JP2000054913A - Co-generation system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To generate suitable electric output and thermal output in the case where an electric load and a thermal load are largely fluctuated by providing an engine controller for controlling an output OF an internal combustion engine according to a present value of the electric load and a present value of a fluid temperature, on control means. SOLUTION: An internal combustion engine 11 is connected to an engine control unit (an ECU) 32, and is controlled by control values such as a fuel injection time and ignition timing that are calculated in the ECU 32. The ECU 32 is connected to a system control unit (a SCU) 40, and a data signal is outputted from a sensor provided on the internal combustion engine 11. In the SCU 40, a thermal load is calculated, and a load current (e) is calculated from load voltage and load current detected by a sensor provided on an inverter (an INV) 80. A controller is composed of the ECU 32 and the SCU 40. It is thus possible to generate suitable electric output and a thermal output.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a cogeneration system for supplying electric power to an electric load and supplying heat to a heat load by using an internal combustion engine.

[0002]

2. Description of the Related Art As a device for supplying electric power to an electric load using a plurality of internal combustion engines, for example, a power generation device disclosed in Japanese Patent No. 2743047 is known. In this conventional example, while a power generator is provided for each electric load, power is supplied,
The corresponding power generators are also stopped or driven according to the presence or absence of the electric load, so the operating time of the engine may vary, and in order to avoid this, the electric load and the engine We will adjust the correspondence.

[0003]

However, the power consumption of each of the electric loads may fluctuate greatly, and the fluctuation range of the electric output of each corresponding power generator is limited. There was a problem that it was not possible to sufficiently cope with fluctuations in Furthermore, in a cogeneration system that utilizes the heat generated from an internal combustion engine for power generation to heat hot water, control of the internal combustion engine is not easy because not only electric loads but also fluctuations in thermal loads must be dealt with. .

[0004] To cope with this problem, Japanese Patent Publication No. 3-59658 discloses a cogeneration system in which a plurality of AC generators driven by an internal combustion engine are prepared and operated in parallel. However, in this device, a system based on the parallel operation of the AC generator is adopted, and the synchronized state of the phases of the respective outputs is always established due to fluctuations in the engine speed when the AC generator is driven. Is not easy and has various problems.

Accordingly, the present invention is to provide a cogeneration system capable of generating not only an appropriate electric output but also a thermal output with respect to a large fluctuation of an electric load and a thermal load. Aim.

[0006]

SUMMARY OF THE INVENTION A cogeneration system according to the present invention includes a plurality of generators, a plurality of internal combustion engines each driving each of the plurality of generators, and an output power of each of the generators. An inverter that converts the power into DC power, superimposes the DC power on the power, and supplies the power to the electric load as common power; a control unit that controls output of the generator by controlling each output of the internal combustion engine; A circulation path for circulating a fluid that absorbs heat generated from the engine; and a heat exchanger provided in the circulation path, wherein the control unit controls a current value of the magnitude of the electric load and the fluid. And an engine controller for controlling the output of the internal combustion engine in accordance with the current value of the temperature of the internal combustion engine.

That is, according to the feature of the present invention, since the output of the internal combustion engine is controlled according to the current value of the magnitude of the electric load and the current value of the temperature of the fluid, the electric load and the thermal load are large. Even if it fluctuates, it is possible to generate appropriate electric and thermal outputs. According to another feature of the present invention, the output of the internal combustion engine according to the current operating range obtained by comparing the current value of the magnitude of the electric load and the current value of the temperature of the fluid with the two-dimensional map. , It is possible to quickly determine the current operating state and generate appropriate electrical and thermal outputs.

Further, according to another feature of the present invention, the rotational speed of each of the internal combustion engines and the number of operating internal combustion engines are adjusted, so that the internal combustion engine is operated in a preferable operating state to obtain an appropriate electric power and heat. Output can be generated. Further, according to another feature of the present invention, the rotational speeds of the internal combustion engines are adjusted to be substantially equal to each other, so that the internal combustion engines are operated in a preferable operating state to balance the operation amounts of the plural internal combustion engines. The internal combustion engine can be operated while maintaining it.

