scholarly journals Thermodynamic analysis of design and part-load operation of a novel waste heat recovery unit

2018 ◽  
Vol 245 ◽  
pp. 04010 ◽  
Author(s):  
Aleksandr Sebelev ◽  
Aleksandr Kirillov ◽  
Gennadii Porshnev ◽  
Kirill Lapshin ◽  
Aleksandr Laskin
Keyword(s):  
Gas Turbines ◽  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Internal Combustion Engines ◽  
Waste Heat ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Plant Performance ◽  
Part Load ◽  
Cycle Simulation

Organic Rankine Cycle (ORC) thermodynamic optimization is of critical importance while developing new plants. Optimization procedures may be imed at the highest efficiency as well as cost or sizing minimization. Optimization process is generally carried out for plant nominal rating. At the same time, part-load operation has to be carefully considered in case of waste heat recovery from flue gases coming from internal combustion engines or gas turbines. Gas mass flow and temperature variations are specific to this application, significantly influencing ORC plant performance. Secure prediction of part-load operation is of particular importance for assessment of plant power output, providing stability and safety and utilizing proper control strategy. In this paper design and off-design cycle simulation model is proposed. Off-design performance of the ORC cycle recovering waste heat from gas turbine unit installed at gas compressor station is considered. Major factors affecting system performance are outlined.

Waste Heat Recovery From Internal Combustion Engines: Feasibility Study on an Organic Rankine Cycle With Application to the Ohio State EcoCAR PHEV

2012 ◽  
Author(s):  
Philipp Skarke ◽  
Shawn Midlam-Mohler ◽  
Marcello Canova
Keyword(s):  
Heat Recovery ◽  
Hybrid Electric Vehicle ◽  
Waste Heat Recovery ◽  
Internal Combustion Engines ◽  
Waste Heat ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Internal Combustion ◽  
Combustion Engines ◽  
Driving Conditions

This paper presents a feasibility analysis on the application of Organic Rankine Cycles as a Waste Heat Recovery system for automotive internal combustion engines. The analysis is conducted considering the Ohio State University EcoCAR, a student prototype plug-in hybrid electric vehicle, as a case study for preliminary fuel economy evaluation. Starting from a energy-based powertrain simulation model validated on experimental data from the prototype vehicle, a first and second-law analysis was conducted to identify the potential for engine waste heat recovery, considering a variety of driving cycles and assuming the vehicle operating in charge-sustaining (HEV) mode. Then, a quasi-static thermodynamic model of an Organic Rankine Cycle (ORC) was designed, calibrated from data available in literature and optimized to fit the prototype vehicle. Simulations were then carried out to evaluate the amount of energy recovered by the ORC system, considering both urban and highway driving conditions. The results of the simulations show that a simple ORC system is able to recover up to 10% of the engine waste heat on highway driving conditions, corresponding to a potential 7% improvement in fuel consumption, with low penalization of the added weight to the vehicle electric range.

scholarly journals A comprehensive study on waste heat recovery from internal combustion engines using organic Rankine cycle

2013 ◽  
Vol 17 (2) ◽  
pp. 611-624 ◽  
Author(s):  
Mojtaba Tahani ◽  
Saeed Javan ◽  
Mojtaba Biglari
Keyword(s):  
Fuel Consumption ◽  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Internal Combustion Engines ◽  
Waste Heat ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Internal Combustion ◽  
Exhaust Gas ◽  
Combustion Engines

There are a substantial amount of waste heat through exhaust gas and coolant of an Internal Combustion Engine. Organic Rankine cycle is one of the opportunities in Internal Combustion Engines waste heat recovery. In this study, two different configurations of Organic Rankine cycle with the capability of simultaneous waste heat recovery from exhaust gas and coolant of a 12L diesel engine were introduced: Preheat configuration and Two-stage. First, a parametric optimization process was performed for both configurations considering R-134a, R-123, and R-245fa as the cycle working fluids. The main objective in optimization process was maximization of the power generation and cycle thermal efficiency. Expander inlet pressure and preheating temperature were selected as design parameters. Finally, parameters like hybrid generated power and reduction of fuel consumption were studied for both configurations in different engine speeds and full engine load. It was observed that using R-123 as the working fluid, the best performance in both configurations was obtained and as a result the 11.73% and 13.56% reduction in fuel consumption for both preheat and Two-stage configurations were found respectively.

scholarly journals A comparative analysis of waste heat recovery systems in vehicles and their viability in real-world applications

2019 ◽  
Vol 6 ◽  
pp. 88-109
Author(s):  
Jaiden Op de Veigh ◽  
Nick Glynatsis ◽  
Pasang Gurung ◽  
Chengmin Wang
Keyword(s):  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Internal Combustion Engines ◽  
Waste Heat ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Motor Vehicles ◽  
Regenerative Braking ◽  
Thermoelectric Generators ◽  
Environment Impact

In motor vehicles, an average of 60-70% of the overall fuel energy is dissipated primarily through the heated exhaust gases and engine coolant, which accounts for 90% of an engine’s thermal output. The fuel efficiency and environment impact of vehicles can therefore be improved by implementation of systems designed to recover this wasted energy. This meta- study explores the current methods for waste heat recovery (WHR) currently in production and research phases. A comparison is also made between the thermodynamic viability of each proposed system, from which future strategies to maximise the efficiency of WHR systems can be obtained. These include the use of the organic Rankine cycle (ORC), thermoelectric generators (TEG), and regenerative braking. The purpose of this paper is to analyse the current state of research for waste heat recovery in vehicles and therefore provide a basis for further research and investigation. The results indicate a promising future for further study of ORCs in the field of WHR for internal combustion engines (ICE) in vehicles. This is due to the various design opportunities that ORCs offer, including multiple loop configurations, different working fluids and integration of thermal energy storage devices. Current research for TEGs indicate a high cost to efficiency ratio for the materials required for production, meaning that TEGs are not as viable of a solution for WHR in vehicles relative to ORCs. This paper concludes that a fuel savings of 8-19% can be achieved through the integration of multiple energy recovery systems. Keywords: Waste Heat Recovery; Vehicles; Thermodynamics; Organic Rankine Cycle; Thermoelectric Generators; Regenerative Braking; Exergy

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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