ΔT ₀ of the temperature detecting means is compared with the set temperature ΔT _{1. If} the detected temperature difference ΔT ₀ is larger than the set temperature difference ΔT ₁ ,
It is determined that a two-way valve is leaking.

When a two-way valve leaks, the two-way valve is opened and closed several times, and contaminants causing a valve leak are caused to flow out. When the opening / closing operation of the two-way valve is performed a set number of times N within a predetermined time, the cooling operation is stopped and an abnormality is displayed.

[0019]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a refrigeration cycle circuit of the air conditioner. In the figure, reference numeral 1 denotes a compressor. On the discharge side of the compressor 1, a four-way valve 2, an outdoor heat exchanger 3, an electronic expansion valve 4 which is a cooling throttle device, and an indoor heat exchanger 5 are arranged in this order in a refrigerant pipe. Connected via P. Check valves 6 and 7 are provided between the outdoor heat exchanger 3 and the electronic expansion valve 4 and between the four-way valve 2 and the compressor 1 suction side, respectively.

A connection pipe 8 connects between the check valve 6 and the electronic expansion valve 4 and a connection between the check valve 7 and the suction section of the compressor 1. The connection pipe 8 is connected to the connection pipe 8. The vessels 10 are connected in series. The refrigerant heater 10 includes a gas burner, and a combustion unit 11 that communicates with the gas supply source via a proportional control valve through the gas burner is disposed to face the combustion unit 11.

In such a refrigeration cycle, the four-way valve 2, the outdoor heat exchanger 3, the electronic expansion valve 4, the indoor heat exchanger 5, the four-way valve 2, and the suction side of the compressor 1 are arranged from the discharge side of the compressor 1. , A cooling refrigerant circuit C for cooling is configured.

From the discharge side of the compressor 1, a four-way valve 2,
A heating refrigerant circuit H is connected in the order of the indoor heat exchanger 5, the electronic expansion valve 4, the refrigerant heater 10, the four-way valve 2, and the suction side of the compressor 1.

The configuration of the refrigeration cycle is as described above, but an outdoor blower (not shown) and an indoor blower (not shown) are provided opposite to the outdoor heat exchanger 3 and the indoor heat exchanger 5, respectively.

A first temperature sensor 12 is provided between the two-way valve 9 and the check valve 6 on the upstream side of the two-way valve 9. The refrigerant heater 10 on the downstream side of the refrigerant heater 10
A second temperature sensor 13 is provided between the compressor and the suction section of the compressor 1.
Is provided.

The compressor 1 on the downstream side of the outdoor heat exchanger 3
A third temperature sensor 14 is provided between the discharge part and the four-way valve 2. These first to third temperature sensors 12, 1
3, 14 constitute a temperature detecting means.

The compressor 1, the four-way valve 2, the electronic expansion valve 4, the two-way valve 9, the first to third temperature sensors 1 described above.
2, 13, 14 and the proportional control valve of the combustion unit 11 are all electrically connected to a control circuit 15 to send a detection signal to the control circuit or to receive a control signal from the control circuit.

During the cooling operation, the refrigerant is guided as shown by the solid arrow in the figure. With the two-way valve 9 closed, the refrigerant circulates through the cooling refrigerant circuit C. That is, the compressor 1-the four-way valve 2-the outdoor heat exchanger 3-the check valve 6-
Electronic expansion valve 4-Indoor heat exchanger 5-Four-way valve 2-Check valve 7-
It is led in the order of the compressor 1.

[0028] The refrigerant evaporates in the indoor heat exchanger 5, and the air to be air-conditioned to be guided there is deprived of the latent heat of evaporation to lower the temperature.
The air is blown out as it is to cool the room to be conditioned. At this time, the first temperature sensor 12 and the third temperature sensor 14
Detects the temperature of each mounting portion and sends a detection signal to the control circuit 15.

These sensors 12 and 14 detect the inlet side temperature and the outlet side temperature of the outdoor heat exchanger 3 which is a condenser and send them to the control circuit 15, and the appropriate refrigerant flow rate by the superheat control on the high pressure side. , The heat exchange efficiency and the cooling performance are improved, and the high pressure of the compressor 1 is protected.

