Comparison of coefficient of performance (COP) between an underground water source heat pump system and an air source heat pump system for greenhouse heating in cold and snowy areas in Japan

• FURUNO Shinsuke

  Agricultural Technique Improvement Research Office, Shonai Area General Branch, Administration of Yamagata Prefectural Office

• OKUSHIMA Limi

  Department of Rural Technologies, National Institute for Rural Engineering

• SASE Sadanori

  College of Bioresource Sciences, Nihon University

書誌事項

タイトル別名

• Comparison of coefficient of performance (<i>COP</i>) between an underground water source heat pump system and an air source heat pump system for greenhouse heating in cold and snowy areas in Japan

抄録

　With the increasing cost of fossil fuels, the use of air source heat pumps (ASHPs) for greenhouse heating has become widespread in Japan. In general, the coefficient of performance (COP) of a ASHP depends on the outside air conditions, while the same is not expected for an underground water source heat pump (UWS-HP) system. Few studies have examined these comparisons in colder regions. In the present study, a UWS-HP system is developed, and the COPs of a UWS-HP (COP_uws) and a ASHP (COP_air) for use in greenhouse heating are investigated. The key results of the study can be summarized as follows:<br>1) COP_uws ranged from 4.0 to 5.7 and had an average value of 4.9. COP_uws was generally higher than COP_air regardless of the outside temperature.<br>2) COP_air ranged from 2.2 to 4.5 and had an average value of 3.4. Using the average hourly heat transfer coefficient obtained from the analysis of the UWS-HP, COP_air was found to decrease with decreasing outside temperature.<br>3) COP_air decreased with increasing frequency of the reverse cycle defrosting.<br>4) COP_uws was not affected by the outside temperature, and inlet and outlet water temperature was approximately 1°C and 11.5°C respectively.

収録刊行物

• 農業気象

  農業気象 72 (3-4), 173-177, 2016

  日本農業気象学会

キーワード

• Coefficient of performance (<i>COP</i>)
• Cold and snowy areas
• Heating load
• Renewable energy
• Underground water

詳細情報

• CRID: 1390282679645715968
• NII論文ID: 40020932837
• NII論文ID: 130006847565
• NII書誌ID: AN00200732
• DOI: 10.2480/agrmet.d-15-00029
• ISSN: 18810136
• ISSN: 00218588
• NDL書誌ID: 027599086
• Web Site: http://id.ndl.go.jp/bib/027599086
• Web Site: https://ndlsearch.ndl.go.jp/books/R000000004-I027599086
• Web Site: https://www.jstage.jst.go.jp/article/agrmet/72/3-4/72_D-15-00029/_pdf
• 本文言語コード: en
• データソース種別:
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  • NDL
  • Crossref
  • CiNii Articles
• 抄録ライセンスフラグ: 使用不可