Investigation of waste heat sources and their utilization in process industry
Valtonen, Sari (2021)
Valtonen, Sari
2021
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Julkaisun pysyvä osoite on
https://urn.fi/URN:NBN:fi-fe2021052631703
https://urn.fi/URN:NBN:fi-fe2021052631703
Tiivistelmä
Waste heat is a commonly used term for such heat energy that is not utilized in the process but dissipates to the environment unused. Waste heat is a by-product which can be found in various streams exiting the process, and it can be categorized according to its temperature into three categories: temperature below 50 °C, temperature between 50...100 °C and temperature above 100 °C.
Utilization of waste heat is a means to improve the energy efficiency of a process or a plant. Actions towards improving energyefficiency are incorporated to strategies and legislation on the national and international level as actions to increase sustainability and reduce CO2and other emissions are crucial in ensuring a functional and viable society and environment in the future.
The theoretical, technical and economic potentials of waste heat sources must be evaluated when its utilization is contemplated. Theoretical potential describes the physical properties of the waste heat source and its possible limitations, technical potential determines the technologies available for heat recovery, and economic potential evaluates the investment’s economic feasibility.
The heating and cooling demands as well as minimal utility demands for a process can systematically be analysed with Pinch Analysis. This analysis data can be utilized to determine the potentials for heat recovery through process integration as well as to evaluate the how energy efficiently the process is currently being operated.
According to the Laws of Thermodynamics, heat energy is interconvertible and energy will spontaneously flow between substances from a higher temperature to a lower one. These principled must be taken into account when the potentials for waste heat recovery are identified and suitable techniques for heat recovery are contemplated. Heat transfer between the waste heat source and a heat sink can be carried out in the same temperature with passive or by increasing the temperature or transforming heat energy to electric energy with active means. Passive means include heat transfer through heat exchangers and storage of heat. Active means include, for example, heat pumps and Organic Rankine Cycle.
A case study for the process of Finnfeeds Finland Co Naantali factory was carried out in this survey, in order to identify and evaluate the waste heat sources available in their operation and to contemplate on potentials for waste heat utilization. The process was analysed with Pinch Analysis and based on this analysis, there is a limited potential for waste heat recovery without increasing the temperature as the temperature of most of the identified waste heat sources remains relatively low. Several preliminary investment proposals were sketched to demonstrate the potentials for waste heat utilization both internally and externally.
Utilization of waste heat is a means to improve the energy efficiency of a process or a plant. Actions towards improving energyefficiency are incorporated to strategies and legislation on the national and international level as actions to increase sustainability and reduce CO2and other emissions are crucial in ensuring a functional and viable society and environment in the future.
The theoretical, technical and economic potentials of waste heat sources must be evaluated when its utilization is contemplated. Theoretical potential describes the physical properties of the waste heat source and its possible limitations, technical potential determines the technologies available for heat recovery, and economic potential evaluates the investment’s economic feasibility.
The heating and cooling demands as well as minimal utility demands for a process can systematically be analysed with Pinch Analysis. This analysis data can be utilized to determine the potentials for heat recovery through process integration as well as to evaluate the how energy efficiently the process is currently being operated.
According to the Laws of Thermodynamics, heat energy is interconvertible and energy will spontaneously flow between substances from a higher temperature to a lower one. These principled must be taken into account when the potentials for waste heat recovery are identified and suitable techniques for heat recovery are contemplated. Heat transfer between the waste heat source and a heat sink can be carried out in the same temperature with passive or by increasing the temperature or transforming heat energy to electric energy with active means. Passive means include heat transfer through heat exchangers and storage of heat. Active means include, for example, heat pumps and Organic Rankine Cycle.
A case study for the process of Finnfeeds Finland Co Naantali factory was carried out in this survey, in order to identify and evaluate the waste heat sources available in their operation and to contemplate on potentials for waste heat utilization. The process was analysed with Pinch Analysis and based on this analysis, there is a limited potential for waste heat recovery without increasing the temperature as the temperature of most of the identified waste heat sources remains relatively low. Several preliminary investment proposals were sketched to demonstrate the potentials for waste heat utilization both internally and externally.