scholarly journals Advance Exergo-Economic Analysis of a Waste Heat Recovery System Using ORC for a Bottoming Natural Gas Engine

Energies ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 267 ◽  
Author(s):  
Guillermo Valencia Ochoa ◽  
Jhan Piero Rojas ◽  
Jorge Duarte Forero
Keyword(s):  
Heat Exchanger ◽  
Economic Analysis ◽  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Waste Heat ◽  
Operating Conditions ◽  
Cost Rate ◽  
Waste Heat Recovery System ◽  
Recovery System ◽  
Heat Recovery System

This manuscript presents an advanced exergo-economic analysis of a waste heat recovery system based on the organic Rankine cycle from the exhaust gases of an internal combustion engine. Different operating conditions were established in order to find the exergy destroyed values in the components and the desegregation of them, as well as the rate of fuel exergy, product exergy, and loss exergy. The component with the highest exergy destroyed values was heat exchanger 1, which is a shell and tube equipment with the highest mean temperature difference in the thermal cycle. However, the values of the fuel cost rate (47.85 USD/GJ) and the product cost rate (197.65 USD/GJ) revealed the organic fluid pump (pump 2) as the device with the main thermo-economic opportunity of improvement, with an exergo-economic factor greater than 91%. In addition, the component with the highest investment costs was the heat exchanger 1 with a value of 2.769 USD/h, which means advanced exergo-economic analysis is a powerful method to identify the correct allocation of the irreversibility and highest cost, and the real potential for improvement is not linked to the interaction between components but to the same component being studied.

Research on Waste Heat Recovery in Drain Water of Barbershop

2012 ◽  
Vol 204-208 ◽  
pp. 4229-4233 ◽  
Author(s):  
Fang Tian Sun ◽  
Na Wang ◽  
Yun Ze Fan ◽  
De Ying Li
Keyword(s):  
Heat Exchanger ◽  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Waste Heat ◽  
Utilization Efficiency ◽  
Drain Water ◽  
Waste Heat Recovery System ◽  
Heat Utilization ◽  
Recovery System ◽  
Heat Recovery System

Drain water at 35°C was directly discharged into sewer in most of barbershop with Electric water heater. Heat utilization efficiency is lower, and energy grade match between input and output is not appropriate in most of barbershops. Two waste heat recovery systems were presented according to the heat utilization characteristics of barbershops and principle of cascade utilization of energy. One was the waste heat recovery system by water-to-water heat exchanger (WHR-HE), and the other is the waste heat recovery system by water-to-water heat exchanger and high-temperature heat pump (WHR-CHEHP). The two heat recovery systems were analyzed by the first and second Laws of thermodynamic. The analyzed results show that the energy consumption can be reduced about 75% for HR-HE, and about 98% for WHR-CHEHP. Both WHR-HE and WHR-CHEHP are with better energy-saving effect and economic benefits.

Design and Performance of a Fuel Cell Plant Heat Recovery System

2007 ◽  
Author(s):  
Robert G. Ryan ◽  
Tom Brown
Keyword(s):  
Fuel Cell ◽  
Latent Heat ◽  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Waste Heat ◽  
Operating Conditions ◽  
Hot Water ◽  
Waste Heat Recovery System ◽  
Recovery System ◽  
Heat Recovery System

A 1 MW Direct Fuel Cell® (DFC) power plant began operation at California State University, Northridge (CSUN) in January, 2007. This plant is currently the largest fuel cell plant in the world operating on a university campus. The plant consists of four 250 kW DFC300MA™ fuel cell units purchased from FuelCell Energy, Inc., and a waste heat recovery system which produces dual heating hot water loops for campus building ventilation heating, and domestic water and swimming pool heating water for the University Student Union (USU). The waste heat recovery system was designed by CSUN’s Physical Plant Management and engineering student staff personnel to accommodate the operating conditions required by the four individual fuel cell units as well as the thermal energy needs of the campus. A Barometric Thermal Trap (BaTT) was designed to mix the four fuel cell exhaust streams prior to flowing through a two stage heat exchanger unit. The BaTT is required to maintain an appropriate exhaust back pressure at the individual fuel cell units under a variety of operating conditions and without reliance on mechanical systems for control. The two stage heat exchanger uses separate coils for recovering sensible and latent heat in the exhaust stream. The sensible heat is used for heating water for the campus’ hot water system. The latent heat represents a significant amount of energy because of the high steam content in the fuel cell exhaust, although it is available at a lower temperature. CSUN’s design is able to make effective use of the latent heat because of the need for swimming pool heating and hot water for showers in an adjacent recreational facility at the USU. Design calculations indicate that a Combined Heat and Power efficiency of 74% is possible. This paper discusses the integration of the fuel cell plant into the campus’ energy systems, and presents preliminary operational data for the performance of the heat recovery system.

Electrical and CHP Efficiencies of a 1 MW University Fuel Cell Power Plant

2009 ◽  
Author(s):  
Robert Ryan
Keyword(s):  
Heat Exchanger ◽  
Fuel Cell ◽  
Power Plant ◽  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Waste Heat ◽  
Hot Water ◽  
Waste Heat Recovery System ◽  
Recovery System ◽  
Heat Recovery System

A 1 MW fuel cell power plant began operation at California State University, Northridge (CSUN) in January, 2007. The power plant was installed on campus to complement a Satellite Chiller Plant which is being constructed in response to increased cooling demands related to campus growth. The power plant consists of four 250 kW fuel cell units, and a waste heat recovery system which produces hot water for the campus. The waste heat recovery system was designed by CSUN’s Physical Plant Management personnel, in consultation with engineering faculty and students, to accommodate the operating conditions required by the fuel cell units as well as the thermal needs of the campus. A unique plenum system, known as a Barometric Thermal Trap, was created to mix the four fuel cell exhaust streams prior to flowing through a two stage heat exchanger unit. The two stage heat exchanger uses separate coils for recovering sensible and latent heat in the exhaust stream. The sensible heat is being used to partially supply the campus’ building hot water and space heating requirements. The latent heat is intended for use by an adjacent recreational facility at the University Student Union. This paper discusses plant performance data which was collected and analyzed over a several month period during 2008. Electrical efficiencies and Combined Heat and Power (CHP) efficiencies are presented. The data shows that CHP efficiencies have been consistently over 60%, with the potential to exceed 70% when planned improvements to the plant are completed.

Modelling and Design of Thermoelectric Generator for Waste Heat Recovery

2016 ◽  
Author(s):  
Dongxu Ji ◽  
Alessandro Romagnoli
Keyword(s):  
Heat Exchanger ◽  
Output Power ◽  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Thermoelectric Generator ◽  
Waste Heat ◽  
Current Model ◽  
Waste Heat Recovery System ◽  
Recovery System ◽  
Heat Recovery System

In order to design an effective thermoelectric generator (TEG) heat exchanger for waste heat recovery, an accurate model is required for system design and performance predicting. In this paper, 1-D model is developed in MATLAB, taking into consideration of the multi-physics phenomena within TEG. The proposed model is different from existing thermoelectric models which mainly focus on the thermoelectric couple or device level without providing any guidance for designing an optimal system. When optimizing some TEG parameters, the optimal value found in a device level model might not be suitable when put into a waste heat recovery system. Therefore, in order to develop an optimized TEG system with optimum output power performance, a more comprehensive thermoelectric model integrated with the other components is needed. The current model integrates the thermoelectric module with the heat exchangers. Through this study, we found that the heat exchanger and module design have an impact on the total TEG output power in waste heat recovery system and a systematic design approach is needed.

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