JP4555718B2 - Air conditioning and power generation system - Google Patents

Description

  The present invention relates to an air conditioning / power generation system that simultaneously performs air conditioning and power generation by driving a compressor and a generator by an engine.

In a conventional engine-driven air conditioner, a compressor that compresses a refrigerant is driven by an engine such as a gas engine to perform an air conditioning operation. In recent years, a generator is connected to the gas engine, and the power generated by the generator is supplied to a load device such as a blower that blows air to an outdoor heat exchanger or a cooling water pump that cools the engine. Realization of a supply-less air conditioner is being sought (for example, see Patent Document 1).
In general, when a demand controller is installed and a power reduction instruction is output from the demand controller so that the commercial power usage does not exceed the contract power, control is performed so that the power consumption is within the contract power.
JP-A-5-231745

  However, an air conditioning / power generation system in which the function of the demand controller is added to an air conditioning / power generation system that outputs the generated power of the generator connected to the gas engine to a commercial system has not been proposed yet.

  Accordingly, an object of the present invention is to provide an air conditioning / power generation system that can solve the above-described problems of the conventional technology and efficiently store the power usage amount in the contract power when a power reduction instruction is output. There is to do.

  The present invention includes an air conditioner having a compressor driven by an engine, an outdoor heat exchanger, a decompression device, and an indoor heat exchanger, and a generator driven by the engine, and the generator is connected to the grid. When a power reduction instruction is output during cooling operation, the system includes a demand controller that outputs a power reduction instruction according to contracted power of the commercial system, and connects the system inverter to perform electrical output to the commercial system. By increasing or maintaining the rotation speed of the blower of the outdoor heat exchanger, the load on the engine is reduced and the power generation output of the generator is increased.

In the present invention, when a power reduction instruction is output during the cooling operation, in order to increase or maintain the rotational speed of the blower of the outdoor heat exchanger, condensation of the refrigerant of the outdoor heat exchanger is promoted, and the compressor load is increased. It will be reduced, and it will be possible to generate power with this load reduction added.
Therefore, for example, even if the customer load is not reduced, the amount of commercial power used can be reduced and the amount of power used can be kept within the contract power.

In this case, the fan rotation speed of the outdoor heat exchanger is fuzzy controlled using the high pressure of the compressor and the outlet differential temperature as the antecedent part, and when a power reduction instruction is output, the basic high pressure of the antecedent part The engine load may be reduced to increase the power generation output of the generator by shifting the value lower and increasing or maintaining the blower rotation speed.
In the present invention, if the basic value of high pressure is shifted to a lower value, the rotational speed of the blower can be increased or maintained, and can be configured with simple control.

  An air conditioner having a compressor driven by an engine, an outdoor heat exchanger, a decompression device and an indoor heat exchanger, and a generator driven by the engine, and a grid-connected inverter connected to the generator And a demand controller that outputs electric power to the commercial system and outputs a power reduction instruction according to contracted power of the commercial system, and when the power reduction instruction is output during the heating operation, the outdoor heat exchanger By lowering or maintaining the rotational speed of the blower, the load on the engine may be reduced and the power generation output of the generator may be increased.

In the present invention, when a power reduction instruction is output during heating operation, the rotation speed of the blower of the outdoor heat exchanger is lowered or maintained, so that the evaporation of the refrigerant in the outdoor heat exchanger is suppressed and the compressor load is reduced. It will be reduced, and it will be possible to generate power with this load reduction added.
Therefore, for example, even if the customer load is not reduced, the amount of commercial power used can be reduced and the amount of power used can be kept within the contract power.

In this case, the fan rotation speed of the outdoor heat exchanger is fuzzy controlled using the low pressure of the compressor and the discharge differential temperature as the antecedent part, and when a power reduction instruction is output, the basic low pressure of the antecedent part The engine load may be reduced and the power generation output of the generator increased by shifting the value lower and lowering or maintaining the blower rotation speed.
In the present invention, if the basic value of the low pressure is shifted to a lower value, the rotational speed of the blower can be lowered or maintained, and can be configured with simple control.

