Study of solar powered charcoal/methanol adsorption refrigerator | |
| Author | Hu, Jing |
| Call Number | AIT Diss. no. ET-92-2 |
| Subject(s) | Refrigeration and refrigerating machinery Solar energy--Researc |
| Note | A dissertation submitted in partial fulfillment of the requirement for the degree of Doctor of Engineering, School of Environment, Resources and Development |
| Publisher | Asian Institute of Technology |
| Abstract | Detailed research on the solar powered refrigerator using intermittent activated charcoal and methanol adsorption cycle has been carried out in this study, which includes testing of basic adsorptive properties of some charcoal on methanol, modeling the refrigerator system, sensitivity analysis of the key parameters, optimizing the design and so on. The first chapter of this study describes the necessity of solar refrigeration in developing countries and the principles of different solar refrigeration systems. The charcoal/methanol adsorption refrigeration system is recommended. The objectives and scope of this study are identified. Chapter II reviews the previous research on solar thermal refrigeration . It reveals the further research (this s~udy) as one of the steps to our final target the commercialization of charcoal/methanol system is needed. To compare and understand the adsorptive properties of activated charcoals from developing countries for their potential usage in such adsorption refrigerator, f.ive charcoal samples (from China, Thailand and the U.K.) have been tested by the isobar method on our own developed experimental rig. The tested adsorption data and results (P-T-X relation) of each charcoal tested linearised with Dubinin-Astakhov equation are presented in Chapter III. The ideal COP calculation with tested data shows that the charcoal from developing countries is competitive with imported charcoal for using in a solar adsorption system, and the granular coconut shell based charcoal seems to produce better performance than extruded charcoal. Chapter IV reports that a full scale solar charcoal/methanol refrigeration unit with solar collector area one square meter was constructed in the Energy Park, AIT, for validating the model experimentally. The testing and the str~cture data from this unit is used in modeling validation and as reference data in parametric analysis. The performance of the unit did not meet our design expectation, due to practical problems involved in the manufacture of the components and installation of the system, as discussed in Chapter IV. -ii- An analytical model of the solar powered intermittent charcoal/ methanol adsorption refrigerator with a tubular flat plate collector to simulate its performance under natural conditions has been developed in Chapter V. The model under the assumption of uniform pressure accounts for the heat and mass transfer in charcoal contained in the collector in a two dimensional transient process. The model (computer program) can be used in the engineering design optimization and in studying heat and mass transfers inside the collector. With the help of the experimentally validated computer program the sensitivity of the COPs to some key parameters, and the impact of different operation conditions and structure parameters on the actual (no valve) cycle have been studied and discussed in Chapter VI. Moreover the illustrations of the inhomogeneous phenomena of heat and mass transfer inside the collector tube during the whole cycle are presented and discussed. Based on results of the parametric analysis from the model and experiences and lessons obtained from the designing and constructing of the test unit, an optimized design for such a refrigerator for potential commercialization is proposed and its economics is studied with Net Present Value method in Chapter VII. It is shown that although the market penetration expected might not be high, consideration of environmental effects and the non-availability of energy in remote areas would make such a system attractive. It could be significantly less costly than the existing Photovoltaic systems. |
| Year | 1992 |
| Type | Dissertation |
| School | School of Environment, Resources, and Development (SERD) |
| Department | Department of Energy and Climate Change (Former title: Department of Energy, Environment, and Climate Change (DEECC)) |
| Academic Program/FoS | Energy Technology (ET) |
| Chairperson(s) | Exell, R.H.B. |
| Examination Committee(s) | Mora, Jean-Claude ;Bhattacharya, Sribas C. ;Illangantileke, Sarath G. |
| Scholarship Donor(s) | Government of France; |
| Degree | Thesis (Ph.D.) - Asian Institute of Technology, 1992 |