In this paper the energy performance of a Dual-Source Heat Pump (DSHP) system able to use both air and ground as external heat source is analysed by using TRNSYS and the experimental data obtained by testing a DSHP prototype. The DSHP seasonal and annual performance factors are compared with those offered by the same DSHP in which only ground (ground-source mode) or only external air (air-source mode) is used as external heat source in order to evaluate the benefits achievable with the exploitation of a double external heat source (ground and air) with the same unit. Yearly dynamic simulations have been carried out by coupling the DSHP to a detached residential building located in Bologna, characterized by unbalanced heating and cooling loads, and coupled to a geothermal loop based on borehole heat exchangers (BHEs). With the help of the dynamic simulations it has been demonstrated that DSHPs can be very useful in order to solve the problems linked to the ground temperature drift which can be originated by the presence of an undersized borehole heat exchanger field and/or by unbalanced heating and cooling loads. In fact, the use of external air as auxiliary heat source with respect to ground during the most severe season enables to obtain more stable energy performance even in presence of undersized BHEs. In this paper it is shown how an optimal trade-off in terms of annual energy performance and investment costs can be obtained by reducing the size of the DSHP borehole field of 15–55% with respect to the borehole field needed by a conventional ground-coupled heat pump having the same size. In this way the DSHP can be used during the retrofitting of thermal plants based on ground-coupled heat pumps in which an undersized BHEs field is present.

Dynamic modelling and energy performance analysis of an innovative dual-source heat pump system / I. Grossi; M. Dongellini; A. Piazzi; GL Morini. - In: APPLIED THERMAL ENGINEERING. - ISSN 1359-4311. - STAMPA. - 142:(2018), pp. S1359431118309128.745-S1359431118309128.759. [10.1016/j.applthermaleng.2018.07.022]

Dynamic modelling and energy performance analysis of an innovative dual-source heat pump system

I. Grossi;M. Dongellini
;
A. Piazzi
Membro del Collaboration Group
;
GL Morini
2018

Abstract

In this paper the energy performance of a Dual-Source Heat Pump (DSHP) system able to use both air and ground as external heat source is analysed by using TRNSYS and the experimental data obtained by testing a DSHP prototype. The DSHP seasonal and annual performance factors are compared with those offered by the same DSHP in which only ground (ground-source mode) or only external air (air-source mode) is used as external heat source in order to evaluate the benefits achievable with the exploitation of a double external heat source (ground and air) with the same unit. Yearly dynamic simulations have been carried out by coupling the DSHP to a detached residential building located in Bologna, characterized by unbalanced heating and cooling loads, and coupled to a geothermal loop based on borehole heat exchangers (BHEs). With the help of the dynamic simulations it has been demonstrated that DSHPs can be very useful in order to solve the problems linked to the ground temperature drift which can be originated by the presence of an undersized borehole heat exchanger field and/or by unbalanced heating and cooling loads. In fact, the use of external air as auxiliary heat source with respect to ground during the most severe season enables to obtain more stable energy performance even in presence of undersized BHEs. In this paper it is shown how an optimal trade-off in terms of annual energy performance and investment costs can be obtained by reducing the size of the DSHP borehole field of 15–55% with respect to the borehole field needed by a conventional ground-coupled heat pump having the same size. In this way the DSHP can be used during the retrofitting of thermal plants based on ground-coupled heat pumps in which an undersized BHEs field is present.
2018
Dynamic modelling and energy performance analysis of an innovative dual-source heat pump system / I. Grossi; M. Dongellini; A. Piazzi; GL Morini. - In: APPLIED THERMAL ENGINEERING. - ISSN 1359-4311. - STAMPA. - 142:(2018), pp. S1359431118309128.745-S1359431118309128.759. [10.1016/j.applthermaleng.2018.07.022]
I. Grossi; M. Dongellini; A. Piazzi; GL Morini
File in questo prodotto:
File Dimensione Formato  
PP Dynamic modelling and energy.pdf

Open Access dal 07/07/2020

Tipo: Postprint
Licenza: Licenza per Accesso Aperto. Creative Commons Attribuzione - Non commerciale - Non opere derivate (CCBYNCND)
Dimensione 927.16 kB
Formato Adobe PDF
927.16 kB Adobe PDF Visualizza/Apri

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11585/646409
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 48
  • ???jsp.display-item.citation.isi??? 41
social impact