JP2007271094A - Air conditioner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an air conditioner capable of improving heating performance by continuing indoor heating even during defrosting an outdoor heat exchanger, though in performing a defrosting operation in a conventional air conditioner, a heating operation at an indoor machine side is temporarily stopped until the defrosting is terminated, and the heating of the indoor air by the indoor-side heat exchanger must be stopped, which causes degradation of average heating performance. <P>SOLUTION: In this air conditioner where a plurality of heat source machines and at least one or more indoor machines are connected through a flow channel switching valve device which constantly keeps a prescribed connection pipe under a low pressure and keeps the other prescribed connection pipe under a high pressure in operation, the plurality of heat source machines are respectively provided with frost formation detecting means, the defrosting operation is performed only in the heat source machine where frost formation is detected, when a state of frost formation is detected in any one of the heat source machines, and the other heat source machines continue the heating operation. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

The present invention relates to an air conditioner in which a plurality of indoor units are connected in parallel to a plurality of heat source units, and in particular, cooling and heating can be selected for each indoor unit. The other indoor unit relates to an air conditioner that can perform heating at the same time.

Conventionally, a single heat source unit having a compressor, a four-way switching valve, and a heat source side heat exchanger, and a plurality of indoor units each having a flow control device and an indoor side heat exchanger are provided. It is an air conditioner in which a refrigerant circuit that can perform operation and heating operation simultaneously is configured.

In this conventional air conditioner, the refrigerant is evaporated in the outdoor heat source side heat exchanger during the heating operation, and if the outside air temperature is low, the outdoor heat source side heat exchanger is frosted and sufficient heating is performed. The ability cannot be obtained. Therefore, a defrosting operation is usually performed to solve this problem. By temporarily interrupting the heating operation and switching the refrigerant flow using the four-way selector valve, the high-temperature gas from the compressor flows through the heat source side heat exchanger to perform defrosting. After the defrosting is completed, the heating operation is performed by switching the four-way switching valve to the original state again. The following publications are exemplified as reference patent documents.

JP 2004-294036 A JP 2002-286273 A JP 2001-116383 A

When defrosting operation is performed with the above-described conventional air conditioner, heating of the indoor air in the indoor heat exchanger must be stopped because the heating operation on the indoor unit side is temporarily suspended until the defrosting is completed. There was a problem that the average heating capacity declined.

The present invention has been made to solve the above-described conventional problems, and its object is to continue the heating operation of the indoor unit even during the defrosting of the heat source side heat exchanger, thereby heating the indoor unit. The purpose is to improve ability.

In order to achieve the above-mentioned object, the air conditioner according to the first or second aspect of the present invention includes a plurality of heat source units including a compressor, a switching valve and a heat source side heat exchanger, and a flow rate control device. And at least one indoor unit with a built-in indoor heat exchanger connected in parallel via a plurality of connection pipes, provided between the plurality of connection pipes, and flowing through the switching valve At least one or more flow-path switching valve devices formed by a plurality of check valves that always switch a predetermined connection pipe to a low pressure and other predetermined connection pipes to a high pressure by switching the direction of the refrigerant. A first branch portion formed by a plurality of electromagnetic on-off valves capable of switching one of the indoor side heat exchangers to the predetermined connection pipe having the low pressure or the other predetermined connection pipe having the high pressure. In addition, the heat of the plurality of units Each source unit is provided with frost detection means. When it is detected that any one of the heat source units is in a frosted state, only the heat source unit that has detected frost formation performs a defrosting operation, and the other heat source units are heated. It is characterized by continuing operation.

The air conditioner of the present invention according to claim 3 is a plurality of heat source units equipped with a compressor, a switching valve and a heat source side heat exchanger, and at least one unit equipped with a flow rate control device and an indoor side heat exchanger. In the above indoor units connected in parallel through a plurality of connection pipes, provided between the plurality of connection pipes, by switching the direction of the refrigerant flowing in the switching valve, always during operation, One of at least one indoor heat exchanger and a flow path switching valve device formed by a check valve that makes a predetermined connecting pipe low pressure and other predetermined connecting pipe high pressure A first branching portion that can be switched to the above-mentioned connecting pipe, or another predetermined connecting pipe that becomes the high pressure, and further provided with frosting detection means in each of the plurality of heat source units, and at least one of them One or more heat source machine When it is detected that other heat source devices are in a frosted state, the heat source device that has detected frost formation performs a defrosting operation, and at least one other heat source device continues the heating operation. .

