Recovery of low-grade waste heat from smelter process water streams using heat pumps

CIM Journal ◽  
2016 ◽  
Vol 7 (4) ◽  
Author(s):  
I. M. Ross ◽  
G. M. Ross ◽  
J. A. Scott
Keyword(s):  
Waste Heat ◽  
Heat Pumps ◽  
Process Water ◽  
Low Grade

Multi-criterion comparison of compression and absorption heat pumps for ultra-low grade waste heat recovery

Energy ◽  
2022 ◽  
Vol 238 ◽  
pp. 121804
Author(s):  
Z.Y. Xu ◽  
J.T. Gao ◽  
Bin Hu ◽  
R.Z. Wang
Keyword(s):  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Waste Heat ◽  
Heat Pumps ◽  
Low Grade

Adiabatic Absorption by Absorbent Atomization for Improving Absorption Heat Transformer Performance

2020 ◽  
Vol 142 (5) ◽  
Author(s):  
Yigal Evron ◽  
Khaled Gommed ◽  
Gershon Grossman
Keyword(s):  
Distribution System ◽  
Distribution Systems ◽  
Waste Heat ◽  
Heat Pumps ◽  
Low Grade ◽  
Liquid Distribution ◽  
Experimental Step ◽  
Higher Temperature ◽  
Future Work ◽  
Heat Transformer

Abstract Absorption heat transformers (AHTs) are a type of absorption heat pumps that are primarily driven by low-grade (typically waste) heat and produce higher temperature (high-grade) heat. Under the Indus3Es project, a 10 kW LiBr-H2O “Lab Scale” absorption heat transformer was built as a first experimental step toward larger scales. The focus was on the high-pressure vessel (HPV) (absorber and evaporator) design. To enhance performance, the aim was to obtain complete adiabatic absorption prior to the main absorption process accompanied by heat transfer. This maximizes the temperature within the absorber. This is particularly beneficial for absorption heat transformers, compared to chillers, because obtaining an elevated temperature is the objective. To obtain adiabatic absorption, atomizing spray nozzles were used as the liquid absorbent distribution system. This method proved successful; complete adiabatic absorption was obtained before the droplets contacted the absorber heat exchange surfaces. However, the spray nozzles must be supplied with pressurized liquid and are potentially more delicate than alternative liquid distribution systems. Therefore, future work may focus on determining the required atomization level to avoid excessive pressures and nozzle requirements.

Low grade waste heat recovery using heat pumps and power cycles

Energy ◽  
2015 ◽  
Vol 89 ◽  
pp. 864-873 ◽  
Author(s):  
D.M. van de Bor ◽  
C.A. Infante Ferreira ◽  
Anton A. Kiss
Keyword(s):  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Waste Heat ◽  
Heat Pumps ◽  
Low Grade ◽  
Power Cycles

scholarly journals Efficiency of use of waste heat energy on the example of Chelyabinsk

2019 ◽  
Vol 140 ◽  
pp. 11003
Author(s):  
Grigoriy Tseyzer ◽  
Olga Ptashkina-Girina ◽  
Olga Guseva
Keyword(s):  
Thermal Energy ◽  
Waste Heat ◽  
Heat Pumps ◽  
Heat Output ◽  
Low Grade ◽  
Heat Sources ◽  
Sources Of Information ◽  
Equivalent Fuel ◽  
Low Grade Heat

We consider the possibility of improving the existing heat-suppling system in Chelyabinsk through the introduction of heat pump technology for the disposal of waste low-grade heat. Sources of information concerning the ways of utilization of waste thermal energy, the principles of work of heat pumps, classification of city sources of waste heat are analyzed. The technique directed to assess the effectiveness of applying heat pumps for each category of city sources of waste thermal energy is designed. The calculated assessment showed that the utilization of waste heat in the conditions of Chelyabinsk will reduce the annual energy of fuel consumption by 2.2 million tons of conventional fuel (24.9%). At the same time, thermal pollution will decrease by 1.5 million tons of equivalent fuel. This effect is possible with the use of heat pumps with a total heat output of 1,145 MW.

Sludge Disposal from an Island Community

1992 ◽  
Vol 25 (12) ◽  
pp. 33-47 ◽  
Author(s):  
T. S. C. Gross ◽  
R. R. Cohen
Keyword(s):  
Agricultural Land ◽  
Waste Heat ◽  
Treatment Plant ◽  
Small Island ◽  
Low Grade ◽  
Sludge Disposal ◽  
Disposal Option ◽  
Total Process ◽  
Island Community ◽  
Farm Produce

The small island of Jersey is served by a single wastewater treatment plant at Bellozanne. Since its inception some 30 years ago the sludge produced has been used on agricultural land. Inevitably there are circumstances which prevent this happening without interruption, eg, poor weather, or seasonal demand. On these occasions, the island has no other disposal option to fall back on. Furthermore, concerns over the practice have created a perception that it might be doing harm to the ‘quality' of the farm produce. The responsible body, the Public Services Department, formulated a flexible, multiple option solution and commissioned Halcrow to engineer the capital works. The works centre around a thermal drying plant using biogas produced by the digestion process as the main fuel. Waste heat is recovered for digester heating making the total process potentially self sufficient in energy. At the same time, the bulk of the product is reduced considerably, providing an easily transported material with potential for use directly on the land as a fertilizer substitute or as a low grade fuel. Farfrom being a disposal problem requiring manpower and expense, sludge will soon be regarded by the States of Jersey as a valuable resource with a revenue potential.

scholarly journals Local Heating Networks with Waste Heat Utilization: Low or Medium Temperature Supply?

