JP3317869B2 - 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 for heating a refrigerant during heating.

[0002]

2. Description of the Related Art Among conventional refrigerant-heated air conditioners, a multi-type air conditioner in which a plurality of indoor units are connected in parallel is configured as shown in FIG. Here, reference numeral 3 denotes a compressor in the outdoor unit, which is connected to the four-way valve 4. A plurality of indoor units 5a and 5b are connected to the four-way valve 4 in parallel. The connection path includes refrigerant flow control valves 8c, 8c.
d and three-way valves 18a and 18b are provided. The indoor units 5a and 5b as indoor units include an indoor heat exchanger 6
a, 6b and indoor fans 7a, 7b. The three-way valves 18c, 1c are provided on the liquid side pipes of the indoor heat exchangers 6a, 6b.
8d and refrigerant flow control valves 8a and 8b are provided. A portion ahead of the refrigerant flow control valves 8a and 8b is a merging conduit, and a main flow control valve 9 is provided in the merging conduit. This main flow control valve 9
Is connected to a refrigerant heater 11 via a two-way valve 10 that opens during a heating operation and closes during a cooling operation. The refrigerant heater 11 is provided with a burner motor 13 for supplying air for combustion and an electromagnetic pump 14 for supplying fuel for combustion. The refrigerant heater 11 is connected to an accumulator 12, and the accumulator 12
To form a heating operation cycle.

[0003] An outdoor heat exchanger 15 is used during the cooling operation. One end is connected to the four-way valve 4 and the other end is connected to the four-way valve 4.
It is connected to a pipe in a portion between the main refrigerant flow control valve 9 and the two-way valve 10. 16 is an outdoor fan. 17
Reference numerals a and 17b denote check valves for preventing the refrigerant from flowing to the outdoor heat exchanger 15 during the heating operation.

[0004] A refrigeration cycle during cooling will be described.
During the cooling, the two-way valve 10 is closed so that the refrigerant does not flow through the refrigerant heater 11. Then, the four-way valve 4 is switched to flow the refrigerant in the direction of the dashed arrow, and the refrigerant discharged from the compressor 3 flows into the outdoor heat exchanger 15, where it is heated by the outdoor fan 16, and the heated refrigerant is checked. Valve 1
After 7b, the main refrigerant flow control valve 9 undergoes expansion. The gas refrigerant whose flow amount to each heat exchanger 6a, 6b is controlled by the refrigerant flow control valves 8a, 8b for refrigerant distribution absorbs heat from the atmosphere by the indoor fans 7a, 7b in the indoor heat exchangers 6a, 6b. Do. Then, a refrigeration cycle that circulates to the accumulator 12 via the four-way valve 4 and the check valve 17a is configured.

[0005] A refrigeration cycle during heating will be described.
During this heating, the four-way valve 4 is switched to flow the refrigerant in the direction of the solid arrow, and the two-way valve 10 is opened. Then, the refrigerant discharged from the compressor 3 flows into the indoor heat exchangers 6a and 6b via the four-way valve 4. Indoor fan 7a7
The liquid refrigerant radiated by the blown air from the refrigerant flow control valves 8a and 8b for refrigerant distribution and the main refrigerant flow control valve 9
And flows into the refrigerant heater 11 through the open two-way valve 10. The refrigerant heat is absorbed by the refrigerant heater 11 and circulated to the accumulator 12, thereby forming a refrigeration cycle.

Next, the operation during heating will be described.
When the indoor units 5a and 5b receive the signal of the heating operation, first, the four-way valve 4 is turned off and the two-way valve 10 is closed. The refrigerant flow control valves 8a and 8b for distributing the refrigerant are provided in each of the indoor units 5a5.
The set opening degree is set to the amount of refrigerant necessary for the required capacity b, and the set opening degree of the main refrigerant flow control valve 9 is set to control the amount of refrigerant required for the total required capacity. Then, a signal of combustion preparation is instructed to the refrigerant heater 11, and the compressor 3 is driven, and the refrigerant in the pipeline from the check valve 17 a through the outdoor heat exchanger 15 to the check valve 17 b is transferred to the refrigerant heater 11. Collect through.
When the outdoor heat exchanger 15 has a negative pressure due to the recovery of the refrigerant, the driving of the compressor 3 is stopped and the two-way valve 10 is opened. The four-way valve 4 is returned to the original state.

