Patent Description:
In general, there is known an air conditioner in which an indoor unit performs air conditioning by use of an outdoor unit in which a compressor to be driven by a gas engine or the like is mounted and an outdoor unit in which a compressor to be driven by electricity is mounted.

As this air conditioner, there has been heretofore disclosed, for example, an air conditioner including a second outdoor unit including a high-capacity compressor, a four-way valve and an outdoor heat exchanger, a first outdoor unit including a low-capacity compressor, a four-way valve and an outdoor heat exchanger, and an indoor unit connected to these outdoor units via one refrigerant system (e.g., see Patent Literature <NUM>).

A further known air conditioner that includes an indoor unit, a first EHP-type outdoor unit, a second GHP-type outdoor unit and an air conditioner adjustment device, is controlled such that model information, like load related information, is acquired of the first and second outdoor units, to operate the air conditioner such that either one or both of the first and second outdoor units are driven (see Patent Literature <NUM>).

In another known air conditioning apparatus, which includes a plurality of indoor units, a GHP-type outdoor unit and an EHP-type outdoor unit, the GHP-Type outdoor unit is provided with a generator and a battery charged by said generator. In case of an interruption of the commercial power supply, the generator can generate electric power, such that the operation of the air conditioning apparatus may be continued (see Patent Literature <NUM>).

However, in the above conventional air conditioner, when operations of a plurality of outdoor units are switched, a controller sends an operation switching instruction. For the respective outdoor units, when the stopped outdoor unit and the operating outdoor unit are switched based on the instruction from the controller, the operating outdoor unit and the stopped outdoor unit perform stopping and operating actions at individual timings.

In this case, when the stopped outdoor unit and the operating outdoor unit are switched, the outdoor unit to be stopped from an operating state immediately stops. However, the outdoor unit to be started from a stopped state cannot immediately start because a predetermined start preparing operation is performed. In this case, air conditioning may be temporarily interrupted, and air conditioning properties may deteriorate.

The present invention has been developed in view of the above described respects, and an object thereof is to provide an air conditioner in which a plurality of outdoor units can be switched without interrupting air conditioning, and deterioration of air conditioning properties can be prevented.

To achieve the above object, according to the present invention, there is provided an air conditioner in which each of a plurality of outdoor units is connected to an indoor unit via an interunit pipe, each outdoor unit is operated, and indoor air conditioning is performed by the indoor unit, wherein the plurality of outdoor units comprise a GHP outdoor unit including a GHP compressor that is driven by an engine and an EHP outdoor unit including an EHP compressor that is driven by a commercial power source, wherein the air conditioner includes a controller that sends a control instruction signal to each of the GHP outdoor unit, the EHP outdoor unit and the indoor unit, and wherein the controller includes a controller control section to generally control a GHP control section, an EHP control section and an indoor control section. The GHP control section is set to a master, and the EHP control section and the indoor control section are set to slaves, the control instruction signal from the controller control section is first transmitted to the GHP control section, and this control instruction signal is sequentially transmitted from the GHP control section to the EHP control section and the indoor control section, and when the start of the GHP outdoor unit is completed, the GHP control section sends a stop instruction signal to the EHP control section, and based on this stop instruction signal, the EHP control section controls and stops the EHP outdoor unit.

According to the air conditioner of the present invention, the air conditioning operation can be prevented from being temporarily interrupted, and deterioration of air conditioning properties can be prevented.

According to the present invention, there is provided an air conditioner in which each of a plurality of outdoor units is connected to an indoor unit via an interunit pipe, each outdoor unit is operated and indoor air conditioning is performed by the indoor unit, wherein the plurality of outdoor units comprise a GHP outdoor unit including a GHP compressor that is driven by an engine and an EHP outdoor unit including an EHP compressor that is driven by a commercial power source, wherein the air conditioner includes a controller that sends a control instruction signal to each of the GHP outdoor unit, the EHP outdoor unit and the indoor unit, the controller includes a controller control section to generally control a GHP control section, an EHP control section and an indoor control section, the GHP control section is set to a master, and the EHP control section and the indoor control section are set to slaves, the control instruction signal from the controller control section is first transmitted to the GHP control section, and this control instruction signal is sequentially transmitted from the GHP control section to the EHP control section and the indoor control section, and when the start of the GHP outdoor unit is completed, the GHP control section sends a stop instruction signal to the EHP control section, and based on this stop instruction signal, the EHP control section controls and stops the EHP outdoor unit.

