Cascade air to water heat pumps (AWHPs), which have better performance and lower compressor ratios than single-stage AWHPs at low ambient temperatures and high outlet water temperature lift, may be a potential technology for decarbonising space and hot water heating in the UK domestic sector. This is because they can directly replace existing fossil-fueled boilers without the requirement of significant modifications to the heating distribution systems, which can reduce installation costs and disruptions when retrofitting. Also, the coupling of AWHPs and TES along with demand-side management (DSM) is a promising technology to meet the domestic thermal demands with an efficient utilization of grid operation and cost savings for the occupants. In this paper, validated building energy simulations of a cascade AWHP and TES applying different DSM strategies are presented. Particularly, three rule-based control approaches based on: 1) dynamic electricity market prices, 2) ambient temperatures, 3) both dynamic market prices and ambient temperatures, were applied to compare their performance with the base case in which the heat pump supplied heat directly to the domestic without using the TES. TRNSYS 17 software was utilised to model and simulate the system performance of the cascade AWHP with TES applying the DSM strategies. Simulation results showed that while the heat pump with the DSM strategies had lower efficiency than the base case, cost savings were obtained. Although the DSM controlled based on favourable ambient temperatures yielded slightly better efficiency than the one based on dynamic market prices, its running cost was higher. Finally, how the control approaches affected the grid demand and wind energy curtailment is also discussed in the paper.
|Title of host publication||Thermal Energy Challenge Network|
|Number of pages||10|
|Publication status||Published - 31 May 2019|
|Event||SusTEM2019 - Hangzhou, China|
Duration: 14 May 2019 → 16 May 2019
|Period||14/05/19 → 16/05/19|