JPS6365802B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a marine engine plant heat recovery system.

In general, the graph shown in Figure 1 shows the power required during regular voyage in a ship with a diesel engine as the main engine, and the power that can be generated by a turbo generator using exhaust gas from the main engine. . Note that the vertical axis represents electric power and the horizontal axis represents the output of the main engine. As can be seen from Figure 1, when the main engine output exceeds a certain level (e.g. 15,000 horsepower), the turbo generator alone is sufficient to cover the necessary power, but for ships with less than this output, and over a wide range of temperatures from the main engine exhaust gas. Even ships with three-stage output exhaust gas economizer systems that provide heat recovery cannot rely solely on turbo generators. Therefore, in the past, when the main engine output was about 10,000 horsepower, for example, a diesel generator was separately installed to cover the necessary power, and the heat from the main engine exhaust gas was not fully utilized.

Therefore, the inventors of the present invention discovered that the cylinder jacket and cylinder head of the main engine cooling system in the past were integrated into the same system, resulting in a low cooling water temperature and insufficient heat recovery. Focusing on the fact that seawater is used in drain coolers for steam processing discharged from steam consuming equipment, and that the seawater that has absorbed heat is simply discarded into the sea, we have proposed the present invention that can eliminate the above-mentioned drawbacks. .

That is, the present invention provides a high-pressure side evaporation pipe connected to a high-pressure side brackish water separator and an intermediate-pressure side brackish water separator, which are sequentially connected to a high-pressure side brackish water separator from a high temperature section toward a low temperature section, in an exhaust gas discharge pipe for recovering heat of main engine exhaust gas. A medium pressure side evaporation pipe connected to the low pressure side brackish water separator and a low pressure side evaporation pipe connected to the low pressure side brackish water separator are arranged, and a part of the cooling water circulation pipe for the cylinder head of the main engine is guided into the liquid phase part of the low pressure side brackish water separator. A part of the steam generated in each of the above steam separators is led to a power generation steam turbine, the rest is led to general steam consumption equipment, and condensate from the steam turbine vacuum condenser is led to a Hotwell tank. A condensate transfer pipe is provided, a vacuum drain cooler is provided to cool the steam (drainage) discharged from the general steam consumption equipment, and a flash pipe is provided to flush the condensate in the condensate transfer pipe within the vacuum drain cooler, and This is a marine engine plant heat recovery system characterized in that a drain water phase shift tube is provided to send drain water from the vacuum drain cooler to the hot well tank. According to the configuration of the present invention, in addition to the heat recovery by the three-stage pressure exhaust gas economizer system, the high temperature cooling water of the cylinder head of the main engine is guided into the low pressure side brackish water separator for heat recovery, and the general steam consumption is The steam drain discharged from the equipment is guided into the vacuum drain cooler to increase the utilization of low-pressure steam, and the steam drain is cooled in the vacuum drain cooler by condensed water from the steam turbine to recover the heat held by the steam drain. As a result, compared to conventional systems, the amount of steam generated by the heat of the main engine exhaust gas can be significantly increased. Therefore, even if the main engine output is around 10,000 horsepower, the general steam consumption can be reduced. The steam left over from the steam used to power the equipment can be used to drive a turbo-generator to provide the necessary power for the trip at all times, thus saving all the fuel needed for conventional diesel generators.

