JP2014077358A - Engine power generation system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an engine power generation system capable of shortening a starting time necessary from start of an engine to output of a rated power by an electric generator.SOLUTION: An engine power generation system has a primary cooling system capable of supplying primary cooling water to an engine. The primary cooling system has a heater capable of heating the primary cooling water, a pressure adjustment device capable of adjusting a pressure of the primary cooling water, and a control device for controlling the heater and the pressure adjustment device. The control device determines target values of a pressure and a temperature of the primary cooling water as a starting pressure target value and a starting temperature target value respectively higher than a steady pressure target value and a steady temperature target temperature in a steady operating state of the engine, in starting the engine, and changes the target values of the pressure and temperature of the primary cooling water respectively to the steady pressure target value and the steady temperature target value after the lapse of a prescribed time from the start of the engine.

Description

  The present disclosure relates to an engine power generation system.

  The engine power generation system includes an engine such as a gas engine or a diesel engine, and a generator driven by the engine. When starting the engine power generation system, first, the engine is started in a state where the generator is not connected to the load. Then, after the engine speed reaches the rated speed, the generator is connected to the load at a predetermined load input rate, and finally the output of the generator reaches the rated output.

  By the way, the engine has a problem that cold startability is poor. Thus, for example, it is known that the cooling water after the engine is stopped is supplied to the heat storage tank, and the cooling water of the heat storage tank is supplied to the engine at the time of cold start (see, for example, Patent Document 1).

JP 2008-82225 A

  Engine power generation systems for emergency power supplies and the like are required to reduce the start time required from engine start to rated output. In response to such a requirement, it is not possible to adequately respond to the demand by simply supplying the cooling water after the engine is stopped to the heat storage tank to store the heat and supplying the cooling water from the heat storage tank to the engine at the cold start.

  Therefore, at least one embodiment of the present invention aims to provide an engine power generation system in which the start time required from the start of the engine until the generator outputs a rated output is shortened.

  According to at least one embodiment of the present invention, a generator, an engine capable of driving the generator, a primary cooling system capable of supplying primary cooling water to the engine, and the primary cooling water can be cooled. In the engine power generation system comprising a secondary cooling system, the primary cooling system is provided in a primary circulation path for supplying the primary cooling water to the engine, and in the primary circulation path, A pump capable of generating a flow of secondary cooling water, a heater provided in the primary circulation path and capable of heating the primary cooling water, and a pressure of the primary cooling water in the primary circulation path being adjustable. A pressure adjusting device; and a control device that controls the heater and the pressure adjusting device, wherein the control device sets the target values of the pressure and temperature of the primary cooling water when starting the engine. When the engine is in steady operation Are set to a starting pressure target value and a starting temperature target value that are higher than the steady pressure target value and the steady temperature target value, respectively, and after a predetermined time has elapsed from the start of the engine, the pressure and temperature of the primary cooling water An engine power generation system is provided that is configured to change a target value to the steady pressure target value and the steady temperature target value, respectively.

  In the engine generator system of the above-described embodiment, when the engine is started, the primary cooling water pressure target value is set to a starting pressure target value that is higher than the steady pressure target value. Even if the target temperature value is set to a starting temperature target value higher than the steady temperature target value, the primary cooling water does not boil. For this reason, the engine can be warmed up quickly and efficiently by the high-temperature primary cooling water. As a result, since the engine output reaches the rated output early, the power generation amount of the generator also reaches the rated output early.

  On the other hand, in this engine generator system, after a predetermined time has elapsed from the start of the engine, the temperature target value of the primary cooling water is changed to the steady temperature target value for the steady operation state, so the engine is overheated. Without first, the temperature of the primary cooling water quickly reaches the steady-state temperature target value. For this reason, the operation of the engine is quickly stabilized, and the power generation amount of the generator is also stabilized quickly.

  Further, in this engine generator system, the primary coolant pressure target value is changed to the steady pressure target value for the steady operation state after a predetermined time has elapsed from the start of the engine. Power can be reduced and efficiency can be increased.