In the present invention, when the power reduction instruction is output during the cooling operation, the rotation speed of the blower of the outdoor heat exchanger is increased or maintained, so that the condensation of the refrigerant of the outdoor heat exchanger is promoted and the compressor load is reduced. Therefore, it is possible to generate power with the load reduction added.
In addition, when a power reduction instruction is output during heating operation, in order to lower or maintain the rotation speed of the blower of the outdoor heat exchanger, evaporation of the refrigerant in the outdoor heat exchanger is suppressed, and the compressor load is reduced. It is possible to generate electricity with the added load reduction.
Therefore, for example, even if the customer load is not reduced, the amount of commercial power used can be reduced and the amount of power used can be kept within the contract power.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 shows a gas engine driven air conditioner 1. The air conditioner 1 includes an outdoor unit 2 and a plurality of indoor units 3a to 3c, which are connected by an inter-unit pipe 4 including a liquid pipe 4a and a gas pipe 4b. The outdoor unit 2 accommodates a gas engine 10, a generator 11 that generates power using the driving force of the gas engine 10, and a compressor 12 that compresses the refrigerant using the driving force of the gas engine 10. The gas engine 10 generates a driving force by combusting an air-fuel mixture of a fuel such as a gas supplied via a fuel adjustment valve 7 and air supplied via a throttle valve 8.

  The compressor 12 is composed of compressors 12a and 12b having large and small capacities, and two units are connected in parallel to the gas engine 10 via electromagnetic clutches 14a and 14b, respectively. The discharge pipes 12c of the compressors 12a and 12b are connected in the order of the plate heat exchanger 31, the four-way valve 15, and the outdoor heat exchanger 17, and each of the outdoor heat exchangers 17 is connected to the outdoor heat exchanger 17 via the liquid pipe 4a. Expansion valves 19a to 19c and indoor heat exchangers 21a to 21b of the indoor unit 3 are connected. A four-way valve 15 is connected to the indoor heat exchangers 21a to 21b via a gas pipe 4b. Are connected to the compressors 12a and 12b. Further, the discharge pipe 12c and the suction pipe 12d of the compressors 12a and 12b are connected by a bypass pipe 18, and an unload bypass valve 20 is connected to the bypass pipe 18.

  Incidentally, when the compressors 12a and 12b are driven, if the four-way valve 15 is switched and if it is heating switching, the compressors 12a and 12b, the four-way valve 15 and the indoor heat exchange are indicated as indicated by solid arrows. The refrigerant circulates in the order of the chambers 21a to 21b, the expansion valves 19a to 19c, and the outdoor heat exchanger 17, and the room is heated by the refrigerant condensation heat in the indoor heat exchangers 21a to 21b. On the contrary, if the four-way valve 15 is switched to cooling, the compressors 12a and 12b, the four-way valve 15, the outdoor heat exchanger 17, the expansion valves 19a to 19c, and the indoor heat exchanger are indicated by the broken arrows. The refrigerant circulates in the order of 21a to 21b, and the room is cooled by the refrigerant evaporating heat in the indoor heat exchangers 21a to 21b.

Next, a cooling device for the gas engine 10 will be described.
The gas engine 10 is water-cooled, and the cooling water circulated through the water jacket of the gas engine 10 is supplied to the radiator 25 through the first three-way valve 22, the reverse power flow heater 23, and the second three-way valve 24. The The radiator 25 is provided with the outdoor heat exchanger 17, and these are cooled by air sent by the same blower 26, and the cooling water passing through the radiator 25 is supplied to the cooling water pump 27 and the exhaust gas heat exchanger 29. It flows in order and is returned to the water jacket of the gas engine 10.
Exhaust gas from the gas engine 10 is passed through the exhaust gas heat exchanger 29, and this exhaust gas is discharged out of the outdoor unit 2 through the exhaust top 30.

The first three-way valve 22 described above is automatically switched according to the cooling water temperature. That is, when the cooling water temperature is lower than the predetermined temperature, the cooling water from the water jacket of the gas engine 10 bypasses the radiator 25 and is directly led to the cooling water pump 27 and the exhaust gas heat exchanger 29 in this order, Return to the jacket.
The second three-way valve 24 is switched, for example, during heating operation. In this case, the cooling water bypasses the radiator 25, passes through the plate heat exchanger 31, and flows in the order of the cooling water pump 27 and the exhaust gas heat exchanger 29, Returned to the water jacket.

Next, a power generation system using the generator 11 will be described.
A grid interconnection inverter 33 is connected to the generator 11. The grid interconnection inverter 33 converts the three-phase AC power from the generator 11 into DC power through an AC / DC converter, and It is converted into 200 V three-phase AC power and output to the commercial system 35. The commercial system 35 includes a commercial power source 36, a breaker 37, and a customer load 38, and the grid interconnection inverter 33 is connected between the breaker 37 and the customer load 38.

  Further, the grid interconnection inverter 33 appropriately supplies power to the above-described reverse flow heater 23 and is communicably connected to the outdoor controller 39 of the outdoor unit 2 via the communication line 40. The outdoor controller 39 obtains operating power from the commercial system 35 via the power line 41 and is communicably connected to the indoor controller of each indoor unit 3 via the communication line 42.

