12m Curved Bare Steam Boiler Superheater And Reheater Natural Circulation

12m Long High Frequency Carbon Steel Curved Bare Superheater And Reheater for Steam Boiler​

Superheater is to increase the temperature of the steam above its saturation point.

Reheater is basically a superheater that superheats steam exiting the high-pressure stage of a turbine. The reheated steam is then sent to the low-pressure stage of the turbine. By reheating steam between high-pressure and low-pressure turbine it is possible to increase the electrical efficiency of the power plant cycle beyond 40%.The reheat cycle is used in large power boilers since it is feasible economically only in larger power plants.

Product Introduction

• Superheater is a part of a boiler that heats the steam from the saturation temperature to the overheating temperature. It is also called a steam superheater.Superheater can be divided into convective type, radial type and semi-radial type according to heat transfer mode;According to the characteristics of the structure, it can be divided into serpentine pipe type, screen type, wall type and wall type.They are made up of parallel pipes and inlet and outlet manifold.
• Most industrial boilers do not have superheaters because many industrial processes and living facilities require only saturated steam.In power stations, locomotives and Marine boilers, superheater is usually installed to improve the circulating thermal efficiency of the whole steam power plant.

Functions

1.Superheater is the saturated steam heated into a certain temperature of superheated steam equipment.

2.After the saturated steam is heated into superheated steam, the working capacity of steam in the steam turbine is improved, that is, the useful enthalpy of steam in the steam turbine is increased, thus improving the cycle efficiency of the heat engine.

3.In addition, the adoption of hot steam can also reduce the steam exhaust humidity of the steam turbine, avoid the corrosion of the steam turbine blade, and create favorable conditions for the further reduction of steam exhaust pressure and safe operation of the steam turbine.

Performation

Changes in boiler operating conditions, such as load level, fuel change, combustion condition change, etc., all have an impact on superheater outlet steam temperature, so in power station boilers there are means to adjust boiler outlet steam temperature to make it stable at the specified value.Commonly used means are:

(1) with water jet or surface type temperature reducer directly adjust the steam temperature;

(2) with the swing burner to change the temperature of the furnace outlet smoke;

(3) with smoke recirculation adjustment superheater heat absorption.When the boiler load increases, the temperature rise value of the inlet and outlet steam of the flow superheater increases, while the temperature rise value of the radiant superheater decreases.If the convective superheater, radiant superheater and semi-radiant superheater are properly combined and configured, the outlet steam temperature can change less when the load and combustion conditions change.The heat absorption and steam flow rate of the parallel pipes in the superheater stack will be different in operation.In order to avoid excessive temperature in individual pipes, the superheater is divided into several pipe groups in large boilers. Steam of each pipe group is mixed with a collecting box outside the furnace and the steam guide pipe is used to make each pipe group transposition, so as to avoid excessive temperature difference between each pipe.

Differences

Attention

• Superheating raises overall efficiency as well as avoids too much condensation in last stages of turbine which avoids blade erosion.
• The heat of combustion gases from furnace is utilised for removal of moisture from steam and to superheat the steam.
• Super-heaters ususlly have several tube circuits in parallel with one or more return bends,connected between headers.
• Heat from the hot gases to the vapour in the surperheater is transferred at high temperatures.
• Therefore promary section of superheater is arranged in counterflow and secondary section in parallel flow to reduce the temp.stressing of the tube wall.

Company Information

Hua Dong Boiler Co., Ltd. is a high-tech enterprise specialized in manufacturing boilers. Established in early 1985s, has two manufacturing bases, this company covers 400,000 ㎡ with fixed assets amounting to USD 110,000,000. There are 1100 employees including 150 technicians and 600 coded welders. Hua Dong holds the manufacturing licenses for Grade A boilers and Grade A1&A2 pressure vessels issued by Chinese General Administration of Quality Supervision, Inspection and Quarantine; also it holds the "S" and "U" "NB" stamps issued by American Society of Mechanical Engineers; meanwhile, this Company has passed the certification of ISO9001, SO3834, EN12952 Quality Management System.