Identifying a robust waste heat recovery system for varying hot water temperature demand

2017 ◽  
Author(s):  
Maizura Mokhtar
Keyword(s):  
Water Temperature ◽  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Waste Heat ◽  
Hot Water ◽  
Waste Heat Recovery System ◽  
Recovery System ◽  
Heat Recovery System

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.

ANALYSIS ON THE EFFECT OF NANO PARTICLES IN WASTE HEAT RECOVERY SYSTEM USING HEAT PIPES BY RSM

2019 ◽  
Vol 14 (1) ◽  
Author(s):  
Gunabal S
Keyword(s):  
Response Surface Methodology ◽  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Waste Heat ◽  
Heat Pipes ◽  
Filling Ratio ◽  
Nano Particles ◽  
Waste Heat Recovery System ◽  
Recovery System ◽  
Heat Recovery System

Waste heat recovery systems are used to recover the waste heat in all possible ways. It saves the energy and reduces the man power and materials. Heat pipes have the ability to improve the effectiveness of waste heat recovery system. The present investigation focuses to recover the heat from Heating, Ventilation, and Air Condition system (HVAC) with two different working fluids refrigerant(R410a) and nano refrigerant (R410a+Al2O3). Design of experiment was employed, to fix the number of trials. Fresh air temperature, flow rate of air, filling ratio and volume of nano particles are considered as factors. The effectiveness is considered as response. The results were analyzed using Response Surface Methodology

On the suitable superstructure thermoeconomic optimization of a waste heat recovery system for a Brazilian diesel engine power plant

2021 ◽  
Vol 234 ◽  
pp. 113947
Author(s):  
Alexandre Persuhn Morawski ◽  
Leonardo Rodrigues de Araújo ◽  
Manuel Salazar Schiaffino ◽  
Renan Cristofori de Oliveira ◽  
André Chun ◽  
...  
Keyword(s):  
Diesel Engine ◽  
Power Plant ◽  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Waste Heat ◽  
Waste Heat Recovery System ◽  
Recovery System ◽  
Heat Recovery System ◽  
Engine Power

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.

Selection of a Waste Heat Recovery System for a Marine Diesel Engine Based on Exergy Analysis

2016 ◽  
Vol 25 ◽  
pp. 36-51
Author(s):  
Salman Abdu ◽  
Song Zhou ◽  
Malachy Orji
Keyword(s):  
Diesel Engine ◽  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Waste Heat ◽  
Marine Diesel Engine ◽  
Exergetic Efficiency ◽  
Waste Heat Recovery System ◽  
Recovery System ◽  
Heat Recovery System ◽  
Marine Diesel

Highly increased fuel prices and the need for greenhouse emissions reduction from diesel engines used in marine engines in compliance with International Maritime Organization (IMO) on the strict regulations and guidelines for the Energy Efficiency Design Index (EEDI) make diesel engine exhaust gas heat recovery technologies attractive. The recovery and utilization of waste heat not only conserves fuel, but also reduces the amount of waste heat and greenhouse gases dumped to the environment .The present paper deals with the use of exergy as an efficient tool to measure the quantity and quality of energy extracted from waste heat exhaust gases in a marine diesel engine. This analysis is utilized to identify the sources of losses in useful energy within the components of the system for three different configurations of waste heat recovery system considered. The second law efficiency and the exergy destroyed of the components are investigated to show the performance of the system in order to select the most efficient waste heat recovery system. The effects of ambient temperature are also investigated in order to see how the system performance changes with the change of ambient temperature. The results of the analysis show that in all of the three different cases the boiler is the main source of exergy destruction and the site of dominant irreversibility in the whole system it accounts alone for (31-52%) of losses in the system followed by steam turbine and gas turbine each accounting for 13.5-27.5% and 5.5-15% respectively. Case 1 waste heat recovery system has the highest exergetic efficiency and case 3 has the least exergetic efficiency.

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