A power detector 43 installed between the commercial power source 36 and the breaker 37 is connected to the grid interconnection inverter 33. The power detector 43 acquires the power value supplied to the commercial grid 35 in real time, and the acquired power value data is input to the grid interconnection inverter 33 and is transmitted to the outdoor controller 39 via the communication line 40. Sent.
Further, the grid interconnection inverter 33 has a function of controlling the power generation amount of the generator 11 and decreases or increases the power generation amount as necessary.

In the above configuration, for example, when the load on the compressors 12a and 12b increases according to the air conditioning request on the indoor unit 3 side, and the power generation request increases according to the increase in the consumer load 38 of the commercial system 35, the engine The load of 10 increases.
The customer load 38 is constantly monitored by the power detector 43, the grid interconnection inverter 33, and the outdoor controller 39.

In this configuration, a demand controller 51 that outputs a power reduction instruction according to the contract power of the commercial system is installed.
The demand controller 51 outputs a power reduction instruction in n + 1 stages from level 0 to level n, and if the output is level 0, there is a considerable margin in the amount of power used by the contract power, and gradually toward level n. The level of danger increases, and level n indicates that the contract power has been approached. The demand controller 51 outputs a power reduction instruction to the outdoor controller 39, and the outdoor controller 39 permits the grid interconnection inverter 33 to increase the power generation output according to the level of the power reduction instruction.

FIG. 2 shows a control flow during cooling operation.
In this processing flow, first, the level of the power reduction instruction from the demand controller 51 is determined (S1). If the instruction level is the power reduction level 0, the air conditioning priority operation is performed. If the instruction level is the power reduction level 1 or more, the power generation priority operation is performed.

In the case of power reduction level 0, there is a considerable margin before contract power, and the system's original air conditioning priority operation is performed.
In this air conditioning priority operation, the current load level of the engine 10 is acquired (S2). The current load level is estimated according to the valve opening of the throttle valve 8 (FIG. 1). The throttle valve 8 is an air amount adjusting valve of the engine 10, and the opening degree of the throttle valve 8 is classified into, for example, seven stages (level: 0 <high load> to 6 <low load>). In addition, if the associated load levels are obtained in advance and mapped, for example, the load level can be estimated according to the valve opening of the throttle valve 8.

Next, the power generation amount obtained from the difference between the current load level and the engine allowable load level is added to the current power generation amount (S3). Specifically, for example, as shown in FIG. 3, when the curve T is an engine allowable load level (allowable torque), the current engine load level T1 corresponding to the current engine speed R1 and the speed R1 thereof. The load level T3 that is the difference from the engine allowable load level T2 is determined, and the power generation amount Q1 corresponding to the load level T3 is determined from a predetermined load level / power generation amount map or the like, or from a predetermined arithmetic expression, The obtained power generation amount Q1 is added to the current power generation amount Q.
And it is determined whether this electric power generation amount Q2 (= Q1 + Q) is below the predetermined maximum electric power generation amount (S4). The maximum power generation amount may be a specification (rated) power generation amount or a predetermined power generation amount less than that. This maximum power generation amount varies depending on the rotation speed of the engine 10 and the load level.

  If the power generation amount Q2 is equal to or less than the maximum power generation amount in S4, the grid interconnection inverter 33 is permitted to generate the power generation amount Q2 (S5). If the power generation amount is equal to or greater than the maximum power generation amount, in order to prevent an overload of the engine 10, the grid interconnection inverter 33 is not permitted to generate the power generation amount Q2, but the power generation stopped at the maximum power generation amount is permitted (S6).

In this configuration, in the case of the power reduction level 0, when the air conditioning request increases, the engine speed increases according to the air conditioning request, and the compressor 12 is driven according to the engine speed.
Then, the refrigerant discharge amount according to this rotational speed is obtained, and air conditioning according to the air conditioning request is performed by circulation of this refrigerant amount.

In the state where the air-conditioning operation is performed at the rotational speed, a margin (corresponding to the load T2) is generated in the engine load with reference to FIG. In this configuration, since the output of the inverter 33 is controlled so that the power generation amount corresponding to the engine allowable load at that rotational speed is achieved, power generation at the full engine allowable load is always performed, the air conditioning load varies, and the rotational speed is Even if it fluctuates, it is possible to obtain the maximum amount of power that can be generated at that rotational speed.
In addition, since the engine is capable of generating the full allowable load of the engine, an excessive load is not applied to the engine 10 and engine durability is ensured.

