Modeling a Finned Tube Evaporator for Engine Exhaust Heat Recovery

2012 ◽  
Vol 229-231 ◽  
pp. 576-581
Author(s):  
En Hua Wang ◽  
Hong Guang Zhang ◽  
Bo Yuan Fan
Keyword(s):  
Diesel Engine ◽  
Waste Heat ◽  
Combustion Engine ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Finned Tube ◽  
Exhaust Temperature ◽  
Exhaust Heat ◽  
Heat Quantity ◽  
Power Point

The evaporator is a critical component when using organic Rankine cycle (ORC) to recover waste heat from an internal combustion engine. Evaluating the amount of heat quantity that can be transferred in a designed evaporator is very important for a successful ORC system. In this paper, a finned tube evaporator used for recovering the exhaust waste heat of a diesel engine was presented. The mathematical model for the evaporator was set up according to the dimensions of the designed evaporator along with the specified working conditions of ORC. The evaporator performance was analyzed as the matched diesel engine operating at the rated power point. The results indicate that the heat transfer quantity of the designed evaporator can be reached at 76 kW, and the exhaust temperature at the evaporator exit can be reduced to 115°C.

Energy and Exergy Waste Heat Recovery Analysis of a Bulk Carrier Main Diesel Engine Equipped with Dual-Loop Organic Rankine Cycle

2021 ◽  
Author(s):  
Elias A. Yfantis ◽  
Efthymios G. Pariotis ◽  
Theodoros C. Zannis ◽  
Konstantina Asimakopoulou
Keyword(s):  
Diesel Engine ◽  
Energy Analysis ◽  
Waste Heat ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Ambient Conditions ◽  
Bulk Carrier ◽  
Operational Profile ◽  
Exhaust Heat ◽  
Marine Diesel

The energy and the exergy performance of a dual-loop Organic Rankine Cycle (ORC), which harvests exhaust heat from a two-stroke slow-speed main marine diesel engine of a bulk carrier is examined herein. An energy analysis is adopted to calculate the energy flows to the components of the high-temperature (HT) and the low-temperature (LT) loops of the bottoming ORC and through them, to calculate the energy efficiency of the ORC and the generated power from both expanders. Also, an exergy analysis is implemented to predict the irreversibility rates of the components of both HT and LT loops of the ORC system. Various organic fluids are examined for the HT and the LT ORC loops and the optimum combination is selected based on the results of a parametric analysis. The effect of ambient conditions on the energetic and exergetic performance of the dual-loop ORC is examined. The energy analysis of the bottoming dual-loop ORC is projected to a specific mission operational profile of a bulk carrier for predicting the benefits in fuel cost saving and CO2 and SO2 emission reduction compared to conventional vessel operation.

Performance Prediction and Optimization of an Organic Rankine Cycle (ORC) Using Back Propagation Neural Network for Diesel Engine Waste Heat Recovery

2018 ◽  
Author(s):  
Fubin Yang ◽  
Heejin Cho ◽  
Hongguang Zhang
Keyword(s):  
Diesel Engine ◽  
Power Output ◽  
Waste Heat ◽  
Back Propagation ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Back Propagation Neural Network ◽  
Exhaust Temperature ◽  
Proposed Model ◽  
Bpnn Model

This paper presents a methodology to predict and optimize performance of an organic Rankine cycle (ORC) using a back propagation neural network (BPNN) for diesel engine waste heat recovery. A test bench of an ORC with a diesel engine is established to collect experimental data. The collected data is used to train and test a BPNN model for performance prediction and optimization. After evaluating different hidden layers, a BPNN model of the ORC system is determined with consideration of mean squared error and correlation coefficient. The effects of key operating parameters on the power output of the ORC system and exhaust temperature at the outlet of the evaporator are evaluated using the proposed model and further discussed. Finally, a multi-objective optimization of the ORC system are conducted for maximizing power output and minimizing exhaust temperature at the outlet of the evaporator based on the proposed BPNN model. The results show that the proposed BPNN model has a high prediction accuracy and the maximum relative error of the power output is less than 5%. It also shows that when the operations are optimized based on the proposed model, the power output of the ORC system can be higher than the experimental results.