The air conditioner according to a fourth aspect of the present invention is the air conditioner according to the first aspect, wherein the plurality of heat source units are simultaneously frosted by giving each of the plurality of heat source units a priority in control. Even if it detects, defrosting operation is started and completed one by one.

The air conditioner of the present invention according to claim 5 is the air conditioner according to claim 3, wherein the air conditioner is in a defrosting operation even if it is detected that at least one heat source unit is in a frosted state. When there is a heat source unit, the defrosting operation of other heat source units is not started until the defrosting operation is completed.

An air conditioner according to a sixth aspect of the present invention is the air conditioner according to the second or fourth aspect, wherein at least one heat source unit performs a defrosting operation and another heat source unit continues a heating operation. In this case, the flow control device built in the stopped indoor unit is fully closed by narrowing down.

An air conditioner according to a seventh aspect of the present invention is the air conditioner according to the fifth aspect, wherein at least one heat source unit performs the defrosting operation and the other heat source units continue the heating operation. In this case, the electromagnetic on-off valve built in the first branch portion connected to the stopped indoor unit is fully closed.

The air conditioner of the present invention according to claim 8 is the air conditioner according to claim 6, wherein at least one heat source unit performs the defrosting operation, and the other heat source unit continues the heating operation. In the heat source apparatus during heating operation, the compressor operating frequency is increased or decreased according to the target high pressure or condensation temperature.

The air conditioner of the present invention has at least two heat source units including a compressor, a switching valve, and a heat source side heat exchanger, and the refrigerant in the first and second connection pipes flows in one direction. The heat capacity is reduced by continuing the heating operation with other heat source machines at the same time that the other heat source machines perform the defrosting operation while at least one heat source machine is in the heating operation. Can be prevented. This makes it possible to ensure a stable heating operation on the indoor side.

In addition, when performing defrosting operation and heating operation simultaneously with multiple heat source units, the compressor operating frequency of the heat source unit during heating operation is increased or decreased according to the high pressure or the condensation temperature. By increasing the condensation temperature of the indoor unit to the target value in a short time, the heating capacity can be maintained and the defrosting operation time of the heat source unit during the defrosting operation can be shortened. At that time, since the compressor operating frequency of the heat source unit during heating operation is controlled according to the high pressure or the condensation temperature, the high pressure overheating can be suppressed.

In addition, at least one heat source unit other than the heat source unit performs defrosting operation, and when the other heat source unit continues heating operation, the flow control device built in the stopped indoor unit is fully closed. Or, by fully closing the electromagnetic on-off valve built in the first branch connected to the stopped indoor unit, the flow of refrigerant flowing through the stopped indoor unit during simultaneous defrosting and heating is prevented. At the same time, by fully closing both the flow control device and the electromagnetic on-off valve, it is possible to prevent the refrigerant shortage in the heat source unit by preventing the refrigerant from staying in the stop indoor unit.

In addition, when at least two heat source units are operated in the same cycle, the cooling / heating capacity equivalent to the total refrigerant flow rate of a plurality of heat source units can be exhibited.

In addition, even when at least one heat source unit fails, backup operation can be performed by operating the remaining heat source units.

Embodiments of an air conditioner according to the present invention will be described below with reference to the drawings. 1 to 3 show an embodiment of the present invention, FIG. 1 is a refrigerant circuit diagram, FIG. 2 is a refrigerant circuit diagram showing a refrigerant flow during heating main operation in simultaneous cooling and heating operation, and FIG. It is a refrigerant circuit figure which shows the flow of the refrigerant | coolant of a defrost operation, however. In this embodiment, a case where three indoor units are connected to two heat source units will be described, but the same applies to a case where two or more heat source units and two or more indoor units are connected.

