scholarly journals Thermoeconomic Analysis of Different Exhaust Waste-Heat Recovery Systems for Natural Gas Engine Based on ORC

2019 ◽  
Vol 9 (19) ◽  
pp. 4017 ◽  
Author(s):  
Valencia ◽  
Duarte ◽  
Isaza-Roldan
Keyword(s):  
Natural Gas ◽  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Waste Heat ◽  
Working Fluid ◽  
Exergy Destruction ◽  
Relative Cost ◽  
Cost Difference ◽  
Cost Rate ◽  
The Cost

Waste-heat recovery (WHR) systems based on the organic Rankine cycle (ORC) improve the thermal efficiency of natural gas engines because they generate additional electric power without consuming more gas fuel. However, to obtain a cost-effective design, thermoeconomic criteria must be considered to facilitate installation, operation, and penetration into real industrial contexts. Therefore, a thermo-economic analyses of a simple ORC (SORC), ORC with recuperator (RORC) and a double-pressure ORC (DORC) integrated with a 2 MW Jenbacher JMS 612 GS-N. L is presented using toluene as the organic working fluid. In addition, the cost rate balances for each system are presented in detail, with the analysis of some thermoeconomics indicator such as the relative cost difference, the exergoeconomic factor, and the cost rates of exergy destruction and exergy loss. The results reported opportunities to improve the thermoeconomic performance in the condenser and turbine, because the exergoeconomic factor for the condenser and the turbine were in the RORC (0.41 and 0.90), and DORC (0.99 and 0.99) respectively, which implies for the RORC configuration that 59% and 10% of the increase of the total cost of the system is caused by the exergy destruction of these devices. Also, the pumps present the higher values of relative cost difference and exergoeconomic factor for B1 (rk = 8.5, fk = 80%), B2 (rk = 8, fk = 85%).

scholarly journals Waste heat recovery from a heavy-duty natural gas engine by Organic Rankine Cycle

2020 ◽  
Vol 197 ◽  
pp. 06023
Author(s):  
Antonio Mariani ◽  
Biagio Morrone ◽  
Maria Vittoria Prati ◽  
Andrea Unich
Keyword(s):  
Natural Gas ◽  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Waste Heat ◽  
Combustion Engine ◽  
Thermal Power ◽  
Working Fluid ◽  
Maximum Pressure ◽  
Fluid Temperature ◽  
Road Transportation

Waste heat recovery can be a key solution for improving the efficiency of energy conversion systems. Organic Rankine Cycles (ORC) are a consolidated technology for achieving such target, ensuring good efficiencies and flexibility. ORC systems have been mainly adopted for stationary applications, where the limitations of layout, size and weight are not stringent. In road transportation propulsion systems, the integration between the powertrain and the ORC system is difficult but still possible. The authors investigated an ORC system bottoming a spark ignited internal combustion engine (ICE) powering a public transport bus. The bus, fuelled by natural gas, was tested in real driving conditions. Exhaust gas mass flow rate and temperature have been measured for calculating the thermal power to be recovered in the ORC plant. The waste heat was then used as energy input in a model simulating the performance of an ORC system. The heat transfer between the exhaust gases and the ORC fluid is crucial for the ORC performance. For this reason, attention was paid to considering the interaction between hot fluid temperature and ORC maximum pressure. ORC performance in terms of real cycle efficiency and power produced were calculated considering n-Pentane as working fluid. The fuel consumption was reduced from 271.5 g/km to 261.4 g/km over the driving cycle, corresponding to 3.7% reduction.

scholarly journals Seawater Desalination via Waste Heat Recovery from Generator of Wind Turbines: How Economical Is It to Use a Hybrid HDH-RO Unit?

2021 ◽  
Vol 13 (14) ◽  
pp. 7571
Author(s):  
Hadi Rostamzadeh ◽  
Saeed Rostami ◽  
Majid Amidpour ◽  
Weifeng He ◽  
Dong Han
Keyword(s):  
Wind Turbine ◽  
Thermal Energy ◽  
Wind Turbines ◽  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Waste Heat ◽  
Unit Cost ◽  
Cost Rate ◽  
Investment Cost ◽  
The Cost

