Waste Heat Potential Research Articles

Methodologies to estimate industrial waste heat potential by transferring key figures: A case study for Spain

In the current European energy context, the use of recovered industrial waste heat provides an attractive opportunity to substitute primary energy consumption by a low-emission and low-cost energy carrier. In the case of industrial waste heat, this potential is currently not only largely untapped, but also unaccounted for. In order to achieve a widespread use of recovered industrial waste heat, assessments with a large scope and high spatial resolution are needed. Three methods published in the period 2002–2010 have been found in the literature, which are potentially transferable to other regions. These three methods are based on either the energy consumption of each manufacturing sector or the individual site CO2 emissions. The scope of this analysis is, first, to investigate in how far a transfer of the figures to different countries or regions is sensible in comparison to former studies in the literature. In the process, some uncertainties when transferring methods were identified (different definitions of industry, different standard industrial activities classifications or no standard at all, etc.). The second goal is, once the methodology is accepted, to apply it to a case study, in this case the industrial sector in Spain and two of its counties (Catalonia and the Basque Country) for the years 2001, 2009, 2010 and 2013. In this period, and based on the different approaches employed, the Spanish annual industrial waste heat potential ranges from 54.3 to 151.1 PJ, Catalonia from 8.6 to 29.7 PJ, and from 7.2 to 11.9 PJ for the Basque Country. The methods are considered highly transferable but uncertainties inevitably arise in the case that the source and destination industrial sectors are very different.

Unlocking Waste Heat Potentials in Manufacturing

Industry releases vast amounts of heat energy as dissipative waste heat to the atmosphere. It is therefore necessary to acquire a better understanding of the waste heat potentials in manufacturing. The paper presents an integrated approach for identifying and quantifying waste heat potentials of different production processes. The identification is based on an estimation procedure followed by a simulative assessment of production processes to quantify and allocate waste heat over time. The approach further elaborates on a potential source and demand matching of heat streams. A case study from the automotive industry demonstrates the applicability of the approach.

The Potential and Approach of Flue Gas Waste Heat Utilization of Natural Gas for Space Heating

After the combustion of natural gas, the flue gas contains large amounts of water vapor. The latent heat of the water vapor in the flue gas account for 10%-11% of the lower heating value of natural gas, that is, if the condensing heat of the flue gas were recovered, the energy efficiency could be improved greatly. In order to improve the efficiency of the space heating system by natural gas, the potential of waste heat of the flue gas were analyzed, and the problems of the conventional space heating system were proposed. A new approach was proposed, which could decrease the temperature of the flue gas, and recover the waste heat of the flue gas simultaneously. The flue gas outlet temperature could be reduced to below 25°C. The different processes were proposed for gas boiler, distributed energy system, and natural gas cogeneration systems. The energy saving analysis and economic evaluation were investigated. A remarkable economic advantage can be achieved in this technology. The payback year is within 4 years. It provides the important reference for reasonable application of the technique.

Capturing the invisible resource: Analysis of waste heat potential in Chinese industry

Waste heat recovery and utilization represents a missed opportunity to reduce China’s total energy use, decrease carbon dioxide emissions, and improve air quality. Currently, China does not have a standardized or transparent methodology to quantify the waste heat potential in the industrial sector, which accounts for more than two thirds of China’s primary energy consumption. This paper presents the results of thermal energy modeling to quantify the technical maximum waste heat potential in three energy-intensive industrial sectors: cement, iron and steel, and glass. In addition, this paper identifies the practical potential for producing electricity from waste heat in these sectors. The analysis finds that the glass sector has the highest waste heat to power generation potential per unit of production basis among the studied sectors. This paper provides key principles for managing waste heat in the industrial sector and key sector characteristics for implementing waste heat to power generation technologies.

Industrial waste heat recovery technologies: An economic analysis of heat transformation technologies

Abstract In this paper, the potential of industrial waste heat for heating and cooling applications is investigated. Therefore, heat transformation technologies are presented and their technical and economic potential are discussed. First, different industrial processes and their operating temperatures are presented as possible waste heat sources as well as low temperature processes, which can be supplied with waste heat. Then, a general economic analysis is performed for three different cases of waste heat use: an absorption chiller producing cold and heat production with a compression and an absorption heat pump. The maximum acceptable investment cost for each technology is estimated and compared with the current investment cost depending on the operating hours of the system. For this, three different consumer types, Enthusiast, Real Estate and Industry, are defined to represent different expectations in interest rate, payback period and the resulting annuity factor. Instead of judging if a technology is profitable or not, it is calculated how much the system is allowed to cost in order to be competitive for certain operating hours. Combined with present day cost of the technology, this serves as a rough judgment of the market deployment process. Finally, a sensitivity analysis of the initial assumptions for the economic analysis is performed, revealing a strong influence of the annuity factor. For the present day technology cost, absorption chillers were found to be profitable for two of the three consumer types when operated for at least 2500 h per year. Electric heat pumps are profitable for all consumer types when exceeding 4000 operating hours per year while absorption heat pumps start at 3000 h of operation per year to be profitable for all consumer types.