Energies ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 954 ◽  
Author(s):  
Hanne Kauko ◽  
Daniel Rohde ◽  
Armin Hafner
Keyword(s):  
Low Temperature ◽  
Heat Pump ◽  
Urban Areas ◽  
Waste Heat ◽  
Local Heating ◽  
District Heating ◽  
Heat Pumps ◽  
Hot Water ◽  
Local Network ◽  
Medium Temperature

District heating enables an economical use of energy sources that would otherwise be wasted to cover the heating demands of buildings in urban areas. For efficient utilization of local waste heat and renewable heat sources, low distribution temperatures are of crucial importance. This study evaluates a local heating network being planned for a new building area in Trondheim, Norway, with waste heat available from a nearby ice skating rink. Two alternative supply temperature levels have been evaluated with dynamic simulations: low temperature (40 °C), with direct utilization of waste heat and decentralized domestic hot water (DHW) production using heat pumps; and medium temperature (70 °C), applying a centralized heat pump to lift the temperature of the waste heat. The local network will be connected to the primary district heating network to cover the remaining heat demand. The simulation results show that with a medium temperature supply, the peak power demand is up to three times higher than with a low temperature supply. This results from the fact that the centralized heat pump lifts the temperature for the entire network, including space and DHW heating demands. With a low temperature supply, heat pumps are applied only for DHW production, which enables a low and even electricity demand. On the other hand, with a low temperature supply, the district heating demand is high in the wintertime, in particular if the waste heat temperature is low. The choice of a suitable supply temperature level for a local heating network is hence strongly dependent on the temperature of the available waste heat, but also on the costs and emissions related to the production of district heating and electricity in the different seasons.

scholarly journals Probing the Effect of Water Recycling on Flotation through Anion Spiking Using a Low-Grade Cu–Ni–PGM Ore: The Effect of NO3−, SO42− and S2O32−

Minerals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 340
Author(s):  
Mathew Dzingai ◽  
Malibongwe S. Manono ◽  
Kirsten C. Corin
Keyword(s):  
Water Chemistry ◽  
Froth Flotation ◽  
Water Source ◽  
Threshold Concentration ◽  
Process Water ◽  
Low Grade ◽  
Unit Operations ◽  
Flotation Performance ◽  
Anion Distribution ◽  
Nickel Grade

Water scarcity necessitates the recycling of process water within mineral processing practices. This may however come with its disadvantages for unit operations such as froth flotation as this process is water intensive and sensitive to water chemistry. It is therefore important to monitor the water chemistry of the recycle stream of process water and any other water source to flotation. Monitoring the concentrations of the anions in recycled process water is therefore important to consider as these are speculated to impact flotation performance. Batch flotation tests were conducted using synthetically prepared plant water (3 SPW) with a TDS of 3069 mg/L as the baseline experiment. 3 SPW contained 528 mg/LNO3− and 720 mg/L SO42−, other anions and cations, and no S2O32−. Upon spiking 3 SPW with selected anions, viz, NO3−, SO42− and S2O32−, it was noted that NO3− and SO42− exhibited threshold concentrations while S2O32− did not show a threshold concentration for both copper and nickel grade. Spiking 3 SPW with 352 mg/L more of NO3− to a total 880 mg/L NO3− concentration resulted in the highest copper and nickel grade compared to 3 SPW while increasing the S2O32− from 60 to 78 mg/L increased nickel and copper grade. 720 to 1200 mg/L SO42− and 528 to 880 mg/L NO3− were deemed the concentration boundaries within which lies the threshold concentration above which flotation performance declines with respect to metal grades, while for S2O32− the threshold concentration lies outside the range considered for this study. Anion distribution between the pulp and the froth did not seem to impact the recovery of copper or nickel. Notably, the correlation between the concentrate grades and anion distribution between the froth and the pulp seemed to be ion dependent.

scholarly journals Efficient and affordable thermomagnetic materials for harvesting low grade waste heat

APL Materials ◽  
2021 ◽  
Vol 9 (1) ◽  
pp. 011105
Author(s):  
Daniel Dzekan ◽  
Anja Waske ◽  
Kornelius Nielsch ◽  
Sebastian Fähler
Keyword(s):  
Waste Heat ◽  
Low Grade
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