Ground source heat pump (GSHP) systems have a good environmental compatibility and low impact on rooms reserved to heating and cooling systems in buildings. The choice of the GSHP has to be justified in many applications, such commercial and industrial buildings, by cost advantages. The key feature of this kind of systems is the ground heat exchanger (GHX) whose more likely configurations are vertical or horizontal. The latter can represent a good compromise solution between the cost and the effectiveness, as it can benefit to face with a heat source at quasi-constant temperature and to ask for low installation costs as can be mounted in trenches in areas adjacent to the building. This work verifies numerically, with the help of the CFD code Fluent (Release 6.1.22), the operating conditions for horizontal heat exchangers, placed under the ground level areas of the South of Italy, that had to be provided with an air conditioning system for both winter and summer. The real operating temperatures and the heat fluxes to and from the ground have been considered in order to evaluate the environmental impact and the real advantages of this kind of heat transfer strategy compared to traditional heat pump (HP) systems, using air as heat sources and sinks. The CFD calculations showed the influence of the heat transfer process to the soil, so estimating the annual net energy flux to the ground. A cost/benefit analysis in three different scenarios was then performed, to evaluate both GSHP vertical and horizontal GHX solutions applied to different cases. The results showed the convenience times for three different applications.
Horizontal Heat Exchangers for GSHP. Efficiency and Cost Investigation for Three Different Applications
2005-01-01
Abstract
Ground source heat pump (GSHP) systems have a good environmental compatibility and low impact on rooms reserved to heating and cooling systems in buildings. The choice of the GSHP has to be justified in many applications, such commercial and industrial buildings, by cost advantages. The key feature of this kind of systems is the ground heat exchanger (GHX) whose more likely configurations are vertical or horizontal. The latter can represent a good compromise solution between the cost and the effectiveness, as it can benefit to face with a heat source at quasi-constant temperature and to ask for low installation costs as can be mounted in trenches in areas adjacent to the building. This work verifies numerically, with the help of the CFD code Fluent (Release 6.1.22), the operating conditions for horizontal heat exchangers, placed under the ground level areas of the South of Italy, that had to be provided with an air conditioning system for both winter and summer. The real operating temperatures and the heat fluxes to and from the ground have been considered in order to evaluate the environmental impact and the real advantages of this kind of heat transfer strategy compared to traditional heat pump (HP) systems, using air as heat sources and sinks. The CFD calculations showed the influence of the heat transfer process to the soil, so estimating the annual net energy flux to the ground. A cost/benefit analysis in three different scenarios was then performed, to evaluate both GSHP vertical and horizontal GHX solutions applied to different cases. The results showed the convenience times for three different applications.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
