How do HRSG Boilers work

An HRSG is a kind of heat exchanger that recovers heat from the exhaust gases of a gas turbine to an extreme degree. The heat is recovered in the form of steam which is served as the power source of a power-generating steam turbine.

What is the difference between HRSG and boiler?

Most of the HRSG’s are internally insulated so that expansion does not affect the external surfaces and the structures. Conventional boilers on the other hand are top supported and free to expand so the insulation is on the outside.

How does a HRSG gas plant work?

A HRSG generates steam by capturing heat from the turbine exhaust. These boilers are also known as heat recovery steam generators. High-pressure steam from these boilers can be used to generate additional electric power with steam turbines, a configuration called a combined cycle.

How efficient is a HRSG?

The HRSG forms a major part of the steam system. In the combined cycle mode, the efficiency of the combined gas turbine-plus-HRSG system can reach 55–60% (lower heating value basis) with modern advanced machines, while in cogeneration mode, the system efficiency can be as high as 75–85%.

Where is HRSG used?

Packaged HRSGs They can be used in waste heat or turbine (usually under 20 MW) applications. The packaged HRSG can have a water-cooled furnace, which allows for higher supplemental firing and better overall efficiency.

What is the difference between HRSG and Whrb?

A waste heat recovery boiler (WHRB) is different from a heat recovery steam generator (HRSG) in the sense that the heated medium does not change phase.

What is pinch point in HRSG?

Pinch point is the difference between the gas temperature leaving the evaporator and saturation temperature=Tg3-ts. Fig 1: HRSG temperature profiles. Approach point is the difference between saturation temperature and feed water temperature entering the evaporator= ts -tw2.

What is medium pressure heating boiler?

Medium-pressure boiler: It has a working pressure of steam from 20 bar to 80 bar. It is used for power generation or process heating.

Which HRSG boiler is more compact in structure and use in smaller plants?

Our boilers are manufactured either in horizontal or vertical types. The vertical boiler is more compact in structure and can be fit in smaller plants and even indoor facilities. The horizontal boiler is used mainly in larger plants.

How tall is a HRSG?

The largest HRSGs are approximately 140 ft long, 80 ft wide, and 130 ft tall (excluding the stack, which can be much taller). A large HRSG could include 28 large modules of tubes, 3 or 4 steam drums, and over 100 truckloads of ductwork, casing, piping, and miscellaneous steel.

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Is the compressor having practical usage in a gas turbine plant?

Explanation: Multistage axial flow compressor is the compressor in practical usage in a gas turbine plant.

How does a combined cycle work?

In a two-on-one combined cycle system, two combustion turbine generators work in conjunction with two heat-recovery steam generators and a steam turbine generator. … The steam spins an additional turbine generator to produce more electricity. The steam is then condensed back to water and recycled.

Why is gas turbine efficiency so low?

Gas turbine efficiency For stand-alone gas turbines, without any heat recovery system the efficiency will be as low as 35 to 40 per cent. This is attributed to the blade efficiency of the rotor, leakage through clearance spaces, friction, irreversible turbulence, etc.

What is CPH in HRSG?

In the HRSG, water is heated in the condensate preheater (CPH). The next component is deaerator (DA) which is responsible for removing oxygen and other dissolved gases from the water. The feedwater is pumped and divided into high-pressure (HP) and low-pressure (LP) streams after passing through the DA.

How does a once through steam generator work?

Most SAGD facilities have Once Through Steam Generators (OTSG) which burn natural gas to boil water, producing steam that is injected into the ground to soften bitumen. … It burns the natural gas and the hot turbine exhaust, allowing the unit to operate more efficiently than competing co-generation configurations.

What do you mean by steam condenser?

Steam Condenser is a mechanical device which converts the low pressure exhaust steam from the turbine into water. Or in other words it is a device which is used to condense exhaust steam of the turbine into water. It does so with the help of cooling water circulated into it from the cooling tower.

