Temperature-Weighted Assessment of Waste Heat Availability With Matched End-Use Applications for Optimal Primary Energy Usage in the USA

2010 ◽  
Author(s):  
Alexander S. Rattner ◽  
Srinivas Garimella
Keyword(s):  
Air Conditioning ◽  
Electricity Generation ◽  
Power Plants ◽  
Waste Heat ◽  
Residential Building ◽  
Energy Scale ◽  
Low Grade ◽  
Energy Usage ◽  
Water Heating ◽  
The Usa

Approximately two-thirds of all input energy used for power and electricity generation in the USA is lost as heat during conversion processes. Additionally, 12.5% of primary fuel and 20.3% of the electricity generated through these processes are employed for space heating, water heating, and refrigeration where low-grade heat could suffice. The potential for harnessing waste heat from power generation and thermal processes to perform these low-grade tasks is assessed here. By matching power plant outlet streams with applications at corresponding temperature ranges, this study identifies sufficient waste heat to satisfy all residential, building, and manufacturing space and water heating needs. Sufficient high temperature exhaust from power plants is identified to satisfy 27% of residential air conditioning demand with thermally activated refrigeration or all industrial low temperature (100–150°C) process heating and refrigeration needs. Exhaust from vehicle engines is sufficient to satisfy all in-vehicle air conditioning and 68% of electricity generation demand. Energy usage and waste heat availability and application information collected for this study is compiled in a thermodynamically informed database. By providing SQL queries, this database can answer detailed questions about energy sources and demands delineated by temperature, energy scale, process, and location. This capability can inform future infrastructure and development to effectively capture waste heat that would be lost today, substantially reducing the USA national energy intensity across all end uses.

scholarly journals Performance Characteristics of Solid-Desiccant Evaporative Cooling Systems

Energies ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 2574 ◽  
Author(s):  
Ramadas Narayanan ◽  
Edward Halawa ◽  
Sanjeev Jain
Keyword(s):  
Air Conditioning ◽  
Natural Ventilation ◽  
Waste Heat ◽  
Numerical Study ◽  
Evaporative Cooling ◽  
Peak Load ◽  
Dew Point ◽  
Low Grade ◽  
Subtropical Climate ◽  
Cooling Systems

Air conditioning accounts for up to 50% of energy use in buildings. Increased air-conditioning-system installations not only increase total energy consumption but also raise peak load demand. Desiccant evaporative cooling systems use low-grade thermal energy, such as solar energy and waste heat, instead of electricity to provide thermal comfort. This system can potentially lead to significant energy saving, reduction in carbon emissions, and it has a low dew-point operation and large capacity range. Their light weight, simplicity of design, and close-to-atmospheric operation make them easy to maintain. This paper evaluates the applicability of this technology to the climatic conditions of Brisbane, Queensland, Australia, specifically for the residential sector. Given the subtropical climate of Brisbane, where humidity levels are not excessively high during cooling periods, the numerical study shows that such a system can be a potential alternative to conventional compression-based air-conditioning systems. Nevertheless, the installation of such a system in Brisbane’s climate zone requires careful design, proper selection of components, and a cheap heat source for regeneration. The paper also discusses the economy-cycle options for this system in such a climate and compares its effectiveness to natural ventilation.

scholarly journals Using adsorption chillers for utilising waste heat from power plants

2019 ◽  
Vol 23 (Suppl. 4) ◽  
pp. 1143-1151 ◽  
Author(s):  
Karol Sztekler ◽  
Wojciech Kalawa ◽  
Sebastian Stefanski ◽  
Jaroslaw Krzywanski ◽  
Karolina Grabowska ◽  
...  
Keyword(s):  
Power Generation ◽  
Energy Efficiency ◽  
Power Plant ◽  
Power Plants ◽  
Waste Heat ◽  
Primary Energy ◽  
Simulation Software ◽  
Coefficient Of Performance ◽  
Low Grade ◽  
Adsorption Chiller

At present, energy efficiency is a very important issue and it is power generation facilities, among others, that have to confront this challenge. The simultaneous production of electricity, heat and cooling, the so-called trigeneration, allows for substantial savings in the chemical energy of fuels. More efficient use of the primary energy contained in fuels translates into tangible earnings for power plants while reductions in the amounts of fuel burned, and of non-renewable resources in particular, certainly have a favorable impact on the natural environment. The main aim of the paper was to investigate the contribution of the use of adsorption chillers to improve the energy efficiency of a conventional power plant through the utilization of combined heat and power waste heat, involving the use of adsorption chillers. An adsorption chiller is an item of industrial equipment that is driven by low grade heat and intended to produce chilled water and desalinated water. Nowadays, adsorption chillers exhibit a low coefficient of performance. This type of plant is designed to increase the efficiency of the primary energy use. This objective as well as the conservation of non-renewable energy resources is becoming an increasingly important aspect of the operation of power generation facilities. As part of their project, the authors have modelled the cycle of a conventional heat power plant integrated with an adsorption chiller-based plant. Multi-variant simulation calculations were performed using IPSEpro simulation software.