On the other hand, if the power reduction level is 1 or more in S1, the risk changes for each level, and therefore power generation priority operation according to the risk is performed.
In this case, first, power reduction levels 1 to n are acquired (S7). As described above, the degree of danger gradually increases from the reduction level 1 to the reduction level n, and at the reduction level n, the contract power is considerably approached.

  In order to reduce the load on the compressor side according to the power reduction levels 1 to n, the high pressure of the antecedent part of the fuzzy control is shifted, and the rotational speed of the outdoor blower 26 is increased or maintained (S8). The rotation speed of the outdoor fan 26 is fuzzy control.

By the way, during the cooling operation, as shown in FIG. 4A, the rotational speed (consequent part) of the outdoor fan 26 is the difference between the discharge pressure (high pressure) of the compressor 12 and the target blowing temperature and the current blowing temperature ( The temperature difference is controlled as an antecedent part.
For example, in the case of the high pressure ZO and the blowing differential temperature NM, the rotation speed is controlled by maintaining the current state, and in the case of the high pressure NM and the blowing differential temperature NM, the rotation speed is controlled by the output reduction, and in the case of the high pressure PM and the blowing differential temperature NM, The rotation speed is controlled by increasing the output.

  When controlling based on the high pressure antecedent part: ZO = 2.5 Mpa, in S9, as shown in FIG. 4B, for example, ZO = (2. 5-0.1) Mpa, ZO = (2.5-0.2) Mpa, ZO = (2.5-0.n) Mpa is shifted lower.

In the power reduction levels 1 to n, the degree of danger gradually increases from the reduction level 1 to the reduction level n, and at the reduction level n, the contract power is considerably approached.
If the reduction level 1 is acquired in S7, the basic value of the high pressure is shifted to ZO = (2.5−0.1) Mpa and the reduction level 2 is acquired in S8 as shown in FIG. 4B. , ZO = (2.5−0.2) Mpa, and after obtaining the reduction level n, shift to ZO = (2.5−0.1) Mpa.

If the basic value of the high pressure is shifted to a lower value, the process proceeds to S2 to S6. When shifted to a lower level, the rotational speed of the outdoor fan 26 tends to increase or be maintained, and when this rotational speed is increasing, condensation of the refrigerant in the outdoor heat exchanger 17 is promoted during cooling operation. Compressor load is reduced.
Therefore, when the process proceeds to S2, the acquired current load level is reduced by the amount that the compressor load is reduced, and this causes a margin in the engine load (corresponding to the load T2). Therefore, by controlling the output of the inverter 33 so that the power generation amount corresponds to the engine allowable load at the current rotational speed, it becomes possible to add the power generation amount corresponding to the engine load margin.

  In the present embodiment, during the cooling operation, according to the reduction level output from the demand controller 51, the high pressure basic value of the antecedent part is shifted to a lower value, so that condensation of the refrigerant in the outdoor heat exchanger 17 is promoted, The compressor load is reduced, and power generation with the reduced load added becomes possible. Therefore, when a power reduction instruction is output during cooling operation, the amount of power generation increases efficiently. Therefore, even if the consumer load 38 is not reduced, the amount of commercial power used is reduced, and the amount of power used is within the contract power. Can fit in.

FIG. 5 shows a control flow during heating operation.
This processing flow is different from the processing flow of FIG. 2 in the processing of S18 and the other processing is the same. That is, in order to reduce the load on the compressor side according to the power reduction levels 1 to n, the low pressure of the antecedent part of the fuzzy control is shifted, and the rotational speed of the outdoor blower 26 is lowered or maintained (S18).

At the time of this heating operation, as shown in FIG. 6A, the rotational speed (consequent part) of the outdoor fan 26 is the difference between the suction pressure (low pressure) of the compressor 12 and the target blowing temperature and the current blowing temperature (blowing temperature). The temperature difference is controlled as an antecedent part.
For example, in the case of the low pressure ZO and the outlet differential temperature NM, the rotational speed is controlled by maintaining the current state, and in the case of the low pressure NM and the outlet differential temperature NM, the rotational speed is controlled by increasing the output, and in the case of the low pressure PM and the outlet differential temperature NM, The number of revolutions is controlled by the output reduction.

  When controlling based on the low pressure antecedent part: ZO = 0.6 Mpa, in S19, the basic value of the low pressure is set to ZO = (0. 6-0.1) Mpa, ZO = (0.6-0.2) Mpa, ZO = (0.6-0.n) Mpa is shifted lower.

