scholarly journals Technologies for Waste Heat Recovery in Off-Shore Applications

2013 ◽  
Author(s):  
Leonardo Pierobon ◽  
Fredrik Haglind ◽  
Rambabu Kandepu ◽  
Alessandro Fermi ◽  
Nicola Rossetti
Keyword(s):  
Thermal Efficiency ◽  
Heat Recovery ◽  
Net Present Value ◽  
Waste Heat ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Combined Cycle ◽  
Present Value ◽  
Payback Time ◽  
Low Weight

In off-shore oil and gas platforms the selection of the gas turbine to support the electrical and mechanical demand on site is often a compromise between reliability, efficiency, compactness, low weight and fuel flexibility. Therefore, recovering the waste heat in off-shore platforms presents both technological and economic challenges that need to be overcome. However, onshore established technologies such as the steam Rankine cycle, the air bottoming cycle and the organic Rankine cycle can be tailored to recover the exhaust heat off-shore. In the present paper, benefits and challenges of these three different technologies are presented, considering the Draugen platform in the North Sea as a base case. The Turboden 65-HRS unit is considered as representative of the organic Rankine cycle technology. Air bottoming cycles are analyzed and optimal design pressure ratios are selected. We also study a one pressure level steam Rankine cycle employing the once-through heat recovery steam generator without bypass stack. We compare the three technologies considering the combined cycle thermal efficiency, the weight, the net present value, the profitability index and payback time. Both incomes related to CO2 taxes and natural gas savings are considered. The results indicate that the Turboden 65-HRS unit is the optimal technology, resulting in a combined cycle thermal efficiency of 41.5% and a net present value of around 15 M$, corresponding to a payback time of approximately 4.5 years. The total weight of the unit is expected to be around 250 ton. The air bottoming cycle without intercooling is also a possible alternative due to its low weight (76 ton) and low investment cost (8.8 M$). However, cycle performance and profitability index are poorer, 12.1% and 0.75. Furthermore, the results suggest that the once-trough single pressure steam cycle has a combined cycle thermal efficiency of 40.8% and net present value of 13.5 M$. The total weight of the steam Rankine cycle is estimated to be around 170 ton.

scholarly journals Multiobjective Optimization of a Plate Heat Exchanger in a Waste Heat Recovery Organic Rankine Cycle System for Natural Gas Engines

Entropy ◽  
2019 ◽  
Vol 21 (7) ◽  
pp. 655 ◽  
Author(s):  
Guillermo Valencia ◽  
José Núñez ◽  
Jorge Duarte
Keyword(s):  
Heat Transfer ◽  
Thermal Efficiency ◽  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Waste Heat ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Plate Heat Exchanger ◽  
Exhaust Gas ◽  
Plate Heat

A multiobjective optimization of an organic Rankine cycle (ORC) evaporator, operating with toluene as the working fluid, is presented in this paper for waste heat recovery (WHR) from the exhaust gases of a 2 MW Jenbacher JMS 612 GS-N.L. gas internal combustion engine. Indirect evaporation between the exhaust gas and the organic fluid in the parallel plate heat exchanger (ITC2) implied irreversible heat transfer and high investment costs, which were considered as objective functions to be minimized. Energy and exergy balances were applied to the system components, in addition to the phenomenological equations in the ITC2, to calculate global energy indicators, such as the thermal efficiency of the configuration, the heat recovery efficiency, the overall energy conversion efficiency, the absolute increase of engine thermal efficiency, and the reduction of the break-specific fuel consumption of the system, of the system integrated with the gas engine. The results allowed calculation of the plate spacing, plate height, plate width, and chevron angle that minimized the investment cost and entropy generation of the equipment, reaching 22.04 m2 in the heat transfer area, 693.87 kW in the energy transfer by heat recovery from the exhaust gas, and 41.6% in the overall thermal efficiency of the ORC as a bottoming cycle for the engine. This type of result contributes to the inclusion of this technology in the industrial sector as a consequence of the improvement in thermal efficiency and economic viability.