During the heating operation, the four-way valve 2 is switched to the heating operation, but the two-way valve 9 is initially kept closed. When the compressor 1 is driven and the refrigerant discharged from the compressor 1 is stopped by the check valve 6 and the two-way valve 12,
All the refrigerant on the suction side is sucked. Therefore, the refrigerant that has stagnated (resides) in the outdoor heat exchanger 3 is sucked into the compressor 1 and collected.

After a lapse of a predetermined recovery time, the two-way valve 9 is opened, the gas combustion of the combustion unit 11 is started, and the refrigerant is guided as shown by a broken line arrow in the figure. The refrigerant circulates through the heating refrigerant circuit H. That is,
Compressor 1-four-way valve 2-indoor heat exchanger 5-electronic expansion valve 4-
The two-way valve 9-the refrigerant heater 10-the four-way valve 2-the check valve 7-the compressor 1 are led in this order.

The refrigerant is heated by the refrigerant heater 10 and guided to the compressor 1. At this time, the heat obtained by the refrigerant heater 10 is added to the refrigerant, and the refrigerant carries heat to the indoor heat exchanger 5 to perform an extremely effective heating operation.

The first temperature sensor 12 and the second temperature sensor 13 detect the temperatures of the respective mounting portions and send the detection signals to the control circuit 15. These sensors 12, 1
3 detects the inlet side temperature and the outlet side temperature of the refrigerant heater 10 which is an evaporator and sends them to the control circuit 15. The superheat control on the low pressure side adjusts and maintains the appropriate refrigerant flow rate and heat exchange. The efficiency and the heating performance can be improved, and the appropriate heating control of the combustion unit 11 can be achieved.

During the cooling operation described above, control is performed by the control circuit 15 for the purpose of judging whether the two-way valve 9 is leaking. That is, the first and third temperature sensors 1
In addition to the high-pressure side superheat control by the second and the second temperature sensors 14, the first temperature sensor 12 and the second temperature sensor 13 each send a detected temperature signal to the control circuit 15.

If the two-way valve 9 actually leaks, the leaking refrigerant is guided to the refrigerant heater 10 to be decompressed and discharged at a low temperature. Therefore, there is a difference between the detected temperatures of the first and second temperature sensors 12 and 13.

The control circuit 15 performs necessary control according to a flowchart as shown in FIG. After the start, the counter provided in the control circuit 15 counts the number N = 0.
Set. Then, the timer provided in the control circuit 15 starts counting t.

Normally, the leakage of the two-way valve 9 should be extremely small, and the pressure-reducing phenomenon in the refrigerant heater 10 does not occur immediately after the start. Therefore, the control circuit 15 may be set to be I time t ₁ to a valve leak appears to always compared with the count time t of the timer.

After the count time t exceeds the set time t ₁ , a difference ΔT ₀ between the detected temperature of the first temperature sensor 12 and the detected temperature of the second temperature sensor 13 is detected. Then, the temperature difference ΔT ₀ is compared with the set temperature ΔT ₁ stored in the control circuit 15 in advance.

If the difference ΔT ₀ between the temperatures detected by the temperature sensors 12 and 13 is equal to or greater than the set temperature ΔT _1, it is determined that foreign matter has entered the two-way valve 9 and valve leakage has occurred. Determination.

The control circuit 15 turns ON / OF the two-way valve 9.
The F signal is sent to open and close the valve. The above counter is
The number N of times of opening and closing the two-way valve 9 is counted up by one. Normally, the control returns to the timer count t and performs the control described above. If the contaminants flow out of the two-way valve 9, the completely closed state is maintained. Therefore, the detected temperature difference ΔT ₀ between the first and second temperature sensors 12 and 13 is equal to the set temperature difference. It is smaller than ΔT ₁ and therefore there is no opening and closing of the two-way valve 9.

However, if the detected temperature difference ΔT ₀ is still larger than the set temperature ΔT ₁ , it is determined that the outflow of impurities is insufficient and the valve leakage is still continuing, and the two-way valve 9 is again turned on. To send an ON / OFF signal to open and close the valve. The counter accumulates the open / close count.

Each time, the count number N is compared with the set count number N ₁ stored in the control circuit 15 in advance. The set time t _1, when the count number N exceeds the set count N _1, it is determined that the failure of the two-way valve 9 itself to stop the refrigeration cycle operation, and forms an abnormal display. Therefore,
Appropriate measures must be taken.

