ゼオライト系吸着材を用いた一体型吸着式ヒートポンプの温水加熱性能の評価 Evaluation of Water-warming Characteristics of an Integrated Adsorption Heat Pump with Zeolite Absorbent

本研究では，ゼオライト系吸着材を用いて，吸着器と蒸発／凝縮器を同一の容器に収納した一体型吸着式ヒートポンプユニットの評価を行った．蒸発／凝縮温度293 K，吸着温度303 K，脱着温度363 K，切り替え時間150 sの条件において，理論出力4.35 kW，COP 1.64に対して，今回試作した一体型吸着式ヒートポンプユニットでは出力3.27 kW，COP 1.37を得た．サイクル切り替え直後は熱交換器や吸着材などの顕熱による加熱が支配的となり，吸着熱や凝縮熱の生成速度が遅いため，切り替え時間を短くするとCOPが小さくなった．外気温が下がると蒸発性能が低下し，給水温度が高くなると吸着温度の上昇に伴って吸着量が減少するため，COPや出力が低下した．

An integrated adsorption heat pump with zeolite absorbent, which contained an adsorber and evaporator/condenser in the same vessel, was evaluated. At evaporation/condensation temperatures of 293 K, an adsorption temperature of 303 K, a desorption temperature of 363 K and a cycle time of 150 s, an output thermal power of 3.27 kW and a COP of 1.37 were obtained against theoretical power of 4.35 kW and COP of 1.64. The COP decreased with shortening the adsorption/ desorption cycle time, because the rates of generation of adsorpton and latent heat were slow, and the sensible heat of adsorbent and heat exchanger was dominant immediately after switching the cycle. The output thermal power and COP decreased at low ambient temperature due to a reduction of evaporation performance, and at high supplied water temperature due to a decrease of an amount of adsorbed water.