Heat recovery from vacuum brazing furnaces
(2023) ABKM01 20231Division of Building Services
- Abstract
- By partly replacing the use of primary energy sources with waste heat recovery, climate and environmental goals for the future will be closer at hand. This thesis investigates the waste heat potential of Alfa Laval's vacuum brazing furnaces in Ronneby and alternative ways of integrating the furnace's waste heat into the building's HVAC system.
The main challenge was the low-temperature qualities associated with the cooling water, which constituted an obstacle to recovering waste heat without any additional equipment, such as a heat pump. Tests and analyses performed in this thesis are, therefore, mainly aimed at raising the temperature quality of the cooling water. A test was conducted on the cooling system to calculate the energy... (More) - By partly replacing the use of primary energy sources with waste heat recovery, climate and environmental goals for the future will be closer at hand. This thesis investigates the waste heat potential of Alfa Laval's vacuum brazing furnaces in Ronneby and alternative ways of integrating the furnace's waste heat into the building's HVAC system.
The main challenge was the low-temperature qualities associated with the cooling water, which constituted an obstacle to recovering waste heat without any additional equipment, such as a heat pump. Tests and analyses performed in this thesis are, therefore, mainly aimed at raising the temperature quality of the cooling water. A test was conducted on the cooling system to calculate the energy losses with regards to the cooling water. In one 11-hour cycle, 1546 kWh of electricity was used to heat the furnace. Out of that, 1360 kWh was cooled off to the atmosphere.
Additionally, a test on the furnace's clean-up cycle was performed. The maximum cooling water temperature reached during this test was 44°C. This shows excellent potential in the possibility of recovering the waste heat without any additional equipment.
Further, this thesis aims to broaden the knowledge around areas concerning increased cooling water temperatures, which, during the writing, seemed to have a gap in documented sources. The results of this thesis indicate that a temperature quality increase of the furnaces' cooling water is possible. Cooling system changes have also been suggested, which is necessary for an efficient and safe heat recovery. (Less) - Popular Abstract
- The thesis investigates the waste heat potential of Alfa Laval’s vacuum brazing furnaces in Ronneby and alternative ways of integrating the furnaces waste heat to the buildings HVAC system on site.
Alfa Laval in Ronneby uses vacuum brazing furnaces in its manufacturing process. These furnaces demand water cooling, and today the cooling energy is not recovered. The cooling temperature of the water is kept relatively low due to the risk of hot surfaces and personal safety, but also because of specifications from the furnace manufacturer. This thesis aimed to study how to raise the temperature of the cooling water in and out from the vacuum brazing furnace, and by that increase the temperature quality, which makes it easier to recover. By... (More) - The thesis investigates the waste heat potential of Alfa Laval’s vacuum brazing furnaces in Ronneby and alternative ways of integrating the furnaces waste heat to the buildings HVAC system on site.
Alfa Laval in Ronneby uses vacuum brazing furnaces in its manufacturing process. These furnaces demand water cooling, and today the cooling energy is not recovered. The cooling temperature of the water is kept relatively low due to the risk of hot surfaces and personal safety, but also because of specifications from the furnace manufacturer. This thesis aimed to study how to raise the temperature of the cooling water in and out from the vacuum brazing furnace, and by that increase the temperature quality, which makes it easier to recover. By increasing the temperature quality of the cooling water, additional technology such as heat pumps wouldn't be necessary. Heat pumps use electricity to transfer heat between a hot and a cold space. However, the furnaces are believed to have the potential for high enough temperatures themselves, which could save all the installation and operating costs of those pumps. Different ways of integrating the recovered heat to the building's HVAC system on site at Alfa Laval Ronneby were also studied. The main challenge was the low temperature qualities associated with the cooling water, which posed an obstacle to efficient waste heat recovery. Tests and analyses performed in the thesis are therefore mainly aimed at raising the temperature quality of the cooling water. During the mapping of the current cooling systems used for the furnaces, it became clear that the suggested cooling system changes were necessary if an increase of the cooling water temperature would be possible in a safe and controlled way.
When considering for example three furnaces that were studied, the suggested solutions and implementations have the potential to replace 1.2 GWh of purchased district heating energy yearly, seen in Figure 1. That would account for 71% of Alfa Laval's current total district heating usage. (Less)
Please use this url to cite or link to this publication:
http://lup.lub.lu.se/student-papers/record/9125963
- author
- Robertsson, Oliver LU and Wikman, Rasmus
- supervisor
- organization
- course
- ABKM01 20231
- year
- 2023
- type
- H2 - Master's Degree (Two Years)
- subject
- keywords
- Waste heat, Vacuum furnace, Heat recovery, HVAC
- report number
- TVIT-5099
- other publication id
- ISRN LUTVDG/TVIT—23/5099--SE(75)
- language
- English
- additional info
- Examinator: Åsa Wahlström
- id
- 9125963
- date added to LUP
- 2023-10-23 13:39:46
- date last changed
- 2023-10-23 13:41:33
@misc{9125963,
abstract = {{By partly replacing the use of primary energy sources with waste heat recovery, climate and environmental goals for the future will be closer at hand. This thesis investigates the waste heat potential of Alfa Laval's vacuum brazing furnaces in Ronneby and alternative ways of integrating the furnace's waste heat into the building's HVAC system.
The main challenge was the low-temperature qualities associated with the cooling water, which constituted an obstacle to recovering waste heat without any additional equipment, such as a heat pump. Tests and analyses performed in this thesis are, therefore, mainly aimed at raising the temperature quality of the cooling water. A test was conducted on the cooling system to calculate the energy losses with regards to the cooling water. In one 11-hour cycle, 1546 kWh of electricity was used to heat the furnace. Out of that, 1360 kWh was cooled off to the atmosphere.
Additionally, a test on the furnace's clean-up cycle was performed. The maximum cooling water temperature reached during this test was 44°C. This shows excellent potential in the possibility of recovering the waste heat without any additional equipment.
Further, this thesis aims to broaden the knowledge around areas concerning increased cooling water temperatures, which, during the writing, seemed to have a gap in documented sources. The results of this thesis indicate that a temperature quality increase of the furnaces' cooling water is possible. Cooling system changes have also been suggested, which is necessary for an efficient and safe heat recovery.}},
author = {{Robertsson, Oliver and Wikman, Rasmus}},
language = {{eng}},
note = {{Student Paper}},
title = {{Heat recovery from vacuum brazing furnaces}},
year = {{2023}},
}