According to this aspect, the plurality of outdoor units can be constituted of the GHP outdoor unit and the EHP outdoor unit. When operations of the GHP outdoor unit and the EHP outdoor unit are switched, the operation of the air conditioning system is not interrupted, and it is possible to continuously operate the air conditioning system. As a result, the deterioration of the air conditioning properties can be prevented.

In an aspect disclosed herein, the air conditioner further includes a controller control section that sends a control instruction signal to the control section, wherein when receiving a switching instruction signal of the outdoor unit from the controller control section, the control section of the outdoor unit that is stopped controls and starts the outdoor unit that is stopped, and the control section of the outdoor unit that is operating controls and stops the outdoor unit.

According to this aspect, based on the switching instruction signal sent from the controller control section, the control section of the outdoor unit that is stopped starts the outdoor unit that is stopped, and the control section of the outdoor unit that is operating stops the outdoor unit. Therefore, regardless of the switching instruction signal sent from the controller control section, the control section of each outdoor unit can control the start and stop of the outdoor unit so that the operation of the air conditioning system is not interrupted. As a result, it is possible to continuously operate the air conditioning system, and the deterioration of the air conditioning properties can be prevented.

Hereinafter, description will be made as to an embodiment of the present invention with reference to the drawings.

<FIG> is a configuration diagram showing the embodiment of an air conditioner according to the present invention.

As shown in <FIG>, an air conditioner <NUM> includes a GHP outdoor unit <NUM> (a second outdoor unit) including a compressor that is driven as a high capacity compressor by a gas engine, an EHP outdoor unit <NUM> (a first outdoor unit) including a compressor that is driven as a low capacity compressor by a commercial power source, and a plurality of indoor units <NUM>. The GHP outdoor unit <NUM>, the EHP outdoor unit <NUM> and the respective indoor units <NUM> are connected via an interunit pipe <NUM> and an oil balance pipe <NUM>. Consequently, a refrigeration cycle circuit to perform an air conditioning operation is constituted.

The GHP outdoor unit <NUM> includes two external connection valves 10a and 10b to be connected to the external interunit pipe <NUM> and an oil connection valve <NUM> to be connected to the oil balance pipe <NUM>.

In the GHP outdoor unit <NUM>, there are provided the gas engine <NUM> as an engine, and a GHP compressor <NUM> that compresses a refrigerant by a drive force of the gas engine <NUM>. The GHP compressor <NUM> is constituted of a first GHP compressor 13a and a second GHP compressor 13b that are provided in parallel.

The gas engine <NUM> burns a mixed gas of a fuel such as a gas supplied through a fuel regulating valve (not shown) and air supplied through a throttle valve (not shown) to generate the drive force.

A drive belt <NUM> is bridged between an output shaft of the gas engine <NUM> and a driven shaft of the GHP compressor <NUM>, and the drive force of the gas engine <NUM> is transmitted via the drive belt <NUM>, to drive the GHP compressor <NUM>.

An oil separator <NUM>, a four-way valve <NUM> and two outdoor heat exchangers <NUM> and <NUM> are successively connected to a discharge side of the GHP compressor <NUM>, and each outdoor heat exchanger <NUM> is connected to one external connection valve 10a via a refrigerant pipe <NUM>. An outdoor fan <NUM> to exchange heat between the outdoor heat exchanger <NUM> and outdoor air is provided in the vicinity of the outdoor heat exchanger <NUM>.

Furthermore, the other external connection valve 10b is connected to the refrigerant pipe <NUM>. A middle portion of this refrigerant pipe <NUM> is connected to a suction side of the GHP compressor <NUM> via the four-way valve <NUM> and an accumulator <NUM>.

