Powering Through

With the power industry being transformed to a buyers’ market, L&T MHPS Turbine Generators had to think out of the box and come up with a systematic plan to enhance productivity of its Turbine Blades, meet stringent delivery schedules and cut down costs.

L&T MHPS Turbine Generators Pvt Ltd (LMTG) is a joint venture company of Larsen & Toubro Ltd (L&T) and Mitsubishi Hitachi Power System Ltd (MHPS) Japan. A joint venture agreement for setting up a manufacturing facility to supply super-critical Steam Turbines and Generators in India was formed between the two in 2007.

Manufacturing of Turbines and Generators is a promising product of L&T’s offerings, which is currently facing a challenge due to immense competition. In the present scenario, the power industry has transformed from a sellers’ to a buyers’ market with stringent delivery timelines. As an OEM for power generating equipment with aspirations to become a market leader in the field, it was highly essential for LMTG to make high-performing products available at a competitive cost. To make this possible, the company had to implement a systematic plan which could improve the manufacturing of Turbine Blades to double the capacity.

Trigger for the Project

In a bid to cater to the changing market demands, the company had to improve the product in terms of quality, cost, delivery and performance. Hence, LMTG introduced the most effective equipment in power generation – Ultra-Super Critical Turbine. These turbines operate at a very high temperature of 620°C and a steam pressure of 670 Kg/cm².

The Blade is the most critical part of the Turbine. The accuracy in the manufacturing of the blade directly impacts the operating efficiency of a power plant. Aerofoil or the profile part of the blade plays a vital role in the smooth flow of steam. To achieve the required accuracy, turbine blades are manufactured on the most accurate 5-axis machines.

LMTG Plant was designed for 5 sets of Turbines and Generators per annum, which required around 37,000 blades for 63 stages. Switching over to a new design of ultra-super critical Turbine, the numbers of blades for 5 sets were increased to 58,000 for 100 stages i.e. around 5,000 blades/month. To meet the new requirements, the company called for an additional investment of around `20-25 crore for machinery and accessories. for machinery and accessories. The revised requirement of blades prompted LMTG to take a project that delivers 60,000 blades/annum with the same set of manufacturing facility.

 

Solution through Innovation

Considering the increased blades requirement, LMTG took up the project of producing 60,000 blades per annum. The flow diagram shows the company’s approach towards the implementation of the project. The analysis indicates effective utilization of 3-axis machines which was increased by shifting some of non-critical operations from 5-axis machines to 3-axis machines.

Tooling is a major concern in machining. It directly affects quality and productivity. Hence, machining parameters, required accuracies and surface finish are a few factors that the company considers while deciding on the tools for any job. To get acquainted with the latest innovations in tooling, LMTG interacts with tool manufacturers on a regular basis.

In this case, the company tried to work on the form cutters which were used to machine a Fir tree root type Blades. The HSS Form cutters after replacing with the Brazed type Form Cutters gave LMTG the opportunity to increase the parameters and get a reduced cycle time on 4-axis machines. In addition to this, the application of a few advanced tooling like the High Feed Cutters and better coatings allowed the company to utilize higher parameters which, in turn, reduced the cycle time further.

Results

After the implementation of the improvements and other Kaizen initiatives, LMTG’s YOY average has increased from 2,253 blades per month to 5,066 blades per month over a span of three years.

Environmental Impact

The life cycle of the product consists of three phases: manufacturing, service and recycling. The manufacturing phase alone accounts for one-fourth of global energy usage. The leading consumer of energy within this sector is the production machinery. There are numerous reasons to reduce this energy consumption. The leading one for the operating company is the reduction of the Total Cost of Ownership (TCO) but the higher goal is a sustainable manufacturing of goods with minimal energy required with a smaller environmental footprint.

By reducing the overall cycle time of Blade manufacturing on machine, the company could reduce the energy use from 86 KWh to 36 KWh per manufactured blade. Secondly, reduction in the raw material requirement reduces the natural resources for the steel manufacturing and also the consumables required per number of blades.

Scope for Horizontal Deployment

Any system or improvement stands right only when it gives a sustainable scope. The trend of the current financial year, after all LMTG’s improvements and implementations have shown a drastic improvement in the quantity of blade manufacturing from the previous financial years. The new process adopted is giving better output with improved norms in the quality of blades produced.

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