Performance Simulation of an Integrated Organic Rankine Cycle and Air Inter-Cooling System for Heavy-Duty Diesel Truck Engines

2017 ◽  
Author(s):  
Haoxiang Chen ◽  
Weilin Zhuge ◽  
Yangjun Zhang ◽  
Tao Chen ◽  
Lei Zhang
Keyword(s):  
Diesel Engine ◽  
Output Power ◽  
Thermal Efficiency ◽  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Waste Heat ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Operating Conditions ◽  
Engine System

Waste heat recovery using Organic Rankine cycle (ORC) systems has been regarded as the most potential technology for diesel engine fuel economy improvement. The compactness of ORC system is very important, so reducing the total volume of heat exchangers of the ORC system is the main challenge for ORC applications in truck engines. This paper proposes a new ORC system for waste heat recovery of truck diesel engines. The ORC system uses the hot compressed intake air and the exhaust gas as heat sources. The conventional air intercooler is substituted with the pre-heater of the ORC system. Hence the condenser of the ORC system can be installed at the original place of the intercooler, which could make the system integration much easier. A one-dimension simulation model of the combined diesel engine and ORC power system is set up. In combined ORC-engine system the output power of turbine is combined with the output power of crack shaft at a specific gear ratio to increase effective power of the engine system. The combined ORC-engine system performance is analyzed at common operating conditions and compared with the original engine. Results show that the combined system thermal efficiency is increased by 8.38% and the brake special fuel consumption (BSFC) reduces by 7.82% at peak. In design point, net output power of ORC system is 28.72kW, which increases thermal efficiency by 9.31% and reduces BSFC from 199.76 g/(kW·h) to 182.76 g/(kW·h). In addition, the cost of ORC system is estimated, and Payback time is 4.92 years.

Implementation of a Waste Heat Recovery Combined Cycle System Employing the Organic Rankine Cycle for a Gas Turbine

2022 ◽  
Author(s):  
Martin Cerza ◽  
Benjamin Meinster ◽  
Capt. Stuart Blair
Keyword(s):  
Gas Turbine ◽  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Waste Heat ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Combined Cycle ◽  
Cycle System

scholarly journals The Performance of waste Heat Recovery Systems using Steam Rankine Cycle and Organic Rankine Cycle For Power Generation

2019 ◽  
Vol 9 (2) ◽  
pp. 4172-4177
Keyword(s):  
Power Plant ◽  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Waste Heat ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Combined Cycle ◽  
System Efficiency ◽  
Waste Heat Recovery System ◽  
Steam Cycle

This paper presents extensive modelling of an Organic Rankine Cycle (ORC) system for a combined cycle power plant and to compare and evaluate the performance of ORC and Steam Rankine Cycle (SRC). In addition, ORC as a second stage waste heat recovery system after SRC too was modelled. Conceptual design of an ORC was made to replace the SRC system used in the power plant and its performance was compared with that of the SRC above. Upon replacing the steam cycle with ORC, the system efficiency is 7.63 %. The total energy destruction is 5140.41 kW. The result shows that ORC delivers very low system efficiency. The steam cycle produces 202.5MW whereas the presented ORC produces just 1.016MW of power. On the other hand, if ORC is implemented on the chimney the system will produce 0.2% of extra power on top the current power production of 675MW. The efficiency of this system is 7.81%. It is recommended to add the ORC at the chimney to tap more useful energy from the otherwise waste energy rejected into the environment.

Advanced waste heat recovery system based on organic rankine cycle

2021 ◽  
Vol 7 (3) ◽  
pp. 024-045
Author(s):  
Iniobong Gregory Frank ◽  
B. Nkoi ◽  
I. E. Douglas
Keyword(s):  
Thermal Efficiency ◽  
Waste Heat ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Combined Cycle ◽  
Working Fluid ◽  
Low Grade ◽  
Exhaust Gas ◽  
Brake Power ◽  
Exhaust Heat

