Experimental study on the thermal performance of a grey water heat harnessing exchanger using Phase Change Materials

Research output: Contribution to journalArticle

1 Citation (Scopus)

Abstract

To integrate heat extraction and storage into a single unit along with decoupling of demand and supply,\Phase Change Materials (PCMs) can be used to harness heat from grey water (GW). A simple heat\exchanger linking both the GW and incoming mains cold water (CW) in a counter flow arrangement with\a PCM is experimentally tested. To enhance the thermal conductivity of the PCM, metallic copper fins are\placed throughout the cross-section of the pipes.
The charging with a GW temperature of 325 K and the discharging with a CW temperature of 285 K, of\the PCM is investigated. The influence of the mass flow rates of both the fluids is investigated by varying\it between discrete values of 0.1 kg/s and 0.05 kg/s. Similarly the operation strategy of the heat exchanger
is varied between the solo operation of the GW and CW compared with the simultaneous flows of both.
Finally two different PCMs; with a melting temperature of 298 K (RT-25) and 315 K (RT-42) are also\tested.
The mass flow rate is proportional to performance with 0.1 kg/s showing the best results but being less\influential for RT-25 as compared to RT-42. In RT-25 most heat is transferred as latent heat with a higher\phase change rate whilst RT-42 transfers sensible heat. The solo operation strategy of non-simultaneous
GW and CW flow is more effective as this exchanger is meant to decouple demand and supply. The ability\of RT-25 to retain heat over the long term is also greater compared to RT-42. Ullage issues and corrosion\concerns of the metallic container and pipes are also dominant over the long-term usage of these PCMs.
Original languageEnglish
Pages (from-to)1805-1817
Number of pages13
JournalRenewable Energy
Volume146
Early online date9 Aug 2019
DOIs
Publication statusPublished - Feb 2020

Fingerprint

Phase change materials
Heat exchangers
Water
Pipe
Flow rate
Hot Temperature
Latent heat
Containers
Melting point
Thermal conductivity
Corrosion
Heat transfer
Copper
Temperature
Fluids

Keywords

  • Grey water
  • Heat harnessing
  • PCMs
  • Passive houses

ASJC Scopus subject areas

  • Renewable Energy, Sustainability and the Environment

Cite this

@article{2a8f8c30a0a340f782e9c3db21aee67b,
title = "Experimental study on the thermal performance of a grey water heat harnessing exchanger using Phase Change Materials",
abstract = "To integrate heat extraction and storage into a single unit along with decoupling of demand and supply,\Phase Change Materials (PCMs) can be used to harness heat from grey water (GW). A simple heat\exchanger linking both the GW and incoming mains cold water (CW) in a counter flow arrangement with\a PCM is experimentally tested. To enhance the thermal conductivity of the PCM, metallic copper fins are\placed throughout the cross-section of the pipes.The charging with a GW temperature of 325 K and the discharging with a CW temperature of 285 K, of\the PCM is investigated. The influence of the mass flow rates of both the fluids is investigated by varying\it between discrete values of 0.1 kg/s and 0.05 kg/s. Similarly the operation strategy of the heat exchangeris varied between the solo operation of the GW and CW compared with the simultaneous flows of both.Finally two different PCMs; with a melting temperature of 298 K (RT-25) and 315 K (RT-42) are also\tested.The mass flow rate is proportional to performance with 0.1 kg/s showing the best results but being less\influential for RT-25 as compared to RT-42. In RT-25 most heat is transferred as latent heat with a higher\phase change rate whilst RT-42 transfers sensible heat. The solo operation strategy of non-simultaneousGW and CW flow is more effective as this exchanger is meant to decouple demand and supply. The ability\of RT-25 to retain heat over the long term is also greater compared to RT-42. Ullage issues and corrosion\concerns of the metallic container and pipes are also dominant over the long-term usage of these PCMs.",
keywords = "Grey water, Heat harnessing, PCMs, Passive houses",
author = "Mazhar, {Abdur Rehman} and Shuli Liu and Ashish Shukla",
year = "2020",
month = "2",
doi = "10.1016/j.renene.2019.08.053",
language = "English",
volume = "146",
pages = "1805--1817",
journal = "Renewable Energy",
issn = "0960-1481",
publisher = "Elsevier",

