Regenerative Heat Exchanger Leakage Recirculation
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Solution Overview
Problem
Regenerative heat exchangers in power plants face inefficiencies due to leakage volume flows between gas streams, leading to energy losses and unsatisfactory thermal energy transfer, despite existing methods to address these issues not improving efficiency and potentially causing cooling effects that can damage downstream components.
Innovation Solution
A method where leakage volume flows are detected and collected at the end faces of the rotor, with the option to recirculate them back to the gas streams on either the 'hot' or 'cold' side, allowing for temperature-based decision-making on where to reintroduce the leakage to minimize cooling effects and enhance heat transfer efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If leakage volume flows are not addressed, then the heat exchanger structure remains simple, but energy losses occur and efficiency deteriorates
Solution Approach 1:
The patent extracts the leakage volume flows from the main gas streams by introducing suction devices at the rotor seals. These leakage flows are separated and handled through dedicated return lines that transport them back to the appropriate gas stream, preventing energy loss while maintaining a relatively simple overall structure
Solution Approach 2:
The patent implements feedback by using sensors to detect leakage volume flows and controlling suction devices to actively回收 these flows. The system continuously monitors and adjusts the recirculation of leakage flows to optimize heat transfer efficiency and prevent energy losses
2Productivity
If leakage volume flows are recirculated to the hot side, then heat transfer efficiency improves, but cooling effects may damage downstream components
Solution Approach 1:
The patent applies local quality by differentiating the treatment of leakage flows based on their origin and temperature. Cold-side leakage flows are recirculated to the cold side, while hot-side leakage flows are recirculated to the hot side, ensuring that each stream receives appropriately temperature-matched flows to maximize heat transfer efficiency without causing harmful cooling effects
Solution Approach 2:
The patent segments the leakage volume flows into separate cold-side and hot-side streams based on their temperature and origin. This segmentation allows independent recirculation of each stream to the appropriate location, preventing mixing of temperature zones and avoiding harmful cooling effects on downstream components while maintaining heat transfer efficiency
3Loss of substance
If complex seals are used to prevent leakage, then volume losses are reduced, but manufacturing complexity and cost increase
Solution Approach 1:
The patent applies self-service by using the existing pressure differential and temperature differences in the gas streams to drive the recirculation of leakage flows. The suction devices are positioned to utilize the natural flow characteristics, and the return lines are configured to automatically direct flows to the appropriate streams without requiring complex active control systems or additional energy input
Solution Approach 2:
The patent changes the parameters of the leakage flows by recirculating them back to the main gas streams where they can be heated or cooled to match the stream temperature. This parameter change approach allows simpler seal designs while maintaining low volume losses, as the recirculated flows adapt to the temperature conditions of their destination stream
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 increases the efficiency of heat transfer by avoiding unwanted cooling, maintaining flue gas temperature above the acid dew point, and reducing fuel requirements, resulting in significant cost savings and lower emissions.
Implementation Method 1
the heat exchanger can include a rotating (or rotating or also revolving) storage mass (hereinafter referred to as rotor), which moves relative to fixed flow connections and is alternately heated by the at least one gas volume flow and cooled again by the at least one other gas volume flow, whereby thermal energy can be transferred from at least one to at least one other gas volume flow
Implementation Method 2
at least one suction device for a leakage volume flow is provided on the first end face of the rotor, in particular in the area of a radial seal and/or a peripheral seal
Implementation Method 3
at least one blower device with which a defined flow can be generated in this line system
Data Source
Figure 1
Figure 2
AI summary
The invention relates to a method for operating a regenerative heat exchanger (1) comprising a rotatably mounted rotor (2) through which at least one first gas volume flow (10) to be heated and at least one second gas volume flow (11) to be cooled flows. The incoming first gas volume flow (10a) enters the rotor (2) at a first end face (5a) and exits the rotor (2) at a second end face (5b) as the outgoing first gas volume flow (10b). To increase the heat output, a leakage volume flow is collected at the first end face (5a) of the rotor (2) and fed to the incoming first gas volume flow (10a), and/or a leakage volume flow is collected at the second end face (5b) of the rotor (2) and fed to the outgoing first gas volume flow (10b). The invention further relates to a regenerative heat exchanger (1) on which the method according to the invention can be carried out.