Electric valves <NUM> and a check valve <NUM> are connected in parallel with the middle portion of the refrigerant pipe <NUM>, and the refrigerant pipe <NUM> is connected to a liquid pipe <NUM> connected to an inflow side of the accumulator <NUM>. A dry core <NUM> is provided between the outdoor heat exchanger <NUM> and the external connection valve 10a.

Furthermore, a heat exchange refrigerant pipe <NUM> that connects the suction side of the GHP compressor <NUM> to the refrigerant pipe <NUM> is connected between the suction side of the GHP compressor <NUM> and the refrigerant pipe <NUM>, and in this heat exchange refrigerant pipe <NUM>, an electric valve <NUM> is provided. A plate type heat exchanger <NUM> is provided between the electric valve <NUM> of the heat exchange refrigerant pipe <NUM> and the suction side of the GHP compressor <NUM>.

The GHP outdoor unit <NUM> includes a bypass pipe <NUM> that connects a discharge side of the GHP compressor <NUM> to the suction side thereof. One end of the bypass pipe <NUM> is connected between the oil separator <NUM> and the four-way valve <NUM>, and the other end of the bypass pipe <NUM> is connected between the accumulator <NUM> and the four-way valve <NUM>. A part of the refrigerant on the discharge side of the GHP compressor <NUM> flows through the bypass pipe <NUM> to the suction side of the GHP compressor <NUM> due to a pressure difference.

In the bypass pipe <NUM>, a bypass valve <NUM> that regulates a flow rate of the bypass pipe <NUM> is provided. The bypass valve <NUM> is an electric valve that can open and close stepwise.

The GHP outdoor unit <NUM> includes an oil return pipe <NUM> that connects the oil separator <NUM> to the suction side of the GHP compressor <NUM>. Lubricating oil stored in the oil separator <NUM> flows through the oil return pipe <NUM> to the suction side due to the pressure difference between the discharge side and the suction side of the GHP compressor <NUM>.

The oil return pipe <NUM> includes a first return pipe <NUM> that connects an oil outflow port of the oil separator <NUM> to the suction side of the GHP compressor <NUM>, and a second return pipe <NUM> provided in parallel to the first return pipe <NUM>.

The first return pipe <NUM> includes a capillary tube <NUM>.

The second return pipe <NUM> is connected to the first return pipe <NUM> to pass by the capillary tube <NUM>. One end of the second return pipe <NUM> is connected to an upstream side of the capillary tube <NUM> in the first return pipe <NUM>, and the other end of the second return pipe <NUM> is connected to a downstream side of the capillary tube <NUM> in the first return pipe <NUM>.

The second return pipe <NUM> includes a capillary tube <NUM>, and an oil return valve <NUM> provided on a downstream side of the capillary tube <NUM>.

The oil connection valve <NUM> is connected to an oil pipe <NUM>. A middle portion of the oil pipe <NUM> is branched, so that one oil pipe is connected to the downstream side from the oil separator <NUM> of the refrigerant pipe <NUM>, and the other oil pipe is connected between the capillary tube <NUM> of the second return pipe <NUM> and the oil return valve <NUM>.

The external connection valve 10a connected to the refrigerant pipe <NUM> is connected to one end of an indoor heat exchanger <NUM> of each indoor unit <NUM> via the interunit pipe <NUM>. An expansion valve <NUM> is provided in a middle portion of the interunit pipe <NUM>.

In each indoor unit <NUM>, an indoor fan <NUM> is provided to exchange heat between the indoor heat exchanger <NUM> and indoor air.

Furthermore, the other end of each indoor heat exchanger <NUM> is connected via the interunit pipe <NUM> to the external connection valve 10b connected to the refrigerant pipe <NUM>.

Furthermore, the GHP outdoor unit <NUM> includes a cooling water circuit <NUM> of the gas engine <NUM>.

The cooling water circuit <NUM> includes a cooling water three-way valve <NUM>, the plate type heat exchanger <NUM>, a radiator <NUM> disposed close to the one outdoor heat exchanger <NUM>, a cooling water pump <NUM>, and an exhaust gas heat exchanger <NUM> of the gas engine <NUM>, which are connected in order from the gas engine <NUM> via a cooling water pipe <NUM>. The cooling water pump <NUM> is driven, to circulate cooling water through this circuit.

