scholarly journals Multi-Objective Thermo-Economic Optimization of a Combined Organic Rankine Cycle (ORC) System Based on Waste Heat of Dual Fuel Marine Engine and LNG Cold Energy Recovery

Energies ◽  
2020 ◽  
Vol 13 (6) ◽  
pp. 1397 ◽  
Author(s):  
Zhen Tian ◽  
Yingying Yue ◽  
Yuan Zhang ◽  
Bo Gu ◽  
Wenzhong Gao
Keyword(s):  
Waste Heat ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Payback Period ◽  
Operating Conditions ◽  
Dual Fuel ◽  
Exergy Destruction ◽  
Marine Engine ◽  
Investment Cost ◽  
Cold Energy

In this paper, a combined organic Rankine cycle (ORC) system that can effectively utilize the cold energy of Liquefied Nature Gas (LNG) and the waste heat of dual fuel (DF) marine engine was proposed. Particularly, the engine exhaust gas and the jacket cooling water of the DF marine engine were used as heat sources. Firstly, a thorough assessment of thermo-economic performance was conducted for the combined ORC system using 11 environmentally friendly working fluids (WFs). Afterwards, the effects of evaporation and condensation pressures on the net output work, energy efficiency, exergy efficiency, total investment cost and payback period were examined. Furthermore, the thermo-economic performances of the ORC system were optimized via multi-objective optimization with a genetic algorithm. Finally, exergy destructions and investment costs of each component under the optimal operating conditions were analyzed to make suggestions for further improvement. The results show that R1150-R1234yf-R600a and R170-R1270-R152a are the two most promising WF combinations. The exergy destruction of the combined ORC system mainly exists in heat exchangers. Through WF optimization, the exergy destruction in the intermediate heat exchanger was reduced by 18.99%. The proportion of expanders investment cost could be greater than 50% and the payback period of the combined ORC system varies in the range of 7.68–9.43 years. This study demonstrated that the selection of WF and the optimization of operating conditions had important potential to improve thermo-economic performances of ORC systems.

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.

Waste Heat Recovery in a Cruise Vessel in the Baltic Sea by Using an Organic Rankine Cycle: A Case Study

2015 ◽  
Author(s):  
Fredrik Ahlgren ◽  
Maria E. Mondejar ◽  
Magnus Genrup ◽  
Marcus Thern
Keyword(s):  
Power Output ◽  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Waste Heat ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Operating Conditions ◽  
Maritime Transportation ◽  
Working Fluid ◽  
Net Power Output

Maritime transportation is a significant contributor to SOx, NOx and particle matter emissions, even though it has a quite low CO2 impact. New regulations are being enforced in special areas that limit the amount of emissions from the ships. This fact, together with the high fuel prices, is driving the marine industry towards the improvement of the energy efficiency of current ship engines and the reduction of their energy demand. Although more sophisticated and complex engine designs can improve significantly the efficiency of the energy systems in ships, waste heat recovery arises as the most influent technique for the reduction of the energy consumption. In this sense, it is estimated that around 50% of the total energy from the fuel consumed in a ship is wasted and rejected in fluid and exhaust gas streams. The primary heat sources for waste heat recovery are the engine exhaust and the engine coolant. In this work, we present a study on the integration of an organic Rankine cycle (ORC) in an existing ship, for the recovery of the main and auxiliary engines exhaust heat. Experimental data from the operating conditions of the engines on the M/S Birka Stockholm cruise ship were logged during a port-to-port cruise from Stockholm to Mariehamn over a period of time close to one month. The ship has four main engines Wärtsilä 5850 kW for propulsion, and four auxiliary engines 2760 kW used for electrical consumers. A number of six load conditions were identified depending on the vessel speed. The speed range from 12–14 knots was considered as the design condition, as it was present during more than 34% of the time. In this study, the average values of the engines exhaust temperatures and mass flow rates, for each load case, were used as inputs for a model of an ORC. The main parameters of the ORC, including working fluid and turbine configuration, were optimized based on the criteria of maximum net power output and compactness of the installation components. Results from the study showed that an ORC with internal regeneration using benzene would yield the greatest average net power output over the operating time. For this situation, the power production of the ORC would represent about 22% of the total electricity consumption on board. These data confirmed the ORC as a feasible and promising technology for the reduction of fuel consumption and CO2 emissions of existing ships.

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.

