Installation and Performance Analysis of 125 kW Organic Rankine Cycle for Stationary Fuel Cell Power Plant

2016 ◽  
Author(s):  
Kwanghak Huh ◽  
Parsa Mirmobin ◽  
Shamim Imani
Keyword(s):  
Renewable Energy ◽  
Fuel Cell ◽  
Power Plant ◽  
Performance Analysis ◽  
Power Plants ◽  
Waste Heat ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Molten Carbonate ◽  
And Performance

Installation and performance analysis of Thermapower™ 125MT Organic Rankine Cycle (ORC) System for recovery of waste heat from an existing Molten Carbonate Fuel Cell (MCFC) plant are presented. Over the last three years, about 100 MWe of new FC stationary power plants are in operation in Korea and more FC stationary power plants are on order and planned. The success of these fuel cell plants is their capability to supply both electricity and heat to customers. In order to promote renewable energy in Korea, the Korean Government is enforcing large power plants to supply electricity generated by renewable energy. The Korea Power Exchange (KPX) buys fuel cell generated electricity as renewable energy with higher price than other fossil fuel power plants [1]. Most of these FC plants supply electricity to power companies with their full capability, however valuable heat is wasted due to the limited demand, especially in summer season and off working hours or lack of heat pipe infrastructures. Due to the recent decrease in electricity price for renewable energy in Korea, the need for efficient utilization of waste heat is ever more demanding. In this study, 125 kWe ORC system is installed to 11.2 MWe FC power plant to demonstrate cost saving benefits. This FC Power plant has 4 units of 2.8 MWe fuel cell in operation and has capacity of producing 6.0 ton/h of 167°C steam. In order to install an ORC system to existing FC plant, their Balance of Plant (BoP) has to be modified since only excess steam is allow to be utilized by the ORC system, after supplying steam to their prime customer. Furthermore, site has distinctly hot and cold seasons, thus affecting condensing conditions and therefore ORC performance. Design considerations to accommodate varying ambient conditions as well as steam flow rate variation are presented and discussed.

Enhancement of the Electrical Efficiency of Commercial Fuel Cell Units by Means of an Organic Rankine Cycle: A Case Study

2013 ◽  
Vol 135 (4) ◽  
Author(s):  
Carlo De Servi ◽  
Stefano Campanari ◽  
Alessio Tizzanini ◽  
Claudio Pietra
Keyword(s):  
Fuel Cell ◽  
Power Output ◽  
High Performance ◽  
Waste Heat ◽  
Electrical Power ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Molten Carbonate ◽  
Levelized Cost Of Electricity ◽  
Electrical Efficiency

Among the various fuel cell (FC) systems, molten carbonate fuel cells (MCFC) are nowadays one of the most promising technologies, thanks to the lower specific costs and a very high electrical efficiency (net low heating value (LHV) electric efficiency in the range 45%–50% at MWel scale using natural gas as fuel). Despite this high performance, MCFC rejects to the ambient almost half of the fuel energy at about 350–400 °C. Waste heat can be exploited in a recovery Rankine cycle unit, thereby enhancing the electric efficiency of the overall system. Due to the temperature of the heat source and the relatively small power capacity of MCFC plants (from few hundred kWel to 10 MWel), steam Rankine cycle technology is uneconomical and less efficient compared to that of the organic Rankine cycle (ORC). The objective of this work is to verify the practical feasibility of the integration between a MCFC system (topping unit) and an ORC turbogenerator (bottoming unit). The potential benefits of the combined plant are assessed in relation to a commercial MCFC stack. In order to identify the most suitable working fluids for the ORC system, organic substances are considered and compared. The figure of merit is the maximum net power of the overall system. Finally, the economical benefits of the integration are determined by evaluating the levelized cost of electricity (LCOE) of the combined plant, with respect to the standalone MCFC system. In order to assess the economic viability of the bottoming power unit, two cases are considered. In the first one, the ORC power output is approximately 500 kWel; in the latter, about 1 MWel. Results show that the proposed solution can increase the electrical power output and efficiency of the plant by more than 10%, well exceeding 50% overall electrical efficiency. In addition, the LCOE of the combined power plant is 8% lower than the standalone MCFC system.