In the power reduction levels 1 to n, the degree of danger gradually increases from the reduction level 1 to the reduction level n, and at the reduction level n, the contract power is considerably approached.
When the reduction level 1 is acquired in S7, the basic value of the low pressure is shifted to ZO = (0.6−0.1) Mpa and the reduction level 2 is acquired in S18 as shown in FIG. 6B. , ZO = (0.6−0.2) Mpa, and after obtaining the reduction level n, shift to ZO = (0.6−0.1) Mpa.

If the basic value of the low pressure is shifted to a lower value, the process proceeds to S2 to S6. When shifting to a lower level, the rotational speed of the outdoor fan 26 tends to decrease or maintain. Compressor load is reduced.
Therefore, when the process proceeds to S2, the acquired current load level is reduced by the amount that the compressor load is reduced, and this causes a margin in the engine load (corresponding to the load T2). Therefore, by controlling the output of the inverter 33 so that the power generation amount corresponds to the engine allowable load at the current rotational speed, it becomes possible to add the power generation amount corresponding to the engine load margin.

  In the present embodiment, during the heating operation, according to the reduction level output from the demand controller 51, the low-pressure basic value of the antecedent part is shifted to a lower value, so that evaporation of the refrigerant in the outdoor heat exchanger 17 is suppressed, The compressor load is reduced, and power generation with the reduced load added becomes possible. Therefore, when a power reduction instruction is output during heating operation, the amount of power generation increases efficiently. Therefore, even if the consumer load 38 is not reduced, the amount of commercial power used is reduced and the amount of power used is within the contract power. Can fit in.

  As mentioned above, although this invention was demonstrated based on one Embodiment, this invention is not limited to this. For example, the grid interconnection inverter 33 is provided separately from the outdoor unit 2, but may be housed integrally in the outdoor unit 2. Further, when a plurality of outdoor units 2 are installed, a grid interconnection inverter 33 is installed in each outdoor unit 2, and these grid interconnection inverters 33 are connected by a converter, and this converter is connected to each grid interconnection inverter 33. An output control instruction may be issued. In the present embodiment, the power supplied from the inverter is three-phase 200V, but may be three-phase 100V or a single-phase three-wire system.

It is a circuit diagram showing one embodiment of the present invention. It is a figure which shows the processing flow at the time of air_conditionaing | cooling operation. It is explanatory drawing of an engine allowable load level. A is a diagram showing a fuzzy map, and B is an explanatory diagram of a high-pressure shift. It is a figure which shows the processing flow at the time of heating operation. A is a diagram showing a fuzzy map, and B is an explanatory diagram of a low-pressure shift.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Engine drive type air conditioner 2 Outdoor unit 3 Indoor unit 8 Throttle valve 10 Engine 11 Generator 17 Outdoor heat exchanger 26 Blower 33 Grid interconnection inverter 35 Commercial system 36 Commercial power supply 37 Breaker 38 Customer load 39 Outdoor controller 43 Power detector 51 Demand controller

Claims (4)

  An air conditioner having a compressor driven by an engine, an outdoor heat exchanger, a decompression device and an indoor heat exchanger, and a generator driven by the engine, and a grid-connected inverter connected to the generator And a demand controller that outputs electric power to the commercial system and outputs a power reduction instruction according to contracted power of the commercial system, and when the power reduction instruction is output during the cooling operation, the outdoor heat exchanger An air conditioning and power generation system characterized in that the load on the engine is reduced and the power generation output of the generator is increased by increasing or maintaining the rotational speed of the blower.   The fan rotation speed of the outdoor heat exchanger is fuzzy controlled using the high pressure of the compressor and the outlet differential temperature as the antecedent part, and when the power reduction instruction is output, the basic value of the high pressure of the antecedent part is lowered. 2. The air conditioning and power generation system according to claim 1, wherein the engine output is reduced and the power generation output of the generator is increased by shifting or increasing or maintaining the rotational speed of the blower.   An air conditioner having a compressor driven by an engine, an outdoor heat exchanger, a decompression device and an indoor heat exchanger, and a generator driven by the engine, and a grid-connected inverter connected to the generator And a demand controller that outputs electric power to the commercial system and outputs a power reduction instruction according to contracted power of the commercial system, and when the power reduction instruction is output during the heating operation, the outdoor heat exchanger An air conditioning and power generation system characterized in that the load on the engine is reduced and the power generation output of the generator is increased by lowering or maintaining the rotational speed of the blower. The fan rotation speed of the outdoor heat exchanger is fuzzy controlled with the low pressure of the compressor and the outlet differential temperature as the antecedent part, and when a power reduction instruction is output, the basic value of the low pressure of the antecedent part is lowered. 4. The air conditioning and power generation system according to claim 3 , wherein the engine output is reduced and the power generation output of the power generator is increased by shifting and lowering or maintaining the blower rotation speed.

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