In this research, Organic Rankine Cycle (ORC) is used to recover heat from exhaust gas of a four-stroke diesel engine. After retrofitting ORC to the engine, Brake power increased from 10473.91 kW to combined – cycle Brake power of 10736.00kW, thermal efficiency increased from 36.01% to combined – cycle thermal efficiency of 51.32% and Exhaust gas temperature decrease from 358oC to 120oC at the exit of the turbocharger. ORC with R12, R22, R134a and R290 as working fluids at saturation and superheated temperatures, pressures and condenser pressures at different ranges were used to compare refrigerants performance in converting low grade exhaust gas waste heat into useful work. This research presents theoretical analysis on four different refrigerants. Applying the above-mentioned refrigerants as working fluid superheated vapour temperature for R12 is 131.72oC, R134a is 129.37oC, R22 is 113.40oC and R290 is 116.95oC. ORC Power generated by turbine gives 94.98kW, 95.56kW. 130.32kW. 262.64kW respectively, ORC Thermal efficiency gives 36%, 29%, 37% and 38% for R12, R22, R134a, and R290 respectively. Combined – cycle power for each of the refrigerant gives 10568.89kW, 10604.23kW, 10569.47kW and 10736.00kW respectively, combined – cycle thermal efficiency for each refrigerant gives 51.14%, 51.18%, 51.14% and 51.32% for R12, R134a, R22 and R290 respectively. R290 offers optimal performance compared to other refrigerants used in this research. The retrofitting of the ORC has saved some supposedly waste exhaust heat energy and has increased both combined cycle power output and thermal efficiency of the engine cycle.

scholarly journals Performance and Sustainability Analysis of an Organic Rankine Cycle System in Subcritical and Supercritical Conditions for Waste Heat Recovery

Energies ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 3035
Author(s):  
Syamimi Saadon ◽  
Nur Athirah Mohd Nasir
Keyword(s):  
Output Power ◽  
Thermal Efficiency ◽  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Waste Heat ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Working Fluid ◽  
Turbofan Engine ◽  
The Impact

This study addresses the performance analysis of a subcritical and supercritical Organic Rankine Cycle (ORC) with the addition of a preheater or superheater integrated with a turbofan engine. This analysis will try to explore the heat transfer throughout the evaporator for the purpose of determining the ORC output power and thermal efficiency. A simplified numerical model of the ORC for waste heat recovery is presented. The model depicts the evaporator by using a distributed model, and includes parameters such as the effectiveness, heat capacity and inlet temperature of the waste heat and the organic fluid. For a given set of initial parameter values, the output power and thermal efficiency, as well as the mass flow rate of the working fluid are acquired by solving the system’s thermodynamic cycle with the aid of MATLAB software. The model is then verified by using data from an industrial waste heat recovery system. The connection between the turbofan engine and the ORC system was established and evaluated by means of Thrust-Specific Fuel Consumption (TSFC) as well as fuel burn. It was found that the supercritical ORC with a preheater and superheater exhibits lower TSFC than the subcritical ORC, whereas the impact of the ORC in terms of waste heat recovery in relation to the environment and sustainability indices is quite small, but still considerable depending on the engine’s weight.

scholarly journals Component-Oriented Modeling of a Micro-Scale Organic Rankine Cycle System for Waste Heat Recovery Applications

2021 ◽  
Vol 11 (5) ◽  
pp. 1984
Author(s):  
Ramin Moradi ◽  
Emanuele Habib ◽  
Enrico Bocci ◽  
Luca Cioccolanti
Keyword(s):  
Electric Power ◽  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Waste Heat ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Operating Conditions ◽  
Working Fluid ◽  
Pump Efficiency ◽  
Micro Scale

Organic Rankine cycle (ORC) systems are some of the most suitable technologies to produce electricity from low-temperature waste heat. In this study, a non-regenerative, micro-scale ORC system was tested in off-design conditions using R134a as the working fluid. The experimental data were then used to tune the semi-empirical models of the main components of the system. Eventually, the models were used in a component-oriented system solver to map the system electric performance at varying operating conditions. The analysis highlighted the non-negligible impact of the plunger pump on the system performance Indeed, the experimental results showed that the low pump efficiency in the investigated operating range can lead to negative net electric power in some working conditions. For most data points, the expander and the pump isentropic efficiencies are found in the approximate ranges of 35% to 55% and 17% to 34%, respectively. Furthermore, the maximum net electric power was about 200 W with a net electric efficiency of about 1.2%, thus also stressing the importance of a proper selection of the pump for waste heat recovery applications.

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