A small-scale silica gel-water adsorption system for domestic air conditioning and water heating by the recovery of solar energy

Abstract

A small-scale silica gel-water adsorption system with modular adsorber, which utilizes solar energy to achieve the cogeneration of domestic air conditioning and water heating effect, is proposed and investigated in this paper. A heat recovery process between two adsorbers and a mass recovery process between two evaporators are adopted to improve the overall cooling and heating performance. First, the adsorption system is tested under different modes (different mass recovery, heat recovery, and cogeneration time) to determine the optimal operating conditions. Then, the cogeneration performance of domestic cooling and water heating effect is studied at different heat transfer fluid temperatures. The results show that the optimal time for cogeneration, mass recovery, and heat recovery are 600 s, 40 s, and 40 s, respectively. When the inlet temperature of hot water is around 85°C, the largest cooling power and heating power are 8.25 kW and 21.94 kW, respectively. Under the condition of cooling water temperature of 35°C, the obtained maximum COP_c, COP_h, and SCP of the system are 0.59, 1.39, and 184.5 W/kg, respectively.

Keywords

silica gel-water / heat and mass recovery / solar energy / domestic cooling and heating

References

[1] Wang R Z, Wang L W, Wu J Y. Adsorption Refrigeration Technology: Theory and Application. Singapore: John Wiley & Sons, 2014

[2] Sah R P, Choudhury B, Das R K. A review on adsorption cooling systems with silica gel and carbon as adsorbents. Renewable & Sustainable Energy Reviews, 2015, 45: 123–134

[3] San J Y, Tsai F K. Testing of a lab-scale four-bed adsorption heat pump. Applied Thermal Engineering, 2014, 70(1): 274–281

[4] Aristov Y I. Challenging offers of material science for adsorption heat transformation: a review. Applied Thermal Engineering, 2013, 50(2): 1610–1618

[5] Deshmukh H, Maiya M P, Srinivasa Murthy S. Continuous vapour adsorption cooling system with three adsorber beds. Applied Thermal Engineering, 2015, 82: 380–389

[6] Wang R Z, Ge T S, Chen C J, Ma Q, Xiong Z Q. Solar sorption cooling systems for residential applications: options and guidelines. International Journal of Refrigeration, 2009, 32(4): 638–660

[7] Chen C J, Wang R Z, Xia Z Z, Kiplagat J K, Lu Z S. Study on a compact silica gel-water adsorption chiller without vacuum valves: design and experimental study. Applied Energy, 2010, 87(8): 2673–2681

[8] Khalil A, El-Agouz E S A, El-Samadony Y A F, Sharaf M A. Experimental study of silica gel/water adsorption cooling system using a modified adsorption bed. Science and Technology for the Built Environment, 2016, 22(1): 41–49

[9] Wang C D, Zhang J P, Yang Q, Li N, Sumathy K. Study of adsorption characteristics in silica gel-water adsorption refrigeration. Applied Energy, 2014, 113: 734–741

[10] Khan M Z I, Alam K C A, Saha B B, Akisawa A, Kashiwagi T. Performance evaluation of multi-stage, multi-bed adsorption chiller employing re-heat scheme. Renewable Energy, 2008, 33(1): 88–98

[11] Rezk A R M, Al-Dadah R K. Physical and operating conditions effects on silica gel/water adsorption chiller performance. Applied Energy, 2012, 89(1): 142–149

[12] Akahira A, Alam K C A, Hamamoto Y, Akisawa A, Kashiwagi T. Mass recovery adsorption refrigeration cycle—improving cooling capacity. International Journal of Refrigeration, 2004, 27(3): 225–234

[13] Pan Q W, Wang R Z, Lu Z S, Wang L. Thermodynamic analysis and performance simulation of different kinds of mass recovery processes applied in adsorption refrigeration system. HVAC & R Research, 2014, 20(3): 311–319

[14] Liu Y L, Wang R Z, Xia Z Z. Experimental performance of a silica gel-water adsorption chiller. Applied Thermal Engineering, 2005, 25(2–3): 359–375

[15] Zajaczkowski B. Optimizing performance of a three-bed adsorption chiller using new cycle time allocation and mass recovery. Applied Thermal Engineering, 2016, 100: 744–752

[16] Alam K C A, Akahira A, Hamamoto Y, Akisawa A, Kashiwagi T. A four-bed mass recovery adsorption refrigeration cycle driven by low temperature waste/renewable heat source. Renewable Energy, 2004, 29(9): 1461–1475

[17] Akahira A, Amanul Alam K C, Hamamoto Y, Akisawa A, Kashiwagi T. Mass recovery four-bed adsorption refrigeration cycle with energy cascading. Applied Thermal Engineering, 2005, 25(11–12): 1764–1778

[18] Li S L, Xia Z Z, Wu J Y, Li J, Wang R Z, Wang L W. Experimental study of a novel CaCl₂/expanded graphite-NH₃ adsorption refrigerator. International Journal of Refrigeration, 2010, 33(1): 61–69

[19] Wang X, Chua H T, Ng K C. Experimental investigation of silica gel-water adsorption chillers with and without a passive heat recovery scheme. International Journal of Refrigeration, 2005, 28(5): 756–765

[20] Chang W S, Wang C C, Shieh C C. Design and performance of a solar-powered heating and cooling system using silica. Applied Thermal Engineering, 2009, 29(10): 2100–2105

[21] Luo H L, Wang R Z, Dai Y J, Wu J Y, Shen J M, Zhang B B. An efficient solar-powered adsorption chiller and its application in low-temperature grain storage. Solar Energy, 2007, 81(5): 607–613

[22] Pan Q W, Wang R Z, Wang L W, Liu D. Design and experimental study of a silica gel-water adsorption chiller with modular adsorbers. International Journal of Refrigeration, 2016, 67: 336–344

[23] Lu Z, Wang R Z, Xia Z Z, Gong L. Experimental investigation adsorption chillers using micro-porous silica gel-water and compound adsorbent-methanol. Energy Conversion and Management, 2013, 65: 430–437

[24] Vodianitskaia P J, Soares J J, Melo H, Gurgel J M. Experimental chiller with silica gel: adsorption kinetics analysis and performance evaluation. Energy Conversion and Management, 2017, 132: 172–179

[25] Pan Q W, Wang R Z, Wang L W. Comparison of different kinds of heat recoveries applied in adsorption refrigeration system. International Journal of Refrigeration, 2015, 55: 37–48

Acknowledgments

This work is supported by the Key Project of the National Natural Science Foundation of China for international academic exchanges (Grant No. 51561145012) and the National Natural Science Foundation of China (Grant No. 51576120).

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2020 Higher Education Press