Search results for "Heat recovery"
showing 10 items of 35 documents
Concepts for medium-high to high temperature thermoelectric heat-to-electricity conversion: a review of selected materials and basic considerations o…
2015
Within the last decade, novel materials concepts and nanotechnology have resulted in a great increase of the conversion efficiency of thermoelectric materials. Despite this, a mass market for thermoelectric heat-to-electricity conversion is yet to be opened up. One reason for this is that the transfer of the lab records into fabrication techniques which enable thermoelectric generator modules is very challenging. By closing the gap between record lab values and modules, broad industrial applications may become feasible. In this review, we compare three classes of materials, all designed for medium-high to high temperature applications in the field of waste heat recovery: skutterudites, half…
On the Phase Separation in n-Type Thermoelectric Half-Heusler Materials
2018
Half-Heusler compounds have been in focus as potential materials for thermoelectric energy conversion in the mid-temperature range, e.g., as in automotive or industrial waste heat recovery, for more than ten years now. Because of their mechanical and thermal stability, these compounds are advantageous for common thermoelectric materials such as Bi 2 Te 3 , SiGe, clathrates or filled skutterudites. A further advantage lies in the tunability of Heusler compounds, allowing one to avoid expensive and toxic elements. Half-Heusler compounds usually exhibit a high electrical conductivity σ , resulting in high power factors. The main drawback of half-Heusler compounds is their high lattice th…
The first operating thermolytic reverse electrodialysis heat engine
2020
Abstract Thermolytic reverse electrodialysis heat engine (t-RED HE) has been recently proposed as a technology for converting low-temperature waste heat into electricity. The construction and operation of the first world lab-scale prototype unit are reported. The system consists of: (i) a reverse electrodialysis unit where, the concentration gradient between two solutions of thermolytic salts is converted into electricity and (ii) a thermally-driven regeneration unit where low-temperature heat is used to restore the initial conditions of the two feed streams. Regeneration is based on a degradation process of salts into gaseous ammonia and carbon dioxide, which can be removed almost entirely…
Methods for Enhancing the Thermal Durability of High-Temperature Thermoelectric Materials
2013
Author's version of an article in the journal: Journal of Electronic Materials. Also available from the publisher at: http://dx.doi.org/10.1007/s11664-013-2917-0 Thermoelectric materials, for example skutterudites and magnesium silicides, are being investigated as promising materials for medium-to-high-temperature waste heat recovery in transport and in industry. A crucial aspect of the success of a thermoelectric material is its stability over time when exposed to rapid heating and cooling. In this work different aspects of the degradation of these thermoelectric materials at high temperature were examined. Initial thermal durability was studied, and several candidate coatings were evaluat…
Optimization of ventilation system in the open office space
2018
The paper presents the results of study into the air parameters in open space offices. As office workers spend about 1/3 of the day in such spaces, it is important to provide them with the right climate comfort, and that is determined, most importantly, by: the temperature and humidity of the air, quality of the air, and the concentration of CO2. Two objects of study were selected - both of them open space facilities, each with a different intensity of use. In the course of study, measurements were taken on the basis of which the distributions of temperature, humidity, and concentrations of CO2 in the entire volume of the space were determined. Also the empirical coefficients of CO2 emissio…
Preliminary Thermo-Mechanical Design of the Once Through Steam Generator and Molten Salt Intermediate Heat Exchanger for EU DEMO
2020
The European DEMOnstration power plant (DEMO) is considered to be the nearest-term fusion reactor capable of producing several hundred MWs of net electricity, operating with a closed tritium fuel-cycle (achieving the tritium self-sufficiency), and qualifing technological solutions for a fusion power plant with different breeding blanket (BB) concepts that are under investigation. The BB is a key component for the development of the DEMO plant design and, in particular, of those systems having the responsibility to remove the plasma-generated thermal power and its conversion in the electrical energy. This study deals with the preliminary thermo-mechanical design of the heat exchangers and st…
Industrial waste heat: Estimation of the technically available resource in the EU per industrial sector, temperature level and country
2018
Abstract Industrial waste heat is examined in EU countries, focusing on the amount that can be recovered and exploited, referred to as technical potential of waste heat. An alternative methodology is proposed here, which is based on waste heat fractions derived from a detailed study of the UK industry from the period 2000–2003. These fractions express the part of heat consumption that is wasted and is possible to be recovered. The waste heat fractions have been calculated in this work for each main industrial sector and temperature level. The methodology initially includes the adjustment of waste heat fractions from each industrial sector from the UK industry to the conditions of the differ…
OPTIMIZATION OF COGENERATION PLANT FOR APPLICATIONS IN FOOD INDUSTRY
2013
Cogeneration systems represent an effective solution for optimizing energy performance of users with contemporary thermal and electrical energy demand. An energy audit of an industrial pasta factory equipped with a cogeneration system natural gas fuelled has carried out along last two years. This CHP plant, with a 650 kWe capacity, currently covers a relevant fraction of the electric and high-temperature heat loads during peak hours, while it is switched off during off-peak hours because of the much lower electricity price. Heat content of flue gases is recovered by two cascaded gas-diathermic oil and diathermic oil- water heat exchangers; the superheated water obtained is then supplied to …
Supertargeting-based hierarchic evaluation for setting paths in relaxation of retrofitted Heat Exchanger Networks
2010
The application of pinch analysis to the retrofit of existing heat exchanger networks is a complex task, which can be hardly standardised due to the large number of unquantifiable design considerations. Top-down and bottom-up approaches have been usually pursued, respectively oriented to relax a Maximum Energy Recovery (MER) configuration and to improve the existing network by removing network pinches. In this paper the bottom-up approach is critically examined, considering a well known case study represented by an aromatics plant; a MER design is also obtained and evaluated, to represent a target for process improvement. The final objective of researches in this sector is the identificatio…
Energy Saving Optimizing the Ventilation Control in a Big Shopping Center
2018
The paper investigates the potential energy savings in the context of big shopping centers, thanks to the introduction of innovative technologies able to control the ventilation according the real requirement for comfort and health of indoor spaces. The case study analyses a big shopping center, where the ventilation is realized with a centralized air-conditioning plant, working with fixed air flows. Two solutions are proposed to reduce the energy consumption for ventilation. The first considers the installation of heat recovery exchangers, the second the introduction of a control system able to modulate the air exchange, according to the real requirements. An energetic and economic evaluat…