[0043]

As described above, the first invention is a refrigeration cycle in which a two-way valve is opened during a heating operation to guide refrigerant to a refrigerant heater. Temperature detection means is provided downstream of the heater, and during cooling operation, a two-way valve leak is determined by comparing a temperature difference detected by the temperature detection means with a set temperature difference, and the two-way valve is determined based on the determination signal. Since the valve is opened and closed several times, the second invention is a refrigeration cycle in which the two-way valve is opened and the refrigerant is guided to the refrigerant heater during the heating operation. Side, and a temperature detection means provided on the downstream side of the refrigerant heater,
During the cooling operation, valve leakage of the two-way valve is determined by comparing the temperature difference detected by the temperature detecting means with the set temperature difference, and the two-way valve is opened and closed several times based on this determination signal. When the opening / closing operation of the two-way valve has been performed a set number of times, the cooling operation is stopped and an error is displayed, so aggressive measures against valve leakage for the two-way valve are taken. It is also possible to determine that a failure has occurred, and it is possible to improve the reliability.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a refrigeration cycle and a control circuit of an air conditioner, showing an embodiment of the present invention.

FIG. 2 is a flowchart relating to the removal of contaminants of a two-way valve.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Compressor, 2 ... Four-way valve, 3 ... Outdoor heat exchanger, 6 ... Check valve, 4 ... Cooling expansion device (electronic expansion valve), 5 ... Indoor heat exchanger, C ... Cooling refrigerant circuit, 10 ... a refrigerant heater, H ... a refrigerant circuit for heating, 9 ... a two-way valve, 12 ... a first temperature sensor,
13: second temperature sensor, 15: control circuit.

Claims (2)

(57) [Claims] 1. An outdoor heat exchanger, a check valve, a cooling throttle device, an indoor heat exchanger, a four-way valve from a discharge side of a compressor.
A refrigerant circuit for cooling, which sequentially connects the suction sides of the compressor, and a branch from a connection pipe between the check valve and the indoor heat exchanger,
A heating refrigerant circuit that includes a refrigerant heater connected to the compressor suction side, and sequentially connects the indoor heat exchanger, the refrigerant heater, and the compressor suction side from the compressor discharge side through a four-way valve, Refrigerant comprising a two-way valve interposed on the upstream side of the refrigerant heater, and a control means for recovering the refrigerant of the outdoor heat exchanger by closing the two-way valve and performing operation in the refrigerant circuit for heating. In the heating type air conditioner, temperature detection means provided on each of an upstream side of the two-way valve and a downstream side of the refrigerant heater, and a temperature difference detected by the temperature detection means during a cooling operation,
Refrigerant heating air conditioning characterized by comprising means for judging valve leakage of a two-way valve by comparison with a set temperature difference, and means for opening and closing the two-way valve several times based on a signal from the judging means. Machine. 2. An outdoor heat exchanger, a check valve, a cooling throttle device, an indoor heat exchanger, a four-way valve from the discharge side of the compressor.
A refrigerant circuit for cooling, which sequentially connects the suction sides of the compressor, and a branch from a connection pipe between the check valve and the indoor heat exchanger,
A heating refrigerant circuit that includes a refrigerant heater connected to the compressor suction side, and sequentially connects the indoor heat exchanger, the refrigerant heater, and the compressor suction side from the compressor discharge side through a four-way valve, Refrigerant comprising a two-way valve interposed on the upstream side of the refrigerant heater, and a control means for recovering the refrigerant of the outdoor heat exchanger by closing the two-way valve and performing operation in the refrigerant circuit for heating. In the heating-type air conditioner, temperature detection means provided respectively on the upstream side of the two-way valve and on the downstream side of the refrigerant heater, and a temperature difference detected by the temperature detection means during a cooling operation,
Means for determining valve leakage of the two-way valve by comparing with a set temperature difference; means for opening and closing the two-way valve several times based on a signal of the determination means; and means for determining valve leakage of the two-way valve. A refrigerant heating type air conditioner characterized in that when a set number of signals is issued within a predetermined time, a cooling operation is stopped and an abnormality is displayed.