}

TY - JOUR

T1 - Experimental study on the thermal performance of a grey water heat harnessing exchanger using Phase Change Materials

AU - Mazhar, Abdur Rehman

AU - Liu, Shuli

AU - Shukla, Ashish

PY - 2020/2

Y1 - 2020/2

N2 - To integrate heat extraction and storage into a single unit along with decoupling of demand and supply,\Phase Change Materials (PCMs) can be used to harness heat from grey water (GW). A simple heat\exchanger linking both the GW and incoming mains cold water (CW) in a counter flow arrangement with\a PCM is experimentally tested. To enhance the thermal conductivity of the PCM, metallic copper fins are\placed throughout the cross-section of the pipes.The charging with a GW temperature of 325 K and the discharging with a CW temperature of 285 K, of\the PCM is investigated. The influence of the mass flow rates of both the fluids is investigated by varying\it between discrete values of 0.1 kg/s and 0.05 kg/s. Similarly the operation strategy of the heat exchangeris varied between the solo operation of the GW and CW compared with the simultaneous flows of both.Finally two different PCMs; with a melting temperature of 298 K (RT-25) and 315 K (RT-42) are also\tested.The mass flow rate is proportional to performance with 0.1 kg/s showing the best results but being less\influential for RT-25 as compared to RT-42. In RT-25 most heat is transferred as latent heat with a higher\phase change rate whilst RT-42 transfers sensible heat. The solo operation strategy of non-simultaneousGW and CW flow is more effective as this exchanger is meant to decouple demand and supply. The ability\of RT-25 to retain heat over the long term is also greater compared to RT-42. Ullage issues and corrosion\concerns of the metallic container and pipes are also dominant over the long-term usage of these PCMs.

AB - To integrate heat extraction and storage into a single unit along with decoupling of demand and supply,\Phase Change Materials (PCMs) can be used to harness heat from grey water (GW). A simple heat\exchanger linking both the GW and incoming mains cold water (CW) in a counter flow arrangement with\a PCM is experimentally tested. To enhance the thermal conductivity of the PCM, metallic copper fins are\placed throughout the cross-section of the pipes.The charging with a GW temperature of 325 K and the discharging with a CW temperature of 285 K, of\the PCM is investigated. The influence of the mass flow rates of both the fluids is investigated by varying\it between discrete values of 0.1 kg/s and 0.05 kg/s. Similarly the operation strategy of the heat exchangeris varied between the solo operation of the GW and CW compared with the simultaneous flows of both.Finally two different PCMs; with a melting temperature of 298 K (RT-25) and 315 K (RT-42) are also\tested.The mass flow rate is proportional to performance with 0.1 kg/s showing the best results but being less\influential for RT-25 as compared to RT-42. In RT-25 most heat is transferred as latent heat with a higher\phase change rate whilst RT-42 transfers sensible heat. The solo operation strategy of non-simultaneousGW and CW flow is more effective as this exchanger is meant to decouple demand and supply. The ability\of RT-25 to retain heat over the long term is also greater compared to RT-42. Ullage issues and corrosion\concerns of the metallic container and pipes are also dominant over the long-term usage of these PCMs.

KW - Grey water

KW - Heat harnessing

KW - PCMs

KW - Passive houses

UR - http://www.scopus.com/inward/record.url?scp=85070538881&partnerID=8YFLogxK

U2 - 10.1016/j.renene.2019.08.053

DO - 10.1016/j.renene.2019.08.053

M3 - Article

VL - 146

SP - 1805

EP - 1817

JO - Renewable Energy

JF - Renewable Energy

SN - 0960-1481

ER -