Over recent years, the concept of waste heat recovery from the generators of wind turbines for driving a thermal-driven desalination system was introduced, and its advantages were highlighted. However, any selection of a bottoming thermal-driven desalination system among different existing technologies should be taken under consideration before making an ultimate recommendation. Unfortunately, no comprehensive comparison is available in the literature to compare the performance as well as the cost aspects of using the waste thermal energy of the generator of a wind turbine for desalinating seawater, comparing them with those of a layout where the power of the wind turbine is directly supplied to a mechanically driven desalination system for the same amount of drinkable water production. This study aims at analyzing the economic aspects of waste heat recovery from the generators of wind turbines for seawater desalination via the humidification-dehumidification (HDH) approach, versus the reverse osmosis (RO) unit. For this purpose, a closed-air water-heater HDH unit, directly coupled with a RO unit (called a hybrid HDH-RO unit) is employed, in which thermal energy is provided by the heat dissipating from the generator of the wind turbine while its power is supplied directly by the wind turbine. The energetic and exergetic performance, along with the cost aspects of a hybrid HDH-RO unit driven by the wind turbine, are compared with those of a solo RO unit. The results of the study were extended for six different types of wind turbines, and we concluded that the unit cost associated with the freshwater produced by the waste heat recovery approach is astronomically higher than that of the solo RO system for all wind turbine models, and hence is not practically feasible. It was found that more power can be recovered from the discarded brine from the solo RO unit than the hybrid HDH-RO unit. In addition, the solo RO desalination system, working directly with the power of the wind turbine, has a less complex configuration, and hence its investment cost rate is significantly lower than that needed for setting up an HDH-RO unit. At high wind speeds, however, the cost penalty associated with the freshwater produced by the HDH-RO unit decreases, but it is still huge. Among all screened wind turbines, the GW-136/4.8 is most appealing in terms of greater power generation, but its investment cost rate is the highest among all models due to its high rated power value. However, the freshwater unit cost of the GW-136/4.8 is significantly lower than the values obtained for other models. Finally, the two locations of Manjil and Zabol are selected as a benchmark and the results of the simulation are extended for these locations.

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 Evaluation and analysis of exergoeconomic performance for the calcination process of green petroleum coke in vertical shaft kiln

2021 ◽  
pp. 294-294
Author(s):  
Peng Li ◽  
Baokuan Li ◽  
Zhongqiu Liu ◽  
Wenjie Rong
Keyword(s):  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Waste Heat ◽  
Shaft Furnace ◽  
Exergy Efficiency ◽  
Heat Recovery Boiler ◽  
Vertical Shaft ◽  
Exergy Destruction ◽  
Calcination Process ◽  
Recovery Boiler

The main objective of this paper is to establish a mathematical framework to analyze the complex thermal economic performance of the calcination process. To find the factors affecting exergy efficiency loss, different exergy destruction is investigated in detail. Furthermore, the exergy flow cost model for exergy cost saving has also been developed. The results show that the vertical shaft furnace is a self-sufficiency equipment without additional fuel required, but the overall exergy destruction accounts for 54.11% of the total exergy input. In addition, the energy efficiency of the waste heat recovery boiler and thermal deaerator are 83.52% and 96.40%, whereas the exergy efficiency of the two equipment are 65.98% and 94.27%. Furthermore, the import exergy flow cost of vertical shaft furnace, waste heat recovery boiler and thermal deaerator are 366.5197 RMB/MJ, 0.1426 RMB/MJ and 0.0020RMB/MJ, respectively. Based on the result, several suggestions were proposed to improve the exergoeconomic performance. Assessing the performance of suggested improvements, the total exergy destruction of vertical shaft furnace is reduced to 134.34 GJ/h and the exergy efficiency of waste heat recovery boiler is raised up to 66.02%. Moreover, the import exergy flow cost of the three different equipment is reduced to 0.0329 RMB/MJ, 0.1304 RMB/MJ and 0.0002 RMB/MJ, respectively.

scholarly journals Energy and Exergy Analysis of Different Exhaust Waste Heat Recovery Systems for Natural Gas Engine Based on ORC

2019 ◽  
Author(s):  
Guillermo Valencia ◽  
Armando Fontalvo ◽  
Yulineth Cardenas ◽  
Jorge Duarte ◽  
Cesar Isaza
Keyword(s):  
Natural Gas ◽  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Exergy Analysis ◽  
Waste Heat ◽  
Natural Gas Engine ◽  
Exhaust Waste Heat ◽  
Energy And Exergy ◽  
Energy And Exergy Analysis ◽  
Net Power Output

One way to increase overall natural gas engine efficiency is to transform exhaust waste heat into useful energy by means of a bottoming cycle. Organic Rankine cycle (ORC) is a promising technology to convert medium and low grade waste heat into mechanical power and electricity. This paper presents an energy and exergy analysis of three ORC-Waste heat recovery configurations by using an intermediate thermal oil circuit: Simple ORC (SORC), ORC with Recuperator (RORC) and ORC with Double Pressure (DORC), and Cyclohexane, Toluene and Acetone have been proposed as working fluids. An energy and exergy thermodynamic model is proposed to evaluate each configuration performance, while available exhaust thermal energy variation under different engine loads was determined through an experimentally validated mathematical model. Additionally, the effect of evaportating pressure on net power output , absolute thermal efficiency increase, absolute specific fuel consumption decrease, overall energy conversion efficiency, and component exergy destruction is also investigated. Results evidence an improvement in operational performance for heat recovery through RORC with Toluene at an evaporation pressure of 3.4 MPa, achieving 146.25 kW of net power output, 11.58% of overall conversion efficiency, 28.4% of ORC thermal efficiency, and an specific fuel consumption reduction of 7.67% at a 1482 rpm engine speed, a 120.2 L/min natural gas Flow, 1.784 lambda, and 1758.77 kW mechanical engine power.

scholarly journals Exergy analysis of the Szewalski cycle with a waste heat recovery system

