HRSG

A heat recovery steam generator (HRSG) is an energy recovery heat exchanger that recovers heat from a hot gas stream, such as a combustion turbine or other waste gas stream. It produces steam that can be used in a process to heat water to certain temperature(cogeneration) or used to drive a steam turbine (combined cycle) and other industrial fields.

Horizontal HRSG heating surface adopts sprial fin tube structure, can be either solid fins or serrated fins, no splice is permitted for fin tubes. In order to reduce heat stress, unstage superheater and reheater bundles adopts two-row type. Upper headers with air vent and lower headers with drainage. In order to make the heating surface flow rate reasonable, the evaporator and superheater adopt single return structure, and the economizer adopts multiple return structure. The high-pressure evaporator is suspended from the bottom of the high-pressure drum through the riser.The medium and low pressure evaporators are suspended from the boiler roof by a suspension rod. The heating medium flows through the heating surface tube in a single return journey from bottom to top.

For vertical waste heat boiler, all heating surface tubes are arranged horizontally, the flue gas flow is vertical flow. The waste heat boiler adopts a modular structure, the heating surface consists of staggered spiral fin tubes arranged horizontally and two headers, all levels of heating surface's sizes are basically similar. Internal inspection can be carried out by walking on the finned tube without the use of scaffolding, which is a unique feature of vertical waste heat boilers. Each heating surface has one inlet header and one outlet header, betweens the headers there will be one row or multiple rows of fin tubes. The inlet header or outlet header can be placed in front of the boiler or behind the boiler, and the tubes can be arranged in different rows to facilitate the full absorption of flue gas heat.

A heat recovery steam generator (HRSG) is an energy recovery heat exchanger that recovers heat from a hot gas stream, such as a combustion turbine or other waste gas stream. It produces steam that can be used in a process to heat water to certain temperature(cogeneration) or used to drive a steam turbine (combined cycle) and other industrial fields.

A heat recovery steam generator (HRSG) is an energy recovery heat exchanger that recovers heat from a hot gas stream, such as a combustion turbine or other waste gas stream. It produces steam that can be used in a process to heat water to certain temperature(cogeneration) or used to drive a steam turbine (combined cycle) and other industrial fields.

At present, DNT owns 10 spiral fin tube finning machines (two of them are advance machine lines that are imported from JTC Korea), and 6 H-type fin tube finning machine. For spiral finning machine, the diameter we can do is from φ25~φ219, maximum length of tube can be 28 meters, material can be stainless steel, alloy steel, carbon steel, ND steel etc. For H-Type finning machine, the diameter we can do is φ32~φ51, maximum length of tube can be 16 meters, material can be stainless steel, alloy steel, carbon steel and ND steel etc.

The header is a pipe fitting for mixing boiler working media and ensuring uniform heating of working media. The walls of industrial boilers are usually made up of rows of tubes (water-cooled walls) joined together, But the boiler volume is large, the structure is complex, can not ensure that all the working medium in the tube will absorb heat evenly, different parts , different absorption. The installation of the header allows the working medium in each tube to be merged and then distributed to each tube in the next stage. In this way, the thermal deviation can be reduced and the heat absorption, flow, boiler cooling and boiler thermal efficiency can be optimized and improved; In addition, the boiler upper, middle and lower sections are with different tube sizes, tube quantity and arrangement, the header is responsible for connecting each section and ensure the smooth flow of working medium.