การลดการใช้พลังงานโดยประยุกต์ใช้เทคนิควิศวกรรมคุณค่าสำหรับโรงไฟฟ้าพลังความร้อน

Abstract

The objective of this research is to apply value engineering technique to reduce energy consumption for thermal power plant. This research focuses on electricity and heat generation by a 315 MW gas-fired electricity generating plant in Krabi province. The value engineering technique is used to analyze the most suitable energy management and to generate an energy saving regulation. The six steps of value engineering technique are adapted from Society of American Value Engineers International (SAVE) as the following: 1) data and information collection 2) function analysis 3) creative 4) evaluation 5) development and 6) presentation. According to the research, two categories (electrical and thermal) of energy reduction strategy are suggested. With respect to electrical aspect, replace high-performance cooling tower motor, install variable speed drive on condensate pump and low pressure heater drain pump, reduce compressor air inlet temperature, and manage air conditioned operating time are recommended. Regarding thermal part, replace damaged and deteriorated insulation, insulate steam pipe, valves and flanges and air heater leakage are applied. All in all, the application of new approach lead to reduce electrical energy consumption from 18,686,429.67 kWh/y to 16,124,411.58 kWh/y or 2,562,018.09 kWh/y (13.71%). In addition, the application of new approach lead to reduce thermal energy consumption from 15,378,904.86 MJ/y to 6,516,886.88 MJ/y or 8,862,017.97 MJ/y (57.62%). Total cost saving is 20,783,888 baht/year. The total investment is 30,420,000 baht. The payback period for the whole project is 1.58 years. The return on investment (ROI) is 661.19%, the net present value (NPV) is 114,999,173 baht and the internal rate of return (IRR) is 63.26%.