scholarly journals Addressing Industrial Waste Heat Supply Variability With Organic Rankine Cycle Systems Incorporating Thermal Energy Storage

2021 ◽  
Author(s):  
Bipul Krishna Saha ◽  
Basab Chakraborty ◽  
Rohan Dutta
Keyword(s):  
Power Generation ◽  
Energy Storage ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Power Plants ◽  
Waste Heat ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Working Fluid ◽  
Low Grade

Abstract Industrial low-grade waste heat is lost, wasted and deposited in the atmosphere and is not put to any practical use. Different technologies are available to enable waste heat recovery, which can enhance system energy efficiency and reduce total energy consumption. Power plants are energy-intensive plants with low-grade waste heat. In the case of such plants, recovery of low-grade waste heat is gaining considerable interest. However, in such plants, power generation often varies based on market demand. Such variations may adversely influence any recovery system's performance and the economy, including the Organic Rankine Cycle (ORC). ORC technologies coupled with Cryogenic Energy Storage (CES) may be used for power generation by utilizing the waste heat from such power plants. The heat of compression in a CES may be stored in thermal energy storage systems and utilized in ORC or Regenerative ORC (RORC) for power generation during the system's discharge cycle. This may compensate for the variation of the waste heat from the power plant, and thereby, the ORC system may always work under-designed capacity. This paper presents the thermo-economic analysis of such an ORC system. In the analysis, a steady-state simulation of the ORC system has been developed in a commercial process simulator after validating the results with experimental data for a typical coke-oven plant. Forty-nine different working fluids were evaluated for power generation parameters, first law efficiencies, purchase equipment cost, and fixed investment payback period to identify the best working fluid.

A Study on the Combined Driven Refrigeration Cycle Using Ejector

2021 ◽  
pp. 2150004
Author(s):  
Waseem Raza ◽  
Gwang Soo Ko ◽  
Youn Cheol Park
Keyword(s):  
Air Conditioning ◽  
Waste Heat ◽  
Primary Source ◽  
Mechanical Efficiency ◽  
Coefficient Of Performance ◽  
Cycle Performance ◽  
Working Fluid ◽  
Low Grade ◽  
Refrigeration Cycle ◽  
R 134A

The rising need for thermal comfort has resulted in a rapid increase in refrigeration systems’ usage and, subsequently, the need for electricity for air-conditioning systems. The ejector system can be driven by a free or affordable low-temperature heat source such as waste heat as the primary source of energy instead of electricity. Heat-driven ejector refrigeration systems become a promising solution for reducing energy consumption to conventional compressor-based refrigeration technologies. An air-conditioning system that uses the ejector achieves better performance in terms of energy-saving. This paper presents a study on the combined driven refrigeration cycle based on ejectors to maximize cycle performance. The experimental setup is designed to determine the coefficient of performance (COP) with ejector nozzle sizes 1.8, 3.6, and 5.4[Formula: see text]mm, respectively. In this system, the R-134a refrigerant is considered as a working fluid. The results depict that the efficiency is higher than that of the conventional refrigeration method due to comparing the performance of the conventional refrigeration cycle and the combined driven refrigeration cycle. The modified cycle efficiency is better than the vapor compression cycle below 0∘C, which implies sustainability at low temperatures by using low-grade thermal energy. For the improvement of mechanical efficiency, proposed cycle can be easily used.

scholarly journals Low-grade waste heat driven desalination technology

2014 ◽  
Vol 5 ◽  
pp. A02 ◽  
Author(s):  
Alexander Christ ◽  
Xiaolin Wang ◽  
Klaus Regenauer-Lieb ◽  
Hui Tong Chua
Keyword(s):  
Carbon Dioxide ◽  
Power Plants ◽  
Waste Heat ◽  
Carbon Dioxide Emission ◽  
Expected Improvement ◽  
Low Grade ◽  
Low Emission ◽  
Process Plants ◽  
Desalination Technology ◽  
Low Grade Heat

Low-grade heat driven multi-effect distillation (MED) desalination is a very promising environmentally friendly, low emission technology. Many countries, such as Australia, are water short and conventional desalination technology is energy intensive. If a primary fossil fuel source is used, then desalination will significantly contribute to carbon dioxide emission. Low-grade waste heat from process plants and power plants generate minimal additional carbon dioxide. This source of energy is typically abundant at a temperature around 65–90 °C, which dovetails with MED technology. In this paper, we report on a new MED technology that couples perfectly with low grade waste heat to give at least a 25% freshwater yield improvement compared with conventional MED design. Typical applications and their expected improvement will also be reported.