The cooling water pipe <NUM> of the cooling water circuit <NUM> is shown by a double line in <FIG>, and flow of the cooling water is shown by a solid arrow line.

In the radiator <NUM>, heat is exchanged between the outdoor air and the cooling water.

Furthermore, in the plate type heat exchanger <NUM>, the electric valve <NUM> is operated so that the refrigerant that returns to the GHP compressor <NUM> is heated by the cooling water that flows through the cooling water pipe <NUM>. Consequently, a low pressure of the refrigerant rises, and a heating efficiency improves.

The cooling water circuit <NUM> can form a first route in which the cooling water flows in order from the gas engine <NUM> through the cooling water three-way valve <NUM>, the radiator <NUM>, the cooling water pump <NUM>, and the exhaust gas heat exchanger <NUM> to the gas engine <NUM>.

Furthermore, the cooling water circuit <NUM> can form a second route in which the cooling water flows in order from the gas engine <NUM> through the cooling water three-way valve <NUM>, the plate type heat exchanger <NUM>, the cooling water pump <NUM> and the exhaust gas heat exchanger <NUM> to the gas engine <NUM>.

In a middle of the first route that connects the radiator <NUM> to the cooling water three-way valve <NUM>, a hot water three-way valve <NUM> is provided. The hot water three-way valve <NUM> is connected to a hot water heat exchanger <NUM> that exchanges heat between the cooling water and hot water, and the cooling water that flows through the hot water heat exchanger <NUM> is returned to an upstream side of the cooling water pump <NUM>.

Next, description will be made as to the EHP outdoor unit <NUM>.

The EHP outdoor unit <NUM> includes two external connection valves <NUM> to be connected to the external interunit pipe <NUM> and an oil connection valve <NUM> to be connected to the oil balance pipe <NUM>.

The EHP outdoor unit <NUM> includes the EHP compressor <NUM> to be driven by the commercial power source. It is considered that an example of this EHP compressor <NUM> is an inverter type compressor that can vary an output.

A discharge side of the EHP compressor <NUM> is connected to an oil separator <NUM>, a four-way valve <NUM> and two outdoor heat exchangers <NUM> and <NUM> in order, and the outdoor heat exchanger <NUM> is connected to one external connection valve 60a via a refrigerant pipe <NUM>. In the vicinity of the outdoor heat exchanger <NUM>, an outdoor fan <NUM> (see <FIG>) is provided to exchange heat between the outdoor heat exchanger <NUM> and the outdoor air.

A supercooling heat exchanger <NUM> is provided between the outdoor heat exchanger <NUM> and the external connection valve 60a.

Two systems of pipe lines are formed in the outdoor heat exchanger <NUM>, and the refrigerant pipe <NUM> on a four-way valve <NUM> side and the refrigerant pipe <NUM> on a supercooling heat exchanger <NUM> side are respectively branched and connected to the outdoor heat exchanger <NUM>. Furthermore, outdoor electronic control valves <NUM> and <NUM> are provided in the refrigerant pipe <NUM> on the supercooling heat exchanger <NUM> side of the outdoor heat exchanger <NUM>.

The supercooling heat exchanger <NUM> includes two heat exchange units <NUM> and <NUM>. The refrigerant pipe <NUM> on an outdoor heat exchanger <NUM> side and a refrigerant pipe <NUM> on an external connection valve 60a side are respectively branched and connected to each heat exchange unit <NUM> of the supercooling heat exchanger <NUM>.

In the present embodiment, each heat exchange unit <NUM> is a double pipe type heat exchanger. Outer pipes of the heat exchange units <NUM> are connected to the refrigerant pipe <NUM> on the outdoor heat exchanger <NUM> side and the refrigerant pipe <NUM> on the external connection valve 60a side, respectively.

