scholarly journals Development of an Integrated Building Load-Ground Source Heat Pump Model as a Test Bed to Assess Short- and Long-Term Heat Pump and Ground Loop Performance

2012 ◽  
Author(s):  
Jonathan L. Gaspredes ◽  
Glenn Y. Masada ◽  
Tess J. Moon
Keyword(s):  
Heat Pump ◽  
System Performance ◽  
Ground Source Heat Pump ◽  
Test Bed ◽  
Ground Source ◽  
Wide Range ◽  
Short And Long Term ◽  
Building Load ◽  
Ground Loop

An integrated building load-ground source heat pump model is developed in this paper to serve as a test bed for assessing the short- and long-term performance of GSHP and HGSHP systems with vertical boreholes. The model uses the Simulink/Matlab environment to take advantage of their built-in functionality, allowing for full coupling of the component building load, heat pump, ground loop, and supplemental heat rejection models at every time step The building load model uses the HAMBASE thermal program which can model residential and commercial buildings. The heat pump model uses available data provided by GSHP manufacturers and sensible heat corrections to accurately model operation across a wide range of input conditions. The vertical borehole ground loop model is based on Eskillsons g-function model, but includes a one-dimensional numerical model by Xu to calculate the short-term thermal response of the borehole and ground. The supplemental heat rejection section allows various techniques to be tested. The integrated model captures system performance over a wide range of time scales from seconds to 10–20 years. Results of a 15-year simulation are presented to illustrate the different time scale information that reveal the slow degradation in system performance due to the effects of ground heating.

A Simulink®-Based Building Load-Ground Source Heat Pump Model Used to Assess Short-and Long-Term Heat Pump and Ground Loop Performance

2014 ◽  
Vol 6 (2) ◽  
Author(s):  
Jonathan L. Gaspredes ◽  
Glenn. Y. Masada ◽  
Tess. J. Moon
Keyword(s):  
Heat Pump ◽  
Loop Model ◽  
Ground Model ◽  
Ground Source Heat Pump ◽  
Short Term ◽  
Ground Source ◽  
Wide Range ◽  
Building Load ◽  
Ground Loop

An integrated building load-ground source heat pump model is developed to capture short-term (30 s) and long-term (10–20 yr) performance of ground source heat pumps with vertical boreholes. The model takes advantage of the built-in computation and organization functions of the simulink®/matlab environment to couple the component building load, heat pump, and ground loop models at every time step. The building load model uses the HAMBASE thermal program and is applicable to residential and commercial buildings. The heat pump model uses manufacturer data and sensible heat corrections to accurately model heat pump operation across a wide range of input conditions. The ground loop model is a combination of Hellstrom's borehole tube model, Eskillson's long-term (>10 yr) g-function ground model and the one-dimensional, short-term (<5 min) numerical ground model by Xu. Fifteen year simulation results for a base case residential house are presented to illustrate the integrated model's ability to predict a wide range of time responses and to illustrate a limiting ground loop sizing criterion that reveals the slow degradation in system performance due ground heating effects. Simulations with varying borehole lengths also illustrate the sensitivity of ground loop sizing on the system's thermal and economic performances. The work emphasizes the importance of proper borehole sizing, design, and placement especially in cooling-dominated climates, where the unbalance of heat loads to the ground cause slowly rising ground temperatures.

Effects of Ground Loop Design Parameters on Short- and Long-Term Operational and Economics of Ground Source Heat Pumps in Hot, Semi-Arid Areas

2012 ◽  
Author(s):  
Jonathan L. Gaspredes ◽  
Glenn Y. Masada ◽  
Tess J. Moon
Keyword(s):  
Heat Pump ◽  
Heat Pumps ◽  
Design Parameters ◽  
Test Bed ◽  
Ground Source Heat Pumps ◽  
Loop Design ◽  
Ground Source ◽  
Short And Long Term ◽  
Ground Loop

Deployment of ground source heat pumps in Texas and the Southwest has been limited by high initial cost and potential ground heating. To address these limitations for a residential application a sensitivity study of the ground loop design parameters was completed. The study uses an integrated building load-ground source heat pump model that is designed to be a test bed for assessing the short- and long-term performance of GSHPs. This study examines a 195 m2 residential house located in Austin, Texas with a 14.6 kW heat pump and 4 vertical boreholes each with a length of 68.5 m. The performance effects and the long-term economics of the total ground loop length, spacing of the boreholes, placement of the boreholes, grout thermal conductivity, and supplemental heat rejector sizes are compared. The study shows the importance of proper sizing, design, and placement of the borehole in locations with severely unbalanced heating and cooling loads.