In one embodiment, the pressure regulator comprises an inverter.
In this configuration, the pressure adjusting device includes an inverter, and the pressure of the primary cooling water can be accurately adjusted with a simple configuration.

In one embodiment, the engine is a gas engine.
Even if the engine is a gas engine, when the engine is started, the target value of the primary cooling water pressure is set to a starting pressure target value higher than the steady pressure target value, and the primary cooling water temperature target value is set. Is set to a starting temperature target value higher than the steady temperature target value, the starting time required from the start of the engine until the generator outputs the rated output is shortened.

  According to at least one embodiment of the present invention, there is provided an engine power generation system in which a start time required from when the engine is started until the generator outputs a rated output is shortened.

It is a figure showing a schematic structure of an engine power generation system concerning one embodiment of the present invention. It is a graph which shows roughly the time change of the pressure target value of primary cooling water and the temperature target value which were preset by the control device in FIG. It is a graph for demonstrating the operation | movement at the time of starting of the engine electric power generation system of FIG. It is a graph for demonstrating the operation | movement at the time of the start of the engine power generation system of a comparative example. It is a schematic diagram for demonstrating the structure of the pressure regulator of a modification.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. However, the dimensions, materials, shapes, and relative arrangements of the components described in this embodiment or shown in the drawings are not intended to limit the scope of the present invention, but are merely illustrative examples. Only.

  FIG. 1 shows a schematic configuration of an engine power generation system according to an embodiment of the present invention. The engine power generation system is suitable for an emergency backup power source (emergency power source) at the time of a power failure or the like, but can also be used for other purposes.

  The engine power generation system includes a generator 10, an engine 12, a primary cooling system 14, and a secondary cooling system 16. The generator 10 is connected to the engine 12, and the engine 12 can drive the generator 10 to generate electric power. The engine 12 is a stationary gas engine, but may be a diesel engine. The fuel of the gas engine is, for example, natural gas, but may be coal mine methane gas.

The primary cooling system 14 can supply primary cooling water to the engine 12, and the secondary cooling system 16 can cool the primary cooling water.
Specifically, the secondary cooling system 16 is an open circuit, and includes a cooling tower 18, a heat exchanger 20, a secondary circulation path 22, and a secondary pump 24.
The secondary circulation path 22 is a flow path for circulating secondary cooling water between the cooling tower 18 and the heat exchanger 20. The secondary pump 24 can generate a flow of secondary cooling water in the secondary circulation path 22. The secondary cooling water cools the primary cooling water by the heat exchanger 20 and is cooled by the cooling tower 18.

The primary cooling system 14 is a closed circuit, and includes a primary circulation path 26, a primary pump 28, a heater 30, a pressure adjustment device 32, and a control device 34.
The primary circulation path 26 is a flow path for supplying primary cooling water to the engine 12. The primary pump 28 is provided in the primary circulation path 26. The primary pump 28 is capable of generating a flow of primary cooling water in the primary circulation path 26 by discharging the primary cooling water sucked from the suction port from the discharge port.

The heat exchanger 20 is provided across the primary circulation path 26 and the secondary circulation path 22, and the primary cooling water that has passed through the engine 12 is cooled when passing through the heat exchanger 20.
The heater 30 is provided in the primary circulation path 26. The heater 30 can heat the primary cooling water flowing through the primary circulation path 26. The heater 30 includes, for example, an induction heating device or a jacket that allows a heat medium to flow.
The pressure adjusting device 32 can adjust the pressure of the primary cooling water in the primary circulation path 26. In the present embodiment, the pressure adjusting device 32 is an inverter that supplies electric power to the primary pump 28.

  The control device 34 can control the temperature and pressure of the primary cooling water in the primary circulation path 26 by controlling the heater 30 and the pressure adjusting device 32. When adjusting the pressure of the primary cooling water, the control device 34 increases or decreases the rotational speed of the primary pump 28 by increasing or decreasing the power supplied to the primary pump 28 by controlling the inverter, Thereby, the pressure of the primary cooling water is adjusted.