A middle portion of the refrigerant pipe <NUM> that connects the supercooling heat exchanger <NUM> to the external connection valve 60a is connected to a supercooling branch pipe <NUM>. A middle portion of this supercooling branch pipe <NUM> is connected to an inner pipe <NUM> of each heat exchange unit <NUM> via a supercooling electronic control valve <NUM>. The refrigerant that flows through the inner pipe <NUM> of the heat exchange unit <NUM> is returned to the refrigerant pipe <NUM> between the four-way valve <NUM> and an accumulator <NUM> via a supercooling refrigerant pipe <NUM>.

The other external connection valve 60b is connected to a suction side of the EHP compressor <NUM> via the refrigerant pipe <NUM>, and the four-way valve <NUM> and the accumulator <NUM> are provided in a middle portion of the refrigerant pipe <NUM>.

Furthermore, a middle portion of the refrigerant pipe <NUM> which is between the EHP compressor <NUM> and the oil separator <NUM> is provided with a refrigerant return pipe <NUM> branched and connected to the refrigerant pipe <NUM> between the EHP compressor <NUM> and the accumulator <NUM>. A refrigerant returning solenoid valve <NUM> is provided in a middle portion of the refrigerant return pipe <NUM>. Then, when the refrigerant returning solenoid valve <NUM> is opened, a part of the refrigerant does not circulate in a refrigeration cycle and is guided to the suction side of the EHP compressor <NUM>.

Additionally, a lower portion of the oil separator <NUM> is connected to an oil pipe <NUM>, and a middle portion of the oil pipe <NUM> is connected to an oil return pipe <NUM> connected to the suction side of the EHP compressor <NUM>. The oil return pipe <NUM> includes two branch pipes <NUM> and <NUM> that branch from the oil pipe <NUM>, one branch pipe <NUM> is provided with an oil return valve <NUM>, and the other branch pipe <NUM> is provided with a capillary tube <NUM>. Furthermore, a capillary tube <NUM> is provided between connection portions of the oil pipe <NUM> to the respective branch pipes <NUM> and <NUM>.

A middle portion of the refrigerant pipe <NUM> which is between the oil separator <NUM> and the four-way valve <NUM> is connected to a high pressure refrigerant pipe <NUM> midway branched and connected to a middle portion of the oil pipe <NUM>. A middle portion of the high pressure refrigerant pipe <NUM> is provided with a solenoid valve <NUM> for a high pressure refrigerant.

Furthermore, the accumulator <NUM> includes an inflow pipe <NUM> into which the refrigerant of the refrigerant pipe <NUM> flows, and an outflow pipe <NUM> that sends an inner gas refrigerant of the accumulator <NUM> to the EHP compressor <NUM>. The outflow pipe <NUM> is configured to open in an inner upper portion of the accumulator <NUM>, and to send, to the EHP compressor <NUM>, a gas refrigerant accumulated in the inner upper portion of the accumulator <NUM>.

Additionally, the EHP compressor <NUM> is connected to an overflow pipe <NUM> connected to the suction side of the EHP compressor <NUM>. In this overflow pipe <NUM>, a strainer <NUM> and a throttle <NUM> to decompress oil are incorporated.

The external connection valve 60a of the EHP outdoor unit <NUM> is connected to one end of the interunit pipe <NUM>, and the other end of this interunit pipe <NUM> is connected to a middle portion of the interunit pipe <NUM> which connects the external connection valve 10a of the GHP outdoor unit <NUM> to the indoor unit <NUM>. The external connection valve 60b connected to a refrigerant pipe of the EHP outdoor unit <NUM> is connected to one end of the interunit pipe <NUM>, and the other end of this interunit pipe <NUM> is connected to a middle portion of the interunit pipe <NUM> which connects the external connection valve 10b of the GHP outdoor unit <NUM> to the indoor unit <NUM>.

Furthermore, the oil connection valve <NUM> of the EHP outdoor unit <NUM> is connected to the oil connection valve <NUM> of the GHP outdoor unit <NUM> via the oil balance pipe <NUM>. Consequently, the GHP compressor <NUM> of the GHP outdoor unit <NUM> and the EHP compressor <NUM> of the EHP outdoor unit <NUM> can supply the oil to each other via the oil balance pipe <NUM>, and balance of an oil amount can be held between the GHP compressor <NUM> of the GHP outdoor unit <NUM> and the EHP compressor <NUM> of the EHP outdoor unit <NUM>.