Further, according to another feature of the present invention, the priority order of the operation of the internal combustion engine is changed according to the cumulative operation time of each of the internal combustion engines, so that the cumulative operation times of the plurality of internal combustion engines are balanced. While operating the internal combustion engine.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an outline of a cogeneration system according to the present invention equipped with a plurality of internal combustion engines, for example, four internal combustion engines. The internal combustion engines 11, 12, 13 and 14 contain flammable gas,
For example, an engine that generates a torque by burning a mixture of natural gas and air.

The internal combustion engines 11 to 14 are provided with cooling medium passages 21, 22, 23 and 24 for recirculating a cooling medium (coolant) for cooling the internal combustion engine. Each of the cooling medium passages 21 to 24 is connected in series and also connected to the circulation passage 25. The cooling medium described above is sealed inside the cooling medium flow paths 21 to 24 and the circulation flow path 25, and the cooling medium is supplied by a pump (not shown) provided in a part of the circulation flow path 25. The cooling medium passages 21 to 24 and the circulation passage 25 are circulated. Each cylinder 1 of the internal combustion engines 11 to 14
In the vicinity of 5, 16, 17 and 18, heat exchange units 26, 2
7, 28 and 29 are arranged, and when the cooling medium circulates through the cooling medium passages 21 to 24 and the circulation passage 25,
In the heat exchange units 26 to 29, heat generated from the internal combustion engine is absorbed to cool the internal combustion engines 11 to 14.

The hot water supply tank 30 is connected to a heating flow path 31, and water stored in the hot water supply tank 30 in advance is pumped by a pump (not shown) provided in the heating flow path 31. The heating channel 31 is circulated. A part of the circulation flow path 25 and a part of the heating flow path 31 are arranged near each other inside the heat exchanger 36,
The water circulating through the heating channel 31 is heated by absorbing heat generated from the cooling medium in the heat exchanger 36, and the water stored in the hot water supply tank 30 is circulated through the heating channel 31. , Gradually warmed up. The cooling medium and water constitute a thermal load.

The above-described internal combustion engine 11 is connected to an engine control unit (hereinafter referred to as ECU) 32 and is controlled by control values such as fuel injection time and ignition timing calculated inside the ECU 32. The ECU 32
The ECU 32 is connected to a system control unit (hereinafter, referred to as SCU) 40, and
A data signal corresponding to a sensor output value of various sensors (not shown) such as a temperature of a cooling medium and a throttle valve opening provided in the internal combustion engine 11 and a calculated value such as a rotation speed of the internal combustion engine is issued. , SCU 40 issues a control signal such as start or stop of the internal combustion engine or a target engine speed. The SCU 40 includes an ECU that controls each of the internal combustion engines 12, 13, and 14.
33, 34 and 35 are also connected.

An operation panel 50 is connected to the SCU 40, and control signals for starting and stopping the cogeneration system shown in FIG.
While the signal is output to 0, a signal corresponding to the result of the determination of the operation state of the internal combustion engines 11 to 14 in the SCU 40 is supplied from the SCU 40 to the operation panel 50. Also,
The SCU 40 includes an inverter (hereinafter referred to as INV) 8
0 is also connected, and from the SCU 40 to the INV 80,
While a control signal for controlling the load power supplied from the INV 80 to the electric load 100 is supplied, the INV 8
From 0, a data signal corresponding to the values of the load voltage and the load current detected by the sensor (not shown) provided in the INV 80 is supplied to the SCU 40.

The INV 80 includes the internal combustion engines 11, 1
Generators (generators) 71, 72, 73 provided on each of the crankshafts (not shown) of 2, 13, and 14
And 74 are connected. This generator 71-7
4 outputs an AC voltage, for example, a three-phase 180 volt voltage. A commercial power supply 60 is also connected to the INV 80, and the INV 80 generates the generators 71, 72, 7 based on a control signal supplied from the SCU 40 as described later.
The necessary electric power is supplied to the electric load 100 based on the electric power generated in 3 and 74 and the electric power from the commercial power supply 60.

FIG. 2 shows a system control unit (SCU4) of the cogeneration system shown in FIG.
0). The operation panel 50 described above is connected to the input / output bus 42 via the interface circuit 41. The input / output bus 42 inputs and outputs a data signal or an address signal to a CPU (central processing circuit) 45. The sensor group 92 provided in the INV 80 is supplied to a multiplexer (hereinafter, referred to as MPX) 43 in the SCU 40. The MPX 43 is a switch that selectively supplies any one of output signals from the sensor group 92 to the A / D converter 44 in accordance with a command from the CPU 45 at a predetermined timing. The A / D converter 44 converts the supplied signal into a digital signal and supplies the digital signal to the input / output bus 42. A communication interface circuit 49 is connected to the input / output bus 42. This communication interface circuit 49
Is provided with a port (not shown) for serial communication in accordance with a predetermined communication standard, for example, the RS-232C standard.
Receiving data signals supplied from the ECU 32 and the INV 80, and from the CPU 45 to the ECU 32 and the INV
A control signal to be transmitted to 80 is transmitted.

