| Author | Yasin, Muhammad |
| Call Number | AIT Thesis no. ET-93-12 |
| Subject(s) | Heat recovery--Equipment and supplies
|
| Note | A thesis submitted in partial fullfillment of the requirement for the degree of Master of Engineering. |
| Publisher | Asian Institute of Technology |
| Series Statement | Thesis ; no. ET-93-12 |
| Abstract | This experimental and theoretical study presents a comparison among two gravity assisted heat pipe heat exchangers and a moving packed bed heat exchanger. In one gravity assisted heat pipe heat exchanger design, the evaporator and condenser sections consisted of three rows of heat pipes and each row of heat pipes were connected to a common header at the top and the bottom. The upper header of the evaporator was connected to upper condenser header by a copper tube and similarly the lower headers were also connected. In the other design, evaporator and condenser sections were formed by the lower and upper parts of the individual heat pipes. The heat pipes in both the designs were put in a staggered arrangement. The moving packed bed heat exchanger consisted of a mild steel column fitted with a central screw and water coils (copper tubes wrapped around three metallic cylinder). The water coils were immersed in a 30 cm high bed of particles in such a way that they formed staggered arrangement. The particles circulate around immersed surface due to the central screw rotation. The effectiveness of air-to air gravity assisted heat pipe heat exchanger was found higher for lower flow rate while heat transfer coefficient was found higher at lower flow rate. Simulated results shows that the effectiveness of gravity assisted heat pipe heat exchanger is higher for higher numbers of fins and greater number of rows of heat pipes. The moving packed bed heat exchanger (MPBHE) was tested for two different materials i.e. copper particles of length about 1.00 mm and diameter 1.40 mm and sand with average diameter 500 microns. The outside heat transfer coefficient for copper was found higher than for sand particles. The effectiveness of MPBHE was predicted for different particle sizes, rate of flow of particles, length of water coils, and diameter of immersed surface. It was found that the effectiveness increases as immersed tube length , diameter of tube, and flow rate ofparticles increases. The effectiveness decreases as particle size i.e. diameter of particle increases. One performance parameter i.e. effectiveness was chosen to compare the performance of moving packed bed heat exchanger with gravity assisted heat pipe heat exchanger. The effectiveness of GAHPHE was found higher than MPBHE for same bare tube area. |
| Year | 1993 |
| Corresponding Series Added Entry | Asian Institute of Technology. Thesis ; no. ET-93-12 |
| Type | Thesis |
| 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) | Bhattacharya, Sribas C. |
| Examination Committee(s) | Surapong Chirarattananon;Supachart Chungpaibulpattana |
| Scholarship Donor(s) | The Government of Denmark. |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 1993. |