Then, when a cooling operation is performed, the refrigerant flows as shown by a solid arrow line in <FIG>, and when a heating operation is performed, the refrigerant flows as shown by a broken line in <FIG>.

Next, description will be made as to a control configuration of the air conditioner of the present embodiment. <FIG> is a block diagram showing the control configuration in the present embodiment.

As shown in <FIG>, in the present embodiment, the GHP outdoor unit <NUM> includes a GHP control section <NUM> as a control section, and the EHP outdoor unit <NUM> includes an EHP control section <NUM> as a control section. Furthermore, each of the indoor units <NUM> includes an indoor control section <NUM>.

Furthermore, in the present embodiment, the air conditioner includes a controller <NUM> that sends a control instruction signal to each of the GHP outdoor unit <NUM>, the EHP outdoor unit <NUM> and the indoor unit <NUM>.

The controller <NUM> includes a controller control section <NUM> to generally control the GHP control section <NUM>, the EHP control section <NUM> and the indoor control section <NUM>.

Each of the GHP control section <NUM>, the EHP control section <NUM>, the indoor control section <NUM> and the controller control section <NUM> includes, for example, a computation processing circuit such as a CPU, memories such as a ROM and a RAM, and others, and executes a predetermined program to perform predetermined control.

The GHP control section <NUM> is configured to perform drive control of the gas engine <NUM>, the outdoor fan <NUM> and the cooling water pump <NUM> of the GHP outdoor unit <NUM>, and to perform opening and closing control or opening degree control of the external connection valves 10a and 10b, the oil connection valve <NUM>, the electric valve <NUM>, the electric valve <NUM>, the bypass valve <NUM>, the oil return valve <NUM> and the cooling water three-way valve <NUM> of the GHP outdoor unit <NUM>.

The EHP control section <NUM> is configured to perform drive control of the EHP compressor <NUM> and the outdoor fan <NUM> of the EHP outdoor unit <NUM>, and to perform opening and closing control or opening degree control of the external connection valves 60a and 60b, the oil connection valve <NUM>, the outdoor electronic control valve <NUM>, the refrigerant returning solenoid valve <NUM>, the oil return valve <NUM>, the solenoid valve <NUM> for the high pressure refrigerant and the supercooling electronic control valve <NUM> of the EHP outdoor unit <NUM>.

The indoor control section <NUM> is configured to perform drive control of the indoor fan <NUM> of each indoor unit <NUM>, and to perform opening degree control of the expansion valve <NUM> of the indoor unit <NUM>.

These control operations of the GHP control section <NUM>, the EHP control section <NUM> and the indoor control section <NUM> are performed based on the control instruction signal sent from the controller control section <NUM>.

At this time, in the present embodiment, the GHP control section <NUM> is set to a master, and the EHP control section <NUM> and the indoor control section <NUM> are set to slaves. The control instruction signal from the controller control section <NUM> is first transmitted to the GHP control section <NUM>, and this control instruction signal is sequentially transmitted from the GHP control section <NUM> to the EHP control section <NUM> and the indoor control section <NUM>.

In the present embodiment, each of the GHP outdoor unit <NUM> and the EHP outdoor unit <NUM> regulates an output in accordance with a cooling load. For example, when the cooling load is a low load, the EHP outdoor unit <NUM> is driven, and as the cooling load increases, the EHP outdoor unit <NUM> is stopped, and the GHP outdoor unit <NUM> is started. When the cooling load is a high load, the GHP outdoor unit <NUM> is driven, and additionally the EHP outdoor unit <NUM> is driven.

The controller <NUM> controls the GHP outdoor unit <NUM>, the EHP outdoor unit <NUM> and the indoor unit <NUM> based on a number of the indoor units <NUM> to be operated, a set temperature, an outdoor air temperature, and the like. Consequently, a control signal is output to each of the GHP control section <NUM>, the EHP control section <NUM> and the indoor control section <NUM> so that an operation of the GHP outdoor unit <NUM> and an operation of the EHP outdoor unit <NUM> save energy most. In consequence, it is configured that the GHP control section <NUM> efficiently controls the operation of the GHP outdoor unit <NUM>, the EHP control section <NUM> efficiently controls the operation of the EHP outdoor unit <NUM>, and the indoor control section <NUM> efficiently controls the operation of the indoor unit <NUM>.

