Balance of Plant (BOP) consists of all the facilities and infrastructural elements of the plant minus the main production facilities. A Balance of Plant contract generally covers the supporting facilities and auxiliary systems of a power plant required to convey electricity, with the exception of the generating unit.
BOT in a power plant includes transformers, monitoring and control systems, inverters, and supporting structures. It generally does not include the generator, turbine, and step-up transformer, plus all its associated elements.
A BOP power plant system consists of electrical and mechanical devices.
Electrical Balance of Plant (EBoP)
Electrical BOP systems monitor, regulate, protect components of a power plant using high, medium, and low voltage electrical devices. Some of these systems under the framework of a Balance of Plant contract include:
Power transformers – raise or lower the voltage to levels necessary to keep the plant operating efficiently.
Auxiliary transformers – operate in conjunction with power transformers to provide power to auxiliary equipment of the plant.
Switchgear – consists of a combination of switching devices, circuit breakers, and fuses. Its primary function is to isolate portions of the electrical system where a fault is diagnosed.
Circuit breakers – devices designed for automatic power cut-off and switching for short-circuit and overcurrent protection.
Electrical busbars – convey electrical energy from the generating portion of the plant to the step-up transformers.
Surge arresters – devices designed to provide overvoltage protection.
Mechanical Balance of Plant (MBoP)
Under a Balance of Plant contract, MBOP systems consist of non-electrical auxiliary systems that facilitate the efficient operation of power plant components. It can consist of the following components and systems:
Fuel Gas Conditioning Systems – designed to eliminate liquids, solids, and aerosols from natural gas.
NOx Reduction Packages – carried out by the injection of aqueous or anhydrous ammonia into the turbine combustion exhaust, then over a catalyst bed to convert the NOx to water vapor in nitrogen.
Pressure Reduction Systems – accurately and safely reduce gas pipeline pressure to match the reciprocating engine or gas turbine maximum inlet pressure.
Nitrogen Generation Packages – nitrogen gas is used for vessel purging, seal gas, and additional utility applications. These packages are formulated to provide a constant supply of pure nitrogen gas in the 95% to 99.95% range.
Compressed air systems – deliver a continual supply of compressed air (higher than atmospheric pressure) for the operation of pneumatic valves, pumps, guide valves, and other power plant equipment.
Fire protection systems – Respond to and prevent accidental combustion of power generating equipment such as the combustion cans of turbines.
Contact an experienced steam and combustion turbine maintenance company to help optimize the efficiency and reliability of your industrial power plant.
