JPS6115243B2 - - Google Patents

Description

[Detailed Description of the Invention] This invention provides a parallel operation method that maximizes the use of the waste heat recovery turbine generator to save energy when a waste heat recovery turbine generator and a diesel generator are operated in parallel on a ship. It is related to.

Ships mainly powered by diesel engines are equipped with an exhaust gas eco-mizer that recovers thermal energy from the engine exhaust gas to supply the onboard load, and the generated steam is used to drive the turbine generator and the exhaust gas eco-mizer lacks steam volume. Some ships are equipped with a diesel generator as a supplement when the turbine generator alone cannot cover the onboard load. In this case, an economical parallel operation method becomes a problem. Parallel operation methods include manual methods and automatic methods using automatic load sharing devices. Parallel operation using the manual method allows stable control between generators of the same model, but it is difficult to operate the governor between generators of different models, as in this case.
Unbalanced load makes stable operation control impossible. On the other hand, automatic load sharing methods include a proportional distribution method and an overflow distribution method. In the proportional distribution method, the total load is distributed proportionally to the generation capacity of each generator, and each generator is operated with a margin except when the load is at its maximum. Therefore, in parallel operation of a waste heat recovery turbine generator and a diesel generator, even if there is sufficient exhaust gas thermal energy, it cannot be used 100% effectively, and conversely, the diesel generator consumes fuel. This is uneconomical and is not preferred as a parallel operation method in this case. On the other hand, with the overflow distribution method, the maximum load that the first generator should bear is set, and if the onboard load exceeds this, the excess load is transferred to the second generator. In this case, exhaust gas thermal energy can be recovered by using a waste heat recovery turbine generator as the first generator, but
When operating in parallel with a diesel generator, there are the following problems. That is, when a diesel engine is continuously operated at low output for a long period of time, the amount of fuel consumed naturally decreases, and therefore the thermal energy of the exhaust gas decreases. As a result, the rotational speed of the supercharger driven by exhaust gas decreases, resulting in insufficient pressure in the combustion chamber, causing oil build-up, and lowering the sintering temperature, causing incomplete combustion. In order to prevent these adverse effects, it is necessary to continuously operate the diesel engine at the minimum allowable output. This output is called the lower limit output here. In the overflow distribution system, when the first diesel generator is operated as a waste heat recovery turbine generator, when the load on the ship decreases, the output of the second diesel generator decreases and falls below the lower limit output, resulting in a long Continuous operation for hours becomes impossible. Therefore, in order to prevent the output of the diesel generator from falling below the above-mentioned lower limit output within the range of onboard load fluctuations, the maximum value of the load that should be borne by the first waste heat recovery turbine generator is lowered. It is necessary to set this so that even if the load on the ship is small, the load on the diesel generator is greater than the lower limit output. However, this results in wasted heat energy that could be generated.

This invention was made in order to solve the above-mentioned problems, and for the purpose of energy saving, in order to make maximum use of exhaust gas thermal energy, a waste heat recovery turbine generator is operated with priority, and a diesel engine The object of the present invention is to provide a method for parallel operation of a waste heat recovery turbine generator and a diesel generator in a ship, in which the generator is automatically controlled to operate at a lower limit output or higher.

An embodiment of the present invention will be described below with reference to FIG. 1 is the main diesel engine, 2
recovers the exhaust gas heat energy of this engine,
This is an exhaust gas economizer that generates steam. Reference numeral 3 denotes a steam turbine driven by the steam generated by the economizer, which serves as the motive power for a generator 4. This generator 4 and the steam turbine 3 constitute a waste heat recovery turbine generator 4a. The steam that has done work in the turbine 3 is condensed in the condenser 5 and is fed to the economizer 2 by the water pump 6. Reference numeral 8 denotes a pressure gauge for steam supplied to the turbine 3, and its measured value is transmitted to the control device 11. Reference numeral 12 denotes a governor that controls the turbine 3 to a specified rotational speed by adjusting a steam control valve 7 that controls the amount of steam fed to the turbine 3. The opening degree of the steam control valve 7 is transmitted to the control device 11. 9
A is a diesel generator consisting of a diesel engine 10 and a generator 9 driven by the diesel engine 10.
Reference numeral 13 denotes a governor that adjusts the amount of fuel supplied to the diesel engine 10 and controls the rotational speed of the engine to a specified rotational speed. The control device 11 inputs the outputs of the turbine generator 4a and the diesel generator 9a, performs comparison calculations with the set upper limit output of the turbine generator 4a and the lower limit output of the diesel generator 9a, and controls the steam control valve. 7 and the steam pressure supplied to the turbine 3 to start and stop the diesel generator. Also, a reference governor is selected depending on the load situation, and the power generation frequency is controlled to the reference frequency.