Next, before the refrigerant heater 11 becomes ready for combustion, the compressor 3 is driven again to circulate the refrigerant to the heating refrigeration cycle. By circulating the refrigerant before the refrigerant heater 11 burns in this way, it is possible to prevent the refrigerant heater 11 from overshooting when the combustion is started. When the refrigerant heater 11 is in a combustible state, combustion fuel is fed from the electromagnetic pump 14 and combustion air is fed by the burner motor 13 to start combustion. It should be noted that the main refrigerant flow control valve 9 during the heating operation does not play a role of shrinkage in the heat pump refrigeration cycle.

[0008]

However, in the above-mentioned conventional configuration, the refrigerant is heated by the refrigerant heater 11, so that the suction pressure of the compressor 3 is increased, and a high-low pressure difference is hardly generated. At a long pipe height drop, the refrigerant does not circulate as much as the heat pump type, and the refrigerant becomes insufficient and the operation of the refrigerant heater 11 and the indoor units 5a and 5b is repeatedly stopped frequently to improve the comfort in the living environment and the refrigerant heater 11 Can cause problems in terms of reliability.

Particularly, as shown in the figure, a plurality of indoor units 5a, 5
When b is connected, the operation state frequently changes, and the combustion output of the refrigerant heater 11 changes accordingly. However, the refrigerant circulation amount cannot correspond to the required combustion power, and the refrigerant tends to overheat. In addition, there is a possibility that the operation of the refrigerant heater 11 is frequently stopped repeatedly to cause a problem in reliability. Further, a refrigerant heater 11 having a large combustion output is required to connect the plurality of indoor units 5a and 5b. The ability could not be secured, and this was also a problem in terms of comfort, and improvement was required.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above problems and to prevent a refrigerant heater from being overheated by combustion heat due to a shortage of refrigerant in a refrigerant heater. Another object of the present invention is to prevent a refrigerant heater from becoming insufficient and being overheated, particularly when a plurality of indoor units are installed.

[0011]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a bypass circuit for bypassing a discharge side of the compressor and an inlet side of a refrigerant heater during a heating operation, and a bypass circuit provided in the bypass circuit. Refrigerant flow control valve,
Prevents overheating of refrigerant in the refrigerant superheater during heating operation
And means for controlling the refrigerant flow control valve .

According to this, during the heating operation, the gas refrigerant discharged from the compressor and passing through the bypass circuit is combined with the liquid refrigerant discharged from the indoor unit. For this reason, even if the liquid refrigerant discharged from the indoor unit tends to be insufficient, it is supplemented by the gas refrigerant from the bypass circuit, so that the refrigerant is not overheated by the refrigerant heater, resulting in a stable refrigeration cycle and comfortable operation. Performance and reliability.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 has an indoor unit and an outdoor unit provided with a compressor and a refrigerant heater, and exchanges the refrigerant discharged from the compressor during heating with the indoor unit. In the refrigerant heating air conditioner having a configuration in which the refrigerant flowing out of the heat exchanger is heated by a refrigerant heater and sent to the compressor, the refrigerant discharge side and the refrigerant heating during the heating operation A bypass circuit for bypassing the inlet side of the machine, and a bypass circuit
Refrigerant flow control valve, and the refrigerant superheater during the heating operation
Refrigerant flow control to prevent overheating of refrigerant in
Means for controlling the valve .

According to this, in the heating operation, the circulation of the refrigerant is reduced due to the long pipe height drop or the extremely low pressure difference, and the required amount of refrigerant for the refrigerant heater is likely to be insufficient. In this case, the gas refrigerant discharged from the compressor and passed through the bypass circuit is merged with the liquid refrigerant discharged from the indoor unit, thereby compensating for this.Therefore, the refrigerant is not overheated by the refrigerant heater, and the refrigerant is stabilized. Refrigeration cycle, and comfort and reliability can be obtained. Further, a large variable width from the minimum to the maximum of the heating capacity can be secured.

According to a second aspect of the present invention, a plurality of indoor units are provided in parallel and one outdoor unit is provided, and the conduits from the heat exchangers of the indoor units merge to reach the refrigerant heater. A connection portion for a bypass circuit is provided in the configured portion.