A ROM (read only memory) 46, a RAM (random access memory) 47 and a nonvolatile memory 48 are connected to the input / output bus 42 described above. The ROM 46 stores a program for controlling the number of operating internal combustion engines according to the flowcharts described in FIGS. 5 and 6 and FIGS. Also,
The nonvolatile memory 48, for example, an EEPROM, stores the value of the accumulated operating time of the internal combustion engine calculated according to the flowcharts of FIGS.

The SCU 40 is described later with reference to FIGS.
And the heat load h used in the flowchart of FIG.
For example, the average value of the temperature of the cooling medium detected by each of the temperature sensors (not shown) provided near each of the internal combustion engines, and the temperature sensor (not shown) provided near the heat exchanger 36. And the load power e is calculated from the load voltage and the load current detected by the sensor provided in the inverter 80.

The ECU 32 and the SCU 40 constitute an engine controller, the SCU 40 constitutes control means, the ROM 46 constitutes storage means, and the generators 71, 72, 73 and 74 constitute generators. FIG. 3 shows an inverter (INV80) of the cogeneration system shown in FIG.

The above-described generators 71, 72, 73 and 74 are connected to contactor switches (hereinafter referred to as CS) 81, 82, 83 and 84, respectively. The commercial power supply 60 is connected to the CS 85. CS
Reference numerals 81 to 85 are connected to converters (hereinafter referred to as CONV) 86 to 90, respectively.
Converts each of the AC voltages generated from the generators 71 to 74 into a DC voltage, for example, a voltage of 180 volts,
It is supplied to the inverter circuit 91. CONV90 also
AC voltage supplied from the commercial power supply 60, for example, three-phase 20
After converting 0 volts to a DC voltage, for example, 180 volts, it is supplied to the inverter circuit 91. Inverter circuit 9
1 superimposes each supplied DC voltage and converts it into a common AC voltage, for example, 100 volts.
00 is supplied with an AC voltage.

A sensor group 92 is provided near each of the output terminals (not shown) of the CONVs 86 to 90.
The sensor group 92 detects the voltage and the current of the DC power generated from each of the CONVs 86 to 90, and
The detection signal is supplied to the A / D converter 44 of 0.
A sensor group 93 is provided near an output terminal (not shown) of the inverter circuit 91.
A load voltage and a load current of the load power generated from the inverter circuit 91 are detected, and a detection signal is supplied to an A / D converter (not shown) of the ICU 94. The ICU 94 supplies the detected load voltage and load current values to the SCU 40 as data signals at predetermined timings, for example, every 200 milliseconds.

Also, based on a control signal supplied from the SCU 40 to the ICU 94, the ICU 94
By controlling the on / off operations of 81 to 85, the electric power supplied from generators 71 to 74 and commercial power supply 60 can be selectively supplied to electric load 100. FIG. 4 shows an operation panel of the cogeneration system.

The display panel 51 displays the calculation results calculated by the SCU 40 and the contents stored in the nonvolatile memory 48. The emergency stop switch 52
This switch is used when the operator wants to stop the operation of the cogeneration system urgently. The reset switch 53 is a switch used when restarting the cogeneration system. The system start-up display LED 54 is a light-emitting diode that indicates that the system has been started up.
Reference numeral 5 denotes a light-emitting diode that lights up when the system stops in an emergency. Further, the display ON switch 56 is a switch for displaying the display content on the display panel 51.
The display OFF switch 57 is a switch for deleting the display on the display panel 51. In addition, the mode changeover switch 58 is provided with a heat main mode, that is, a mode for controlling the internal combustion engine by giving priority to reducing a difference between the temperature of the cooling medium near the internal combustion engine and the temperature of the cooling medium near the heat exchanger, and an electric main mode. That is, a switch for switching between a mode for controlling the internal combustion engine and giving priority to appropriately supplying load power to the electric load connected to the inverter.