2015 ◽  
Vol 36 (3) ◽  
pp. 25-48 ◽  
Author(s):  
Tomasz Kowalczyk ◽  
Paweł Ziółkowski ◽  
Janusz Badur
Keyword(s):  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Power Plants ◽  
Exergy Analysis ◽  
Waste Heat ◽  
Reference Conditions ◽  
Heat Rate ◽  
Working Fluid ◽  
Regeneration System ◽  
Waste Heat Recovery System

Abstract The conversion of a waste heat energy to electricity is now becoming one of the key points to improve the energy efficiency in a process engineering. However, large losses of a low-temperature thermal energy are also present in power engineering. One of such sources of waste heat in power plants are exhaust gases at the outlet of boilers. Through usage of a waste heat regeneration system it is possible to attain a heat rate of approximately 200 MWth, under about 90 °C, for a supercritical power block of 900 MWel fuelled by a lignite. In the article, we propose to use the waste heat to improve thermal efficiency of the Szewalski binary vapour cycle. The Szewalski binary vapour cycle provides steam as the working fluid in a high temperature part of the cycle, while another fluid – organic working fluid – as the working substance substituting conventional steam over the temperature range represented by the low pressure steam expansion. In order to define in detail the efficiency of energy conversion at various stages of the proposed cycle the exergy analysis was performed. The steam cycle for reference conditions, the Szewalski binary vapour cycle as well as the Szewalski hierarchic vapour cycle cooperating with a system of waste heat recovery have been comprised.

Optimization of an Organic Rankine Cycle-Based Waste Heat Recovery System Using a Novel Target-Temperature-Line Approach

2021 ◽  
Vol 143 (9) ◽  
Author(s):  
Md. Zahurul Haq
Keyword(s):  
Heat Exchange ◽  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Waste Heat ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Optimum Operating ◽  
Working Fluid ◽  
Operating Parameters ◽  
Target Temperature

Abstract Organic Rankine cycle (ORC)-based waste heat recovery (WHR) systems are simple, flexible, economical, and environment-friendly. Many working fluids and cycle configurations are available for WHR systems, and the diversity of working fluid properties complicates the synergistic integration of the efficient heat exchange in the evaporator and net output work. Unique guidelines to select a proper working fluid, cycle configuration and optimum operating parameters are not readily available. In the present study, a simple target-temperature-line approach is introduced to get the optimum operating parameters for the subcritical ORC system. The target-line is the locus of temperatures satisfying the pinch-point temperature difference along the length of the heat exchanger. Employing the approach, study is carried out with 38 pre-selected working fluids to get the optimum operating parameters and suitable fluid for heat source temperatures ranging from 100 °C to 300 °C. Results obtained are analyzed to get cross-correlations between key operating and performance parameters using a heat-map diagram. At the optimum condition, optimal working fluid’s critical temperature and pressure, evaporator saturation temperature, effectivenesses of the heat exchange in the evaporator, cycle, and overall WHR system exhibit strong linear correlations with the heat source temperature.

scholarly journals Economic and Exergo-Advance Analysis of a Waste Heat Recovery System Based on Regenerative Organic Rankine Cycle under Organic Fluids with Low Global Warming Potential

Energies ◽  
2020 ◽  
Vol 13 (6) ◽  
pp. 1317 ◽  
Author(s):  
Guillermo Valencia Ochoa ◽  
Cesar Isaza-Roldan ◽  
Jorge Duarte Forero
Keyword(s):  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Waste Heat ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Working Fluid ◽  
Exhaust Gases ◽  
Waste Heat Recovery System ◽  
Recovery System ◽  
Heat Recovery System

The waste heat recovery system (WHRS) is a good alternative to provide a solution to the waste energy emanated in the exhaust gases of the internal combustion engine (ICE). Therefore, it is useful to carry out research to improve the thermal efficiency of the ICE through a WHRS based on the organic Rankine cycle (ORC), since this type of system takes advantage of the heat of the exhaust gases to generate electrical energy. The organic working fluid selection was developed according to environmental criteria, operational parameters, thermodynamic conditions of the gas engine, and investment costs. An economic analysis is presented for the systems operating with three selected working fluids: toluene, acetone, and heptane, considering the main costs involved in the design and operation of the thermal system. Furthermore, an exergo-advanced study is presented on the WHRS based on ORC integrated to the ICE, which is a Jenbacher JMS 612 GS-N of 2 MW power fueled with natural gas. This advanced exergetic analysis allowed us to know the opportunities for improvement of the equipment and the increase in the thermodynamic performance of the ICE. The results show that when using acetone as the organic working fluid, there is a greater tendency of improvement of endogenous character in Pump 2 of around 80%. When using heptane it was manifested that for the turbine there are near to 77% opportunities for improvement, and the use of toluene in the turbine gave a rate of improvement of 70%. Finally, some case studies are presented to study the effect of condensation temperature, the pinch point temperature in the evaporator, and the pressure ratio on the direct, indirect, and fixed investment costs, where the higher investment costs were presented with the acetone, and lower costs when using the toluene as working fluid.

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