Investigation of the potential for heat recovery at low, medium, and high stages in the Turkish industrial sector (TIS): An application

In this study, the potential for waste heat recovery is examined based on real data from 1990 to 2011 (a 21-year period) for processes at low-, medium- and high-temperature levels. The first part of this study included a theoretical analysis for determining the potential for heat recovery at these temperature stages. Second part stated an application in the industrial sector. This study is conducted using actual data for this sector from 1990 to 2011. The total available energy recovery from waste heat recovery appliances for products, flue gas and wall heat recovery was calculated to be 224–503 PJ over the years studied. The available waste heat potential from the total energy in this sector is determined to be 36 to 40% for these years. The technical potential is estimated to be 55 to 65% of these values. The total technical-potential waste energy recovery in the low, medium, and high temperature stages using waste heat recovery appliances for products, flue gas and wall heat recovery was estimated to be from 224 PJ to 503 PJ over the years studied. Usage of technology device according to efficiencies for the sector was estimated to be 22.40 PJ/year to 67.45 PJ/year.

Method of the determination of the rational characteristics of the thermotransformer for cooling the air at the inlet regenerative GTU

The method of the determination of the rational performance characteristics of the thermotransformer for cooling the air at the inlet of regenerative gas turbine unit (GTU) with heating the compressed air before combustion chamber by turbine exhaust gases has been suggested. The method enables calculating the rational installed refrigeration capacity and temperature regimes, providing maximal fuel saving in conditions of limited heat potential of the exhaust gas waste heat. The main characteristics of the method are shown for the waste heat-recovery ejector cooling machine utilizing the waste heat of GTU as an example of thermotransformer. The results of calculation of some performance characteristics of the ejector cooling machine (specific refrigeration capacity and specific waste heat rate of the exhaust gas, coefficient of performance, gas turbine inlet air temperature drop during cooling), which allow selecting the boiling temperature of refrigerant in the high pressure refrigerant vapour generator of the ejector cooling machine for the given boiling temperature of refrigerant in the gas turbine inlet air cooler are represented.

Upgrading waste heat from a cement plant for thermochemical hydrogen production

A calcium oxide/steam chemical heat pump (CHP) is presented in the study as a means to upgrade waste heat from industrial processes for thermochemical hydrogen production. The CHP is used to upgrade waste heat for the decomposition of copper oxychloride (CuO.CuCl2) in a copper–chlorine (Cu–Cl) thermochemical cycle. A formulation is presented for high temperature steam electrolysis and thermochemical splitting of water using waste heat of a cement plant. Numerical models are presented for verifying the availability of energy for potential waste heat upgrading in cement plants. The optimal hydration and decomposition temperatures for the calcium oxide/steam reversible reaction of 485 K and 565 K respectively are obtained for the combined heat pump and thermochemical cycle. The coefficient of performance and overall efficiency of 4.6 and 47.8% respectively are presented and discussed for the CHP and hydrogen production from the cement plant.

Numerical Simulation Research on the Heating Process of Air by Waste Heat

Flue gas of boiler is a kind of great potential waste heat resource. Relatively high temperature of exhaust has caused a vast waste of energy and serious environmental thermal pollutions. To make a full and reasonable use of the heat resource, a simplified single-tube heat exchanger is introduced in this paper. Dry air and wet air with different temperatures transfer heat with flue gas in the same model. And the results show that heat near the inner wall exchanges more violently than any other space in the heater. For dry air, the higher temperature of the air enters into the heater, the lower heat transfer effect of the heater. Heat exchange effect of the wet air with 0.03 mole fraction of water is more higher than that of dry air in this model.

Waste heat recovery in CO2 compression

Carbon capture and storage (CCS) is a strategically important approach for achieving significant reductions in greenhouse gas emissions from large stationary emission sources, and ensures the availability of a reliable global energy supply for the future. Carbon dioxide (CO2) compression accounts for a significant amount of the capital and operating costs, and energy penalties associated with the CCS system. In this paper, different CO2 compression strategies were reviewed, and the opportunities of recovering waste heat as an effort to reduce their energy consumption were examined. Models of an intercooling compression chain and a 2-stage shockwave compression chain were built to investigate their respective energy consumption and potential waste heat recovery. An organic Rankine cycle (ORC) model was employed to recover waste heat. An exergy analysis was applied to assess the performance of the system. The results indicated that, without waste heat recovery, the shockwave compression chain had a higher specific energy requirement than the intercooling option. With waste heat recovery, the compression energy requirement in both cases dropped as expected, and the shockwave option required a lower specific compression energy with respect to the intercooling option. Within the ORC system, thermal efficiency, exergy efficiency, and exergy destruction rates decreased as turbine inlet temperature (TIT) increased. The ORC's evaporator was found to be the largest contributor to exergy destruction. These results demonstrate opportunities to optimize the CCS configuration and improve the overall economics of the plant.

