Numerical study on the long-term performance and load imbalance ratio for medium-shallow borehole heat exchanger system.

Author(s) : WANG R., WANG F., XUE Y., JIANG J., ZHANG Y., CAI W., CHEN C.

Type of article: Periodical article

Summary

To contribute to the goal of carbon neutralization, the closed-loop borehole heat exchanger system is widely applied to use geothermal energy for building cooling and heating. In this work, a new type of medium-shallow borehole heat exchanger (MSBHE) is proposed, which is coaxial type and has a depth range between 200 m to 500 m. To investigate the long-term performance of MSBHE in the area with unbalanced cooling and heating load of buildings and the sustainable load imbalance ratio under different design parameters, a comprehensive numerical model is established. The results show that the drilling depth significantly influences the sustainable load imbalance ratio of MSBHE. As the drilling depth is increased from 200 m to 500 m, the load imbalance ratio of the MSBHE increases from 20.76% to 60.29%. In contrast, the load imbalance ratio is always kept at the same level with different inlet velocities and operation modes. Furthermore, in a 9-MSBHE array system, the heat exchanger located in the middle of the array has the lowest load imbalance ratio of 48.97%, which is 15.98% lower than the borehole in the edge location. This is caused by the significant influence of the shifted-load phenomenon among MSBHEs in an array system. The findings of the work imply that this newly proposed MSBHE can sustain a notable load imbalance ratio, which is particularly applicable to the areas with a strong imbalance of annual building load.

Available documents

Format PDF

Pages: 19 p.

Available

Free

Details

  • Original title: Numerical study on the long-term performance and load imbalance ratio for medium-shallow borehole heat exchanger system.
  • Record ID : 30029856
  • Languages: English
  • Subject: Technology
  • Source: Energies - 15 - 9
  • Publishers: MDPI
  • Publication date: 2022/05
  • DOI: http://dx.doi.org/10.3390/en15093444

Links


See other articles in this issue (12)
See the source