In FIG. 1, A and B are heat source devices connected in parallel, and C, D, and E are indoor units connected in parallel as described later, and have the same configuration. As will be described later, F represents a first branch unit 10, a second flow rate control device 13, a second branch unit 11, a gas-liquid separator 12, a first heat exchanger 17, and a second heat exchanger 16. , A repeater incorporating a third flow rate control device 15. 1a and 1b are compressors, 2a and 2b are four-way switching valves for switching the refrigerant flow direction of the heat source unit, 3a and 3b are heat source side heat exchangers, 4a and 4b are accumulators, and the four-way switching valves 2a and 2b are connected to each other. Are connected to the compressors 1a and 1b. These constitute the heat source devices A and B, respectively. 5c, 5d, and 5e are indoor heat exchangers installed in the three indoor units C, D, and E, and 6 is a four-way switching valve 2a, 2b of the heat source units A and B and a relay F that are described later. The first connection pipes 6c, 6d and 6e connected via the stop valves 19a and 19b and the connection pipes 6a and 6b are the indoor units C, D and E, respectively, and the indoor heat exchangers 5c, 5d and 5e Connect the relay machine F, the first connection pipe on the indoor unit side corresponding to the first connection pipe 6, 7 is the heat source equipment side heat exchanger 3a, 3b of heat source machine A, B and the relay machine F will be described later This is a second connection pipe connected via the third check valves 18a, 18b.

7c, 7d, and 7e connect the indoor side heat exchangers 5c, 5d, and 5e of the indoor units C, D, and E to the relay unit F through the first flow control devices 9c, 9d, and 9e, respectively. This is a second connection pipe on the indoor unit side corresponding to the two connection pipes 7.
The heat source machines A and B incorporate compressors 1a and 1b, four-way switching valves 2a and 2b that are switching valves for switching the refrigerant flow direction of the heat source machine, heat source side heat exchangers 3a and 3b, and accumulators 4a and 4b. .
The indoor units C, D, and E incorporate the first flow control device 9 and the indoor heat exchanger 5, and 5c, 5d, and 5e are the indoor heats of the indoor units C, D, and E, respectively. It is an exchanger. 6 is a thick first connection pipe that connects the four-way valve 2 and the relay F, and 6c, 6d, and 6e connect the indoor heat exchangers 5c, 5d, and 5e of the indoor units C, D, and E to the relay F, respectively. The first connection pipe on the indoor unit side corresponding to the first connection pipe 6, 7 is a second connection narrower than the first connection pipe 6 connecting the heat source side heat exchangers 3a, 3b relay F The pipes 7c, 7d, and 7e connect the indoor side heat exchangers 5c, 5d, and 5e of the indoor units C, D, and E to the relay unit F, respectively, and the indoor unit side second corresponding to the second connection pipe 7 is connected. The connecting pipes 8c, 8d, 8e, 8f, 8g, and 8h can be switched to the first connecting pipe 6c, 6d, 6e on the indoor unit side and the first connecting pipe 6 or the second connecting pipe 7 side. 1st, 2nd, 3rd solenoid valves connected to, 9 is the first flow control device, 9c, 9d, 9e are connected in close proximity to the indoor heat exchangers 5c, 5d, 5e, during cooling Is the first flow adjusted by the degree of superheat on the outlet side of the indoor heat exchanger 5 and the degree of supercooling during heating. In the control device, the second connection pipe 7c of the indoor unit side, 7d, is connected to 7e.

Reference numeral 10 denotes a first branch portion corresponding to the indoor units C, D, and E. The first connection pipes 6c, 6d, and 6e on the indoor unit side and the first connection pipe 6 or the second connection pipe 7 are provided. The first branch part consisting of solenoid valves 8c, 8d, 8e, 8f, 8g, 8h, 11 is a second branch part, corresponding to the indoor units C, D, E, on the indoor unit side The second connecting pipes 7c, 7d, 7e and the second branch part 12 formed by the meeting parts thereof, 12 is a gas-liquid separator provided in the middle of the second connecting pipe 7, and the gas phase component is The liquid phase component is connected to the second branch part 11, which is connected to one branch part 10. 13 is a first bypass pipe connecting the gas-liquid separator 12 and the second branching section 11 and the first connection pipe, and 15 is a third flow rate control apparatus, which is provided in the middle of the first bypass pipe 14. A third flow control device 16 that can be freely opened and closed is a heat exchanger provided downstream of the first bypass pipe 14 and the third flow control device 15, and the second flow control device 13 and the second flow control device 15. A second heat exchanger for exchanging heat between the connecting pipe between the branch section 11 and the first bypass pipe 14, 17 is downstream of the first bypass pipe 14 and the third flow control device 15 and This is a first heat exchanger that is provided downstream of the second heat exchanger 16 and performs heat exchange between a pipe connecting the gas-liquid separator 12 and the second flow rate controller 13.