What is the pinch temperature?

The pinch occurs where the heat transferred is zero, that is at interval number 4, interval temperature 90 °C. This is equivalent to 100°C in the hot stream or 80°C in the cold stream.

What is boiler pinch?

PINCH POINT IN EXHAUST GAS BOILER IS THE DIFFERENCE IN TEMPERATURE BETWEEN THE EXHAUST GAS LEAVING THE EVAPORATOR SECTION AND SATURATED STEAM. LOWER THE PINCH POINT, HIGHER THE E.G.B EFFICIENCY AND IS ACHIEVED BY HAVING A HIGHER HEAT SURFACE AREA.

How efficient is a steam turbine?

Multistage (moderate to high pressure ratio) steam turbines have thermodynamic efficiencies that vary from 65 percent for very small (under 1,000 kW) units to over 90 percent for large industrial and utility sized units. Small, single stage steam turbines can have efficiencies as low as 40 percent.

What are types of boiler?

• Shell and tube boilers. Shell and tube boilers are also referred to as fire tube or smoke tube boilers. …
• Different types of fire tube boilers: Cornish boiler. …
• Lancashire boiler: …
• Locomotive boiler. …
• Reversal Chamber: …
• Wet Back Boilers: …
• Dry Back Boilers: …
• Two pass boilers:

How is WHR boiler efficiency calculated?

In general, we take this formula to calculate waste heat boiler thermal efficiency. η= 100-(q2+q3+q4+q5+q6), which include the Q2 flue gas losses, Q3 gas incomplete combustion losses, Q4 solid incomplete combustion losses, Q5 heat radiation losses and Q6 slag ash physical losses.

What is slop fired boiler?

CBL’s Slop fired boiler technology concentrates spent wash and then fires it in a specially designed boiler, enabling the distilleries to dispose of slop in an environment-friendly manner making them ZELE (ZERO EFFLUENT LIQUID DISCHARGE). CBL offers the unique slop incineration solution in the following manner.

On what basis are fire and water tube boilers are classified?

On what basis are fire and water tube boilers are classified? Explanation: Based on the contents of the tubular heating surface, boilers are primarily classified as fire tube boiler and water tube boiler.

What does HRSG stand for?

Heat Recovery Steam Generators (HRSG)

What are steam turbines made of?

The nickel-based blades are alloyed with aluminum and titanium to improve strength and creep resistance. The microstructure of these alloys is composed of different regions of composition.

What are the 3 types of boilers?

There are three main types of boilers you can install into your home: combi boilers, heat only (regular boilers) and system boilers.

What is considered a high pressure boiler?

This term includes boilers used in steam tractors, threshers, steam powered sawmills, and similar uses; (b) “High pressure boiler” means a boiler in which steam or other vapor is generated at a pressure of more than 15 psig or water is heated to a temperature greater than 250°F and a pressure greater than 160 psig for …

What is the main disadvantage of Lamont boiler?

Explanation: The main disadvantage of Lamont boiler is the formation of bubbles. These bubbles come in contact with the inner surface of the heating tubes and subsequently are attached to it.

What is a duct burner?

Duct burner means a device that combusts fuel and that is placed in the exhaust duct from another source, such as a stationary gas turbine, internal combustion engine, kiln, etc., to allow the firing of additional fuel to heat the exhaust gases before the exhaust gases enter a heat recovery steam generating unit.

What is the difference between cogeneration and combined cycle?

1) What is the difference between co-generation and combined-cycle power generation? Co-generations uses waste heat for many different processes, such as space heating or drying. Combined-cycle power generation is a two-cycle electricity generation process that uses the heat from the first cycle to run a second cycle.

How a gas turbine is used for?

A gas turbine is a combustion engine at the heart of a power plant that can convert natural gas or other liquid fuels to mechanical energy. This energy then drives a generator that produces the electrical energy that moves along power lines to homes and businesses.