Methods to estimate the industrial waste heat potential of regions – A categorization and literature review

Abstract To investigate heat demand, one can usually base the estimation on sales data for the energy carriers or even use the data directly. This works for companies, regions, towns and sectors (e.g., industry or domestic sector). But for the waste heat produced by the industry it is not that simple: waste heat is an output value, which neither costs nor earns any money and it is therefore seldom measured or reported. In this paper, different methods to estimate the excess heat of industrial production within a region are categorized and compared. Besides the obviously necessary distinction between theoretical, technical and economic potential, the authors suggest categorization of the methods in three dimensions: study scale, data collection and approach/perspective (bottom up vs. top down). Following this schematic, previous regional waste heat studies are reviewed. Studies focusing on single sectors or companies are not considered in this review, as well as studies estimating the heat demand. As a result it can be seen that the available data are the driving force in the choice for the used estimation method. For general factors, the resulting waste heat potential ranges between 5 and 30% of the energy demand of the industrial sector of a region. Once derived, key figures are often reused in other studies for other countries. Therefore, more data and a thorough meta study of the available figures are desirable.

Using industrial and commercial waste heat for residential heat supply: A case study from Hamburg, Germany

Abstract Residential heat accounts for a large share of final energy consumption in European countries. Hence it offers a large CO2 savings potential: either through reducing heat demand by energy-efficiency retrofitting of buildings or by substituting CO2 intensive heating fuels. Industrial and commercial waste heat could be one such substitute. Using it for residential heating purposes could postpone or even avoid the costly energy-efficiency refurbishing of the building stock. Urban areas differ in their potential for using waste heat in residential space and water heating, depending not only on supply and demand of heat in the aggregate, but also on the makeup of the building stock, waste heat temperature levels and their spatial distribution. Case studies of real-world neighborhoods will help us understand these relationships. The work presented here offers such a case study for Lokstedt, a rather typical neighborhood in the North German city of Hamburg. Residential heat demand in Lokstedt was estimated based on building age, floor space and volume. The potential of industrial and commercial waste heat supply was estimated with data collection from companies in the neighborhood, combined with waste heat characteristics for different sectors taken from literature. We estimated a heat demand of 12.8 GWh/a for the area and a waste heat potential of 0.47–0.93 GWh/a. The available waste heat could, in theory cover about 5% of residential heat demand, accounting for the heat demand that could be saved within 8 years of refurbishing the building stock at the current rate.

Defining “Waste Heat” for industrial processes

This paper aims at presenting a method for identifying, characterising and quantifying the available waste heat of an industrial system that can be converted into a useful form. A distinction is made between avoidable and unavoidable waste heat. This distinction is especially important when it comes to deciding on an investment for the integration of a waste heat valorisation process. In the proposed methodology, process integration techniques and exergy analysis are used to measure the useful potential of waste heat. It results in a definition of waste heat as a resource and a reserve in analogy to the definitions of natural resources and reserves.

PENGEMBANGAN PIRANTI HIBRID TERMOELEKTRIK – SEL SURYA SEBAGAI PEMBANGKIT LISTRIK RUMAH TANGGA

The potential of waste heat from the sun is still not optimally utilized. Tool-based energy harvester optimized solar cells that are stored on the photons of light energy from the sun. This research aims to design and develop prototypes of alternative power scale household exploit the potential of photons (solar cells) and heat (thermoelectric cells) of solar radiation. The design process through standard mechanical design principles followed by the fabrication and assembly of prototypes. The solar panels are fitted with a solar tracker with sun position tracking strategy where data is entered into the position of the sun as a reference microcontroller motion solar cells. Tues thermoelectric apart from solar panels installed as the cold side equipped with air-water cooling. Testing the performance of solar cells and thermoelectric done separately for ease of measurement defined variables such as current, voltage and temperature. The equipment used for the measurement of variables - variables include multimeter, thermo-reader and pyranometer. The experimental results of solar panels on July 10, 2012 shows average power output - average of 25.75 W 10% higher than the panel passive (static). Testing TEC1-12 710 individual cells has been done to study the early determination of the number of cells that will be used on the TE module. By using 32 cells in series strung TE module has been tested in the field but has not shown the expected results.