According to this, the operating state changes frequently due to the connection of a plurality of indoor units, and the combustion output of the refrigerant heater also changes with this. Even in the case where it is not possible to cope with the situation, the supply of the refrigerant is similarly performed by the bypass circuit, and the overheating of the refrigerant is prevented. Also, even when a refrigerant heater having a high combustion output is used to connect a plurality of indoor units, the supply of refrigerant by the bypass circuit is performed.
It is not necessary to provide the refrigerant heater with a special small capacity.

[0017]

[0018]

[0019]

[0020]

[0021]

According to a third aspect of the present invention, the control means controls the refrigerant flow control valve based on a detection result of the operation state of the indoor unit. According to this,
It is possible to adjust the amount of refrigerant from the bypass circuit that is supplied to the refrigerant flowing out of the indoor unit according to the operation state of the indoor unit, and also to adjust the amount of refrigerant supplied to the indoor unit. It is possible.

According to a fourth aspect of the present invention, the control means controls the refrigerant flow control valve so that the refrigerant circulation amount maintains the difference between the inlet and outlet temperatures of the refrigerant heater at a set value.

According to this, it is possible to control the suction superheat of the compressor, thereby ensuring the reliability of the compressor and optimizing the refrigeration cycle.

According to a fifth aspect of the present invention, the control means controls the refrigerant flow control valve based on a set value set according to a band of an operating frequency of the compressor. According to this, the circulating amount of the refrigerant in the entire air conditioner is determined based on the operating frequency of the compressor, and the flow rate of the bypass circuit suitable for this circulating amount can be set. It can be carried out.

According to a sixth aspect of the present invention, the control means controls the flow rate of the refrigerant so that the amount of the circulated refrigerant is appropriate for the amount of heating of the refrigerant heater. According to this, since the flow rate of the bypass circuit can be adjusted to the amount of heating of the refrigerant heater, that is, the amount of combustion, it is possible to control the capacity of the entire air conditioner.

Hereinafter, an embodiment of the present invention will be described with reference to FIG.
This will be described with reference to FIG. The same members as those shown in FIG. 4 are denoted by the same reference numerals, and detailed description thereof will be omitted.

(Embodiment 1) FIG. 1 shows a refrigeration cycle of a refrigerant-heated air conditioner according to an embodiment of the present invention. Here, an outlet portion of the four-way valve 4 to the indoor units 5a and 5b,
The bypass circuit 1 is provided between the main refrigerant flow control valve 9 and the portion of the pipeline between the two-way valve 10. The bypass circuit 1 is provided with a check valve 2a that allows a refrigerant to flow only from the four-way valve 4 side to the two-way valve 10 side, that is, only during heating. Reference numeral 19 denotes a control unit as control means, and the four-way valve 4
, Refrigerant flow control valves 8a and 8b, and main flow control valve 9
And the two-way valve 10 can be controlled. Other configurations are the same as those shown in FIG.

In such a configuration, during the cooling operation, the refrigerant does not flow through the bypass circuit 1 due to the action of the check valve 2a. During the heating operation, the liquid refrigerant radiated by the indoor heat exchangers 6a and 6b by the indoor fans 7a and 7b passes through the refrigerant flow control valves 8a and 8b for refrigerant distribution and the main refrigerant flow control valve 9, and The high-temperature gas refrigerant flowing from the bypass circuit 1 through the stop valve 2a merges.
Then, it passes through the two-way valve 10 that has been opened and flows into the refrigerant heater 11, where it absorbs the heat of combustion and circulates to the accumulator 12.

By providing the bypass circuit 1 in this manner, even under a condition in which the amount of refrigerant circulating to the refrigerant heater 11 tends to be insufficient, the required amount of circulating refrigerant can be reduced by supplying high-temperature gas refrigerant from the bypass circuit 1. It can secure and stably absorb heat. Therefore, a phenomenon in which the required amount of refrigerant to the refrigerant heater 11 tends to be insufficient and an overshoot is likely to occur due to combustion heat can be optimized, and the reliability of the refrigerant heater 11 and the refrigerant can be ensured. Further, by mixing the gas refrigerant from the bypass circuit 1 into the refrigerant liquefied by heat exchange in the indoor heat exchangers 6a and 6b, the refrigerant is sent to the refrigerant heater 11 in a gas-liquid two-phase state, so that the refrigerant heater 11 Heating efficiency can be improved.