  In the present embodiment, the primary cooling system 14 includes a pressure sensor 36 for detecting the pressure of the primary cooling water and a temperature sensor 38 for detecting the temperature of the primary cooling water. For example, the pressure sensor 36 is provided upstream of the engine 12 in the flow direction of the primary cooling water, and can measure the pressure of the primary cooling water at the inlet of the engine 12. On the other hand, for example, the temperature sensor 38 is provided downstream of the engine 12 and can measure the temperature of the primary cooling water at the outlet of the engine 12.

  The pressure sensor 36 and the temperature sensor 38 are electrically connected to the control device 34, and the control device 34 measures the pressure measurement value of the primary cooling water measured by the pressure sensor 36 and the temperature sensor 38. The temperature measurement value of the primary cooling water is input. The control device 34 can control the heater 30 and the pressure adjustment device 32 based on the pressure measurement value and the temperature measurement value.

  FIG. 2 schematically shows temporal changes in the primary cooling water pressure target value and temperature target value preset in the control device 34. In the present embodiment, the control device 34 controls the heater 30 and the pressure adjustment device 32 so that the pressure measurement value and the temperature measurement value coincide with the temperature target value and the pressure target value. Note that the control device 34 may further control the secondary pump 24.

  As shown in FIG. 2, the control device 34 sets the temperature target value to the first temperature target value T1 for a predetermined time t1 from the start of the engine 12, and then sets it to the second temperature target value T2. For example, the time t1 is in the range of 3 minutes to 10 minutes, the first temperature target value T1 is in the range of 110 ° C. to 120 ° C., and the second temperature target value T2 is 85 ° C. to 95 ° C. Is in range.

  Further, the control device 34 sets the pressure target value to the first pressure target value P1 for a predetermined time t2 from the start of the engine 12, and then sets the second pressure target value P2. For example, the time t2 is in the range of 8 minutes to 15 minutes, the first pressure target value P1 is in the range of 0.35 MPa to 0.45 MPa, and the second pressure target value P2 is 0.15 MPa to 0 Within the range of 25 MPa or less.

The second pressure target value P2 and the second temperature target value T2 are a steady pressure target value and a steady temperature target value when the engine 12 is in a steady operation state, and the first pressure target value P1 and the first temperature target value T1. Are a starting pressure target value and a starting temperature target value when starting the engine 12. The second pressure target value P2 and the second temperature target value T2 are higher than the first pressure target value P1 and the first temperature target value T1, respectively.
In the present embodiment, the time t1 is shorter than the time t2 and shorter than the time required for the power generation amount of the generator 10 to reach the rated output.

  Hereinafter, the operation at the start of the engine power generation system of the above-described embodiment will be described. When starting the engine power generation system, the engine 12 is first started. When the engine 12 is started, the control device 34 sets the pressure target value and the temperature target value to the first pressure target value P1 and the first temperature target value T1, respectively. When the time t1 has elapsed from the start of the engine 12, the control device 34 changes the temperature target value to the second temperature target value T2, and when the time t2 has elapsed, the pressure target value is changed to the second pressure target value P2. Change to

  FIG. 3 schematically shows temporal changes in the temperature of the primary cooling water, the rotational speed of the engine 12, and the amount of power generated by the generator 10 when the engine power generation system is started. After the engine 12 is started, when the rotational speed of the engine 12 reaches the rated rotational speed, a load is applied and the generator 10 generates power. And the electric power generation amount of the generator 10 increases gradually with progress of time, and reaches | attains a rated output.

Here, as shown in FIG. 3, the temperature of the primary cooling water exceeds the second temperature target value T2 and reaches the first temperature target value T2 before the power generation amount reaches the rated output, as shown in FIG. It rises towards the value T1, and then starts to fall towards the second temperature target value T2. Then, the temperature of the primary cooling water reaches the second temperature target value T2 and stabilizes immediately after the power generation amount reaches the rated output.
The pressure of the primary cooling water is maintained at the first pressure target value P1 until the temperature of the primary cooling water falls below 100 ° C., and then maintained at the second pressure target value P2, as controlled by the control device 34. Is done.

