Thermal Power Plants- The Powerhouse of India

Introduction

India is one of the fastest-growing economies of the world, where the development is not limited to some specific area; it goes on from infrastructure to uplifting the standard of living. As a nation, India has put an extraordinary effort to elevate its GDP and infrastructure is a key driver. Electricity, a major chunk of infra plays a critical role in building the basic framework of any economy & India has achieved a milestone in generating it of being power surplus.

India is a country, whose electricity consumption is the third-largest in the world &the demand cannot be fulfilled without Thermal power plants. The demand for electricity has gone up because new manufacturing hubs are developing across the nation in order to generate more output & to provide employment. These days the focus of the government is not only to provide food, shelter & clothes but also 24 hours electricity to all cities & villages.

D&H Sécheron Supporting Thermal Power Plants to Generate Electricity Efficiently

About the company

D&H Sécheron Electrodes Pvt. Ltd. is one of the largest welding consumable manufacturers in India (established in the year 1966). We offer a complete range of welding products comprising welding consumables (Electrodes, Flux Cored Wires, and Wires & Flux), welding equipment, fabrication solutions, and training to the new welders – which fulfills our motto “Complete Welding Support”.

How to repair the different components of a thermal power plant:

Let us divide thermal electricity generation into segments, firstly let’s discuss coal handling- in a thermal power plant, coal underplays the role of fuel, where it is important to store and handle it effectively. To keep the coal dry & prevent it from the external environment, coal gets stocked up into massive silos. There are various factors that can lead to wear & tear. To protect it, Lotherme-468 is designed to provide high-strength, crack-free welds.

Coal handling system

The Coal handling system in a thermal power unit usually means the technique procedure that coal from loading and unloading outside the factory. Accessories equipment includes crushing, coal mill vertical shaft, coal blending, and coal supply, removal iron, weigh, sample, dust removal equipment.

Coal mill vertical shaft

Coal Mill Vertical shaft, is equipment that helps in superfine grinding of raw coal. Its special design structure and production process create higher production efficiency with lower energy consumption, less dust, lower noise than ball mill, which meets the national standard of the energy-saving industry.  The coal mill vertical shaft generally faces the wear issues like friction, impact, etc.  To prevent this important equipment LoTherme-468 is ideally suited.

Coal crushing

Due to crushing the coal blocks the machine faces abrasion & impact issues and to overcome it Lotherme-605 is the best choice. It is because the deposited weld metal has exceptional abrasion wear resistance in combination with resistance to impact & mild corrosion.

Coal Burner Nozzle Tip

The Coal Burner Nozzle Tip helps to push pulverized coal to the boiler & is subjected to wear during their operation. The rate of wear on the burner is attributed to several factors and metallurgical failure phenomena. Here LoTherme-464 (is a low heat input, special purpose stainless steel electrode for welding stainless steel and steels to resist scaling up to 1100°C) &LoTherme T-904 (which is a tubular electrode that deposits complex carbides of Cr, Mo, Nb, W & V weld metal for severe abrasion resistance and erosion resistance at elevated temperatures up to 800°C) provide durable solutions.

Boiler

With a proper water feeding system, the Boiler help to convert the water to steam and the Superheater helps to make pure hot gas which helps to move the steam turbines. Due to corrosion, erosion & creep, Boiler Tubes, Superheater Tubes, etc used to get the wear and in order to protect them: D&H Sécheron has perfect welding consumables – Cromotherme-1, Cromotherme-2 & Cromotherme-91, etc.

• Cromotherme-1 is a low hydrogen iron powder type electrode that yields a weld deposit containing 1.25% Cr – 0.5% Mo.
• Cromotherme-2 is an iron powder, low hydrogen electrode which produces a weld deposit containing 2.25Cr – 1Mo & its oxidation resistance is up to 575°C.
• Cromotherme-91 is a 9Cr – 1Mo, non-synthetic, low hydrogen electrode which is modified with Aluminum, Niobium, Vanadium, and Nitrogen.

Turbine Blade

Due to the extreme pressure & heat of Dry Steam, the Turbine blade/cover used to face various wear issues & to protect them, D&H 1212(NS) & D&H 1223 (NS) are an ideal choice.

• D&H 1212(NS) is a non-synthetic electrode which deposits homogeneous Ni-Cr-Fe alloy composition.
• D&H 1223 (NS) is a non-synthetic electrode depositing homogeneous Ni-Cr-Mo alloy composition.

After that, the steam turbine rotates the generator, and then it converts the mechanical energy of the rotor to electrical energy. These generators contain a group of insulated wire coils in a cylindrical shape. Each part of the wire coil then turns into a small, individual electric conductor and the tiny currents of individual sections merge to create a single large current. The resulting electricity is then sent to the transformers & further to the power grid and after that to consumers through power lines.

Coal Ash handling

Now you must be thinking that the electricity is generated through the long process, but what happens to coal ashes? In the next step, the ash from the boiler is collected in a hopper directly below the furnace; ID fans in systems remove gases from combustion chambers, by creating a vacuum of negative air pressure. This is achieved by using a blower to suck air through the combustion chamber and the rest of the system, before discharging the air and flue gas through a stack or chimney.

In this way, not only ID fans enables the regulation of pressure within systems such as boilers, but they also work to facilitate the combustion process in boilers and other systems, by supplying the air needed for the combustion.

Due to continuous work, the ID fan faces high abrasion and impact along with mild corrosion in order to avoid this situation LoTherme-611 provides the lasting solution because it is a versatile low heat input electrode producing a weld metal having exceptional resistance to heavy abrasion in combination with high compressive load and moderate impact even at temperatures up to 500°C.

Flue-Gas Desulfurization

Did you know that Flue-Gas Desulfurization (FGD) is a sulfur dioxide (SO2) removal process from flue gas emissions, often chemically? FGD processes vary depending on the amount of SO2 involved, the solution being used to absorb the SO2, and the particular equipment used in the absorption tower. The FGD usually faces various types of wear issues that can affect efficiency but with LoTherme range, one can avoid several wear factors.

Ash handling unit

Thenceforth, it is moved to the ash handler where very finely sized fly ash often accounts for the major portion of the material conveyed in an ash handling system. It is collected from bughouse-type dust collectors, electrostatic precipitators, and other apparatus in the flue gas processing stream. These ash handlers generally face the issue of abrasion, corrosion, high temperature, and oxidation for which D&H 1400(MOD) can provide the best solution because its weld metal contains low carbon Cr-Mo-W-Co.

There is some other equipment which plays a crucial role in generating electricity in thermal power plants like: wagon tippler gear which helps in unloading the coal. It generally faces wear & abrasion, but LoTherme-352 &LoTherme-611 provides the best solution.

Track Pads/Links

Track pads & links can get repaired by Lotherme-625 which is ideally suited for welding high manganese steel. CI Pump Body by LoTherme-703 which is a low heat input electrode for high-strength machinable deposit & highly suitable for crack-free joining of cast Iron to steel. Valve Seat which is a crucial part can get repaired by LoTherme-444L which is a martensitic stainless steel welding rod with high strength for increased resistance to cavitation erosion.

Conclusion

D&H Sécheron Electrodes Pvt. Ltd. has partnered with several thermal power plants across India & internationally. Where our experienced team works closely with the clients and with an exceptional product range our team of professionals has a tremendous technical understanding to provide lasting solutions.