The control device 11 compares and calculates whether the turbine generator 4a is below its upper limit output and there is a margin in the opening degree of the steam control valve 7, and if the onboard load is below the power generation amount of the turbine generator 4a, the turbine generator 4a starts generating electricity. When only the generator 4a is operated independently, the load is transferred to the turbine generator 4a.
The frequency is controlled by the turbine governor 12 (first step). In this state, if the load on the ship increases or the output of the turbine generator 4a decreases, and the turbine generator 4a alone cannot cover the load on the ship, that is, if the control device 11 determines that the above conditions are not satisfied, the command is Therefore, it is automatically switched to parallel operation with the diesel generator 9a.
At this time, the turbine governor 12 and the diesel engine governor 13 are used in conjunction with the diesel generator 9.
A is operated to maintain the lower limit output, and is controlled using the reference governor as the turbine governor 12. (Second step) In this state, if the situation changes so that the conditions of the first step are satisfied during operation, the state of the first step is returned. On the other hand, diesel generator 9a
The control device 11 compares the output of , the governor 13 of the diesel generator is switched to share load fluctuations with the diesel generator 9a and perform frequency control (third step). From this state, the process returns to the second step and then to the first step due to a change in the situation. By the automatic parallel operation method described above, the waste heat recovery turbine generator can be operated with priority, and the diesel generator can be safely operated at more than its lower limit output.

The details of the embodiment will be explained below based on the control sequence shown in FIG. Operation mode manual (A~1)
Then, when the diesel generator 9a is operated independently, the steam pressure of the exhaust gas economizer 2 gradually increases as the output of the main diesel engine 1 increases, and when the state is reached where the waste heat recovery turbine generator 4a can be operated, The governor 12 of the turbine 3 is manually operated to reach the specified rotation speed (A-2). Next, the turbine generator 4a is turned on synchronously to operate in parallel with the diesel generator 9a (A-3). Next, switch the operation mode to automatic (B~1) and check if the output of the turbine generator 4a is less than the set upper limit output (B~1).
3) Check whether there is enough room in the steam control valve opening.
A comparison operation is performed in step 1 (B~2). If this condition is satisfied, a comparison operation is performed to see whether the output of the diesel generator 9a and the set lower limit output are larger or smaller (B~5). If the output is not the lower limit output, the diesel engine Operate the governor 13 of 10 (B~4) to turn on the diesel generator 9.
A is operated at the lower limit output, and frequency control is performed by the governor 12 of the turbine 3 (B-6) (second step). Further, when the above conditions (B to 3) are not satisfied and the output of the diesel generator 9a is equal to or higher than the lower limit output, a comparison calculation is made between the output of the turbine generator 4a and the upper limit output (B to 8), and the upper limit output is calculated. If the output exceeds the output, operate the turbine governor 12 (B to 7) to operate the turbine generator 4a at the upper limit output, and switch the reference governor from the turbine governor 12 to the diesel engine governor 13 to increase or decrease the load and control the steam. Frequency changes due to pressure fluctuations are controlled by the diesel engine governor 13 (B-9) (third step). If the conditions (B-2) are not satisfied, only frequency control is performed by the diesel engine governor 13 without operating the turbine governor 12. During operation in the operating state of the second step, a comparison calculation is performed between the output of the turbine generator 4a and a value obtained by subtracting the lower limit output of the diesel generator 9a from 90% of the upper limit output of the turbine generator 4a. B~10), when it is determined that the turbine generator 4a has a margin, check whether the turbine feed steam pressure is higher than the specified value (B
~11) If it is above the specified value, diesel generator 9
Transfer the load of a to the tanbin generator 4, stop the diesel engine 10, and (B~12) (B~13) (B
~14) Return to the first step. Also, during operation in the first step, the diesel engine 10 is automatically started in response to a signal (B~15) indicating that the output of the turbine generator 4a has exceeded the upper limit output or a signal (B~16) indicating the upper limit of the opening degree of the regulating valve. Enter synchronous operation (B~
17), return to the second or third step. When the turbine generator 4a is in the upper limit output operating state and the output of the diesel generator 9a continues to be at the lower limit output for a certain period of time (B-18), the operation mode is switched to the second step. Further, during operation in the second step, the output of the turbine generator 4a is switched to the operation mode in the third step in response to a signal indicating that the output reaches the upper limit output (B-2).

Therefore, the parallel operation method of the present invention allows the waste heat recovery turbine generator to be operated with priority to maximize the use of exhaust gas thermal energy to save diesel fuel, and moreover, allows the diesel generator to operate at higher output than its lower limit. Able to drive safely.

[Brief explanation of the drawing]

FIG. 1 is an operation control system diagram of an embodiment of the invention, and FIG. 2 is an embodiment of the control sequence of the invention. 3... Turbine, 4... Generator, 4a... Turbine generator, 10... Diesel engine, 9...
... Generator, 9a... Diesel generator, 11...
Control device.

Claims (1)

[Claims] 1 In a system that supplies electricity using a ship's waste heat recovery turbine generator and diesel generator, if the onboard load is less than the power generation amount of the waste heat recovery turbine generator, only the waste heat recovery turbine generator is operated. However, if the onboard load exceeds the amount of power generated by the waste heat recovery turbine, this turbine generator will be operated with priority, and the diesel generator will be operated to make up for the shortfall. A method for parallel operation of a waste heat recovery turbine generator and a diesel generator for a ship, characterized by automatically controlling the diesel generator to operate at the lower limit output when the lower limit output of the engine is exceeded.