Energetica India Magazine December 2020

30 energetica INDIA- December_2020 In the present scenario, due to the integration of Solar PV on large scale to the grid, thermal power plants are forced to run at part load. It is also important to understand that thermal power plant operations at part load op- erates close to its design performance parameters at partial loads using simulation. This can be done by using simulation tools for optimum operation and compares with actual measurements. It is essential to utilize such tools to monitor the performance continuously with reliable data. Amongst various energy-intensive sec- tors, thermal power plants rank first in terms of total energy consumption and its percentage cost. Improving energy efficiency has become an extremely eco - nomical option and an intensely focused drive for profitability. That means, operat - ing a power plant at the lowest heat rate and optimum self-consumption ensures high returns. At the same time viabili - ty of future power plants with reduced emissions can meet environmental reg- ulations. For sustainable economic de - velopment of the power sector, the avail- ability of reliable and affordable power is critical. The National Mission for Enhanced En - ergy Efficiency (NMEEE) is a powerful initiative of the Government of India in meeting the global challenge of climate change. The NMEEE derived regulatory instrument Perform, Achieve and Trade (PAT) aims to reduce specific energy consumption in energy-intensive indus- tries. The PAT cycle 1 covered 144 ther - mal power plants which accounted for the energy consumption of 104.5 million tonnes of oil equivalent, while the end of cycle achievement in a reduction in ener- gy consumption is 3.06 million tonnes of oil equivalent (3%). The majority of ther - mal power plants implemented the use of quality coal (blending or washed coal) and the use of variable speed drives to minimize auxiliary power consumption. Subsequent PAT cycles added another 80 thermal power plants under the PAT scheme. There are numerous methods for im - proving the efficiency of thermal power plants to bring down the generation cost and maximize power generation levels. One example is of Integrated Gasifica - tion Combined Cycle (IGCC) technology, where coal is converted into synthetic gas (or syngas) instead of being com - busted as done in conventional pulver - ized coal-fired power plants. Thermal efficiency is the main factor that puts IGCC above the conventional pulverized coal technology (it could go up to 60%). This is a substantial improvement over the 35% efficiency of pulverized coal plants. Furthermore, with the continuing drive to reduce power plant emissions, coal-fired power plants have been mov - ing to ultra-supercritical (USC) steam conditions. Advanced ultra-supercritical pulverized coal combustion (Advanced USC or A-USC) is a further development of USC. By using A-USC steam condi - tions of 700°C to 760°C at pressures of 30 MPa to 35 MPa, manufacturers and utilities are working to achieve efficien - cies approaching 50% (LHV) and higher. In the existing conventional power plants, based on steam condition and site location, the overall efficiency can be improved by increasing the efficiency of various components (both stationary and rotating) through which the steam flows. Such analysis can be carried out using a computational Fluid Dynamics (CFD) technique, which is a cutting-edge tool to improve the overall efficiency of turbo-machines. In general, a variety of fluid flow related analysis relevant to power plants such as pressure drop and energy losses in steam turbine compo - nents (e.g., casings, blades, cross-over pipes, exhaust hoods, valve chests, inlet sections), efficiency and discharge char - acteristics of pumps, head and efficien - cy for various discharge and speeds for Dr G R Narsimha Rao Director - Industrial Energy Efficiency Division, TERI Bengaluru POWER SECTOR Improving Power Plant Energy Efficiency