scholarly journals Designing and Optimizing Heat Storage of a Solar-Assisted Ground Source Heat Pump System in China

2020 ◽  
Vol 2020 ◽  
pp. 1-18 ◽  
Author(s):  
Yan Gao ◽  
Zhi Sun ◽  
Xinxing Lin ◽  
Chuang Wang ◽  
Zongyu Sun ◽  
...  
Keyword(s):  
Soil Temperature ◽  
Heat Pump ◽  
Solar Collector ◽  
Heat Storage ◽  
Ground Source Heat Pump ◽  
Cold Region ◽  
Annual Average ◽  
Pump System ◽  
Heat Pump System ◽  
Ground Source

The cold accumulation problem can lead to performance degradation of heat pumps. This paper presents the design and optimization of a solar-assisted storage system to solve this issue. A ground source heat pump (GSHP) project was established using the transient system simulation program (TRNSYS) based on a ground heat exchange theoretical model, which was validated by a previously established experiment in Beijing. The Beijing, Harbin, and Zhengzhou regions were used in numerical simulations to represent three typical cities where buildings require space heating (a cold region, a severe cold region, and a hot summer and cold winter region, respectively). System performance was simulated over periods of ten years. The simulation results showed that the imbalance efficiencies in the Beijing, Harbin, and Zhengzhou regions are 55%, 79%, and 38%, respectively. The annual average soil temperature decreases 7.3°C, 11.0°C, and 5.3°C during ten years of conventional GSHP operation in the Beijing, Harbin, and Zhengzhou regions, respectively. Because of the soil temperature decrease, the minimum heating coefficient of performance (COP) values decrease by 23%, 46%, and 11% over the ten years for GSHP operation in these three regions, respectively. Moreover, the simulation data show that the soil temperature would still be decreasing if based on the previous solar energy area calculation method. Design parameters such as the solar collector size are optimized for the building load and average soil temperature in various cold regions. Long-term operation will test the matching rate of the compensation system with the conventional GSHP system. After the system is optimized, the solar collector area increases of 20% in the Beijing region, 25% in the Harbin region, and 15% in the Zhengzhou region could help to maintain the annual average soil temperature balance. The optimized system could maintain a higher annual average COP because of the steady soil temperature. It provides a method for the design of a solar collector area which needs to be determined in the seasonal heat storage solar ground source heat pump system.

scholarly journals Modeling study of ground source heat pump system based on the dynamic load of underground engineering

2020 ◽  
Vol 182 ◽  
pp. 03004
Author(s):  
Jintian Li ◽  
Yunzhe Ji ◽  
Bo Wang ◽  
Ling Xie
Keyword(s):  
Soil Temperature ◽  
Heat Pump ◽  
Dynamic Load ◽  
Operating Conditions ◽  
Ground Source Heat Pump ◽  
Operating Characteristics ◽  
Underground Engineering ◽  
Pump System ◽  
Heat Pump System ◽  
Ground Source

The load properties of underground engineering have an important influence on operating characteristics of ground source heat pump system. It has important reference value for design and operation management that Simulation analyzing operating conditions of ground source heat pump system under dynamic load conditions. It took an underground engineering as an example for dynamic load calculation in the paper, and simulated operating characteristics of ground source heat pump system under three operating conditions. The calculation results show that the engineering maintenance and management period is conducive to the recovery of soil temperature, and it improves the COP value of the unit. Some measures should be taken to restore soil temperature for long-term continuous operation of underground engineering. The use of heat recovery to make domestic hot water can relieve the problem of soil thermal imbalance to some extent. It is beneficial to improve heat pump unit performance.

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.

scholarly journals The Solar-Assisted Vertical Ground Source Heat Pump System in Cold Climates—A Case Study

Proceedings ◽  
2020 ◽  
Vol 51 (1) ◽  
pp. 24
Author(s):  
Piotr Rynkowski
Keyword(s):  
Heat Exchanger ◽  
Heat Pump ◽  
Solar Collector ◽  
Heat Extraction ◽  
Ground Heat Exchanger ◽  
Ground Source Heat Pump ◽  
Pump System ◽  
Heat Pump System ◽  
Ground Source ◽  
Vertical Ground

In this paper, experimental studies were performed for a solar ground source heat pump system (SGSHPS) with a vertical ground heat exchanger (VGHE). The experiment was operated during the summer in 2018. The heat from the solar collector was monitored by measuring the inlet and outlet temperatures and flow rate of the heat transfer fluids. An energy equilibrium balance carried out indicates heat extraction from the solar collector to the ground heat exchanger. It has been established that clear impact is achieved within a radius of 5 m. The average temperature of the actively regenerated borehole was higher than that of the undisturbed profile, which has a direct impact on the significant benefits of the coefficient of performance (COP) of the ground source heat pump system (GSHPS) and effectively helps soil regeneration. The average efficiency ratio of the heat transferred from solar radiation to soil in the SGSHPS was 42.3%.

Heat Imbalance Analysis of a Hybrid Ground-Source Heat Pump System

2014 ◽  
Vol 694 ◽  
pp. 222-226
Author(s):  
En Yu Wang ◽  
You Lu ◽  
Xiang Fei Kong ◽  
Cheng Ying Qi
Keyword(s):  
Heat Pump ◽  
Heat Storage ◽  
Heat Extraction ◽  
Ground Source Heat Pump ◽  
Borehole Heat Exchanger ◽  
Pump System ◽  
Heat Pump System ◽  
Imbalance Problem ◽  
Ground Source ◽  
Heat Injection

Operating data in the last two years of a hybrid ground-source heat pump system (HGSHPS) were analyzed, and were contrasted to TRNSYS simulation results. Heat extraction from the borehole heat exchanger (BHE) of ground-source heat pump system (GSHPS) was too much larger than the heat injection, but heat extraction from the borehole thermal energy storage (BTES) of solar assisted GSHPS (SAGSHPS) was too less than the heat storage, in 2012. Serious problem of heat imbalance of BHE occurred, and the GSHPS almost could not work in the late heating season of 2012. An adjusted operating strategy was utilized in 2013. The ground temperature imbalance for GSHPS and heat excess for SAGSHPS were resolved. It is important to monitor the operation of HGSHPS to resolve the heat imbalance problem.

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