Meanline Analysis and CFD Study of a Radial Inflow Turbine With Vaneless Distributor for Low Temperature Organic Rankine Cycle

2020 ◽  
Author(s):  
M. Deligant ◽  
S. Braccio ◽  
T. Capurso ◽  
F. Fornarelli ◽  
M. Torresi ◽  
...  
Keyword(s):  
Energy Demand ◽  
Waste Heat ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Operating Conditions ◽  
Low Grade ◽  
Heat Sources ◽  
Turbine Wheel ◽  
Good Efficiency ◽  
Low Grade Heat

Abstract The Organic Rankine Cycle (ORC) allows the conversion of low-grade heat sources into electricity. Although this technology is not new, the increase in energy demand and the need to reduce CO2 emissions create new opportunities to harvest low grade heat sources such as waste heat. Radial turbines have a simple construction, they are robust and they are not very sensitive to geometry inaccuracies. Most of the radial inflow turbines used for ORC application feature a vaned nozzle ensuring the appropriate distribution angle at the rotor inlet. In this work, no nozzle is considered but only the vaneless gap (distributor). This configuration, without any vaned nozzle, is supposed to be more flexible under varying operating conditions with respect to fixed vanes and to maintain a good efficiency at off-design. This paper presents a performance analysis carried out by means of two approaches: a combination of meanline loss models enhanced with real gas fluid properties and 3D CFD computations, taking into account the entire turbomachine including the scroll housing, the vaneless gap, the turbine wheel and the axial discharge pipe. A detailed analysis of the flow field through the turbomachine is carried out, both under design and off design conditions, with a particular focus on the entropy field in order to evaluate the loss distribution between the scroll housing, the vaneless gap and the turbine wheel.

Organic Rankine Cycle for Waste Heat Recovery in a Hybrid Vehicle

2010 ◽  
Author(s):  
Quazi E. Hussain ◽  
David R. Brigham
Keyword(s):  
Fuel Economy ◽  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Waste Heat ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Operating Conditions ◽  
Working Fluid ◽  
Drive Cycle ◽  
Exhaust Heat

The Rankine cycle is used commercially to generate power in stationary power plants using water as the working fluid. For waste heat recovery applications, where the temperature is lower, water is typically replaced by a carefully selected organic fluid. This work is based on using the waste heat in an automobile to generate electricity using the Organic Rankine cycle (ORC) with R245fa (1, 1, 1, 3, 3 penta-fluoropropane) as the working fluid. The electricity thus generated can be used to drive the accessory load or charge the battery which in any case helps improve the fuel economy. A simple transient numerical model has been developed that is capable of capturing the main effects of this cycle. Results show that exhaust heat alone can generate enough electricity that is capable of bringing about an improvement to the fuel economy under transient drive cycle conditions. Power output during EPA Highway drive cycle is much higher than EPA City due to higher exhaust mass flow rate and temperature. Time needed to reach operating conditions or in other words, the warm-up time plays an important role in the overall drive cycle output. Performance is found to improve significantly when coolant waste heat is used in conjunction with the residual exhaust heat to pre-heat the liquid. A sizing study is also performed to keep the cost, weight, and packaging requirement down without sacrificing too much power. With careful selection of heat exchanger design parameters, it has been demonstrated that the backpressure on the engine can be actually lowered by cooling off the exhaust gas. This lower backpressure will further boost the fuel economy gained by the electricity produced by the Rankine bottoming cycle.

scholarly journals Análisis termodinámico del intercambiador de calor de un sistema ORC para el aprovechamiento de calor residual en procesos industriales

2019 ◽  
pp. 27-33
Author(s):  
Uzziel Caldiño-Herrera ◽  
Delfino Cornejo-Monroy ◽  
Shehret Tilvaldyev ◽  
José Omar Dávalos-Ramírez
Keyword(s):  
Energy Source ◽  
Heat Exchanger ◽  
Waste Heat ◽  
Organic Rankine Cycle ◽  
Industrial Process ◽  
Rankine Cycle ◽  
Energy System ◽  
Operating Conditions ◽  
Maximum Efficiency ◽  
Working Fluid

In this paper we present the implementation of a system based on organic Rankine cycle coupled to a heat discharge of an industrial process. Waste heat is used as an energy source input to the system, which uses this energy to evaporate an organic fluid and expand it in a turbine, where mechanical power is produced. The system consists of 4 processes and the heat exchanger is specially analyzed. According to the availability of heat energy, the heat exchanger was designed to achieve the maximum efficiency in the energy system. Likewise, the maximum thermal efficiency of the ORC system is calculated as a function of the available energy, the energy source temperature and the available mass flow rate. By these calculations, the working fluid and the suitable operating conditions were selected through a thermodynamic analysis.

Sign in / Sign up

Export Citation Format

Share Document