Shell-and-Tube Condenser Tubes for Condensate and Deposit Control
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Solution Overview
Problem
The existing shell-and-tube condensers face a high risk of decreased heat transfer efficiency due to condensate film formation on the outer surface and crystalline deposits on the inner surface, leading to increased thermal resistance.
Innovation Solution
The use of hydrophobic coatings on the outer surface of heat exchange tubes to repel condensate, grooves to reduce condensate film thickness, and ribs on the inner surface to generate turbulent flow and break deposits, combined with a decreasing gap between guiding spacers to maintain constant steam velocity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If conventional smooth heat exchange tubes are used, then the structure is simple and easy to manufacture, but condensate film forms on the outer surface reducing heat transfer coefficient
Solution Approach 1:
The patent applies grooves only on the outer surface of the heat exchange tubes where condensate forms, while the inner surface remains smooth. This localized modification addresses the condensate film problem without complicating the overall tube structure or manufacturing process significantly.
Solution Approach 2:
The patent combines different surface treatments on the tube - grooved outer surface for condensate removal and smooth inner surface for easy manufacturing. This composite approach allows each surface to optimize its function while maintaining manufacturing feasibility.
2Ease of manufacture
If conventional smooth inner surface tubes are used, then manufacturing is simple, but crystalline deposits form on the inner surface increasing thermal resistance
Solution Approach 1:
The patent applies ribs only on the inner surface of the heat exchange tubes where deposits form during heat carrier flow. This localized modification addresses the deposit formation problem while keeping the rest of the tube structure simple and easy to manufacture.
3Device complexity
If uniform distance between guiding spacers is used, then structure is simple, but steam velocity decreases leading to reduced heat transfer efficiency
Solution Approach 1:
The patent transitions from a static uniform spacer arrangement to a dynamic non-uniform arrangement where spacer distances vary along the shell length. This dynamic adjustment maintains optimal steam velocity by compensating for the decreasing steam volume as condensation progresses, thereby maintaining heat transfer efficiency.
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 combination significantly enhances the heat transfer coefficient by reducing thermal resistance and efficiently removing condensate and deposits, achieving a synergistic effect that exceeds the predicted effects of individual features, with a reported increase of 6.2-13.4 times in the heat transfer coefficient.
Implementation Method 1
The outer surface of the heat exchange tubes is coated with a hydrophobic material, thanks to which the condensate rolls off the outer surface
Implementation Method 2
heat exchange tubes carry grooves on the outer surface... the condensate rolls off the outer surface
Implementation Method 3
The heat exchange tube made in accordance with the second version carries ribs on the inner surface, promoting formation of turbulent eddies, which break the laminar flow of the heat carrier inside the tubes, thus reducing the probability of salt and other impurities deposition
Implementation Method 4
The heat carrier in the shell space, introduced to the condenser- via the inlet- in the form of steam, condenses while moving from the inlet to the outlet
Implementation Method 5
increasing the total heat conductivity coefficient between the heat carriers inside the tubes and in the shell space
Data Source
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AI summary
This group of inventions relates to heat exchange devices, in particular, to designs of condensers. The technological result achieved by this group of inventions is cutting down the risk of increased thermal resistance between the heat carriers inside the tubes and in the shell space. The condenser consists of a shell with a bundle of tubes arranged inside, with grooves on their outer surface, spacers, an inlet and an outlet for the heat carrier inside the tubes and an inlet and an outlet for the shell space heat carrier. Unlike in the case of the prototype for this invention, the tubes are coated with a hydrophobic material on the outside, and the distance between the spacers decreases from the inlet of the shell space heat carrier to its outlet. This condenser also differs from the prototype in that the tubes carry ribs and a coating of a material with a high adhesion resistance coefficient on the inside surface.