In the following, the cogeneration system shown in FIG.
5. It is assumed that all initialization processing such as initialization of variables used in the SCU 40 and INV 80 and activation of a timer described later have been completed. FIG. 5 shows a subroutine for controlling the operation of the internal combustion engine.

First, the temperature of the cooling medium detected by the temperature sensor (not shown) provided near each of the internal combustion engines and the temperature sensor provided near the heat exchanger 36 (not shown). The electric load e is calculated from the difference between the temperature of the cooling medium and the load detected by the sensor group 93 provided in the INV 80 (step S11). Next, FIG.
The current operating region is obtained according to the flowchart described in (1) (step S12), and the suppliable power E is calculated based on the obtained current operating region according to the flowchart shown in FIG. 8 (step S13). Next, the number of operating internal combustion engines required to achieve the calculated suppliable power E is calculated according to the flowchart shown in FIG. 9 (step S14), and the number of operating internal combustion engines and the necessary number calculated in step S14 are calculated. The number to be increased or the number to be decreased is calculated from the operating number (step S1).
5). Next, the cumulative operating time of each internal combustion engine is
Reading is performed from a nonvolatile memory, for example, an EEPROM (step S16). The cumulative operating time of the internal combustion engine is calculated and stored at predetermined time intervals based on flowcharts shown in FIGS. 11 and 12 described later. Next, the order of the internal combustion engines is determined in the order of the cumulative operating time read in order to determine the priority of the internal combustion engines to be started or stopped (step S17). Next, it is determined whether or not the number of internal combustion engines to be operated increases from the increase / decrease number calculated in step S15 (step S1).
8). When it is determined that the number of the internal combustion engines to be operated increases, the internal combustion engines are newly started up by the increasing number in ascending order of the cumulative operation time of the internal combustion engine, and the CS corresponding to the started internal combustion engine is connected ( Step S19). Next, the rotational speed of each of the currently operating internal combustion engines is controlled (step S20), and the present subroutine ends. On the other hand, if it is determined that the number of the internal combustion engines to be operated is reduced, the internal combustion engines are stopped by the reduced number in the order of the cumulative operating time of the internal combustion engine in descending order, and the CS corresponding to the stopped internal combustion engine is stopped.
Is released (step S21). Next, the rotation speed of each of the currently operating internal combustion engines is controlled (step S2).
0), end this subroutine.

In steps S19 and S21, when the number of operating internal combustion engines is zero,
The INV 80 controls so that only electric power from the commercial power supply 60 is supplied to the electric load 100. When the number of operating internal combustion engines is one or more, the INV 80 stops supplying power from the commercial power supply 60 and the generator 71 That is, control is performed so that the electric power from to 74 is supplied to the electric load 100.

