Experimental Study of Heat Transfer in Soil to Inhibit Microbial Growth Using the Underground Release of Hot Water and a Hydraulic Head Method

ABSTRACT

This research aimed to study the effectiveness of heat transfer in soil using the underground release of hot water with a hydraulic head. Pressure heads of 1.0, 1.5 and 2.0 m were utilized for underground release with a nozzle to investigate heat transfer in soil necessary to inhibit microbial growth through underground hot water release using a pressure head of liquid. The nozzle was made of stainless steel pipe (SUS304). The proposed system was designed to inhibit microbes of Ralstonia solanacearum with a hot water volume flow of 300, 400 and 500 ml min⁻¹, while temperature was kept constant at 70 ºC. The hot water released underground provided higher soil temperature with shorter working time. The research found that the number of layers and diameter of drilled holes had a significant effect on soil temperature distributed at various depth levels (y-plan), resulting in enhanced performance (100%) for the inhibition of microbes in an x-plan radius of 15 cm for a shorter time of 20–30 min with one nozzle.

KEYWORDS:

• Heat transfer
• hot water
• hydraulic head
• Ralstonia solanacearum
• underground

Acknowledgments

The authors thank the Rajamangala University of Technology Lanna (Phitsanulok Campus), King Mongkut’s University of Technology Thonburi in ensuring the success of this research.

Additional information

Funding

This work was supported by the Higher Education Research Promotion and National Research University Project of Thailand, Office of the Higher Education Commission.