An analytic hierarchy process (AHP) approach for the design study of organic rankine cycle (ORC) in the food manufacturing plant

• Main Author: Co, Ronald Allan Santos
• Format: text
• Language: English
• Published: Animo Repository 2015
• Subjects: Rankine cycle; Thermodynamics
• Online Access: https://animorepository.dlsu.edu.ph/etd_masteral/6803
• Institution: De La Salle University

This study evaluates the feasibility of implementing the Organic Rankine Cycle (ORC) technology in the Philippines particularly in the food manufacturing plant, Universal Robina Corporation (URC) in Rosario, Pasig City. ORC is a technology which transforms thermal energy into electrical energy typically by utilizing waste heat from exhaust gases. The design evaluation of ORC was based from the evaluation of the under-commissioned boiler at URC as source equipment. The methods used for evaluation include the thermal efficiency determination and the flue gas temperature determination. Design qualification was also considered to ensure that the design criteria for the ORC equipment will fall within standard. The working fluid (WF) selection was based on the following criteria: % ORC Thermal Efficiency, Thermal Conductivity, Cost, Safety, and Environmental Impact. Also, the material of construction (MOC) selection was based on the following criteria: Corrosion Resistance, Strength, Thermal Expansion, Weldability, Cost, and Thermal Conductivity. The Analytic Hierarchy Process (AHP) was then used for appropriate WF and MOC selections. Based on the economic evaluation results, this study produced least expensive power generation cost as compared among the power supplying plants found in Luzon. Likewise, it produced return on investment values of 27.50% (evaluated from price websites) and 25.74% (based from price catalogue) were obtained thus making this study acceptable as compared to the minimum annual rate of return of 11%. The positive net present worth values of PHP 150M (evaluated using price websites), and PHP 149M (based from price catalogue) to make ORC profitable, and the discounted payback period values obtained were 1.80 years (evaluated using price websites) and 1.94 years (based from price catalogue). Based on AHP results and among the possible alternatives considered in this study, R152a was the most appropriate WF based on the most important criterion which is on environmental impact. Furthermore, Hastelloy C-276 was the most appropriate MOC for the four main ORC process equipment, namely waste heat boiler (tubes), pump, turbine (shaft and blades), and condenser (tubes).