FIG. 6 shows a subroutine for determining the current operation area of the internal combustion engine from the load power e and the heat load h. This subroutine is determined based on the two-dimensional map that determines the current operation area of the internal combustion engine from the load power e and the thermal load h shown in FIG. 7, and is executed in step S12 in FIG. is there.
First, it is determined whether or not the value of the load power e calculated in step S11 in FIG. 5 is 1.3 or more (step S21). When it is determined that the value of the load power e is smaller than 1.3, it is determined that the current operation region belongs to the region X (solid horizontal line region shown in FIG. 6) (step S2).
2) End this subroutine. On the other hand, when it is determined that the value of the load power e is equal to or greater than 1.3, it is determined whether the value of the heat load h is equal to or greater than 2600 (step S).
23). When it is determined that the value of the heat load h is smaller than 2600, it is determined that the current operation region belongs to the region X (step S22), and the present subroutine ends. Heat load h
Is determined to be 2600 or more, it is determined whether the value of the heat load h is smaller than 14400 (step S24). When it is determined that the value of the heat load h is equal to or greater than 14400, it is determined that the current operation region belongs to the region Y (solid hatched region shown in FIG. 6) (step S25).
This subroutine ends. On the other hand, when the value of the heat load h is 14
If it is determined that it is smaller than 400, it is determined whether the value of the heat load h is larger than 3600 and smaller than 5200 (step S26). When it is determined that the value of the heat load h is larger than 3600 and smaller than 5200,
It is determined whether the value of the load power e is smaller than 2.6 (step S27). When it is determined that the value of the load power e is equal to or greater than 2.6, the current operation region is the region Z1 (FIG. 6).
(Step S2).
8), end this subroutine. If it is determined in step S27 that the value of the load power e is smaller than 2.6, it is determined that the current operation region belongs to the region Y (the solid hatched region shown in FIG. 6) (step S29), and the present subroutine ends. I do. On the other hand, if it is determined in step S26 that the value of the heat load h is 3600 or less or 5200 or more, it is determined whether the value of the heat load h is larger than 7200 and smaller than 7800 (step S30). ). The value of the heat load h is greater than 7200 and 78
If it is determined that the value is smaller than 00, it is determined whether the value of the load power e is smaller than 3.9 (step S3).
1). When it is determined that the value of the load power e is equal to or greater than 3.9, it is determined that the current operation region belongs to the region Z2 (the one-dot broken line hatched region shown in FIG. 6) (step S32), and this subroutine is terminated. . When it is determined that the value of the load power e is smaller than 3.9, the current operation region is the region Y (FIG. 6).
(The solid hatched area shown in FIG. 3) (step S3).
3), end this subroutine. On the other hand, step S3
0, the value of the heat load h is 7200 or less or 7
If it is determined that it is 800 or more, it is determined whether or not the value of the heat load h is larger than the value obtained by multiplying the load power e by 2000 (step S34). When it is determined that the value of the thermal load h is equal to or greater than the value obtained by multiplying the load power e by 2000, the current operation region is the region Y (solid hatched region shown in FIG. 6).
(Step S35), and the subroutine ends. When it is determined that the value of the heat load h is smaller than the value obtained by multiplying the load power e by 2000, it is determined that the current operation region belongs to the region Z (the solid vertical line region shown in FIG. 6) (step S36). This subroutine ends.

FIG. 8 shows a subroutine for calculating the available electric power (E) that can be supplied from the inverter (INV80). This subroutine is executed in step S13 of the flowchart in FIG. First, the value of the suppliable power E is set to an initial value, for example, 0 (step S41), and the mode changeover switch 58 described above is set.
It is determined whether or not the mode set by is the thermal main mode (step S42). If it is determined that the mode is the thermal main mode, the suppliable power E is set to the detected load power e (step S43), and the present subroutine ends.
On the other hand, if it is determined that the current main operation mode is not the heat main mode, that is, it is the electric main mode, it is determined whether or not the current operation region determined according to the flowchart described with reference to FIG. 6 is the region X (step S44). If it is determined that the current operation area is the area X, the suppliable electric power E is set to 0 (step S45), and the present subroutine ends. Step S4
If it is determined in step 4 that the current operation area is not the area X, it is determined whether the current operation area is the area Y (step S46). If it is determined that the current operation area is the area Y, the suppliable electric power E is set to the load electric power e (step S47), and this subroutine ends. If it is determined in step S46 that the current operation area is not the area Y, it is determined whether the current operation area is the area Z (step S48). When it is determined that the current operation area is the area Z, the suppliable electric power E is changed to the heat load h / 2.
000 (step S49), and this subroutine ends. If it is determined in step S48 that the current operation area is not the area Z, the current operation area is determined to be the area Z1.
Is determined (step S50). When it is determined that the current operation area is the area Z1, the suppliable electric power E is set to 1.8 (step S51), and the present subroutine ends. If it is determined in step S50 that the current operation area is not the area Z1, it is determined whether the current operation area is the area Z2 (step S52).
If it is determined that the current operation area is the area Z2, the suppliable power E is set to 3.6 (step S53), and the present subroutine ends. If it is determined in step S52 that the current operation area is not the area Z2, the present subroutine ends. By making a determination in accordance with the above-described flowchart, it is possible to calculate an appropriate suppliable power E according to the current operating region.

