Showing 1 - 10 of 105
Total thermal resistance of ground heat exchanger (GHE) is comprised of that of the soil and inside the borehole. The thermal resistance of soil can be calculated using the linear source theory and cylindrical source theory, while that inside the borehole is more complicated due to the...
Persistent link: https://www.econbiz.de/10010805098
Ground source heat pump system takes advantage of the stable ground temperature to achieve energy savings and to reduce CO2 emission. However, the system has several barriers for the wider application such as high installation costs, incompletion of design standard and lack of recognition as...
Persistent link: https://www.econbiz.de/10010906882
This paper presents a numerical heat transfer model for vertical U-tube Ground Heat Exchangers (GHE). This model is uniquely able to take into to account different initial soil temperatures and physical properties at different depths. The model has been validated based on an experimental case...
Persistent link: https://www.econbiz.de/10011045744
This paper presents a new hybrid two-dimensional model to simulate single U-tube ground heat exchangers based on the use of the electrical analogy to model heat transfer within the borehole and thermal response factors (short and long time-step g-functions) to estimate heat flow to the...
Persistent link: https://www.econbiz.de/10011208712
A HGSHP (hybrid ground-source heat pump) is proposed to solve the performance degradation of the GSHP (ground-source heat pump) under imbalanced load conditions. The HGSHP is composed of three flow loops: a refrigerant flow loop, a GFL (ground flow loop), and a SFL (supplemental flow loop). In...
Persistent link: https://www.econbiz.de/10011209564
Assessment of potential use of ground-coupled heat pump (GCHP) system in regional scale is important to promote its growth. Groundwater flow system and subsurface temperature distribution of Tsugaru Plain were comprehended by developing 3D numerical model. In absence of measured hydrological and...
Persistent link: https://www.econbiz.de/10011189926
A fully coupled multiphysics model involving heat transfer and groundwater flow within a standing column well and its surrounding ground was modeled by means of a thermal resistance and capacity network coupled to an analytical solution. The transient groundwater velocity field and aquifer...
Persistent link: https://www.econbiz.de/10011189990
Computer simulation of borehole ground heat exchangers used in geothermal heat pump systems was conducted using three-dimensional implicit finite difference method with rectangular coordinate system. Each borehole was approximated by a square column circumscribed by the borehole radius. Borehole...
Persistent link: https://www.econbiz.de/10010803683
Hourly energy simulations are an important part of the design and analysis of ground-source heat pump systems. In order to evaluate the fluid temperature in the borehole of a geothermal heat pump system, most of the current models express the heat transfer rate as a sum of step changes in heat...
Persistent link: https://www.econbiz.de/10010804062
An improvement to the thermal resistance capacity model (TRCM) used to model borehole heat exchangers is presented. Here, the original model is extended to integrate the thermal capacities of the heat carrier fluid and pipe and to better account for the spacing between the pipes. Model results...
Persistent link: https://www.econbiz.de/10010804076