Defining the potential of usable waste heat in industrial processes with the help of pinch and exergy analysis

This paper aims at giving a definition for waste heat in analogy to the definitions of natural resources and reserves. It aims also at presenting a method for identifying, characterizing and quantifying the available waste heat of an industrial system that can be converted into a useful form. A distinction is made between avoidable and unavoidable waste heat. In order to measure the entire useful potential of waste heat, exergy is used for characterization

Potential of waste heat in Croatian industrial sector

Waste heat recovery in Croatian industry is of the highest significance regarding the national efforts towards energy efficiency improvements and climate protection. By recuperation of heat which would otherwise be wasted, the quantity of fossil fuels used for production of useful energy could be lowered thereby reducing the fuel costs and increasing the competitiveness of examined Croatian industries. Another effect of increased energy efficiency of industrial processes and plants is reduction of greenhouse gases i.e. the second important national goal required by the European Union (EU) and United Nations Framework Convention on Climate Change (UNFCCC). Paper investigates and analyses the waste heat potential in Croatian industrial sector. Firstly, relevant industrial sectors with significant amount of waste heat are determined. Furthermore, significant companies in these sectors are selected with respect to main process characteristics, operation mode and estimated waste heat potential. Data collection of waste heat parameters (temperature, mass flow and composition) is conducted. Current technologies used for waste heat utilization from different waste heat sources are pointed out. Considered facilities are compared with regard to amount of flue gas heat. Mechanisms for more efficient and more economic utilization of waste heat are proposed.

A223 複数の熱源を用いたカリーナサイクルの高効率化に関する研究(OS2 再生可能エネルギー)

Kalina cycle is a power generation system for waste heat source of low temperature. This cycle is mainly used to a single heat source. By the way, there are extremely large potential of waste heat having different temperature region simultaneously. Therefore, this research examined the system which can use two or more heat sources effectively by a single system. Three different systems for two waste heat sources were proposed. Their three system were evaluated for waste water(70℃) and exhaust gas(300℃) as hot heat source. As the result, the power output of system which warming the separator latter part of a cycle directly by an exhaust gas was increased about 40 percent than one of conventional system.

Waste heat potentials in the drying section of the paper machine in Umka Cardboard Mill

Paper production is one of the most energy intensive industrial processes. The use of waste heat is very important for energy efficiency improvement in paper industry. This paper deals with methods for calculation of potentials of waste heat generated in paper/board production process. For that purpose, the material and heat balance of the cardboard machine at Umka Cardboard Mill has been determined. Field measurements were conducted in order to define the unknown values of process parameters used for calculation in the balance equations and modelling. The focus was given to the cardboard drying section, which consumes most of the energy supplied to the machine. Additional aim of the work presented in the paper was to evaluate the specific energy consumption and the thermal efficiency of all individual energy units within the machine?s drying section. The results indicate two main sources of waste heat: waste heat released to the atmosphere with the discharge air from the present waste heat recovery system (14,380 kW); and waste heat released into the hall from the machine and extracted by the hall ventilation system (4,430 kW). Waste heat from both sources is characterized by fairly low temperatures 58-75?? and fairly high moisture content (30-40 g/kg). The waste heat can be partly utilized for preheating the fresh air in cardboard drying process, saving up to 13% of steam consumption. The specific heat consumption and specific steam consumption (consumption per tonne of produced cardboard) of the machine was 1,490 kWh/t and 1.4 t/t, respectively. The thermal efficiency of drying section and coating drying section was 55.6% and 33.6%, respectively. All these figures imply necessity for further waste heat utilization with the aim of improving the efficiency of energy use.

Thermodynamic analysis of an existing coal-fired power plant for district heating/cooling application

In a conventional coal-fired power plant, which is only designed for electricity generation, 2/3 of fuel energy is wasted through stack gases and cooling water of condensers. This waste energy could be recovered by trigeneration; modifying the plants in order to meet district heating/cooling demand of their locations. In this paper, thermodynamical analysis of trigeneration conversion of a public coal-fired power plant, which is designed only for electricity generation, has been carried out. Waste heat potentials and other heat extraction capabilities have been evaluated. Best effective steam extraction point for district heating/cooling system; have been identified by conducting energetic and exergetic performance analyses. Analyses results revealed that the low-pressure turbine inlet stage is the most convenient point for steam extraction for the plant analyzed.

The turbosteamer: A system introducing the principle of cogeneration in automotive applications

BMW’s turbosteamer is the first system to use the potential of waste heat in order to enhance the efficiency of the combustion process in the automobile. Applying the principle of cogeneration, fuel consumption can be reduced in a four-cylinder spark ignition engine by more than 10 per cent or, conversely, power and performance may be increased accordingly under relevant stationary operating conditions.