Performance Evaluation of Multi-Stage Shell and Tube Transport Membrane Condenser Heat Exchangers for Low Grade Waste Heat and Water Recovery

2017 ◽  
Author(s):  
Soheil Soleimanikutanaei ◽  
Cheng-Xian Lin ◽  
Dexin Wang
Keyword(s):  
Water Vapor ◽  
Heat Exchanger ◽  
Heat Exchangers ◽  
Power Plants ◽  
Ceramic Membrane ◽  
Waste Heat ◽  
Low Grade ◽  
Water Recovery ◽  
Multi Stage ◽  
Shell And Tube

In this work for the first time the performance of multi-stage shell and tube Transport Membrane Condenser (TMC) based heat exchangers are evaluated numerically. The present heat exchanger is design to work under high pressure and temperature condition for both heat and water recovery in Oxy-Combustion processes. TMC heat exchangers use the nano-porous and ceramic membrane technology to extract the water vapor and latent heat of condensation from the flue-gas. The most important application of TMC heat exchangers is in the power plants which the water vapor in the presence of other non-condensable gases (i.e. CO2, O2 and N2) exist. Effect of the different arrangement of the multi-stage shell and tube TMC heat exchangers, number of branches and number of heat exchangers in each branch on the heat transfer and water recovery have been studied numerically. A single phase multi-component model is used to assess the capability of single stage TMC heat exchangers in terms of waste heat and water recovery at various inlet conditions. Numerical simulation has been performed using ANSYS-FLUENT software and the condensation rate model has been implemented applying User Define Function. Finally, an optimum configuration for the TMC heat exchanger unit has been proposed and the results of numerical simulations are depicted in terms of temperature and water vapor mass fraction contours.

Numerical Simulation of Low Grade Heat and Water Recovery Using Nanoporous Transport Membrane Condensers Bundle Tubes

2015 ◽  
Author(s):  
Soheil Soleimanikutanaei ◽  
Cheng-Xian Lin ◽  
Dexin Wang
Keyword(s):  
Heat Exchanger ◽  
Flue Gas ◽  
Power Plants ◽  
Ceramic Membrane ◽  
Transport Model ◽  
Waste Heat ◽  
Numerical Study ◽  
Tube Bundle ◽  
Low Grade ◽  
Water Recovery

Low grade waste heat and water recovery using ceramic membrane, is an emerging technology which helps to increase the efficiency of boilers and gas or coal combustors in various industrial processes and conventional power plants. The tube wall of a Transport Membrane Condenser (TMC) based heat exchanger is made of a nano-porous material with high membrane selectivity which is able to extract condensate water from the flue gas in the presence of other non-condensable gases (i.e. CO2, O2 and N2). In this work, a numerical study has been carried out to investigate the effects of transversal pitches of the TMC bundle tubes on the performance of a TMC based cross flow heat exchanger. A simplified multi-species transport model is used to investigate the heat and mass transfer characteristics of a condensing combustion flue gas in a crossflow transport membrane tube bundle. Various transversal (0.4”–0.6”) and longitudinal (0.4”–0.8”) pitches were used. The numerical results revealed that the effect of transversal pitches on the outlet parameters are more pronounced.

An Innovative Gas Turbine Cycle With Methanol Fuelled Chemical-Looping Combustion

2008 ◽  
Author(s):  
Hongguang Jin ◽  
Xiaosong Zhang ◽  
Hui Hong ◽  
Wei Han
Keyword(s):  
Gas Turbine ◽  
Power Plants ◽  
Exergy Analysis ◽  
Waste Heat ◽  
Chemical Looping Combustion ◽  
Low Grade ◽  
Chemical Looping ◽  
Percentage Points ◽  
Effective Use ◽  
Gas Turbine Cycle

In this paper, a novel gas turbine cycle integrating methanol decomposition and the chemical-looping combustion (CLC) is proposed. The system study on two methanol-fuelled power plants, the new gas turbine cycle with CLC combustion, and a chemically intercooled gas turbine cycle, has been investigated with the aid of the exergy analysis (EUD methodology). In the proposed system, methanol fuel is decomposed into syngas mainly containing H2 and CO by recovering low-temperature thermal energy from an intercooler of the air compressor. After the decomposition of methanol, the resulting product of syngas is divided into two parts: the most part reacting with Fe2O3, is sent into the CLC subsystem, and the other part is introduced into a supplement combustor to enhance the inlet temperatures of turbine to 1100–1500°C. As a result, the new methanol-fuelled gas turbine cycle with CLC had a breakthrough in performance, with at least about 10.7 percentage points higher efficiency compared to the chemically intercooled gas turbine cycle with recovery of CO2 and is environmentally superior due to the recovery of CO2. This new system can achieve 60.6% net thermal efficiency with CO2 separation. The promising results obtained here indicated that this novel gas turbine cycle with methanol-fuelled chemical looping combustion could provide a promising approach of both effective use of alternative fuel and recovering low-grade waste heat, and offer a technical probability for CLC in applying into the advanced gas turbine with high temperatures above 1300°C.

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