(Embodiment 2) FIG. 2 shows a refrigeration cycle of a refrigerant-heated air conditioner according to another embodiment of the present invention.
Here, the bypass circuit 1 is provided with an electric on-off valve 2b that is opened and closed by a control unit 19 instead of the check valve 2a in FIG. The electric on-off valve 2b can be closed during the cooling operation and opened during the heating operation, similarly to the check valve 2a in FIG.

Alternatively, even during the cooling operation, the bypass circuit 1 can be used by opening the electric on-off valve 2b. That is, during the cooling operation, the electric open / close valve 2b is opened by the control unit 19 as a control unit before the compressor 3 is driven. Then
The bypass circuit 1 serves as a high / low pressure bypass, and the pressure balance of the refrigerant at the time of starting the compressor 3 becomes uniform, so that the liquid return to the compressor 3 and the oil forming phenomenon can be eliminated, and the compressor 3 Reliability can be ensured. In other words, the return of oil is improved by utilizing the bypass circuit 1, and it is possible to prevent the oil in the refrigerant from returning to the compressor 3 and causing abrasion of the sliding portion thereof. After a few minutes have elapsed after the compressor 3 has been driven, the electric on-off valve 2b is closed.

When the refrigerant circulation amount of the refrigerant heater 11 is appropriate during heating, the electric open / close valve 2b can be closed by the control unit 19 as control means. That is, if the amount of circulating refrigerant is too large compared to the amount of heat absorbed by combustion in the refrigerant heater 11 during heating, the refrigerant does not completely gasify and is sent to the compressor 3 as a liquid to cause liquid compression. Become. In order to prevent this liquid compression, it is preferable to use a state where the refrigerant is caused to flow through the bypass circuit 1 by the electric on-off valve 2b even when heating, and a state where the refrigerant is not allowed to flow. By doing so,
The reliability of the compressor 3 can be further improved.

(Embodiment 3) FIG. 3 shows a refrigeration cycle of a refrigerant-heated air conditioner according to still another embodiment of the present invention. In this case, the check valve 2 of FIG.
a and the electric open / close valve 2b shown in FIG.
c is provided.

In such a case, the check valve 2 shown in FIG.
a and the same function as the electric on-off valve 2b of FIG. 2 can be achieved. Further, during the cooling operation, the return to the compressor 3 and the oil forming phenomenon can be eliminated by utilizing the bypass circuit 1 as in the case of the electric on-off valve 2b of FIG.

At the time of heating, the flow rate of the high-temperature refrigerant gas flowing through the bypass circuit 1 is controlled by adjusting the opening degree of the refrigerant flow control valve 2 c by the control unit 19, whereby the gas-liquid flow of the refrigerant flowing to the refrigerant heater 11 is controlled. The two-phase state can be controlled constantly. Thereby, the heat absorption efficiency is stabilized, and the capacity of the refrigerant heater 11 can be secured.

Further, a plurality of indoor units 5a, 5b
Are detected by an appropriate detector, and the detection signal is transmitted to the control unit 19 as control means of the outdoor unit, where the required performance is calculated by processing the required capacity of each of the indoor units 5a and 5b. The total capacity is calculated, and the refrigerant flow control valve 2c can be controlled by the control unit 19 as a control means so as to be a set value based on the result.

The temperature difference between the refrigerant at the inlet and the outlet of the refrigerant heater 11 is detected by an appropriate detector, and the detection signal is transmitted to the control unit 19 as control means to perform arithmetic processing, and the set value based on the result is obtained. The refrigerant flow control valve 2c can be controlled so that As a result, the gas refrigerant at the outlet of the refrigerant heater 11 can be controlled, and thus the suction superheat of the compressor 3 can be controlled, whereby the reliability of the compressor 3 can be ensured and the refrigeration cycle can be optimized. it can.

