مطالعه عددي عملكرد چيلر جذبي خورشيدي با جفت كاري كربن فعال/متانول

Numerical study on the performance of a solar adsorption chiller with working pair of activated carbon / Methanol

ﻫﺪف اﻳﻦ ﻣﻘﺎﻟﻪ ﺑﺮرﺳﻲ ﻋﺪدي ﻋﻤﻠﻜﺮد ﻳﻚ ﺳﻴﺴﺘﻢ ﺳﺮﻣﺎﻳﺸﻲ ﺟﺬب ﺳﻄﺤﻲ ﻓﻴﺰﻳﻜﻲ ﺧﻮرﺷﻴﺪي اﺳﺖ ﻛﻪ در آن از ﻛﺮﺑﻦ ﻓﻌﺎل/ ﻣﺘﺎﻧﻮل ﺑﻪ ﻋﻨﻮان ﺟﻔﺖ ﻛﺎري اﺳﺘﻔﺎده ﻣﻲﺷﻮد ﻛﻪ درون ﻳﻚ ﻛﻠﻜﺘﻮر ﺧﻮرﺷﻴﺪي ﺳﻬﻤﻮي ﺷﻜﻞ ﻗﺮار داده ﺷﺪه اﺳﺖ. ﻣﺪل رﻳﺎﺿﻲ ﺣﺎﻛﻢ ﺑﺮ ﻣﺴﺄﻟﻪ ﺑﺮ اﺳﺎس ﻣﻌﺎدﻻت ﺑﻘﺎء ﺟﺮم، ﺑﻘﺎء اﻧﺮژي و ﺗﺮﻣﻮدﻳﻨﺎﻣﻴﻚ ﻓﺮاﻳﻨﺪ ﺟﺬب ﺳﻄﺤﻲ ﻓﻴﺰﻳﻜﻲ ﺑﺪﺳﺖ آﻣﺪه اﺳﺖ. ﻣﻌﺎدﻻت ﺑﻪ روش اﺧﺘﻼف ﻣﺤﺪود ﻛﺎﻣﻼ ﺿﻤﻨﻲ ﮔﺴﺴﺘﻪ ﺳﺎزي و ﺗﻮﺳﻂ ﺑﺮﻧﺎﻣﻪ ﻛﺎﻣﭙﻴﻮﺗﺮي ﻓﻮرﺗﺮن ﺷﺒﻴﻪﺳﺎزي ﺷﺪه اﺳﺖ. اﻳﻦ ﻣﺪل از ﻃﺮﻳﻖ ﻣﻘﺎﻳﺴﻪ ﺑﺎ ﻧﺘﺎﻳﺞ ﭘﮋوﻫﺶﻫﺎي آزﻣﺎﻳﺸﮕﺎﻫﻲ و ﻋﺪدي ﭘﻴﺸﻴﻦ اﻋﺘﺒﺎرﺳﻨﺠﻲ ﺷﺪ. در ﻫﺮ ﻧﻘﻄﻪ از ﺑﺴﺘﺮ دﻣﺎي ﺑﺴﺘﺮ، ﻓﺸﺎر ﺑﺴﺘﺮ و ﺟﺮم ﻣﺒﺮد ﺟﺬب ﺷﺪه در ﻃﻮل ﻓﺮاﻳﻨﺪ ﺟﺬب/دﻓﻊ ﺳﻄﺤﻲ ﻓﻴﺰﻳﻜﻲ ﻣﺤﺎﺳﺒﻪ ﺷﺪه اﺳﺖ. ﻋﻼوه ﺑﺮ اﻳﻦ ﺗﺄﺛﻴﺮ ﻗﻄﺮ ﺑﺴﺘﺮ، ﻣﻴﺰان ﺗﺎﺑﺶ ﺧﻮرﺷﻴﺪي، دﻣﺎي ﻣﻨﺒﻊ ﺳﺮد، دﻣﺎ و ﻓﺸﺎر اواﭘﺮاﺗﻮر و ﻛﻨﺪاﻧﺴﻮر ﺑﺮ روي ﺿﺮﻳﺐ ﻋﻤﻠﻜﺮد ﺧﻮرﺷﻴﺪي و ﺗﻮان ﺗﺒﺮﻳﺪ وﻳﮋهي ﺳﻴﺴﺘﻢ ﻣﻮرد ﺑﺮرﺳﻲ ﻗﺮار ﮔﺮﻓﺖ. ﻣﻄﺎﺑﻖ ﻣﺪل آزﻣﺎﻳﺸﮕﺎﻫﻲ ﺳﺎﺧﺘﻪ ﺷﺪه و ﺷﺮاﻳﻂ ﻛﺎري ﺳﻴﺴﺘﻢ، ﻣﻴﺰان ﺿﺮﻳﺐ ﻋﻤﻠﻜﺮد ﺧﻮرﺷﻴﺪي و ﺗﻮان ﺗﺒﺮﻳﺪ وﻳﮋهي ﺳﻴﺴﺘﻢ ﺑﻪ ﺗﺮﺗﻴﺐ ﺑﺮاﺑﺮ 0.12 و 1-Wkg 45.6 ﻣﻲﺑﺎﺷﺪ.

In this article an adsorption refrigeration system with Activated Carbon/Methanol as adsorption working pair placed in a parabolic trough solar collector have been studied. A one dimensional numerical model based on heat and mass transfer equation and adsorption thermodynamic within the porous medium is developed. Equations has been discretized through fully implicit finite difference method in cylindrical coordinate. Discretized equations is written in FORTRAN program. The simulated code has been validated by comparison via experimental work and former numerical results. The code at each point computes bed temperature, pressure and adsorbed mass of refrigerant inside the adsorbent bed. In additional effect of some parameters such as bed diameter, solar irradiance, cooling source temperature, evaporator and condenser temperature and pressure has been investigated. Effect of these parameters on the refrigeration adsorption system has shown through variation of the solar coefficient of performance (COPS) and specific cooling power (SCP). Under the operating conditions of evaporation temperature T_ev=0 ℃, condensing temperature T_con=30 ℃ and adsorption temperature T_ads=25 ℃ according to the experimental model, COPS and SCP are found to be 0.12 and 45.6 w1kg-1 respectively.