Search results for "Heat recovery"

Assessment of a pilot system for seawater desalination based on vacuum multi-effect membrane distillation with enhanced heat recovery

2018

Abstract This work presents the evaluation of an innovative system based on vacuum multi-effect membrane distillation modules (V-MEMD) for seawater desalination at pilot scale. This four-effect unit introduces a remarkable modification from previous V-MEMD systems, consisting of the use of the seawater feed flow as cooling in the condenser, rather than a separate circuit. Preheating the feed in the condenser improved heat efficiency (maximum gained output ratio obtained for seawater was 3.2). Maximum distillate fluxes reached 8.5 l h−1 m−2 for hot feed temperature 75 °C and feed flow rate 150 l h−1. Increasing both parameters to raise the productivity was hindered by the inability of the co…

Badania skuteczności wentylacji pomieszczeń sypialni w wielorodzinnych budynkach mieszkalnych

2017

Skuteczność systemów wentylacji budynków mieszkalnych kontrolowana jest jedynie poprzez pomiar prędkości strumienia powietrza w kanale wentylacyjnym, co nie gwarantuje odpowiedniej kontroli jakości powietrza. W pracy przedstawiono wyniki badań skuteczności wentylacji naturalnej wielorodzinnych budynków mieszkalnych, stanowiącej najczęściej spotykane rozwiązanie w budynkach mieszkalnych w Polsce. Szczególną uwagę zwrócono na wentylację pomieszczenia sypialni, jako pomieszczenia, w którym spędza się około 1/3 czasu w ciągu dnia. Badano wpływ skuteczności systemu wentylacji na podstawowe parametry charakteryzujące jakość powietrza, tj. stężenie ditlenku węgla, wilgotność względną oraz temperat…

Resource, environmental and economic considerations in the development of a Reverse Electrodialysis Heat Engine

The RED Heat Engine operates as a closed-loop RED system, where limited amounts of artificial saline solutions are used as working fluids. The solutions exiting from the RED unit are regenerated by means of a separation step, which uses low-temperature heat as its energy source. Essentially the system converts low-grade heat to electricity. There are two main alternative regeneration strategies: (i) extract solvent from the high salinity solution and move it to the low salinity solution or (ii) extract salt from the low salinity solution and move it to the high salinity solution. In this thesis are considered the Multi-effect distillation (MED) and the Membrane Distillation (MD) under the s…

Bilevel heat exchanger network synthesis with an interactive multi-objective optimization method

2012

Abstract Heat exchanger network synthesis (HENS) has been an active research area for more than 40 years because well-designed heat exchanger networks enable heat recovery in process industries in an energy- and cost-efficient manner. Due to ever increasing global competition and need to decrease the harmful effects done on the environment, there still is a continuous need to improve the heat exchanger networks and their synthesizing methods. In this work we present a HENS method that combines an interactive multi-objective optimization method with a simultaneous bilevel HENS method, where the bilevel part of the method is based on grouping of process streams and building aggregate streams …

Waste heat recovery from a marine waste incinerator using a thermoelectric generator

2012

Published version of an article published in the journal: Journal of Electronic Materials. Also available from the publisher at: http://dx.doi.org/10.1007/s11664-012-2009-6 A marine waste incinerator has been evaluated for waste heat harvesting using thermoelectric generators (TEG). The application has been evaluated using mathematical modeling to optimize the heat exchanger and some vital design parameters of the TEG. The calculation shows that it is possible to extract 58 kW el at a price of 6.6 US$/W from an 850-kW th incinerator when optimizing for maximum power. However, minimizing the cost, it is possible to get 25 kW el at a price of 2.5 US$/W. A trade-off between the two targets lea…