In this case, in the present embodiment, when the controller control section <NUM> switches the operations of the GHP outdoor unit <NUM> and the EHP outdoor unit <NUM>, the controller control section sends a switching instruction signal to each of the GHP control section <NUM> and the EHP control section <NUM>.

For example and according to the invention, during the operation of the EHP outdoor unit <NUM>, when the EHP outdoor unit <NUM> is stopped to switch the operation to the operation of the GHP outdoor unit <NUM>, the controller control section <NUM> sends, to the GHP control section <NUM>, a start instruction signal to start the GHP outdoor unit <NUM>. Then, based on the start instruction signal from the controller control section <NUM>, the GHP control section <NUM> starts the gas engine <NUM> of the GHP outdoor unit <NUM>, and starts the GHP outdoor unit <NUM>.

When the start of the GHP outdoor unit <NUM> is completed, the GHP control section sends a stop instruction signal to the EHP control section, and based on this stop instruction signal, the EHP control section <NUM> controls and stops the EHP outdoor unit <NUM>.

Furthermore, during the operation of the GHP outdoor unit <NUM>, when the GHP outdoor unit <NUM> is stopped to switch the operation to the operation of the EHP outdoor unit <NUM>, the controller control section <NUM> sends the start instruction signal of the EHP outdoor unit to the GHP control section, and the GHP control section sends the start instruction signal from the controller control section to the EHP control section. Consequently, based on the start instruction signal, the EHP control section <NUM> starts the EHP compressor <NUM> of the EHP outdoor unit <NUM>, and starts the EHP outdoor unit <NUM>.

Then, when the GHP control section monitors a start state of the EHP outdoor unit and determines that the start of the EHP outdoor unit is completed, the GHP control section <NUM> controls and stops the GHP outdoor unit <NUM>.

In consequence, the operation does not temporarily stop, and a continuous operation is possible.

Next, description will be made as to an operation of an air conditioner with reference to a timing chart shown in <FIG>.

<FIG> shows a timing chart example of the operation and stop of each of the GHP outdoor unit <NUM> and the EHP outdoor unit <NUM>.

As shown in <FIG>, description is first made as to a case where the EHP outdoor unit <NUM> is started from a state where the GHP outdoor unit <NUM> and the EHP outdoor unit <NUM> are stopped.

The controller control section <NUM> sends the start instruction signal to the EHP control section <NUM>, and based on the start instruction signal, the EHP control section <NUM> starts the EHP compressor <NUM>. In this state, an operation of the air conditioning system is started.

Then, when the operation is switched to the operation of the GHP outdoor unit <NUM> from a state where the EHP outdoor unit <NUM> is operated, the controller control section <NUM> sends, to the GHP control section <NUM>, the start instruction signal to start the GHP outdoor unit <NUM>. Then, based on the start instruction signal from the controller control section <NUM>, the GHP control section <NUM> starts the gas engine <NUM> of the GHP outdoor unit <NUM>, and starts the GHP outdoor unit <NUM>. When the start of the GHP outdoor unit <NUM> is completed, the GHP control section sends the stop instruction signal to the EHP control section, and based on this stop instruction signal, the EHP control section <NUM> stops the EHP outdoor unit <NUM>.

In consequence, when the operation is switched from the EHP outdoor unit <NUM> to the GHP outdoor unit <NUM>, the air conditioning system can be continuously operated without interrupting the operation of the air conditioning system.

Furthermore, when the EHP outdoor unit <NUM> is started from a state where the GHP outdoor unit <NUM> is operated and the EHP outdoor unit <NUM> is stopped, the controller control section <NUM> sends the start instruction signal of the EHP outdoor unit to the GHP control section, and the GHP control section sends the start instruction signal from the controller control section to the EHP control section. Consequently, based on the start instruction signal, the EHP control section <NUM> starts the EHP compressor <NUM> of the EHP outdoor unit <NUM>, and starts the EHP outdoor unit <NUM>.