Waste Heat Recovery from Fly Ash of 210 MW Coal Fired Power Plant using Organic Rankine Cycle

2021 ◽  
pp. 1-33
Author(s):  
Nitin Hanuman Rodge ◽  
Goutam Khankari ◽  
Sujit Karmakar
Keyword(s):  
Energy Efficiency ◽  
Fly Ash ◽  
Power Plant ◽  
Power Plants ◽  
Electrostatic Precipitator ◽  
Waste Heat ◽  
Thermal Power ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Ash Content

Abstract Combustion of coal in thermal power plants generates Ash as a residue, which depends on the quality of coal, specific to its ash content and calorific value. In a typical Indian scenario, a standard 210 MW thermal plant produces ~57 T hr−1total ash, which has 80:20 fly and bottom ash share, considering coal with 40% ash content. This study aims to harness the waste heat of fly ash collected at the bottom of the Electrostatic Precipitator (ESP) by coupling Organic Rankine Cycle (ORC) with 210 MW subcritical coal-fired thermal power plant works on R134a. Thermodynamic properties of R134a are taken from the PYroMAT library (PYTHON 3.6) to develop a computer-based program that estimates the variability of key parameters with respect to Log Mean Temperature Difference (LMTD). The main plant's efficiency was 28.714%, with main steam pressure, reheat pressure, and temperature being about 134.35 bar, 24.02 bar, and 540oC, respectively, and combustion of coal is about 141.5 T hr−1. The study shows additional generation from fly ash waste heat is about 30.5 kW with an increase in net power output (0.0145%) and net energy efficiency (0.0146%). The Optimum value of LMTD for the Evaporator, Condenser and Recuperator is 40, 7, and 16 K, which yields the optimum energy efficiency and developed cost-effective design. The proposed system is economically analyzed, considering 25 years of equipment life and 14% of loan interest. The study shows that the payback period and the generation cost of electricity of ORC is about 6.22 years and INR 3.14 per kWh, respectively.

scholarly journals Modeling and Simulation of a Proton Exchange Membrane Fuel Cell Alongside a Waste Heat Recovery System Based on the Organic Rankine Cycle in MATLAB/SIMULINK Environment

2021 ◽  
Vol 13 (3) ◽  
pp. 1218
Author(s):  
Sharjeel Ashraf Ansari ◽  
Mustafa Khalid ◽  
Khurram Kamal ◽  
Tahir Abdul Hussain Ratlamwala ◽  
Ghulam Hussain ◽  
...  
Keyword(s):  
Fuel Cell ◽  
Waste Heat Recovery ◽  
Proton Exchange Membrane ◽  
Waste Heat ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Proton Exchange ◽  
Waste Heat Recovery System ◽  
Recovery System ◽  
Exchange Membrane

The proton exchange membrane fuel cell (PEMFC) is the fastest growing fuel cell technology on the market. Due to their sustainable nature, PEMFCs are widely adopted as a renewable energy resource. Fabricating a PEMFC is a costly process; hence, mathematical modeling and simulations are necessary in order to fully optimize its performance. Alongside this, the feasibility of a waste heat recovery system based on the organic Rankine cycle is also studied and power generation for different operating conditions is presented. The fuel cell produces a power output of 1198 W at a current of 24A. It has 50% efficiency and hence produces an equal amount of waste heat. That waste heat is used to drive an organic Rankine cycle (ORC), which in turn produces an additional 428 W of power at 35% efficiency. The total extracted power hence stands at 1626 W. MATLAB/Simulink R2016a is used for modeling both the fuel cell and the organic Rankine cycle.

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