成果報告書詳細
管理番号20100000002413
タイトル*平成21年度中間年報 省エネルギー革新技術開発事業 先導研究 蒸気ボイラ代替が可能な産業用高温ヒートポンプに関する要素技術の研究開発
公開日2011/1/25
報告書年度2009 - 2009
委託先名株式会社前川製作所
プロジェクト番号P09015
部署名省エネルギー技術開発部
和文要約和文要約等以下本編抜粋:1. 研究開発の内容及び成果等
(1) 最適冷媒・冷凍機油の探索及び基本物性評価
本ヒートポンプの仕様に対して、沸点、臨界温度、臨界圧力などから使用可能な冷媒候補を選出し、さらに表1 に示すように、ODP,GWP,加熱能力,COPh(加熱COP)等を評価指標として最適冷媒を検討した結果、ノルマルペンタンを選定することとした。ノルマルペンタンは、本開発目標であるCOPhについて当社標準スクリュー圧縮機を用いた場合の試算において3を達成できる見通しがあるとともに、加熱能力も他の候補冷媒と比較しても大きく、ODP=0,GWP=3 と環境影響の極めて少ない冷媒である。炭化水素系であるため可燃性は高いものの、この温度帯で使用可能な他の冷媒候補も可燃性を持つために大きなマイナス要素とはならないと考える。但し、低GWP の新冷媒が開発される可能性があるため、今後も冷媒探索は継続することとした。
冷媒にノルマルペンタンを使用した場合の冷凍機油の選定を行うために、圧縮機の最高使用温度180℃、冷媒との混合時の最低動粘度を5mm2/s を条件として、PAG(ポリアルキレングリコール)、PAO(ポリアルファーオレフィン)、鉱物油等、現在市販されている冷凍機油に対して、熱安定性試験、温度-圧力-溶解度・混合粘度試験、化学的安定性試験を実施した。その結果、PAG 系冷凍機油が最も適した特性を示したが、熱安定性に関しては現在の市販品をベースに高温特性の改善が必要であることが分かったため、次年度行う圧縮機要素試験において、さらに検討を行っていくこととした。
英文要約Title : Elemental technology development of the industrial high temperature heat pump system that is replaceable with steam boiler (FY2009-FY2010) FY2009 Annual Report
 Normal-pentane has been selected as a refrigerant in this heat pump system by considering ODP, GWP, Heating capacity, and COPh. As for the refrigeration oil, we have conducted the tests such as heat stability, solubility depending upon temperature and pressure, mixing viscosity, and chemical stability. The results confirmed that PAG (poly-alkylene-glycol) has the most suitable characteristics among PAG, PAO (poly-α-olefin) and mineral oil. From our experience in high temperature conditions, we have selected oil injected twin screw compressor considering the reliability. Displacement of the compressor has been decided so that the heat pump system has same capacity as once-through boiler that has 0.5 to 2.0 ton/hour steam generation. Test apparatus for elemental technologies such as bearing, mechanical seal, elastomer, and electric motor have been designed. These apparatus enable us to check the performance of each element in various operating conditions. Heat storage temperature of this system is going to be 100 to 150 deg. C. Therefore screening of heat storage material has been conducted from among existing organic materials and molten salts. Consequently, Erythritol and Mannitol that are classified as organic materials have been selected. Thermophysical properties of Erythritol and Mannitol has been measured by differential scanning calorimeter (DSC). As a result, measured value of melting point and latent heat of fusion have good agreement with the value in references. Melting and solidification characteristics have also been examined. Melting point of Erythritol is lower than designed heat storage temperature of our heat pump system 150 deg. C. On the other hand, Mannitol has higher melting point than 150 deg. C. Considering these melting point, we have measured thermophysical property of mixture of those two organic materials. This study reveals the possibility of temperature adjustment of latent heat storage by changing mixing ratio of these two materials. Commercial software was utilized for modeling and calculation to optimize the system. According to the best result of this calculation, heat capacity, shaft power, and COPh were 269.4kW, 87.7kW, and 3.1 respectively by assuming that our standard screw compressor was used and normal-pentane was selected as a working fluid. The outlook for the development of our high temperature heat pump system has been obtained by this result. Assuming the case that there was no suitable heat source which has temperature above 80 deg. C, we have also been studied on cascade system with CO2 heat pump system. The result of this study indicated the total theoretical COP of heating was about 2.0. If we used cooling side of CO2 heat pump system simultaneously, total COP exceeded 3.0. From these studies, we conclude that our high temperature heat pump system has energy saving effect when it is compared with existing steam boiler.
ダウンロード成果報告書データベース(ユーザ登録必須)から、ダウンロードしてください。

▲トップに戻る