Layout of main buildings and facilities of power plant

Overview and Target Facilities and Buildings

1. Review Overview

When planning the plot plan for a power plant, it is categorized into power generation facilities, auxiliary facilities, and various buildings. The aim is to arrange the optimal power plant layout considering various factors such as accessibility, cost-effectiveness, constructability, operability, maintenance, safety, comfort, and aesthetics.

2. Target Facilities and Buildings

• Turbine Building (S/T, G/T)
• Boiler Building (Boiler, HRSG, WHRB)
• Auxiliary Boiler Building
• Main Control Building
• General Office
• Water Treatment and Wastewater Treatment Facilities
• Fuel Oil Storage and Transfer Facilities
• Raw Water Storage Tank and Transfer Pumps
• Pure Water Storage Tank and Transfer Pumps
• Desulfurization and Denitrification Facilities
• Coal and Ash Handling Facilities
• Limestone and Gypsum Handling Facilities
• General Warehouse
• Cooling Water Circulation Facilities and Structures
• Workshop
• Main Gate and Guardhouse
• Waste Storage

 

Major Facilities and Building Layout

1. Turbine Building and Boiler Building

• The basic layout of the power generation facility area includes T-shaped layouts where steam turbines and generators are arranged perpendicular to boilers and I-shaped layouts where they are arranged in parallel (T-shaped layout is the default due to its many advantages).
• The T-shaped layout reduces building area, facilitates accessibility between buildings, shortens the crane span within the turbine building, ensures the flexibility of the main piping, and makes it easy to connect the IPB from the generator to the transformer and arrange the cooling water piping (though the main piping is slightly longer compared to the I-shaped layout).
• When arranging more than two units of power generation facilities, the equipment layout in the steam turbine building and boiler area can be mirrored around the central axis between the two units (symmetrical layout) or identically duplicated (copy layout).
• The copy layout is preferable over the symmetrical layout to prevent confusion during design and construction phases, avoid operational errors after completion, and ensure compatibility and safety of the equipment.
• Ensure there is enough space for the assembly and disassembly of parts for maintenance and inspection, and consider passageways and walkways, with main paths designed to accommodate the turning radius of maintenance equipment like forklifts.

 

2. Boiler Building and Main Control Building

• The boiler building and the main control building should be positioned at a suitable distance from the shoreline to avoid damage from typhoons and high waves, and to facilitate the foundational work of the facilities.
• Considering site utilization and the scale of the facilities, each building should be positioned as close as possible, with the main control building configured for optimal accessibility to control the entire power generation facility.

 

3. Auxiliary Buildings

• The water treatment building should be positioned as close as possible to the turbine building to facilitate the supply of boiler feed water and equipment cooling water, with raw water and pure water tanks located outside the water treatment building.
• The wastewater treatment building should be located close to the boiler, desulfurization facilities, and water treatment facilities to facilitate the discharge of treated wastewater.

 

4. Ancillary Buildings

• The administrative building should be located near the main gate with parking spaces and gardens to ensure a pleasant environment.
• Ancillary buildings should be categorized by function and similar buildings integrated together.
• The general warehouse and machine shop should be located near roads to facilitate the storage and removal of parts.

 

5. Review of Desulfurization and Denitrification Facility Layout

• Desulfurization facilities can be placed outside the stack, between the stack and the electrostatic precipitator, or on the left and right sides of the stack, considering site conditions and utilization.
• If a gas reheater is used, the desulfurization facility should be placed in sequence from the electrostatic precipitator to the desulfurization facility and then to the stack, though it is advantageous to place the gas reheater next to the stack.
• Desulfurization facilities should be placed on the left and right sides of the boiler outside the stack for better site utilization.
• The selective catalytic reduction (SCR) reactor of the denitrification facility should be placed between the economizer and the air preheater, considering exhaust gas temperature, site layout characteristics, installation, and operational records. The storage silo, dissolving tank, and supply pump for the reductant should be located near the stack and the desulfurization facility.

6. Outdoor Substation Facilities

• Outdoor substation facilities for transmitting power output should be located in a position suitable for the layout of the transmission lines.
• The length of the power cable ducts should be minimized considering construction costs.
• For power plants with planned subsequent expansions, the layout should consider the area required for the expansion.

 

7. Access Road Review

• Access roads to the power plant should be planned with front and rear gates, ensuring adequate road width and flow to facilitate the entry of construction equipment and main machinery during the construction period.

 

8. Intake and Discharge Facilities

• The layout should consider the possibility of re-circulating warm wastewater, marine conditions in the surrounding area, living environment, residents’ livelihoods, and site conditions.
• The intake and discharge points should be located at a significant distance from the shore, with the intake point equipped with deep-water intake facilities to minimize the intake of foreign substances.
• The discharge point should be located far from the intake point to maintain a sufficient distance.
• The intake point should be positioned to avoid exposure to wave impacts.
• A single gantry crane should be placed in the CWP intake area to be used commonly for parallel installation of circulation water pumps.

 

9. Heavy Oil Storage and Supply Facilities

• Heavy oil and diesel storage tanks should be located near the boiler building and the rear gate, minimizing the length of connecting pipelines, and considering the fuel supply plan.
• The fuel oil pump room should be placed adjacent to the containment area of the fuel storage tanks.
• The oil separator should be installed as a common facility with the general wastewater treatment facility, with oil-contaminated wastewater collection facilities installed at the wastewater generation points, transporting the wastewater to the oil-water separation facility for treatment.
• The containment area for fuel storage tanks should be designed to meet the volume and safety clearance requirements set by regulations, with at least two sides adjacent to roads 3 meters wide.
• If the safety clearance cannot be secured due to nearby buildings and structures, the fuel storage tanks should be equipped with a tank cooling system (water spray system) as required by regulations to ensure safety.

 

10. General Warehouse and Machine Shop

• The warehouse should be located along the main road, and the machine shop should be placed along the main road in the power generation facility area.

 

11. Road Width Within the Power Plant

• Main and perimeter roads: 6-8 meters
• Auxiliary roads: 4 meters

 

12. Alternative Roads

• During the construction period of the power plant, alternative roads should be planned if necessary to facilitate the entry of major equipment and construction machinery.
• The equipment layout can be categorized into symmetrical (mirror type) and copy type arrangements. While symmetrical arrangements may slightly reduce equipment costs when sharing some facilities, copy type arrangements are highly advantageous in terms of design, manufacturing, installation, and operation.
• Large coal-fired power plants generally adopt the copy type arrangement, while combined cycle power plants often use a mix of symmetrical and copy type arrangements, depending on the scale of the facilities.

 

Advantages and Disadvantages of Equipment Layout Methods

• Equipment layout methods can be categorized into symmetrical (mirror type) and copy type arrangements.
• While symmetrical arrangements may slightly reduce equipment costs when sharing some facilities, copy type arrangements are highly advantageous in terms of design, manufacturing, installation, and operation.
• Generally, large domestic coal-fired power plants adopt the copy type arrangement.
• In combined cycle power plants, a mix of symmetrical and copy type arrangements is used, depending on the scale of the facilities.