JPS6238807A - Wide bleeding system using cruising turbine - Google Patents

Abstract

PURPOSE:To enlarge the bleeding range and enable the bleeding even at the decelerating time so as to reduce fuel consumption by automatically controlling both a steam pressure reduction valve, a bleed motor valve and so on according to load to switch a turbine and a bleed line each other. CONSTITUTION:At a load within a range between 75 and 100%, for example, steam is feed through a control valve 16, a high pressure turbine 2, a low pressure turbine 3 and a main condensor 5 sequentially but the steam which to be fed to a cruising turbine 4 is cut off by the control valve 16. At this time bleed air is taken out from the high pressure turbine 2, on account of which motor valves 13 and 14 are opened, other motor valves 11 and 12 are closed, a motor valve 15 is opened and all pressure reduction valves 10 are closed. At a load within a range between 40 and 75%, for example, steam is fed through the control valve 16, the cruising turbine 4, the high pressure turbine 2, the low pressure turbine 3 and the main condenser 50 sequentially and exhaust from the cruising turbine 4 goes into the high pressure turbine 2 so that driving steam will be cut off by the control valve 16. At this time bleed air is taken out from the cruising turbine 4, on account of which the motor valves 11 and 12 are opened and the motor valves 13 and 14 are closed.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention is applied to a feed water heating system for a ship equipped with a steam turbine, and is used in the technical field of reducing fuel consumption.

Conventional technology A typical example of a conventional steam turbine plant is shown in FIG.

Main boiler 01, high pressure turbine 02, low pressure turbine 03,
Consists of main condenser 04, low pressure feed water heater 05, deaerator 06, high pressure first stage feed water heater 07, Takada second stage feed water heater 08, pressure reducing valve 09, bleed motor valve 010, and control valve 011. In conventional plants, air is extracted from a turbine and used as heating steam for each feedwater heater in order to reduce fuel consumption.

Bleed air improves fuel efficiency by about 5 to 7%, and is used in most turbine plants.

However, the operating range in which air extraction is possible is limited to approximately 75-80% or more, so in operating ranges below that, it is necessary to use live steam (slowly heated steam after leaving the boiler), and the extraction effect is lost. .

This is because the amount of steam used by the turbine decreases at low loads, and the amount of steam required for each bleed air to heat the feed water cannot be met. In this case, motor valve 010 closes. , Steam is supplied from the reduced 8E square 09. The pressure reducing valve 09 is controlled by the outlet line pressure,
When the royal power of each bleed air line falls below the specified level, it will open automatically.

Well, motor valve 010 detects the preset main engine load and automatically closes. In the figure, the line V or △ indicates bleed air.

Problems to be Solved by the Invention In the conventional system, when the main engine load decreases, the bleed air effect is lost due to insufficient bleed air pressure, and the fuel consumption rate deteriorates significantly. This has become a very big problem these days, when slow-speed navigation is occurring frequently.

Therefore, a cruise turbine (described above) is installed as a countermeasure for low loading conditions to improve the steam consumption rate of the turbine itself, expand the extraction area, and improve the heat exchange rate of the entire plant.

The cruise turbine is designed at a point below about 75 to 80 inches of plant load, where air extraction is not possible, and oil and air are extracted from the cruise turbine. By extracting air from the cruise turbine, it is possible to extract air up to approximately 40% of the plant load, and 1
It becomes possible to improve the fuel consumption rate at each load from 00% to 40%.

Means for Solving the Problems The present invention takes the following measures in order to solve the above-mentioned problems. That is, a high-pressure turbine extracting air from the first stage, second stage, and third stage from the exhaust pipe;
The steam turbine consists of a low-pressure turbine that takes out stage bleed air, and a cruise turbine that takes out first stage bleed air and second stage bleed air, respectively.The bleed air line used to heat each heat exchanger has 40
Steam reduction king-I that supplies slow heating steam for heating below % load
This is a wide-area oil and gas system using a cruise turbine equipped with a P' and a bleed motor valve installed at each bleed air outlet.