18 is a check valve provided between the heat source side heat exchangers 3a, 3b and the second connection pipe 7, and the refrigerant flows only from the heat source side heat exchangers 3a, 3b to the second connection pipe 7. Is acceptable. 19 is a check valve provided between the four-way switching valves 2a, 2b of the heat source device A or B and the second connection pipe 7, and refrigerant is supplied only from the four-way switching valves 2a, 2b to the second connection pipe 7. Allow distribution. A check valve 21 is provided between the heat source side heat exchanger 3 and the first connection pipe 6 and permits the refrigerant to flow only from the first connection pipe 6 to the heat source side heat exchanger 3. These 18, 19, 20, and 21 constitute a flow path switching valve.

The air conditioning operation of the air conditioner configured as described above will be described. First, according to FIG. 3, the case of heating-main operation in simultaneous cooling and heating operation will be described. Here, the case where the indoor units C and D are heating and only the indoor unit E is going to be cooled will be described.
At this time, the electromagnetic on-off valves 8c, 8d and 8h connected to the indoor unit are closed, and 8e, 8f and 8g are opened. The flow of the refrigerant is shown below. As indicated by solid arrows in FIG. 3, the high-temperature and high-pressure gas refrigerant compressed by the compressors 1a and 1b passes through the four-way switching valves 2a and 2b and the check valves 20a and 20b, and the refrigerant of the heat source machines A and B merges. , The second connecting pipe 7, the gas-liquid separator 12 of the relay F, and the first branching section 10. The refrigerant that has flowed into the first branch section 10 flows into the indoor units C and D, and is heat-exchanged with a utilization medium such as air in the indoor heat exchangers 5c and 5d to be condensed and liquefied. The refrigerant in the liquid state is controlled by the degree of supercooling at the outlets of the indoor heat exchangers 5c and 5d, and is slightly reduced through the first flow rate adjustments 9c and 9d, so that the pressure between the high pressure and the low pressure ( Intermediate pressure) and flows into the second branch portion 11 from the second connection pipes 7c and 7d on the indoor unit side.

The flow of the refrigerant to the indoor unit E to be cooled is controlled by the superheat degree at the outlet of the indoor heat exchanger 5e through the connecting pipe 7e on the indoor unit side from the second branch part 11 The pressure is reduced to a low pressure by the control device 9e, heat is exchanged with a medium such as air in the indoor heat exchanger 5e, evaporates and gasifies, and the first connection pipe is connected via the electromagnetic on-off valve 8e connected to the indoor unit E Flows into 6. The flow rate of the refrigerant flowing into the indoor unit E is determined according to the cooling load of the indoor unit E to be cooled. Therefore, when the refrigerant flow rate flowing into the indoor unit E from the second branch unit 11 is larger than the refrigerant flow rate flowing into the second branch unit 11 from the indoor units C and D, the second branch is generated from the indoor units C and D. Part of the refrigerant that has flowed into the section 11 flows into the second branch section 11, merges with the refrigerant that has flowed into the second branch section 11 from the indoor units C and D, and flows into the indoor unit E. On the other hand, the other refrigerant that has flowed into the second branch portion 11 from the indoor units C and D passes through the first bypass pipe 14 and is decompressed to a low pressure by the third flow control device 15 to be cooled. The refrigerant passes through the machine E and flows into the thick first connection pipe 6. Thereafter, the refrigerant is divided into heat source devices A and B, and the refrigerant that has flowed into the check source valves 21a and 21b and the heat source side heat exchangers 3a and 3b to evaporate into a gas state is divided into four-way switching valves 2a and 2b, an accumulator 4a, A circulation cycle that is sucked into the compressor 1 through 4b is configured, and heating-main operation is performed.

