Geochemical study for utilization of groundwater heat by open heat pump system in northern Okayama and Akaiwa city areas with low precipitation in Japan

Ozawa

Kusakabe³

et al. 2021

Preprint

Self Cite

An underground liquified petroleum gas (LPG) storage facility was constructed between 1998 and 2006 in Namikata, Imabari City, Ehime Prefecture, Japan, to increase domestic LPG stockpiles. The most important issue during construction and operation of this facility is gas leakage prevention. To thwart water leakage, the water curtain system was constructed according to design standards, and a large amount of deionized seawater (seal water) was continuously injected into the rock mass around the cavern to keep the water level constant during both construction and operation. It is possible to distinguish three end member waters (existing groundwater, seawater or fossil seawater, and seal water) using the salinity and isotope (δ18O) difference because seal water injected underground has almost the same δ18O value as seawater. In this study, continuous observation is carried out using the geochemical techniques for flow analysis with a mixing ratio of three end members in the initial construction period (April 2005 to March 2006) of the LPG underground storage facility. It is determined that existing groundwater and seawater originally distributed in this region are partly replaced by seal water in the cavern.

Section: Chemical Compositionmentioning

confidence: 99%

Geochemical monitoring of deionized seawater injected underground during construction of an LPG rock cavern in Namikata, Japan, for the safety water curtain system

Ozawa

Kusakabe³

et al. 2021

Preprint

Self Cite

“…There are many studies of water movement in alluvial fans (e.g., Mizutani and Oda, 1983;Li et al, 2008;Hidalgo and Cruz-Sanjulian, 2001;Mizutani et al, 2001;Chkirbene et al, 2009;Yuan et al, 2011;Vanderzalm et al, 2011;Tsuchihara et al, 2011). Recently, several reports have been published on the chemical characteristics of groundwater in Japan for the purpose of using groundwater heat (Takizawa 2011;Ioka et al 2013;Iwatake et al 2013;Yamada and Ueda 2018;Mori et al, 2020;Okano et al, 2020;Matsuura et al, 2021). There also has been research on the environmental in uence on water quality and water temperature changes of reinjected groundwater after heat extraction (e.g., Hartog et al 2013;Saito and Komatsu 2014;Park et al 2015;García-Gil et al 2016;Gjengedal et al 2019;Pophillat et al 2020;Pratiwi and Trutnevyte, 2021).…”

Section: Introductionmentioning

confidence: 99%

Flow analysis of groundwater with seasonal variation of temperature, electric conductivity, and oxygen isotope for heat utilization in Sho River alluvial fan, Toyama, Japan

Iwatake

2021

Preprint

Self Cite

Seasonal variation of water temperature, electric conductivity, and oxygen isotope composition was determined in the Sho River alluvial fan, western Toyama Prefecture, to examine groundwater heat utilization for indoor climate control. Samples were collected at 31 sites every 2 months for 1 year and at 11 representative sites monthly. The groundwater sources are a mixture of river water and precipitation. The contribution of precipitation to groundwater is generally small along the Sho River but reaches as much as 80% along the Oyabe River and in the south and west of the alluvial fan. Though the origin of the groundwater differs regionally, water temperature is fixed at about 15°C throughout the year in the northern part of the alluvial fan, and open ground source heat pump systems can be used for cooling and heating there.

“…There are many studies of water movement in alluvial fans [5][6][7][8][9][10][11][12]. Recently, several reports have been published on the chemical characteristics of groundwater in Japan for the purpose of using groundwater heat [13][14][15][16][17][18][19]. There also has been research on the environmental influence on water quality and water temperature changes in reinjected groundwater after heat extraction [20][21][22][23][24][25][26].…”

Section: Introductionmentioning

confidence: 99%

“…There are previous reports on the state of recharge and groundwater flow in the Sho River alluvial fan based on stable isotope and chemical components [5,27,28]. Recently, Iwatake et al [15] reported a linear relationship between δD and δ 18 O values for groundwater and river water in the region and posited that groundwater originated as a mixture of Sho and Oyabe River waters and precipitation in varying proportions. The δD and δ 18 O values for groundwater vary from −47‰ to −65‰ and from −8.1‰ to −10.6‰, respectively.…”

Section: Introductionmentioning

confidence: 99%

“…Recently, Iwatake et al [15] reported a linear relationship between δD and δ 18 O values for groundwater and river water in the region and posited that groundwater originated as a mixture of Sho and Oyabe River waters and precipitation in varying proportions. The δD and δ 18 O values for groundwater vary from −47‰ to −65‰ and from −8.1‰ to −10.6‰, respectively. The range of variation in δD and δ 18 O values is smaller for the Sho River than for the Oyabe River, and the Sho River originates from higher elevations.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Geochemical Study on the Annual Variation of Oxygen Isotope and Chemical Composition of Groundwater in the Sho River Alluvium Fan, Toyama, Japan, as an Investigation of Selected Qualitative Aspects of Efficient Utilization of Groundwater Heat

Iwatake

2021

Geosciences

Self Cite

Seasonal variations of water temperature, electric conductivity, and oxygen isotope and chemical composition of shallow groundwaters and river waters were determined in the Sho River alluvial fan, western Toyama Prefecture, Japan, to examine groundwater heat utilization for indoor climate control. Samples were collected at 31 sites every 2 months for 1 year and at 11 representative sites monthly. In addition, the results of monthly precipitation amount and oxygen isotope composition of precipitation collected within the region during the same period were also taken into account. The sources of the shallow groundwaters are a mixture of river water and precipitation. The contribution of precipitation to groundwater is generally small along the Sho River but reaches as much as 80% along the Oyabe River and in the south and west of the alluvial fan. Though the origin of the groundwater differs regionally, water temperature is fixed at around 15 °C throughout the year in the northern part of the alluvial fan, and open-type ground source heat pump systems can be used for cooling and heating there, if adequate quantitative aquifer properties (exploitable groundwater amounts) are present.