Effects According to the means described above, the range in which air can be extracted can be expanded from 100 to 75% load to 100 to 40% load by switching the turbine and extraction line according to the load. In addition, the control valve 16 and the motor valve 11.12
．． 13. For all switching in 14.15, check the shaft rotation speed, etc.
automatically.

EXAMPLE Next, a wide area extraction system using a cruise turbine according to the present invention will be described in detail with reference to FIG. 1 showing its system.

The steam turbine is composed of a high-pressure turbine 2, a low-pressure turbine 3, and a cruise turbine (a dedicated turbine configured to maximize output during deceleration cruising) 4, and extracted air is extracted from the cruise turbine 4 and the high-pressure turbine 2, respectively. Stage bleed air, second stage bleed air, third stage bleed air from the exhaust pipe of the high pressure turbine 2, and fourth stage oil air from the low pressure turbine 3.

The bleed air line (marked with a ma or △ in the diagram to indicate each bleed air) is used to heat each heat exchanger, but for heating below 40% load, all 10 lines of slow heat steam and steam reducer are passed through. supply Bleed motor valve 11.12.13.14 at each oil outlet
．． 15 is installed, at 75% to 100% load, steam flows in the order of control valve 16, high pressure turbine 2, low pressure turbine 3, and main condenser 5, and steam to cruise turbine 4 flows through control valve 1.
It is stopped at 6.

At this time, since the extracted air is taken out from the high-pressure turbine 2, the motor valves 13.14 are opened and the motor valves 11.12 are closed. The motor valve 15 is open, and all pressure reducing valves 10 are closed.

At 40 to 75% load, steam flows in the order of control valve 16, cruise turbine 4, high pressure turbine 2, low pressure turbine 3, and main condenser 5, and the exhaust gas from cruise turbine 4 enters high pressure turbine 2, so the drive The steam is stopped by a control valve 16.

At this time, since the extracted air is taken out from the cruise turbine 4, the motor valves 11.12 are opened and the motor valves 13.14 are closed. The motor valve 15 is open, and all pressure reducing valves 10 are closed.

At a load of 40 or less, the flow of steam is the same as at a load of 40 to 75, and extraction is not possible at this time, so the steam flows through the pressure reducing valve 10.
supply more. Therefore, all motor valves 11, 12, 13, 14, 15 are closed to prevent backflow of steam to the turbine.

As mentioned above, by switching all the turbines and extraction lines, the possible extraction range is 100 to 75%.
It can be expanded to 0 to 40 load.

Also, the control valve 16 and the motor valve 11.12.13.14
．． It is assumed that all of the 15 switchings are performed automatically by detecting the shaft rotation speed, etc.

Effects of the Invention When the present invention is adopted, the air bleed area is widened, making it possible to bleed air even when the ship is sailing at a reduced speed, and fuel consumption can be saved by 5 to 7% at any load between 40 and 75%. .

[Brief explanation of the drawing]

Fig. 1 is a system diagram showing an overview of a wide area extraction system using the cruise turbine of the present invention, and Fig. 2 is a system diagram of a conventional steam turbine plant. 3-.Low pressure turbine, 4..Cruise turbine, 5..Main condenser, 6..Low pressure feed water heater, 7..Deaerator, 8..High pressure first stage feed water heater, 9..High pressure 1st stage feed water heater, 10...Steam area E
ff, 11...Cruise turbine 1st stage bleed motor valve, 12...
- Cruise turbine 2nd stage bleed motor valve, 13... High pressure turbine 1st stage bleed motor valve, 14... High pressure turbine 2nd stage bleed motor valve, 15... 3rd stage bleed motor valve, 16... Control valve. (7 others)

Claims (1)

[Claims] A steam turbine consisting of a high-pressure turbine that extracts 3-stage bleed air from the 1st-stage bleed air, 2-stage bleed air, and an exhaust pipe, a low-pressure turbine that extracts 4-stage bleed air, and a cruise turbine that extracts 1-stage bleed air and 2-stage bleed air, respectively, and each heat source. The bleed air line used to heat the exchanger is equipped with a steam pressure reducing valve that supplies slow-heated steam for heating below 40% load, and each bleed air outlet is equipped with a bleed motor valve. Wide area extraction system using a turbine.