LIFELINE RESTORATION PROJECT FOR 3 MW COAL BASED HIGH PRESSURE A DECADE OLD PLANT
Introduction
Restoration of old equipment involves expertise due to the uncertainty of outcomes. Safe and conventional practice is to suggest replacement of the nonperforming old equipment. The 3 MW plant under discussion was proposed to be discarded in favor of a new 5 MW captive power plant. During the interactions with the plant management, Resonance Integrated Solutions (Resonance) sought the review of the decision and offered to visit plant site to reverify the assumptions.
On-site review of equipment and detailed discussions with the engineers and plant head opened up new avenues of solution. All the current issues and the efficiency levels were documented. Armed with firsthand information, the solution providing team of Resonance’s designers and operators brainstormed to arrive at three probable options which were narrowed down to two for the discussion with management. Simultaneously, the feasibility of the new project was compared with the restoration of lifeline for this project.
Intense and exhaustive discussions with the management and senior technical team where all possible options and the comparatives were presented brought forth a clear possible dimension that has been overlooked for sheer ease of doing work with zero challenges. The impending decision looked eminent. The option to spend INR 47.5 million with a payback of 2.5 years was far attractive than to spend INR 300 million with a payback of 6 years.
The management decided in favor of restoration of the lifeline rather than the new project, as was shown to be the most feasible option.
Challenges and Solutions
The first challenge was to identify which biomass was intended to be used. About nine biomasses were identified, their detailed calorific value and gate price helped arrived at the most economical fuels, whose availability alone could operate the plant for at least six months.
Most of the biomass comes with sand and other foreign particles. A first of its kind biomass cleaning system was installed and commissioned ahead of the project shutdown. Surprisingly, a small mountain (about 15-17 truckloads) was collected in a months’ time. This was deliberately not cleared to have a visual impact on the biomass suppliers. The impact resulted in reduction of foreign matter from 12% to 5% in next two months as management installed a penalty system.
Second challenge was converting the fluidized boiler to appropriate technology for use of selected biomass. Experts would prefer grate boiler, but the cost & space constraints restricted the choices. Resonance decided to retain the fluidized bed with low height combustion and overbed feeding.
Parallelly, non-destructive testing system was developed by a team of experts proficient in handling large thermal and nuclear power plants., Fatigue and structural stability of tubes vs a vis new material was analyzed. Only high temperature superheater and corresponding headers were identified as items of concern.
Efficiency improvement areas were identified using BETA™ [Boiler Evaluation Thermal Analysis], CEEK™ [Cogeneration Heat Rate Optimize] and UTIL™ [Power Plant Utility Design]. At all times, Resonance team was confident of surpassing the projections given to the management.
Efficient project management along with periodic review of the progress is a standard practice for most engineering projects. Resonance, as per the plan, handed over the ownership of the project to the technical and commercial team of the client while controlling the critical processes. The ownership of program being with the local team made the difference. Resonance firmly believes that an operator at plant knows much more than a designer about the day-to-day issues and may give an innovative idea. Many new ideas came through and critical review of some of our suggestions provided substantial learning.
Results
The project was commissioned within time, within cost and exceeded the planned performance. The power consumption was reduced by 3% and efficiency improved by 5% which was over the benchmarked values. While the plant needed cleaning every 15-20 days in base case, the renovated plant successfully operates over 182 days at a stretch. Resonance team was delighted to find that management declared in its annual financial statements that the project has paid its investment!!
Leanings
Resonance immensely improved its technical knowledge base in this project. Commissioning was smooth but for two days team learnt the significance of controlling excess air using power drawn by the fans. Teething issues in biomass fuel switch were easy to overcome with the joint involvement of experts and experienced operators. The biggest learning was the project exceeded its performance due to project ownership by the local team and management rather than solely being handled by the consultants. The “No Know all” approach paid huge dividend in success of the project.