scholarly journals Exergy, Economic, and Life-Cycle Assessment of ORC System for Waste Heat Recovery in a Natural Gas Internal Combustion Engine

Resources ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 2 ◽  
Author(s):  
Guillermo Valencia Ochoa ◽  
Javier Cárdenas Gutierrez ◽  
Jorge Duarte Forero
Keyword(s):  
Life Cycle ◽  
Natural Gas ◽  
Waste Heat ◽  
Combustion Engine ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Working Fluid ◽  
Exergy Destruction ◽  
Tube Heat Exchanger ◽  
Exhaust Heat

In this article, an organic Rankine cycle (ORC) was integrated into a 2-MW natural gas engine to evaluate the possibility of generating electricity by recovering the engine’s exhaust heat. The operational and design variables with the greatest influence on the energy, economic, and environmental performance of the system were analyzed. Likewise, the components with greater exergy destruction were identified through the variety of different operating parameters. From the parametric results, it was found that the evaporation pressure has the greatest influence on the destruction of exergy. The highest fraction of exergy was obtained for the Shell and tube heat exchanger (ITC1) with 38% of the total exergy destruction of the system. It was also determined that the high value of the heat transfer area increases its acquisition costs and the levelized cost of energy (LCOE) of the thermal system. Therefore, these systems must have a turbine technology with an efficiency not exceeding 90% because, from this value, the LCOE of the system surpasses the LCOE of a gas turbine. Lastly, a life cycle analysis (LCA) was developed on the system operating under the selected organic working fluids. It was found that the component with the greatest environmental impact was the turbine, which reached a maximum value of 3013.65 Pts when the material was aluminum. Acetone was used as the organic working fluid.

Performance Prediction and Optimization of an Organic Rankine Cycle Using Back Propagation Neural Network for Diesel Engine Waste Heat Recovery

2019 ◽  
Vol 141 (6) ◽  
Author(s):  
Fubin Yang ◽  
Heejin Cho ◽  
Hongguang Zhang
Keyword(s):  
Diesel Engine ◽  
Power Output ◽  
Waste Heat ◽  
Back Propagation ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Back Propagation Neural Network ◽  
Exhaust Temperature ◽  
Proposed Model ◽  
Bpnn Model

This paper presents a methodology to predict and optimize performance of an organic Rankine cycle (ORC) using a back propagation neural network (BPNN) for diesel engine waste heat recovery. A test bench of an ORC with a diesel engine is established to collect experimental data. The collected data are used to train and test a BPNN model for performance prediction and optimization. After evaluating different hidden layers, a BPNN model of the ORC system is determined with the consideration of mean squared error (MSE) and correlation coefficient. The effects of key operating parameters on the power output of the ORC system and exhaust temperature at the outlet of the evaporator are evaluated using the proposed model and further discussed. Finally, a multi-objective optimization of the ORC system is conducted for maximizing power output and minimizing exhaust temperature at the outlet of the evaporator based on the proposed BPNN model. The results show that the proposed BPNN model has a high prediction accuracy and the maximum relative error of the power output is less than 5%. It also shows that when the operations are optimized based on the proposed model, the power output of the ORC system can be higher than the experimental results.

Research of Two Stage Single Screw Expander Organic Rankine Cycle System Scheme Based on the Waste Heat Recovery of Diesel Engine’s Exhaust Gas

2011 ◽  
Vol 201-203 ◽  
pp. 600-605 ◽  
Author(s):  
Hong Guang Zhang ◽  
Hong Liang ◽  
Xing Liu ◽  
Bin Liu ◽  
Yan Chen ◽  
...  
Keyword(s):  
Diesel Engine ◽  
Heat Recovery ◽  
Waste Heat ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Exhaust Gas ◽  
Two Stage ◽  
Combustion Heat ◽  
Single Screw ◽  
Exhaust Heat

