Skip to main content

LUP Student Papers

LUND UNIVERSITY LIBRARIES

Mitigating Post-Harvest Losses in Bhutan through Solar Food Drying: Optimization and Analysis

Rissler, Christian LU (2023) AEBM05 20222
Department of Architecture and Built Environment
Division of Energy and Building Design
Abstract
Bhutan is the world’s most mountainous country which comes with some logistical difficulties. Due to slow transportation times and lackluster food preservation are the post-harvest losses high which especially affects the rural parts of Bhutan negatively. Solar Food: Reducing post-harvest losses through improved solar drying, is a project set out to design a low-cost solar powered food dryer to improve the quality of food preservation in the Himalayan region and is funded through Swedish Research Council.
This project analyzes the temperature changes seen in each component of the solar dryer, such as the heat exchanger, absorber, heat storage and the drying chamber at different air flows. The collected data is utilized to calculate the... (More)
Bhutan is the world’s most mountainous country which comes with some logistical difficulties. Due to slow transportation times and lackluster food preservation are the post-harvest losses high which especially affects the rural parts of Bhutan negatively. Solar Food: Reducing post-harvest losses through improved solar drying, is a project set out to design a low-cost solar powered food dryer to improve the quality of food preservation in the Himalayan region and is funded through Swedish Research Council.
This project analyzes the temperature changes seen in each component of the solar dryer, such as the heat exchanger, absorber, heat storage and the drying chamber at different air flows. The collected data is utilized to calculate the different efficiencies and heat fluxes. Furthermore, the drying rate was measured for each experiment to determine which flow performs optimally for drying. Thus, getting a good transparency of the system which in turn will assist in identifying potential areas for improvement.
The heat exchanger shows a decrease in performance with increasing flow, however, the heat flux between its sides remains fairly constant regardless of flow. In contrast to this shows the absorber an increase in performance with higher flows, and it plateaus after 10 l/s. The remaining energy in the heat storage at the end of each experiment peaked when the flow was 6 l/s, and 10 l/s short thereafter. The drying chamber had the highest temperatures in experiments with 10 l/s. The drying rate increased with increasing flow and showed no end to this trend.
The results indicate that a larger absorber would likely be the most beneficial modification in a future design. Additionally, a larger more powerful fan would likely result in better drying rates, however this would increase the overall cost and power consumption and the availability of such equipment might be low. (Less)
Popular Abstract
Bhutan is currently struggling with unnecessary food losses due to the logistical challenges posed by its mountainous landscapes, thus, allowing the food to spoil before it reaches the people. To address this issue, the Swedish Research Council has funded a project, coordinated by Lund University, which aims to design a solar food dryer using only locally available material found in Bhutan, which aims to help preserve food and combat food losses. The dryer is going through an iterative process of tests and redesigns, and recently underwent rigorous field testing in Bhutan to reveal potential improvements.
Please use this url to cite or link to this publication:
author
Rissler, Christian LU
supervisor
organization
course
AEBM05 20222
year
type
H2 - Master's Degree (Two Years)
subject
keywords
Solar dryer, Ginger, Drying, Bhutan, Heat exchanger, Heat storage, Solar absorber, Drying rate, Air flow
language
English
additional info

Department affilation moved from v1001471 (Division of Energy and Building Design) to v1000216 (Division of Energy and Building Design) on 2023-07-19 14:57:09.
id
9124967
date added to LUP
2023-06-15 08:32:25
date last changed
2023-07-19 14:57:09
@misc{9124967,
  abstract     = {{Bhutan is the world’s most mountainous country which comes with some logistical difficulties. Due to slow transportation times and lackluster food preservation are the post-harvest losses high which especially affects the rural parts of Bhutan negatively. Solar Food: Reducing post-harvest losses through improved solar drying, is a project set out to design a low-cost solar powered food dryer to improve the quality of food preservation in the Himalayan region and is funded through Swedish Research Council.
This project analyzes the temperature changes seen in each component of the solar dryer, such as the heat exchanger, absorber, heat storage and the drying chamber at different air flows. The collected data is utilized to calculate the different efficiencies and heat fluxes. Furthermore, the drying rate was measured for each experiment to determine which flow performs optimally for drying. Thus, getting a good transparency of the system which in turn will assist in identifying potential areas for improvement.
The heat exchanger shows a decrease in performance with increasing flow, however, the heat flux between its sides remains fairly constant regardless of flow. In contrast to this shows the absorber an increase in performance with higher flows, and it plateaus after 10 l/s. The remaining energy in the heat storage at the end of each experiment peaked when the flow was 6 l/s, and 10 l/s short thereafter. The drying chamber had the highest temperatures in experiments with 10 l/s. The drying rate increased with increasing flow and showed no end to this trend.
The results indicate that a larger absorber would likely be the most beneficial modification in a future design. Additionally, a larger more powerful fan would likely result in better drying rates, however this would increase the overall cost and power consumption and the availability of such equipment might be low.}},
  author       = {{Rissler, Christian}},
  language     = {{eng}},
  note         = {{Student Paper}},
  title        = {{Mitigating Post-Harvest Losses in Bhutan through Solar Food Drying: Optimization and Analysis}},
  year         = {{2023}},
}