An embodiment of the present invention will be described below with reference to FIG. 1 is the main engine (diesel engine) in a ship
A three-stage pressure type exhaust gas economizer system is provided in the exhaust gas discharge pipe for discharging the exhaust gas from 2. That is, inside the exhaust gas discharge pipe 1, from the high temperature section to the low temperature section, there are, in order, a high temperature side superheating tube 3, an intermediate pressure side superheating tube 4, a high pressure side evaporation tube 5, an intermediate pressure side evaporation tube 6, and a low pressure side evaporation tube. 7 is arranged, and the high pressure side evaporation pipe 5 and the high pressure side brackish water separator 8 are connected via the first hot water pipe 9 and the first steam pipe 10, and the medium pressure side evaporation pipe 6 and the medium pressure side brackish water separator 11 are connected to each other via the first hot water pipe 9 and the first steam pipe 10. are connected via a second hot water pipe 12 and a second steam pipe 13,
The low pressure side evaporation pipe 7 and the low pressure side brackish water separator 14 are the third
It is connected via a hot water pipe 15 and a third steam pipe 16. Note that reference numerals 17, 18, and 19 are circulating water pumps provided midway through each of the hot water pipes 9, 12, and 15. 20 is a water supply pipe for supplying water to each of the brackish water separators 8, 11, and 14. That is, one end of the water supply pipe 20 is connected to a Hotwell tank 21 that stores steam drain water and condensate, and the other end is passed through the high-temperature part of the supercharged air cooler 22 of the main engine 2 and A third water supply branch pipe 23 connected to the low pressure side brackish water separator 14, a second water supply branch pipe 24 connected to the medium pressure side brackish water separator 11, and one end connected to the second water supply branch pipe 24. A first water supply branch pipe 25 that is branched and whose other end is connected to the high-pressure side brackish water separator 8
They are each branched into In addition, 26 is a water supply pump provided in the middle of the water supply pipe 20, and 27 is a control valve provided in the middle of the bypass pipe 28 that bypasses the introduction part of the water supply pipe 20 to the supercharged air cooler 22. Temperature controller 2 that detects the temperature of
9. 30 is the second water supply branch pipe 24
A heating heat exchanger provided midway is used to exchange heat with the bypass pipe 31 of the second hot water pipe 12. Note that 32 is a three-way temperature control valve for controlling the bypass pipe 31, and is controlled by a temperature regulator 33 that detects the temperature inside the second hot water pipe 12. A heating heat exchanger 34 is provided in the middle of the first water supply branch pipe 25 and is used to exchange heat with the first hot water pipe 9. In addition, 35,
Reference numerals 36 and 37 denote control valves provided in each water supply branch pipe 25, 24, and 23, which are controlled by liquid level regulators 38, 39, and 40 that detect the liquid level in each brackish water separator 8, 11, and 14. be done. 41, 42, and 43 are first, second, and third steam supply pipes that supply the steam generated in each of the above-mentioned brackish water separators 8, 11, and 14 to the general steam consumption equipment 44, and 45 is a third steam supply pipe whose one end is the third steam supply pipe. A low pressure steam introduction pipe 43 is connected to the middle of the second steam supply pipe 42 and the other end is connected to the low pressure part of the steam turbine 47 for driving the generator 46; An intermediate pressure steam introduction pipe 49 is connected to the intermediate pressure section of the steam turbine 47 via the intermediate pressure side superheating pipe 4, and one end thereof is connected to the middle of the first steam supply pipe 41, and the other end is connected to the high pressure side superheating pipe 3. This is a high-pressure steam introduction pipe connected to the high-pressure part of the steam turbine 47 via the high-pressure steam introduction pipe. Moreover, 50 is a high-pressure steam introduction branch pipe branched from the middle of the high-pressure steam introduction pipe 49, and is introduced into the liquid phase part in the intermediate pressure side brackish water separator 11 to heat the liquid phase part. Note that 51 is a control valve provided in the middle of the high-pressure steam introduction branch pipe 50, and is controlled by a pressure regulator 52 that detects the pressure inside the intermediate-pressure side brackish water separator 11. 53 is a vacuum condenser that condenses the exhaust gas discharged from the steam turbine 47; 54 is a vacuum condenser that transfers condensate from the vacuum condenser 53 to the Hotwell tank 21 by a condensate pump 55 interposed in the middle; This is a condensate transfer pipe. 56 is general steam consumption equipment 44
A vacuum drain cooler cools low-pressure steam drain discharged from the vacuum condenser 53, and is connected to the vacuum condenser 53 through a communication pipe 58 having a control valve 57. The control valve 57 is controlled by a pressure regulator 59 that detects the pressure inside the vacuum drain cooler 56, so that the pressure inside the vacuum drain cooler 56 is kept below a certain value. Inside the vacuum drain cooler 56, a flush pipe 61 is arranged which is connected to the condensate transfer pipe 54 on the downstream side of the condensate pump 55 via a connecting pipe 60. Reference numeral 62 denotes a drain water transfer pipe for transferring drain water from the vacuum drain cooler 56 to the hot well tank 21 by a drain pump 63 interposed in the middle.
Note that 64 is a steam exhaust pipe that directly leads high-pressure steam drain discharged from, for example, the main engine fuel oil heater 44 a of the general steam consumption equipment 44 to the hot well tank 21 . Reference numeral 65 denotes a cooling water circulation pipe provided from the outlet to the inlet of the cylinder head portion 2a of the main engine 2, a part of which is introduced into the liquid phase portion in the low pressure side brackish water separator 14. The above cooling water circulation pipe 65
A heating heat exchanger 66 is installed in the middle of the outlet side piping 65a.
is provided to exchange heat with the second steam supply branch pipe 67 from the second steam supply pipe 42. In addition, the inlet side piping 65 of the cooling water circulation pipe 65
An expansion tank 68, a three-way temperature control valve 69, and a cooling water circulation pump 70 are provided in the middle of b, and the inlet side pipe 65b and the outlet side pipe 65a are communicated via the three-way temperature control valve 69. A bypass pipe 71 is provided. The three-way temperature control valve 69 is controlled by a temperature regulator 72 that detects the temperature inside the inlet pipe 65b.
In addition, 73 is a control valve provided in the middle of the second steam supply branch pipe 67, and is controlled by a pressure regulator 74 that detects the internal pressure of the low-pressure side brackish water separator 14. 75
is a cooler for cooling the jacket cooling water of the main engine 2, and a seawater supply pipe 76 is introduced. 77
and 78 are the cylinder jacket part 2b and the cooler 7
5, a cooling water supply pipe and a cooling water return pipe are disposed across the cooling water supply pipe and the cooling water return pipe. In the middle of the cooling water return pipe 78,
A heating heat exchanger 79, a cooling water circulation pump 80, and a water generator 81 are provided. Note that a third steam supply branch pipe 82 branched from the third steam supply pipe 43 is introduced into the heat exchanger 79. A bypass pipe 83 is provided between the cooling water supply pipe 77 and the return pipe 78 to bypass the cooler 75, and a three-way temperature control valve is provided at the connection between the bypass pipe 83 and the cooling water supply pipe 77. 84 is provided, and this three-way temperature regulating valve 84 is controlled by a temperature regulator 85 that detects the temperature of the cooling water.
One end of 86 is connected to the downstream side of the three-way temperature control valve 84 of the cooling water supply pipe 77, and the other end is connected to the intermediate temperature section of the supercharged air cooler 22 and the inboard air conditioner 8.
This is an air conditioning circulation pipe connected to the cooling water return pipe 78 upstream of the cooling water circulation pump 80 via the cooling water return pipe 78 . Note that 88 is a bypass pipe that bypasses the air conditioner 87, and an on-off valve 89 is provided in the middle of the bypass pipe.

