Heat Pump Recycling Waste Heat in Paper Machine Drying
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Solution Overview
Problem
Paper machines face high energy demands due to the need to dry fibrous webs with high moisture content, leading to inefficient operations compared to conventional methods.
Innovation Solution
Implementing a heat pump system that recycles heat from the medium downstream of the drying area to preheat the medium upstream of the drying area, utilizing a thermochemical or compression heat pump to enhance energy efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If a conventional drying system is used to dry fibrous webs with high moisture content, then the drying function is achieved, but the energy consumption is excessively high
Solution Approach 1:
The invention converts the harmful waste heat discharged from the drying system into a useful resource by directing it to preheat the medium upstream of the drying area. This transforms energy waste into energy savings, reducing overall energy consumption while maintaining drying efficiency
Solution Approach 2:
The invention implements preliminary heating of the medium upstream of the drying area using waste heat from downstream. This preheating action reduces the energy burden on the main drying system, lowering overall energy consumption while maintaining the required drying performance
2Loss of energy
If waste heat from downstream medium is recovered and used to preheat upstream medium, then energy efficiency is improved, but system complexity increases due to heat pump integration
Solution Approach 1:
The invention introduces a heat pump as an intermediary device between the downstream and upstream medium flows. This mediator enables efficient heat transfer from the waste heat source to the preheat target, recovering energy that would otherwise be lost while managing the thermal exchange in a controlled manner
Solution Approach 2:
The invention recovers the waste heat that would normally be discarded from the downstream medium. By capturing and redistributing this thermal energy to preheat the upstream medium, the system converts energy waste into useful heating, reducing overall energy consumption
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach reduces the overall heat requirement, enabling the production of paper, cardboard, or paperboard in an energy-efficient manner by utilizing waste heat, thereby optimizing the paper machine's operation.
Implementation Method 1
the medium downstream of the drying area, in particular the drying cylinder, is discharged from the drying area, in particular the drying cylinder, and is supplied as a heat source to a heat pump, by means of which the medium upstream of the drying area, in particular the drying cylinder, is heated
Implementation Method 2
A first medium for drying the fibrous web is supplied to the drying area, in particular the drying cylinder... The first medium then flows through the mat and in particular through the fibrous web, causing it to be dried
Data Source
Figure 1
AI summary
The invention relates to a method for operating a paper machine (10) for producing paper, paperboard or cardboard, comprising a conveyor device (16) by means of which at least one fibrous material web (14) produced from a fibre suspension is conveyed in a conveyor direction, and at least one drying region (20) in which the fibrous material web (14) which is conveyed through said drying region (20) is dried using at least one drying cylinder (26) to which a medium for drying the fibrous material web (14) is supplied, wherein the medium is conducted away from the drying region (20) downstream of said drying region (20) and is supplied, as a source of heat, to a heat pump (34) which heats said medium upstream of the drying region (20).