Further, the operating frequency of the compressor 3 is detected by an appropriate detector, and the detection signal is transmitted to a control unit 19 as a control means to perform an arithmetic process, so that a set value based on the result is obtained. Can control the refrigerant flow control valve 2c. According to this, the circulation amount of the refrigerant in the entire air conditioner is determined based on the operating frequency of the compressor 3, and the flow rate of the bypass circuit 1 suitable for this circulation amount can be set. Control can be performed.

The amount of heating of the refrigerant heater 11, for example, the operating frequency of the electromagnetic pump 14, is detected by an appropriate detector, and the detection signal is used as a control unit 19 as a control means.
And the arithmetic processing is performed, and the refrigerant flow control valve 2c can be controlled to have a set value based on the result. According to this, the flow rate of the bypass circuit 1 suitable for the amount of heating of the refrigerant heater 11, that is, the amount of combustion can be set, so that the capacity control of the entire air conditioner can be performed.

[0041]

As described above, according to the present invention, the bypass circuit for bypassing the discharge side of the compressor and the inlet side of the refrigerant heater during the heating operation, and the means for flowing the refrigerant to the bypass circuit during the heating operation Is provided, the gas refrigerant discharged from the compressor and passed through the bypass circuit can be combined with the liquid refrigerant flowing out of the indoor unit during the heating operation, so that the liquid refrigerant flowing out of the indoor unit tends to be insufficient. This can also be supplemented by gas refrigerant from the bypass circuit,
Therefore, the refrigerant can be prevented from being overheated by the refrigerant heater, and a stable refrigeration cycle can be provided.
Comfort and reliability can be obtained.

[Brief description of the drawings]

FIG. 1 is a refrigeration cycle diagram of a refrigerant-heated air conditioner according to an embodiment of the present invention.

FIG. 2 is a refrigeration cycle diagram of a refrigerant-heated air conditioner according to another embodiment of the present invention.

FIG. 3 is a refrigeration cycle diagram of a refrigerant-heated air conditioner according to still another embodiment of the present invention.

FIG. 4 is a refrigeration cycle diagram of a conventional refrigerant-heated air conditioner.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Bypass circuit 2a Check valve 2b Electric open / close valve 2c Refrigerant flow control valve 3 Compressor 5a, 5b Indoor unit 6a, 6b Indoor heat exchanger 11 Refrigerant heater

────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoshikazu Nishihara 1006 Kazuma Kadoma, Kadoma City, Osaka Inside Matsushita Electric Industrial Co., Ltd. (56) References JP-A-63-233262 (JP, A) JP-A-4- 359764 (JP, A) JP-A-2-150671 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) F25B 13/00 F25B 1/00

Claims (6)

(57) [Claims] 1. An indoor unit, and an outdoor unit having a compressor and a refrigerant heater, wherein refrigerant discharged from the compressor during heating is sent to a heat exchanger of the indoor unit and flows out of the heat exchanger. Circuit that heats the heated refrigerant with a refrigerant heater and sends the refrigerant to a compressor, in a bypass circuit that bypasses a discharge side of the compressor and an inlet side of the refrigerant heater during a heating operation. When,
A refrigerant flow control valve provided in the bypass circuit;
Prevent refrigerant overheating in the refrigerant superheater during operation
Means for controlling the refrigerant flow control valve for the purpose . 2. A bypass circuit is provided in a portion where a plurality of indoor units are provided in parallel and one outdoor unit is provided, and a pipeline from a heat exchanger of each indoor unit merges to form a pipeline leading to a refrigerant heater. The refrigerant-heated air conditioner according to claim 1, further comprising: a connecting portion. 3. The control means according to claim 1, further comprising:
3. The air conditioner according to claim 1, wherein the refrigerant flow control valve is controlled based on a detection result . 4. A control means for controlling an inlet / outlet temperature of a refrigerant heater.
Refrigerant flow rate so that the difference is maintained at the set value
The refrigerant heating type air conditioner according to claim 1, wherein the control valve is controlled . 5. The compressor according to claim 1, wherein said control means includes a compressor operating frequency band.
Refrigerant flow control valve based on the set value set by
Refrigerant heating type air conditioner according to claim 1 or 2, wherein the controlling the. 6. The control means controls the amount of heating of the refrigerant heater.
The refrigerant-heated air conditioner according to claim 1 or 2, wherein the flow rate of the refrigerant is controlled so that the refrigerant circulation amount becomes appropriate .