Next, to explain the heat recovery effect, the water in each of the brackish water separators 8, 11, 14 is pumped through each evaporation pipe 5, 6, 14 by circulating water pumps 17, 18, 19, respectively.
7, where it is heated and returned to each brackish water separator 8, 11, 14 as steam. A part of the high-pressure steam from the high-pressure side brackish water separator 8 is further heated (10 kg/cm ² , about 215°C) by the high-pressure side superheating pipe 3 and supplied to the high-pressure section of the steam turbine 47. A part of the medium pressure steam from the brackish water separator 11 is further heated (4.7Kg/cm ² , 185℃) by the medium pressure side superheating tube 4.
A part of the steam from the low-pressure side brackish water separator 14 is further supplied to the low-pressure part of the steam turbine 47, and the steam turbine 47 is rotated by each of these steams. At the same time, the generator 46 is rotated to generate electricity.
The steam discharged from the steam turbine 47 is condensed in a vacuum condenser 53 and transferred into the hotwell tank 21 via a condensate transfer pipe 54. On the other hand, the remaining steam is used for general steam consumption equipment (various fuel tank heating devices, miscellaneous steam consumption facilities, etc.)
Steam condensate supplied to and discharged from 44 is introduced into vacuum condensate cooler 56 .
The steam drain introduced into the vacuum drain cooler 56 is cooled by condensate flushed from a flush pipe 61, and then sent to the hot well tank 21 via a drain water transfer pipe 62. In addition,
The hot water that has entered the Hotwell tank 21 is supplied to each of the brackish water separators 8, 11, and 14 through the water supply pipe 20, and a supercharged air cooler 22 and each water supply branch pipe are provided along the way. It is heated by heating heat exchangers 34 and 30 provided at 25 and 24.
In addition, the high temperature cooling water (about 140 degrees Celsius) discharged from the cylinder head section 2a of the main engine 2 warms the water in the low-pressure side brackish water separator 14 to produce low-temperature cooling water (about 130 degrees Celsius).
It then returns to the cylinder head portion 2a and cools the cylinder head. Furthermore, high temperature cooling water (approximately 75°C) discharged from the cylinder jacket part 2b of the main engine 2
is low temperature (about 65℃) in water generator 81 and cooler 75.
A part of the cooling water is sent to the cylinder jacket part 2b to cool the cylinder wall surface, and the rest of the cooled water enters the air conditioning circulation pipe 86 and is heated by the supercharged air cooler 22. absorbs high temperature (75
After the heat is used in the air conditioner 87, it is returned to the cooler 75 together with the high temperature cooling water discharged from the cylinder jacket.