Next, referring to FIG. 2, the case where the heating operation is performed simultaneously with the defrosting operation during the whole heating or the heating main operation will be described. Here, while the indoor units C and D are heating and only the indoor unit E is in the heating main operation, the heat source units A and B each have frost detection means for detecting frost formation, and the heat source of the heat source unit A When the side heat exchanger 3a detects frost formation by the frost detection means, the heat source unit B is put into the defrosting operation, that is, the hot gas reverse cycle while the heat source unit B remains in the heating cycle.
At this time, the electromagnetic on-off valves 8c, 8d, and 8h connected to the indoor units C, D, and E are closed, and the 8e, 8f, and 8g are kept open. The flow of the refrigerant is shown by solid line arrows in FIG. When heat source unit A detects frost formation, the operating frequency of compressors 1a and 1b of heat source units A and B is temporarily reduced to reduce the difference between the high and low pressures and switch heat source unit A to four-way. The defrosting operation is started by switching the valve 2a to the cooling side. The operating frequency of the compressors 1a and 1b is increased again, and the compressed high-temperature and high-pressure gas refrigerant flows into the frosted heat source side heat exchanger 3a via the four-way switching valve 2a with respect to the heat source unit A. Then, defrosting is performed. Regarding the heat source unit B, the high-temperature and high-pressure gas refrigerant compressed by the compressor 1b passes through the four-way switching valve 2b and the check valve 20b, and the gas-liquid two-phase flows out of the heat source side heat exchanger 3a of the heat source unit A. The refrigerant merges with the refrigerant, and is sent to the second connection pipe 7, the gas-liquid separator 12 of the relay F, and the first branch section 10. The refrigerant that has flowed into the first branch section 10 flows into the indoor units C and D, and is heat-exchanged with a utilization medium such as air in the indoor heat exchangers 5c and 5d to be condensed and liquefied. The refrigerant in the liquid state is controlled by the degree of supercooling at the outlets of the indoor heat exchangers 5c and 5d, and is slightly depressurized through the first flow rate adjustments 9c and 9d. Intermediate pressure) and flows into the second branch portion 11 from the second connection pipes 7c and 7d on the indoor unit side. Therefore, since the indoor units C, D, and E can perform the defrosting operation of any one unit while continuing the heating operation, the heating capacity does not become zero.

In addition, the above defrosting means increases or decreases the operating frequency of the compressor 1b of the heat source B during heating operation according to the target high pressure or the condensation temperature, thereby condensing the indoor unit during heating operation. The temperature can be quickly raised and the defrosting operation time of the heat source unit during the defrosting operation can be shortened. At that time, since the compressor operating frequency of the heat source unit during heating operation is controlled according to the high pressure or the condensation temperature, the high pressure overheating can be suppressed.

In addition, after the defrosting of the heat source unit A is completed by the defrosting means described above, the defrosting operation is started by the heat source unit B while the heating source unit A is performing the heating operation. It is possible to always demonstrate the heating capacity without stopping the operation.

In the above-described air conditioner, even when any one heat source unit is defrosting and the other heat source unit detects frost formation by the frost detection means, the defrosting operation of the heat source unit being defrosted is completed. Until the defrosting operation is controlled, the heating operation can always be continued.

In the air conditioner described above, even if two or more heat source units detect frost formation by the frost detection means of each heat source unit, each unit is removed one by one with priority given to each heat source unit. By starting and completing the frost operation, other heat source machines can continue the heating operation.

Although this embodiment has been described based on the heating-main operation, the same effect can be obtained even in the operation only with heating. In addition, the case where three indoor units and one relay unit are connected to two heat source units has been described, but the same applies to two or more heat source units, one or more indoor units, and one or more relay units. There is an effect. It is clear that the same effect can be obtained even if an ice heat storage layer or a water heat storage tank (including hot water) is installed in series or in parallel with the heat source side heat exchangers 3a and 3b.