Then, when the GHP control section monitors a start state of the EHP outdoor unit and determines that the start of the EHP outdoor unit is completed, the GHP control section <NUM> stops the GHP outdoor unit <NUM>.

In consequence, also when the operation is switched from the GHP outdoor unit <NUM> to the EHP outdoor unit <NUM>, the air conditioning system can be continuously operated without interrupting the operation of the air conditioning system.

As described above, the air conditioner includes the controller control section <NUM> that sends the control instruction signal to each of the GHP control section <NUM> and the EHP control section <NUM>. When receiving the switching instruction signal of the GHP outdoor unit <NUM> or the EHP outdoor unit <NUM> from the controller control section <NUM>, the GHP control section <NUM> or the EHP control section <NUM> starts the GHP outdoor unit <NUM> or the EHP outdoor unit <NUM> that is stopped. When the start of the GHP outdoor unit <NUM> or the EHP outdoor unit <NUM> is completed, the GHP control section <NUM> or the EHP control section <NUM> of the GHP outdoor unit <NUM> or the EHP outdoor unit <NUM> controls and stops the GHP outdoor unit <NUM> or the EHP outdoor unit <NUM> that is operating.

Consequently, after the start of the GHP outdoor unit <NUM> or the EHP outdoor unit <NUM> is completed, the GHP control section <NUM> or the EHP control section <NUM> of the outdoor unit that is operating stops the GHP outdoor unit <NUM> or the EHP outdoor unit <NUM>. Therefore, regardless of the switching instruction signal from the controller control section <NUM>, the GHP control section <NUM> or the EHP control section <NUM> can control the start and the stop of the GHP outdoor unit <NUM> or the EHP outdoor unit <NUM> without interrupting the operation of the air conditioning system. As a result, the air conditioning system can be continuously operated, and deterioration of air conditioning properties can be prevented.

Note that the above embodiment illustrates one aspect to which the present invention is applied, and the present invention is only limited by the scope of the appended claim.

According to the invention, the plurality of outdoor units comprise a GHP outdoor unit <NUM> and an EHP outdoor unit <NUM>.

Claim 1:
An air conditioner (<NUM>) in which each of a plurality of outdoor units (<NUM>, <NUM>) is connected to an indoor unit (<NUM>) via an interunit pipe (<NUM>), each outdoor unit (<NUM>, <NUM>) is operated and indoor air conditioning is performed by the indoor unit (<NUM>),
wherein the plurality of outdoor units (<NUM>, <NUM>) comprise a GHP outdoor unit (<NUM>) including a GHP compressor (<NUM>) that is driven by an engine (<NUM>) and an EHP outdoor unit (<NUM>) including an EHP compressor (<NUM>) that is driven by a commercial power source,
wherein the air conditioner (<NUM>) includes a controller (<NUM>) that sends a control instruction signal to each of the GHP outdoor unit (<NUM>), the EHP outdoor unit (<NUM>) and the indoor unit (<NUM>), and
wherein the controller (<NUM>) includes a controller control section (<NUM>) configured to generally control a GHP control section (<NUM>), an EHP control section (<NUM>) and an indoor control section (<NUM>),
characterized in that the controller control section (<NUM>) is configured to set the GHP control section (<NUM>) to a master, and to set the EHP control section (<NUM>) and the indoor control section (<NUM>) to slaves, to transmit the control instruction signal from the controller control section (<NUM>) first to the GHP control section (<NUM>), and to transmit this control instruction signal is sequentially from the GHP control section (<NUM>) to the EHP control section (<NUM>) and the indoor control section (<NUM>), wherein during operation of the EHP outdoor unit (<NUM>) the controller control section(<NUM>) is further configured to send a start signal to start the GHP outdoor unit (<NUM>), and
when the start of the GHP outdoor unit (<NUM>) is completed, the GHP control section (<NUM>) is configured to send a stop instruction signal to the EHP control section (<NUM>), and based on this stop instruction signal, the EHP control section (<NUM>) is configured to control and to stop the EHP outdoor unit (<NUM>).