According to the above configuration, in addition to heat recovery by the three-stage pressure exhaust gas economizer system, high-temperature cooling water from the cylinder head of the main engine is guided into the low-pressure side brackish water separator for heat recovery, and heat is recovered from the general steam consumption equipment. The exhaust steam condensate is guided into a vacuum drain cooler to increase the utilization of low-pressure steam, and the steam condensate is cooled in the vacuum drain cooler by condensed water from the steam turbine to recover the heat held by the steam condensate. This makes it possible to significantly increase the amount of steam generated from the heat of the main engine exhaust gas compared to conventional systems. The power generated when the generator is driven is as shown by the broken line in Figure 1. As can be seen from Figure 1, even a main engine with an output of about 10,000 horsepower can cover the power required for constant navigation, and therefore all the fuel required for conventional diesel generators can be saved.

[Brief explanation of drawings]

FIG. 1 is a graph showing the relationship between main engine horsepower and power required for regular navigation in a ship, and FIG. 2 is a schematic diagram of an embodiment of the present invention. 1...Exhaust gas discharge pipe, 2...Main engine, 2a...Cylinder head part, 2b...Cylinder jacket part, 3...High pressure side superheating pipe, 4...Intermediate pressure side superheating pipe,
5... High pressure side evaporation pipe, 6... Medium pressure side evaporation pipe, 7...
...Low pressure side evaporation pipe, 8...High pressure side brackish water separator, 11
... Intermediate pressure side brackish water separator, 14 ... Low pressure side brackish water separator, 21 ... Hotwell tank, 22 ... Supercharged air cooler, 41 ... First steam supply pipe, 42 ...
Second steam supply pipe, 43...Third steam supply pipe, 44
... General steam consumption equipment, 45 ... Low pressure steam introduction pipe, 46 ... Generator, 47 ... Steam turbine, 4
8... Medium pressure steam introduction pipe, 49... High pressure steam introduction pipe, 53... Vacuum condenser, 54... Condensate transfer pipe,
55... Condensate pump, 56... Vacuum drain cooler, 58... Communication pipe, 60... Connection pipe, 61...
Flush pipe, 62...Drain water transfer pipe, 63...
...Drain water pump, 65...Cooling water circulation pipe, 65
a...Outlet side piping, 65b...Inlet side piping, 77
...Cooling water supply pipe, 78...Cooling water return pipe.

Claims (1)

[Claims] 1 In the exhaust gas discharge pipe for heat recovery of the main engine exhaust gas, a high-pressure side evaporator pipe is connected to the high-pressure side brackish water separator in order from the high temperature part to the low temperature part, and an intermediate-pressure side evaporator pipe is connected to the medium-pressure side brackish water separator. pipe, and a low pressure side evaporation pipe connected to the low pressure side brackish water separator,
A part of the cooling water circulation pipe for the cylinder head of the main engine is guided into the liquid phase part of the low-pressure side brackish water separator, and a part of the steam generated in each of the brackish water separators is led to the power generation steam turbine, and the rest is A condensate transfer pipe is provided to lead the condensate from the vacuum condenser for the steam turbine to the Hotwell tank, and a vacuum drain cooler is provided to cool the steam drain discharged from the general steam consumption equipment. A marine vessel characterized by further comprising: a flush pipe for flushing the condensate in the condensate transfer pipe within a vacuum drain cooler; and a drain water transfer pipe for sending drain water from the vacuum drain cooler to the hot well tank. Engine plant heat recovery system.