1987 Fiscal Year Final Research Report Summary
Characteristics of Plate-Fin Heat Exchanger with Phase Change Material
| Project/Area Number |
61550169
|
|---|
| Research Category |
Grant-in-Aid for General Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Research Field |
Thermal engineering
|
|---|
| Research Institution | Aoyama Gakuin University |
|---|
Principal Investigator |
OKADA Masashi College of Sci. & Enging., Aoyama Gakuin Univ., Professor, 理工学部, 教授 (60082830)
|
|---|
| Project Period (FY) |
1986 – 1987
|
| Keywords | Heat exchanger / Plate-fin / Latent heat / Thermal energy storage / Cross flow / Effectiveness / overall heat-transfer coefficient / 周期運転 |
|---|
| Research Abstract |
Latent heat-of-fusion energy systems are useful, because they are able to supply continuously the thermal energy to the lower-temperature fluid even when the supply of heat from the higher-temperature fluid varies with time. In the present report a plate-fin heat exchanger with a phase change material (PCM) was studied. The present heat exchanger, which was made with 310 copper square-tubes with 9.5 mm sides, 0.5 mm thickness, and 300 mm length, was a single-pass cross-flow type, both fluids (air) unmixed. The n-octadecane, of which the fusion temperature is 28.0 C, was used as the PCM. The 2.13 kg PCM was filled in the 154 tubes. three kinds of experiments were carried out and the inlet and outlet temperatures and the temperatures in the PCM were measured. In the first experiments, the effectiveness and the overall heat-transfer coefficient were obtained at steady states. The plate-fin improved the effectiveness by about 10 %. By the calculations of steady three-dimensional heat conduction, the effects of the parameters, --- dimensions, thermal properties, and heat transfer coefficients of air ---, on the overall heat-transfer coefficients were obtained clearly. In the second experiments, since the higher-temperature air-flow was stoped, the outlet temperatures of the lower-temperature air were maintained at the constant temperatures for 90-150 minutes. In the third experiments, the higher-temperature air was flowed intermittently with an equal interval. The flow rates were equally 400 1/min, and the inlet temperatures of air were 70 C and 10 C, and the period was 2 hours. The outlet temperature of the lower-temperature air was between 20 C <plus-minus> 2.5 C. The above transient and periodical experiments showed that the present heat exchanger with PCM had useful characters of latent heat storagf
|
