Multi-functional probe for small-scale simultaneous measurements of soil thermal properties, water content, and electrical conductivity

<p>Soil temperature, soil water content and soil thermal properties were measured in an artificial forestland and a natural regrowth grassland from November in 2017 to July in 2019. The results show that the effects of soil temperature and soil water content on thermal properties are different in different soil condition. Soil thermal conductivity (K) and soil volumetric heat capacity (C) increase with increasing temperature in unfrozen period, but soil diffusivity (D) has no significant dynamic cycle and it almost keeps a constant level in a certain time. Soil thermal conductivity (K) decreases with increasing temperature during soil frozen period. The C and K increase with increasing soil water content in unfrozen period, while the D decrease with increasing soil water content.</p>

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Open hardware portable dual-probe heat-pulse sensor for measuring soil thermal properties and water content

Computers and Electronics in Agriculture ◽

10.1016/j.compag.2016.12.012 ◽

2017 ◽

Vol 133 ◽

pp. 9-14 ◽

Cited By ~ 8

Author(s):

Giovanni Ravazzani

Keyword(s):

Thermal Properties ◽

Water Content ◽

Heat Pulse ◽

Open Hardware ◽

Pulse Sensor ◽

Soil Thermal Properties ◽

Dual Probe

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A dual-probe heat pulse-based sensor that simultaneously determines soil thermal properties, soil water content and soil water matric potential

Computers and Electronics in Agriculture ◽

10.1016/j.compag.2021.106331 ◽

2021 ◽

Vol 188 ◽

pp. 106331

Author(s):

Yuki Kojima ◽

Tomoyuki Kawashima ◽

Kosuke Noborio ◽

Kohji Kamiya ◽

Robert Horton

Keyword(s):

Thermal Properties ◽

Water Content ◽

Soil Water ◽

Soil Water Content ◽

Heat Pulse ◽

Matric Potential ◽

Soil Thermal Properties ◽

Dual Probe

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Experimental Study to Investigate the Effect of Backfilling Materials on Thermal Performance of Ground Air Heat Exchanger System

Journal of Thermal Science and Engineering Applications ◽

10.1115/1.4044176 ◽

2019 ◽

pp. 1-36 ◽

Cited By ~ 3

Author(s):

Kamal Agrawal ◽

Rohit Misra ◽

Ghanshyam Das Agrawal

Keyword(s):

Thermal Properties ◽

Heat Exchanger ◽

Air Temperature ◽

Thermal Performance ◽

Small Scale ◽

Outlet Section ◽

Experimental Setup ◽

Land Area ◽

Pipe Length ◽

Soil Thermal Properties

In ground-air-heat exchanger (GAHE) system, the heat transfer between air and underground soil largely depends on soil thermal properties and therefore, any improvement in soil thermal properties will shorten the pipe length required and the land area needed for its installation. The objective of the present study is to investigate the effect of different backfilling materials (low cost and locally available) on the thermal performance of GAHE system using a small-scale laboratory experimental setup laboratory scale experimental setup. Seven different backfilling materials have been considered for the study and It was observed that after 6 hours of continuous operation, the drop in air temperature was 6.2°C at outlet section of pipe (2.4m away from inlet) for the native soil. However, for sand-bentonite with graphite as a backfilling material (BFM), the drop in air temperature of 6.2°C was obtained at a pipe length of 1.15m only. Therefore, the use of sand-bentonite with graphite as a BFM reduces the pipe length of GAHE system by more than 50%. The study establishes the fact that the length of pipe and land area requirement for GAHE system can be substantially reduced by using thermally enhanced backfilling materials at the close vicinity of GAHE pipes.

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