Nuclear energy has become an important source of energy in recent times. Nuclear power plants produce heat through fission, which is then used to generate steam which spins the turbine to produce electricity. Nuclear reactors are mainly of two types: pressurized and boiling water reactors.
Heat exchangers play an important role in this entire process of generating electricity in a nuclear power plant which uses pressurized water reactors. These devices transfer energy and heat from one fluid to another without mixing the two fluids. In simple terms, a nuclear power plant heat exchanger is used to pass heat from the primary system, that is, the reactor plant, to the secondary system, the steam plant. They are also called pressurized water reactors or steam generators as they generate steam from water.
How do heat exchangers work in a nuclear power plant?
In a nuclear power plant, two loops of circulating water are used to produce steam. The first loop carries extremely hot water to a heat exchanger where the normal water is circulated. This water heats up and boils to steam, which is then sent to the turbine section. Heat exchangers are mainly classified into two categories based on flow arrangement and type of construction, viz. parallel-flow arrangement and counter-flow arrangement.
A nuclear power plant heat exchanger is mainly of shell and tube type, and it is used in the case of liquid-to-liquid fluid transfer. The main parts of a nuclear power plant heat exchanger are the tube sheet, head, tube bundle, and nozzle. There are also secondary parts like shells, shell baffles, and nozzles.
Types of nuclear power plant heat exchanger from Godrej Process Equipment
In India, there are a few manufacturers who specialize in the production of heat exchangers which are used in nuclear power plants. Godrej Process Equipment, Larsen and Toubro are leaders in making heat exchanges for nuclear power plants.
- Closed cooling water heat exchanger – This process equipment is designed to cool water in the closed system. It can be classified as a shell and tube heat exchanger. Sea water or service water is used for cooling purposes. It contains a large pressure vessel – that is – a shell that has tubes as its interior. Godrej Process Equipment has a remarkable experience in producing these heat exchangers.
- Feedwater heaters – Feedwater heaters are constructed of tubes through which feedwater is passed. Feedwater is the water that undergoes preheating and is supplied to the boiler or the heater. The water is heated by steam from the high-pressure turbine. The water discharge from the feedwater pumps passes through high-pressure feedwater heaters, enters the containment and then flows into the steam generator. Yuba Feedwater Heaters and Closed cooling water heater exchangers produced by Godrej Process Equipment have an impressive track record of 90+ years. These exchangers can be customized to suit the requirements of particular plants.
The heat exchanger is an important part of a nuclear power plant that uses pressurized water reactors to generate energy, making it possible to produce energy efficiently and safely.