FIG. 9 shows a subroutine for calculating the number of operating internal combustion engines based on the suppliable power E calculated in the flowchart shown in FIG. This subroutine is executed in step S14 in the flowchart of FIG. First, it is determined whether the suppliable power E is equal to or more than 0 and less than 1.3 (step S61). When it is determined that the suppliable power E is equal to or more than 0 and less than 1.3, the number of operating units is set to 0
The subroutine is set (step S62), and this subroutine ends. When it is determined that the suppliable power E is not less than 0 and less than 1.3, it is determined whether the suppliable power E is 1.3 or more and less than 2.6 (step S6).
3). When it is determined that the suppliable power E is equal to or more than 1.3 and less than 2.6, the number of operating units is set to one (step S64), and the present subroutine ends. If it is determined that the suppliable power E is not less than 1.3 and less than 2.6, it is determined whether the suppliable power E is 2.6 or more and less than 3.9 (step S65). When it is determined that the suppliable power E is equal to or more than 2.6 and less than 3.9, the number of operating units is set to two (step S66), and the present subroutine ends. When it is determined that the suppliable power E is not less than 2.6 and less than 3.9, it is determined whether the suppliable power E is not less than 3.9 and less than 5.4 (step S67). When it is determined that the suppliable power E is 3.9 or more and less than 5.4, the operating number is set to three (step S68), and this subroutine is ended. When it is determined that the suppliable power E is not less than 3.9 and less than 5.4, it is determined whether the suppliable power E is not less than 5.4 and less than 8.0 (step S6).
9). When it is determined that the suppliable power E is equal to or more than 5.4 and less than 8.0, the operating number is set to four (step S70), and the present subroutine ends. When it is determined that the suppliable power E is not equal to or more than 5.4 and less than 8.0, the operating number is set to four (step S71), and the flag F_OV indicating that the calculated suppliable power E is excessive is set.
The value of ER is set to 1 (step S72), and this subroutine ends. When the value of the flag F_OVER is set to 1, a configuration may be used in which the display panel 51 of the operation panel 50 displays that the suppliable load power is excessive, and issues a warning to the operator.

FIG. 10 shows a subroutine for calculating and controlling the rotational speed of the internal combustion engine. This subroutine is executed in step S20 of the flowchart in FIG. 5, and is for controlling the rotation speed of the internal combustion engine that is operating in steps S19 and S21 of the flowchart shown in FIG. First, it is determined whether or not the value of the suppliable power E is larger than 1.8 and smaller than 2.6 (step S81). If it is determined that the value of the suppliable power E is greater than 1.8 and less than 2.6, the value of the suppliable power E is set to 1.8 (step S82). Next, it is determined whether or not the value of the suppliable power E is greater than 3.6 and less than 4.0 (step S83). When it is determined that the value of the suppliable power E is greater than 3.6 and less than 4.0, the value of the suppliable power E is set to 3.6 (step S8).
4). Next, it is determined whether the value of the suppliable power E is larger than 7.2 and equal to or smaller than 8.5 (step S8).
5). 7. The value of the suppliable power E is larger than 7.2 and 8.
If it is determined that it is 5 or less, the value of the suppliable power E is set to 7.2 (step S86).

Next, the value of the target rotation speed Ne of the internal combustion engine is calculated, for example, by 3000 ×
It is calculated based on a relational expression of (suppliable power E) / (number of operating engines × 1.8) (step S87). Since the target rotational speed Ne is calculated from the relational expression as described above, the internal combustion engine can be operated with the engine rotational speed substantially equal. Next, the ratio of the conduction rate, for example, the sum of the time during which the inverter and the load are conducting and the time when the inverter and the load are not conducting, and the time during which the inverter and the load are conducting are greater than 75%. And it is determined whether it is smaller than 85% (step S8)
8). When it is determined that the conductivity is 75% or less or 85% or more, the value of the target rotation speed Ne of the internal combustion engine is finely set (step S89). Next, a control signal based on the calculated value of the target engine speed Ne of the internal combustion engine
The rotational speed of the internal combustion engine supplied from U40 to the ECU 32 and operating is controlled to be substantially equal to the target rotational speed Ne (step S90), and this subroutine is terminated.
Note that the target rotation speed Ne may have a certain width as a target rotation speed region.