The figure which shows a refrigerant circuit as an example of the air conditioning apparatus by embodiment of this invention. FIG. 2 is a diagram illustrating a refrigerant flow in a defrosting operation while heating the air-conditioning apparatus of FIG. The figure which shows the flow at the time of heating main operation | movement in the air-conditioning simultaneous operation by embodiment of this invention.

Explanation of symbols

A, B: Heat source machine, C, D, E: Indoor unit, F: Relay machine, 1: Compressor, 2: Four-way switching valve, 3: Heat source side heat exchanger, 4: Accumulator, 5: Indoor side heat exchange 6, 6a, 6b, 6c, 6d, 6e: First connection piping, 7, 7a, 7b, 7c, 7d, 7e: Second connection piping, 8c, 8d, 8e: First solenoid valve , 9: First flow controller, 10: First branch, 11: Second branch, 12: Gas-liquid separator, 13: Second flow controller, 14: First bypass pipe, 15: Third flow control device, 16: Second heat exchanger, 17: First heat exchanger, 18a, 18b: Third check valve, 19a, 19b: Fourth check valve, 20 21: Check valve, 22c, 22d, 22e: Second solenoid valve

Claims (8)

A plurality of heat source units and at least one indoor unit are connected via a high-pressure pipe and a low-pressure pipe, and each of the plurality of heat source units is provided with frosting detection means, and any one heat source An air conditioner characterized in that when it is detected that the machine is in a frosting state, only the heat source machine that has detected frosting performs a defrosting operation, and the other heat source machine continues the heating operation. A plurality of heat source units equipped with a compressor, a switching valve and a heat source side heat exchanger, and at least one indoor unit equipped with a flow rate controller and an indoor side heat exchanger are connected via a plurality of connection pipes. Each connected in parallel is provided between the plurality of connecting pipes, and by switching the direction of the refrigerant flowing through the switching valve, the predetermined connecting pipe is always kept at a low pressure and other predetermined connecting pipes are operated. One of at least one indoor heat exchanger and a predetermined connection pipe that is at a low pressure, or another predetermined pressure that is at a high pressure. 2. The air conditioner according to claim 1, further comprising a first branch portion formed by a plurality of electromagnetic on-off valves that can be switched to the connection pipe. A plurality of heat source units equipped with a compressor, a switching valve and a heat source side heat exchanger, and at least one indoor unit equipped with a flow rate controller and an indoor side heat exchanger are connected via a plurality of connection pipes. Each connected in parallel is provided between the plurality of connecting pipes, and by switching the direction of the refrigerant flowing through the switching valve, the predetermined connecting pipe is always kept at a low pressure and other predetermined connecting pipes are operated. One of at least one indoor heat exchanger and a predetermined connection pipe that becomes the low pressure, or another predetermined connection that becomes the high pressure A first branching portion that can be switched to a pipe, and further, frosting detection means is provided for each of the plurality of heat source units, and at least one of the other heat source units other than the one is installed. Detecting frost Then, all the heat source equipment which detected frost formation performs a defrost operation, and the other at least 1 heat source machine continues heating operation. 3. The air conditioner according to claim 1 or 2, wherein each of the plurality of heat source units has a control priority, so that even if the plurality of heat source units detect frost formation at the same time, one unit is defrosted. An air conditioner that starts and completes operation. 5. In the air conditioner according to claim 4, even if it is detected that at least one heat source unit is in a frosted state, if there is a heat source unit in the defrosting operation, the defrosting operation is completed. Is an air conditioner that does not start defrosting operation of other heat source machines. 6. The air conditioner according to claim 3 or 5, wherein at least one heat source unit performs a defrosting operation and the other heat source unit is installed in a stopped indoor unit when the heating operation is continued. An air conditioner that is fully closed by restricting a flow control device. 7. The air conditioner according to claim 6, wherein when at least one heat source unit performs a defrosting operation and another heat source unit continues the heating operation, the first unit connected to the stopped indoor unit. 1. An air conditioner characterized by fully closing an electromagnetic on-off valve built in 1 branching section. The air conditioner according to claim 7, wherein at least one heat source unit performs a defrosting operation and another heat source unit continues the heating operation, and the target is set in the heat source unit in the heating operation. An air conditioner that increases or decreases a compressor operating frequency according to a high pressure or a condensation temperature.

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