Study on Ground Source Heat Pump System of Combined Office and Residential Building in Hot Summer and Warm Winter Region

2013 ◽  
Vol 732-733 ◽  
pp. 564-570 ◽  
Author(s):  
Ying Ning Hu ◽  
Ya Zhao Liu ◽  
Jun Lin ◽  
Yan Wang
Keyword(s):  
Heat Pump ◽  
Heat Balance ◽  
System Performance ◽  
Residential Buildings ◽  
Residential Building ◽  
Ground Source Heat Pump ◽  
Pump System ◽  
Heat Pump System ◽  
Warm Winter ◽  
Ground Source

A ground source heat pump system of combined office and residential buildings in hot summer and warm winter region is introduced. The system performance is studied through the experiment, and the performance of underground heat balance is analyzed by TRNSYS. The results show the superiority and applicability of the ground source heat pump system.

Simulation of Solar Assisted Ground Source Heat Pump System in Different Regions

2011 ◽  
Vol 354-355 ◽  
pp. 798-801
Author(s):  
Qin Tao Zhou ◽  
Hua Dong ◽  
En Ze Zhou ◽  
Wei Yi
Keyword(s):  
Heat Pump ◽  
Storage Temperature ◽  
Weather Data ◽  
Fluid Temperature ◽  
Ground Source Heat Pump ◽  
Time Step ◽  
Pump System ◽  
Heat Pump System ◽  
Ground Source ◽  
Ground Loop

This study presents a simulation approach to assess the viability of solar assisted ground source heat pump system in different regions of China. A short time step model of ground loop exchanger is employed in the simulation with a 30% solar fraction. Weather data files used in the simulation are created based on Chinese Typical Year Weather (CTYW) data. Borehole length is optimized with a safety stop temperature of 0°C. The minimum Entering Fluid Temperature (EFT) decreases 1.3°C after 20-year simulation time and the team effect of ground loop exchangers is weaken as a result of spontaneous recovery of storage temperature. Borehole length replaced by area of solar collector ranges from 3.9m to 2.5m in the six cities. The results show that the annual performance of ground loop exchanger is low in heating-dominated regions and a solar assisted ground source heat pump (SAGSHP) system is needed in order to improve the system performance.

Long-Term Monitoring of the Effectiveness of a Ground Source Heat Pump Borehole

2014 ◽  
Vol 1041 ◽  
pp. 125-128
Author(s):  
Olga Rubinová ◽  
Iva Ambrožová ◽  
Petr Horák
Keyword(s):  
Substrate Temperature ◽  
Heat Pump ◽  
Ground Source Heat Pump ◽  
Not Given ◽  
Ground Source ◽  
Early Results ◽  
Long Term Monitoring ◽  
Term Monitoring ◽  
Over Time

In this study, we evaluate the qualitative thermal performance of a groundwater borehole by monitoring the temperature at the primary (borehole) and secondary (heat pump) sides of a domestic heat pump over three heating seasons between 2010 and 2013. Based on early results, the borehole was extended during the monitoring period in order to increase performance. Our results suggest that the temperature parameters of a borehole do not remain constant and that a borehole’s properties can change significantly over time if the borehole substrate temperature is not given time to regenerate.

scholarly journals A Study on the Effect of Performance Factor on GSHP System through Real-Scale Experiments in Korea

Energies ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 554
Author(s):  
Hongkyo Kim ◽  
Yujin Nam ◽  
Sangmu Bae ◽  
Jae Sang Choi ◽  
Sang Bum Kim
Keyword(s):  
Heat Pump ◽  
System Performance ◽  
Storage Tank ◽  
Heat Storage ◽  
Design Method ◽  
Ground Source Heat Pump ◽  
Pump System ◽  
Heat Pump System ◽  
Ground Source ◽  
High Efficient

A ground source heat pump system is one of the high-efficient technologies for space heating and cooling since it uses stable underground temperature. However, in actual application, many situations cannot be achieved due to the unsuitable design of operation. In particular, the design characteristics of buildings with different building load patterns are not reflected by the conventional design method. Moreover, the design capacity of the heat pump can be reduced by designing less capacity than the peak load through the introduction of the heat storage tank, but there is no related quantitative design method. Therefore, in this study, the effect of the ground source heat pump system design factors such as shape, length of the ground heat exchanger, and the capacity of the heat storage tank on the system performance was analyzed. To quantify the effect of such factors on system performance, an experimental plant was constructed and case studies were conducted for each design factor.

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