FIG. 11 shows a subroutine for executing a timer process for accumulating the accumulated operating time for each engine. This subroutine is executed every predetermined time, for example, 10 minutes.
Interrupt processing is performed every 0 microsecond and executed. First, it is determined whether or not the internal combustion engine 11 has been started (step S111). It is determined whether the internal combustion engine 11 is running when the engine speed supplied from the ECU 32 to the SCU 40 is equal to or higher than a predetermined speed, for example, 1000 rpm, and the engine speed is determined to be the predetermined speed. If it is smaller, it is determined that it has not been activated. When it is determined that the internal combustion engine 11 is not running, the value of the counter COUNTER1 for the internal combustion engine 11 is initialized, for example, set to 0 (step S112), and it is determined whether the internal combustion engine 12 is running (step S112). Step S117). On the other hand, when it is determined that the internal combustion engine 11 is running, the COUNTER1
It is determined whether or not the value is larger than a predetermined value C0 (step S113). When it is determined that the value of COUNTER1 is equal to or smaller than the predetermined value C0, the value of COUNTER1 is increased by 1 (step S114), and the process proceeds to step S117. Also, COUNTE
When it is determined that the value of R1 is greater than the predetermined value C0, COUN
The value of TER1 is initialized (step S115), and the flag F_TI
The value of MER1 is set to 1 (step S116).

By performing the above-described processing, the value of the flag F_TIMER1 can be set to 1 every predetermined time, for example, every minute when the internal combustion engine is running. For example, when this subroutine is executed every 100 microseconds, to set the value of the flag F_TIMER1 to 1 every 1 minute, the predetermined value C0 is set to 60 ×
What is necessary is to set it to 10 ⁴ .

Steps S117 to S122 set a flag F_TIMER2 for the internal combustion engine 12, steps S123 to S128 set a flag F_TIMER3 for the internal combustion engine 13, and steps S129 to S134.
Is a process for setting a flag F_TIMER4 for the internal combustion engine 14. FIG. 12 shows a subroutine for accumulating the cumulative operating time for each engine. This subroutine is executed by interruption processing at predetermined time intervals.

First, it is determined whether or not the value of the flag F_TIMER1 described in FIG. 11 is 1 (step S141). If it is determined that the value of the flag F_TIMER1 is not 1, the routine proceeds to step S145, where the internal combustion engine 1
2 is performed. On the other hand, the flag F_TIME
If it is determined that the value of R1 is 1, the internal combustion engine 1
The value of the operating time TIME_SUM1 of 1 is increased by a predetermined value T0, for example, 1 (step S142). The value of TIME_SUM1 is stored in a nonvolatile memory, for example, an EEPROM, and does not disappear even when power is not supplied. Next, the value of the flag F_TIMER1 is initialized, for example, set to 0 (step S143). The processing of steps S141 to S143 described above is performed by the internal combustion engine 1
This is the operation time integration process for step S1 and steps S144 to S14 after steps S141 to S143.
6 is an operation time integration process for the internal combustion engine 12, steps S147 to S149 are operation time integration processes for the internal combustion engine 13, and steps S150 to S149.
S152 is an operation time integration process for the internal combustion engine 14.

As described in FIG. 11, the flag F_TI
Since the values of MER1 to F_TIMER4 are set to 1 every minute, for example, steps S142, S145, S1
At 48 and S151, the operating time of the internal combustion engine can be integrated by the predetermined value T0, for example, by one minute by adding the predetermined value T0, for example, one by one.

In the above-described cogeneration system, electric power from the commercial power supply 60 is supplied to the electric load 10.
0, when a change in the load power output from the inverter 80 is detected due to a change in the number of electric loads 100 connected to the inverter 80 or a change in the power consumption of the electric load. Immediately have commercial power 6
A configuration in which power from 0 is supplied to the electric load 100 may be adopted. With the configuration as described above, stable electric power can always be supplied to the electric load 100.

Further, in the above-described embodiment, the case where the cooling medium flow paths 21 to 24 are connected in series has been shown, but it is apparent that a part of the cooling medium flow path may be connected in parallel. is there. Further, in the above-described embodiment, the configuration has been described in which the cumulative operation time of the internal combustion engine is processed as the operation amount of the internal combustion engine. It is clear that the quantity may be good.

Furthermore, in the above-described embodiment, the average value of the temperature of the cooling medium detected by each of the temperature sensors (not shown) provided near each of the internal combustion engines and the heat load h and the heat exchanger. A case has been shown in which the temperature is calculated from the difference from the temperature of the cooling medium detected by a temperature sensor (not shown) provided in the vicinity of 36. However, a temperature sensor is provided in the heating channel 31 and stored in the hot water tank 30. Alternatively, the temperature of the water being detected may be detected, and the heat load h may be calculated based on the detected water temperature.

In this specification, the term "internal combustion engine" refers to an internal combustion engine including a hybrid engine and the like.