  Here, FIG. 4 shows, as a comparative example, the temperature of the primary cooling water and the number of revolutions of the engine 12 when the temperature target value of the primary cooling water is set to the second temperature target value T2 from the start of the engine 12. And the time change of the electric power generation amount of the generator 10 is shown roughly. In the case of the comparative example in FIG. 4, it takes nearly twice as long as the amount of power generated by the generator 10 to reach the rated output as compared with the case of the embodiment in FIG. 3.

  In the engine generator system of the above-described embodiment, when the engine 12 is started, by setting the target value of the primary cooling water pressure to the first pressure target value P1 higher than the second pressure target value P2, Even if the target value of the primary cooling water temperature is set to the first temperature target value T1 higher than the second temperature target value T2, the primary cooling water does not boil. For this reason, the engine 12 can be warmed up quickly and efficiently by the high-temperature primary cooling water. As a result, since the output of the engine 12 reaches the rated output early, the power generation amount of the generator 10 also reaches the rated output early.

  In general, a gas engine used in a stationary engine generator system is larger than a gas engine mounted on a transportation device and has a large heat capacity, so it takes time to warm up. With the engine generator system of the above-described embodiment, even if the heat capacity of the engine 12 is large, it is possible to quickly warm up.

On the other hand, in this engine generator system, the temperature target value of the primary cooling water is changed to the second temperature target value T2 for the steady operation state after time t1 has elapsed since the engine 12 was started. The temperature of the primary cooling water quickly reaches the second temperature target value T2 without overheating 12. For this reason, the operation of the engine 12 is quickly stabilized, and the power generation amount of the generator 10 is also stabilized quickly.
Thus, the engine generator system according to the above-described embodiment can be quickly started up and loaded quickly, and is suitable for an emergency backup power source in the event of a power failure.

  Furthermore, in this engine generator system, after the elapse of time t2 from the start of the engine 12, the primary cooling water pressure target value is changed to the second pressure target value P2 for the steady operation state. The power of the next pump 28 can be reduced, and the efficiency can be increased.

  In general, a gas engine has poor cold startability. However, according to the above-described embodiment, even if the engine 12 is a gas engine, the start of the engine 12 until the generator 10 outputs a rated output. The starting time required is shortened.

  Moreover, in the engine generator system of one embodiment mentioned above, the pressure regulator 32 consists of an inverter, and can adjust the pressure of primary cooling water exactly with a simple structure.

The present invention is not limited to the above-described embodiment, and includes a form obtained by modifying the above-described embodiment.
For example, FIG. 5 schematically shows a pressure adjusting device 40 according to a modified example, and the pressure adjusting device 40 includes a bypass passage 42 and a control valve 44 provided in the bypass passage 42. In this case, the control device 34 can control the control valve 44 to adjust the pressure of the primary cooling water.

DESCRIPTION OF SYMBOLS 10 Generator 12 Engine 14 Primary cooling system 16 Secondary cooling system 20 Heat exchanger 26 Primary circulation path 28 Primary pump 30 Heater 32 Pressure adjustment apparatus 34 Control apparatus

Claims (3)

A generator,
An engine capable of driving the generator;
A primary cooling system capable of supplying primary cooling water to the engine;
An engine power generation system comprising a secondary cooling system capable of cooling the primary cooling water;
The primary cooling system is
A primary circuit for supplying the primary cooling water to the engine;
A pump provided in the primary circulation path and capable of generating a flow of the primary cooling water;
A heater provided in the primary circulation path and capable of heating the primary cooling water;
A pressure adjusting device capable of adjusting the pressure of the primary cooling water in the primary circulation path;
A control device for controlling the heater and the pressure adjusting device;
The control device includes:
When starting the engine, the target value of the pressure and temperature of the primary cooling water is set to a starting pressure target value that is higher than a steady pressure target value and a steady temperature target value, respectively, when the engine is in a steady operation state, and The starting temperature target value is set, and after the elapse of a predetermined time from the start of the engine, the primary cooling water pressure and temperature target values are changed to the steady pressure target value and the steady temperature target value, respectively. An engine power generation system configured as described above.   The engine power generation system according to claim 1, wherein the pressure adjusting device includes an inverter. The engine power generation system according to claim 1, wherein the engine is a gas engine.

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