scholarly journals Condenser-Type Heat Exchanger for Compost Heat Recovery Systems

Energies ◽  
2019 ◽  
Vol 12 (8) ◽  
pp. 1583 ◽  
Author(s):  
Jaroslav Bajko ◽  
Jan Fišer ◽  
Miroslav Jícha
Keyword(s):  
Heat Exchanger ◽  
Water Vapour ◽  
Heat Recovery ◽  
Pilot Scale ◽  
Latent Form ◽  
Recovery System ◽  
Heat Recovery System ◽  
Heat Released

The majority of heat released during composting is contained in latent form of water vapour. To improve the rate of heat recovery, a simple heat exchanger based on condensation of compost vapours was designed. A prototype of this condenser-type heat exchanger was built and tested as a part of pilot-scale compost heat recovery system. Passively aerated static pile (modified Jean Pain mound) with enhanced aeration using vertical channels was chosen for this composting experiment. Insulation of the compost mound and adjacent hoop house further improved the efficiency of the heat recovery and utilization.

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.

scholarly journals Effects of the exhaust gas heat recovery system with a plate heat exchanger on the warm-up performance characteristics of the gasoline engine

2018 ◽  
Vol 7 (2.12) ◽  
pp. 136
Author(s):  
Chan JungKim ◽  
Sank Wook-Han ◽  
Ki Hyun Kim ◽  
Moo Yeon Lee ◽  
Gee Soo Lee
Keyword(s):  
Heat Exchanger ◽  
Fuel Economy ◽  
Heat Recovery ◽  
Exhaust System ◽  
Plate Heat Exchanger ◽  
Exhaust Gas ◽  
Warm Up ◽  
Plate Heat ◽  
Recovery System ◽  
Heat Recovery System

Background/Objectives: To meet the regulations for the fuel economy, an EHRS (Exhaust gas Heat Recovery System, which was installed within the vehicle exhaust system and recovered the heat from the exhaust gas, were needed. The EHRS enabled the engine to achieve the fast warm-up performance for reducing friction loss during the cold start.The objective of this paper was to investigate the effects of the design parameters of the EHRS with a plate heat exchanger on the warm-up performance of a gasoline engine.Methods/Statistical analysis: The EHRS with the plate heat exchanger was manufactured and installed behind the catalyst in the exhaust system of the gasoline direct injection engine. The experimental study and multi-disciplinary analysis were carried out to investigate the effects of the EHRS on the warm-up performance of the engine, such as the coolant temperature, the exhaust gas temperature and the recovery heat at idle condition and the step-load condition.Findings: Because the recovery of heat was about 1. 7 kW at idle condition, the effect of the EHRS on the warm-up performance was negligible. However, due to 17.2 kW of the recovery of heat at the stepload condition of T=140 Nm at N=2,400 rpm, the EHRS enabled to shorten the warm-up time by 548 s comparison that of the base engine.Improvements/Applications: The fuel economy will be expected to be improved through an EHRS, which provides the improved combustion in the warm-up phase and a decrease in friction loss.  

Effect of the Heat Recovery System to the Performance of Air Handling Unit of a Shopping Centre

2012 ◽  
Author(s):  
Furkan Kelasovali ◽  
Ali Celen ◽  
Nurullah Kayaci ◽  
Ahmet Selim Dalkilic ◽  
Somchai Wongwises
Keyword(s):  
Heat Exchanger ◽  
Energy Saving ◽  
Heat Recovery ◽  
Cooling Capacity ◽  
Capital City ◽  
Shopping Centre ◽  
Air Handling Unit ◽  
Battery Power ◽  
Recovery System ◽  
Heat Recovery System

In today’s world, the efficient use of energy is very important due to short of energy sources. In order to use energy efficiently, some methods/devices have been developed recently. One of them is heat recovery systems which are used for energy saving in the Heating Ventilating and Air Conditioning applications. Air handling units (AHUs) equipped with heat recovery system can be used applications for energy saving. Not only this paper presents information about rotary heat exchangers which is one of the air to air heat recovery systems but also it investigates their effects to system when they are used in an application. In the study, a shopping centre, which is located in the capital city of Turkey, is taken consideration. The shopping centre has an air handling unit having 54567 m3/h fresh air flow rate, 640 kW heating and 41 kW cooling capacity. Calculations are performed for AHU of the shopping centre both equipped with rotary heat exchanger and without rotary heat exchanger. In order to compare performance of AHUs, annual energy saving, initial investment cost, annual operating expenses, payback time and profit parameters are calculated for each month. According to the results, heating battery power in the heating season and cooling battery power in the cooling season is significantly decreased by using heat recovery system and total annual energy saving is calculated as $83,444. Consequently, it is found that the use of rotary heat exchanger improves performance of system in terms of the reduction in required powers and costs.

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.

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.

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.

Modeling and Simulation of an Inverted Brayton Cycle as an Exhaust-Gas Heat-Recovery System

2017 ◽  
Vol 139 (8) ◽  
Author(s):  
Zhihang Chen ◽  
Colin Copeland ◽  
Bob Ceen ◽  
Simon Jones ◽  
Alan Agurto Goya
Keyword(s):  
Heat Exchanger ◽  
Internal Combustion Engine ◽  
Thermodynamic Model ◽  
Heat Recovery ◽  
Test Bench ◽  
Combustion Engine ◽  
Brayton Cycle ◽  
Exhaust Gas ◽  
Recovery System ◽  
Heat Recovery System

The exhaust gas from an internal combustion engine contains approximately 30% of the thermal energy of combustion. The exhaust-gas heat-recovery systems aim to reclaim a proportion of this energy in a bottoming thermodynamic cycle to raise the overall system thermal efficiency. The inverted Brayton cycle (IBC) considered as a potential exhaust-gas heat-recovery system is a little-studied approach, especially when applied to small automotive power-plants. Hence, a model of the inverted Brayton cycle using finite-time thermodynamics (FTT) is presented to study heat recovery applied to a highly downsizing automotive internal combustion engine. IBC system consists of a turbine, a heat exchanger (HE), and compressors in sequence. The use of IBC turbine is to fully expand the exhaust gas available from the upper cycle. The remaining heat in the exhaust after expansion is rejected by the downstream heat exchanger. Then, the cooled exhaust gases are compressed back up to the ambient pressure by one or more compressors. In this paper, the exhaust conditions available from the engine test bench data were introduced as the inlet conditions of the IBC thermodynamic model to quantify the power recovered by IBC, thereby revealing the benefits of IBC to this particular engine. It should be noted that the test bench data of the baseline engine were collected by the worldwide harmonized light vehicles test procedures (WLTP). WLTP define a global harmonized standard for determining the levels of pollutants and CO2 emissions, fuel consumption. The IBC thermodynamic model was simulated with the following variables: IBC inlet pressure, turbine pressure ratio, heat exchanger effectiveness, turbomachinery efficiencies, and the IBC compression stage. The aim of this paper is to analysis the performance of IBC system when it is applied to a light-duty automotive engine operating in a real-world driving cycle.

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