[0041]

As described above, according to the cogeneration system of the present invention, the output of the internal combustion engine is controlled in accordance with the current value of the magnitude of the electric load and the current value of the temperature of the fluid. Appropriate electrical and thermal outputs can be generated even when the load and thermal load fluctuate significantly.

According to another feature of the present invention, the internal combustion engine according to the current operation range obtained by comparing the current value of the magnitude of the electric load and the current value of the temperature of the fluid with the two-dimensional map. Since the output of the engine is controlled, it is possible to quickly determine the current operation state and generate appropriate electric and thermal outputs. Further, according to another feature of the present invention, the number of revolutions of each of the internal combustion engines and the number of operating internal combustion engines are adjusted, so that the internal combustion engine is operated in a preferable operating state to obtain appropriate electric and thermal outputs. Can be generated.

According to another feature of the present invention, the rotational speeds of the internal combustion engines are adjusted so as to be substantially equal to each other. The internal combustion engine can be operated while maintaining the balance. Still further, according to another feature of the present invention, the priority order of operation of the internal combustion engine is changed according to the cumulative operation time of each of the internal combustion engines. Can be operated.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an outline of a cogeneration system according to the present invention.

FIG. 2 is a block diagram showing a system control unit of the cogeneration system shown in FIG.

FIG. 3 is a block diagram showing an inverter of the cogeneration system shown in FIG.

FIG. 4 is a front view showing an operation panel of the cogeneration system shown in FIG.

FIG. 5 is a flowchart showing a subroutine for controlling the operation of the internal combustion engine.

FIG. 6 is a flowchart showing a subroutine for determining a current operation area of the internal combustion engine from a load power e and a heat load h.

FIG. 7 is a graph showing a current operation region defined by a load power e and a heat load h.

FIG. 8 is a flowchart illustrating a subroutine for calculating a suppliable power E to be output from an inverter.

FIG. 9 is a flowchart illustrating a subroutine for calculating the number of operating internal combustion engines to be operated.

FIG. 10 is a flowchart showing a subroutine for calculating and controlling the rotation speed of the internal combustion engine.

FIG. 11 is a flowchart showing a subroutine for executing a timer process for accumulating the cumulative operating time for each engine.

FIG. 12 is a flowchart showing a subroutine for accumulating the cumulative operation time for each engine.

[Explanation of symbols]

11, 12, 13, 14 Internal combustion engine 25 Circulation flow path 32, 33, 34, 35 ECU (Engine controller) 36 Heat exchanger 40 SCU (Engine controller, control means) 46 ROM (Storage means) 71, 72, 73, 74 generator (generator) 80 inverter 100 electric load

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Tsutomu Wakitani 1-4-1 Chuo, Wako-shi, Saitama F-term in Honda R & D Co., Ltd. (Reference) 3G093 AA16 DA05 DB23 EA03 5H007 BB00 CC01 DB07 DC02 DC05 DC08

Claims (5)

[Claims] 1. A plurality of generators, a plurality of internal combustion engines each of which drives each of the plurality of generators, and each of output powers of the generators is converted to DC power and superimposed and shared. An inverter for supplying electric power to an electric load, a control means for controlling an output of each of the internal combustion engines to control an output power of the generator, and a circulation for circulating a fluid absorbing heat generated from the internal combustion engine. A flow path, and a heat exchanger provided in the circulation flow path, wherein the control unit controls the internal combustion engine according to a current value of the magnitude of the electric load and a current value of the temperature of the fluid. A cogeneration system comprising an engine controller for controlling output. 2. The control unit further includes a storage unit that stores a two-dimensional map in which a magnitude of the electric load and a temperature of the fluid are used as parameters. 2. The cogeneration system according to claim 1, wherein the output of the internal combustion engine is controlled in accordance with a current operation range obtained by comparing a current value of the fluid and a current value of the temperature of the fluid with the two-dimensional map. system. 3. The cogeneration system according to claim 1, wherein the engine controller adjusts each rotation speed of the internal combustion engine and the number of operating internal combustion engines. 4. The cogeneration system according to claim 1, wherein the engine controller adjusts the rotation speed of each of the internal combustion engines so that the rotation speeds are within substantially equal rotation speed ranges. 5. The cogeneration system according to claim 1, wherein the engine controller changes the priority of the operation of the internal combustion engine in accordance with the cumulative operation time of each of the internal combustion engines.