According to the analysis of heat balance, about 1/3 of the fuel combustion heat is taken away into the ambience by exhaust gas of diesel engine. In this article, to improve the using level of the fuel’s combustion heat, a two stage single screw expander organic Rankine cycle (ORC) system has been used to recover the waste heat from exhaust gas of a certain turbine diesel engine. In this article, physical model of the recovery system was built at first, then the T-S curve was drawn, at last, REFPROP was used to calculate thermodynamics parameter in different state point of this system, and analyze the whole system’s thermodynamics character. By analyzing, the evaporation temperature of this system should be optimized to get the relatively evaporation press; by calculating, it could be seen that the middle heater in this system should be taken away to improve the economy of this scheme. This scheme should supply a direction for the exhaust heat recovery of diesel engine.

scholarly journals Development of a Pattern Recognition Methodology with Thermography and Implementation in an Experimental Study of a Boiler for a WHRS-ORC

2019 ◽  
Author(s):  
Concepción Paz ◽  
Eduardo Suarez ◽  
Miguel Concheiro ◽  
Antonio Diaz
Keyword(s):  
Pattern Recognition ◽  
Wall Temperature ◽  
Waste Heat ◽  
Combustion Engine ◽  
Organic Rankine Cycle ◽  
Exhaust System ◽  
Rankine Cycle ◽  
Operating Conditions ◽  
Cycle Performance ◽  
Working Fluid

Waste heat dissipated in the exhaust system in a combustion engine represents a major source of energy to be recovered and converted into useful work. A waste heat recovery system (WHRS) based on an Organic Rankine Cycle (ORC) is a promising approach, and has gained interest in the last few years in an automotive industry interested in reducing fuel consumption and exhaust emissions. Understanding the thermodynamic response of the boiler employed in an ORC plays an important role in steam cycle performance prediction and control system design. The aim of this study is therefore to present a methodology to study these devices by means of pattern recognition with infrared thermography. In addition, the experimental test bench and its operating conditions are described. The methodology proposed identifies the wall coordinates, traces paths, and tracks wall temperature along them in a way that can be exported for subsequent post-processing and analysis. As for the results, through the wall temperature paths on both sides (exhaust gas and working fluid) it was possible to quantitatively estimate the temperature evolution along the boiler and, in particular, the beginning and end of evaporation.

Numerical Investigation of a Partially Loaded Supersonic ORC Turbine Stage

2020 ◽  
Author(s):  
Karl Ziaja ◽  
Pascal Post ◽  
Marwick Sembritzky ◽  
Andreas Schramm ◽  
Ole Willers ◽  
...  
Keyword(s):  
Waste Heat ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Water Mixture ◽  
Loss Model ◽  
Sector Model ◽  
Exhaust Heat ◽  
Partial Admission ◽  
Loss Models ◽  
Lower Temperature

Abstract The Organic Rankine Cycle (ORC) represents an emerging technology aimed at exploiting lower temperature heat sources, like waste heat in industrial processes or exhaust heat in combustion engines. One key aspect of this technology is an efficient and economical operation at part load, typically realized by a partial admission control, which is challenging to predict numerically. Full annulus computation can only be avoided applying empirical partial admission loss models to conventional full-admission computations. This article aims at assessing the reliability of such a loss model under real-gas and supersonic conditions as a first step towards knowledge-based improved loss models. Three different operating points of an 18.3 kW ORC turbine working with an ethanol-water mixture with two open stator passages (2 × 36°) are considered. Full annulus CFD computations are compared to experimental data and results of simulations in a conventional, full admission, periodic 72°-sector model with application of a 1D partial admission loss model. The experimentally obtained mass flow rate and efficiency are matched overall within their measurements accuracy. By highest inlet total pressure, the computed efficiency deviates about 4 % from the experiments. Predictions of efficiency based on the full admission and loss model correction deviate from full annulus computations less than 1 %. These findings suggest that the used empirical correlations for partial admission losses can provide acceptable results in the configuration under investigation.

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