Evaluation of Brayton and Rankine Alternatives for Diesel Waste Heat Exploitation

1994 ◽  
Vol 116 (1) ◽  
pp. 39-45 ◽  
Author(s):  
J. B. Woodward
Keyword(s):  
Diesel Engine ◽  
Gas Turbine ◽  
Thermal Energy ◽  
Diesel Exhaust ◽  
Waste Heat ◽  
Rankine Cycle ◽  
Brayton Cycle ◽  
Exhaust Gas ◽  
Direct Expansion ◽  
Work Done

A diesel engine may produce exhaust-gas thermal energy in excess of that needed for turbocharging. Alternatives for exploitation of the energy by producing work may be direct expansion through a gas turbine (completing a Brayton cycle that begins with the engine’s compression and combustion), or transfer of heat into a Rankine cycle. It is demonstrated that either alternative may have a domain in which it is superior in work done, or in exhaust volume per unit mass of diesel exhaust. Computation models are developed and demonstrated for finding the boundaries along which the Rankine and Brayton alternatives have equal merit in either work or exhaust volume.

Recovering the Energy in Diesel Exhaust: Some Thermodynamic Points

1987 ◽  
Vol 24 (03) ◽  
pp. 205-211
Author(s):  
John B. Woodward
Keyword(s):  
Heat Transfer ◽  
Diesel Engine ◽  
Gas Turbine ◽  
Diesel Exhaust ◽  
Waste Heat ◽  
Rankine Cycle ◽  
Two Alternatives

The concepts of availability and reversible heat transfer are reviewed; the latter is shown to be the basis for diesel engine bottoming cycles. The thermodynamics of bottoming or waste-heat conversion to work by a gas turbine in parallel with the turbocharger turbine are discussed, and compared with those of a Rankine cycle for the same function. The two alternatives are shown to be of equal merit until practical differences are introduced; the first alternative is then favored. Throughout, formulas and calculations are given in detail to provide information on techniques not commonly found in either thermodynamics texts or technical papers.

Pure Working Fluid Selection for the Organic Rankine Cycle in Waste Heat Recovery of Diesel Engine

2011 ◽  
Vol 383-390 ◽  
pp. 6110-6115
Author(s):  
Hong Liang ◽  
Xing Liu ◽  
Hong Guang Zhang ◽  
Bin Liu ◽  
Yan Chen ◽  
...  
Keyword(s):  
Diesel Engine ◽  
Waste Heat ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Working Fluid ◽  
Exhaust Gas ◽  
Alternative Refrigerants ◽  
Combustion Heat ◽  
Working Fluid Selection ◽  
Selection For

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. Depending on the characteristics of the diesel, this paper uses a special system to recover this waste heat, in which the organic Rankine cycle is combined with a single screw expander. The economy should be improved by using this system in the diesel. The model of this system is designed in Matlab combined with REFPROP. Using this way, the thermodynamic parameters should be calculated and the thermodynamic properties of this system with different working fluids should be analyzed. At last, R245fa, R245ca, R123 and R141b are selected as the alternative refrigerants used in this system.

ORC System Development Using Diesel Engine Waste Heat

2014 ◽  
Vol 960-961 ◽  
pp. 405-409
Author(s):  
Jun Qi Dong ◽  
Jiang Zhang Wang ◽  
Rong You Zhang
Keyword(s):  
Diesel Engine ◽  
Waste Heat ◽  
System Development ◽  
Electric Energy ◽  
Organic Rankine Cycle ◽  
Stable Condition ◽  
Rankine Cycle ◽  
Working Fluid ◽  
Exhaust Gas ◽  
Commercial Plant

Based on the waste heat characteristics of the coolant and exhaust gas from diesel engine, the Organic Rankine Cycle (ORC) commercial plant had been developed. The working fluid was the R245fa, and the plate type heat exchangers were used as the condenser and evaporator in the ORC systems. The performance of condenser and evaporator had been simulated and developed using the effective-NTU method. Using the engine jacket coolant as the heating media, the coolant absorbs the waste heat from the exhaust gas and engine cylinders. The ORC system and engine can stably run for a long time without frequent control acting. The ORC systems can bring the 14.6 kw electric energy in the stable condition. The efficiency based on the first law of thermodynamics is 7.2%; complete generating efficiency is 6.25%.

scholarly journals Theoretical and Experimental Analysis of Waste Heat Recovery Effectiveness of a Diesel Engine

2019 ◽  
pp. 1-17
Author(s):  
A. Adeyanju Anthony ◽  
K. Manohar
Keyword(s):  
Heat Exchanger ◽  
Diesel Engine ◽  
Flow Rate ◽  
Waste Heat ◽  
Volumetric Flow Rate ◽  
Rankine Cycle ◽  
Exhaust Gas ◽  
Tube Heat Exchanger ◽  
Shell And Tube ◽  
Volumetric Flowrate

The study utilized the exhaust gas from a diesel engine to preheat water in the constructed shell and tube heat exchanger. The theoretical analysis of the heat exchanger was carried out using the Log Mean Temperature Difference (LMTD) method. The Volumetric flowrate of the water was manipulated using a valve and the resulting output temperature of water leaving the heat exchanger was recorded. Experimentation was carried out to determine the effects of volumetric flow rate on the output temperature and the effectiveness of the heat exchanger. After the test and data analysis, it was discovered that that at flow rate of 3.0 Liter per minute (LPM) the effectiveness of the heat exchanger was peak at 43.34%. The volumetric flow rate of water is inversely proportional to the output temperature of water and it was also established that the effectiveness of the heat exchanger depends on output temperature of and the mass flow rate of the water. Also it was proven that by preheating water before it enters the boiler of the Rankine cycle the efficiency of the cycle increases.

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.

Gas Turbine Bottoming Cycles for Cogenerative Applications: Comparison of Different Heat Recovery Cycle Solutions

2011 ◽  
Author(s):  
Rakesh K. Bhargava ◽  
Michele Bianchi ◽  
Andrea De Pascale
Keyword(s):  
Gas Turbine ◽  
Heat Recovery ◽  
Waste Heat ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Brayton Cycle ◽  
Gas Turbine Exhaust ◽  
Parametric Analyses ◽  
Turbine Exhaust ◽  
Made In

With all the advancements made in the gas turbine technologies in the last 7 decades, a large amount (approximately 60%) of the thermal energy in the gas turbine exhaust is released in to the environment. This discharged heat could be profitably used not only in thermal utilities but also as an intermediate temperature heat source for the bottoming cycles producing electric power. This paper provides a systematic thermodynamic performance evaluation and comparison among the three different waste heat recovery solutions, namely, the Inverted Brayton Cycle, the Bottoming Brayton Cycle and the Organic Rankine Cycle. The results obtained from the parametric analyses of the CHP systems clearly identify advantages and limitations of the gas turbine technology and its size when combined with the three bottoming cycles evaluated in this study. A detailed discussion on the obtained results is presented in this paper.

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.

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