Bulletin of the Geological Survey of Japan Top Page

Bulletin of the Geological Survey of Japan Vol.60 No.9/10 (2009)

Cover photograph | Table of Contents | Abstract

Special Issue: Study on geothermal heat pump application in tropical Asia

Cover photograph

   These pictures show the geothermal heat-pump system installed at an office of Department of Groundwater Resources in Kamphaengphet, Thailand in October, 2006 through our research project.

   Top pictures: installation of double U-tubes into a heat exchange borehole. Left: extending the U-tubes. Right: inserting the U-tube into the borehole.

   Down left: connection of U-tube and plastic pipes from the heat exchange borehole to a heat-pump. Down right: cool air from the fan coil in a room, which is cooled by the geothermal heat-pump system. It's cool!

(Photo and caption: Kasumi Yasukawa)

Table of Contents

Title	Author	PDF
Preface
Preface	Kasumi Yasukawa, Isao Takashima, Youhei Uchida, Norio Tenma (457)	60_09_01.pdf [500 KB]
Article
Groundwater Temperature Survey for Geothermal Heat Pump Application in Tropical Asia.	Kasumi Yasukawa, Youhei Uchida, Norio Tenma, Yusaku Taguchi, Hirofumi Muraoka, Takemasa Ishii, Jittrakorn Suwanlert, Somkid Buapeng and Nguyen Thi Ha (459-467)	60_09_02.pdf [1.5 MB]
Geothermal heat pump application for space cooling in Kamphaengphet, Thailand.	Kasumi Yasukawa, Isao Takashima, Youhei Uchida, Norio Tenma and Oranuj Lorphensri (491-501)	60_09_04.pdf [1.9 MB]
Subsurface thermal influence of experimental geothermal heat pump system operation for space cooling in Kamphaengphet, Thailand.	Norio Tenma, Kasumi Yasukawa, Isao Takashima, Youhei Uchida, Oranuj Lorphensri and George Zyvoloski (503-509)	60_09_05.pdf [1.6 MB]

 

Abstract

Groundwater Temperature Survey for Geothermal Heat Pump Application in Tropical Asia.

Kasumi Yasukawa, Youhei Uchida, Norio Tenma, Yusaku Taguchi, Hirofumi Muraoka, Takemasa Ishii, Jittrakorn Suwanlert, Somkid Buapeng and Nguyen Thi Ha

   In east Asia, where significant economical growth in this century is expected, intensive installation of geothermal heat pump (GHP) system may be important from both energy security and environmental protection aspects. Detailed underground temperature survey is essential for its promotion. Possibility of geothermal heat-pump application in tropical Asia is studied based on groundwater temperature data. Although generally geothermal heat-pump system may not have thermal merit for space cooling in tropics because subsurface temperature is generally higher than average atmospheric temperature, there may be some places in tropical regions where underground can be used as "cold heat-source". In order to confirm this possibility, groundwater temperature surveys were widely conducted in the Chao-Phraya plain, Thailand and Red-river plain, Vietnam to compare with atmospheric temperature data. As a result, regional variation of subsurface temperature at depths from 20 to 50 m of 3.4 K was observed in the whole Chao-Phraya plain while that of 2.0 K was observed in the Red-river plain. In some cities, subsurface temperature lower than monthly mean maximum atmospheric temperature for 5 K or more over four months was identified. Thus underground may be used as cold heat-source even in parts of tropical regions.

Geothermal heat pump application for space cooling in Kamphaengphet, Thailand.

Kasumi Yasukawa, Isao Takashima, Youhei Uchida, Norio Tenma and Oranuj Lorphensri

   An experimental geothermal heat pump system for space cooling was installed in Kamphaengphet, Thailand in 2006 and used for 17 months. Temeprature changes in the subsurface heat exchange tube and its surroundings were monitored to evaluate subsurface thermal properties and short- and long-term effects of operation of the system. Subsurface temperuatre increase due to the system operation recovered in few days and no long-term effect was observed after a year of operation. Room and atmospheric temperatures and electricity consumprion of the system were also measured through the period. Temperatures and flow rates of primary and secondary fluids were measured as well. As a result, a system COP (coefficient of performance) of around 3 was obtained for its stable operation period. The results of temperature measurements and calculation of system performances is presented in this paper.

Subsurface thermal influence of experimental geothermal heat pump system operation for space cooling in Kamphaengphet, Thailand

Norio Tenma, Kasumi Yasukawa, Isao Takashima, Youhei Uchida, Oranuj Lorphensri and George Zyvoloski

   An experimental geothermal heat pump (GHP) system operation for space cooling was conducted in Kamphaengphet, Thailand from October, 2006 to March, 2008. Temperature sensors were installed in the heat exchange tube to monitor underground temperature for this test. Using this measured data, numerical simulation was performed in order to estimate subsurface thermal influence of the GHP system operation for space cooling. As the results of this calculation, the authors consider that the thermal influence of the GHP system operation at this test site is quite limited.