One of the most critical factors in the efficiency and effectiveness of a shell and tube heat exchanger is flow pattern. Flow pattern refers to the direction that the tubeside fluid runs in relation to the shellside fluid. There are several distinct patterns engineers can choose from:
- Parallel flow
- Counter flow
- Crossflow
But while each is unique and has its own pros and cons, there are many times when a combination of multiple flow patterns is beneficial, or even necessary.
Flow Patterns Explained
To help you better understand parallel flow vs. counter flow vs. crossflow patterns, we’ll go into more detail on each option.
Parallel Flow (Cocurrent Flow)
A parallel flow pattern, also referred to as a cocurrent flow, is one in which the shellside and tubeside fluids flow in the same direction. This is widely seen in double-pipe heat exchangers and can be replicated in shell and tube heat exchangers as well.
Pros & Cons
- With parallel flow, the wall temperatures throughout the exchanger will be more uniform than with other flow patterns.
- When there is a notable temperature gap, the cold-fluid temperature will always be colder than the hot-fluid temperature.
- The dramatic temperature difference at the inlet can cause thermal stress in parallel flow heat exchangers.
Counter Flow (Countercurrent Flow)
A counter flow or countercurrent shell and tube heat exchanger’s construction is in many ways identical to that of a parallel flow shell and tube heat exchanger. The main difference is that the tubeside fluid enters the exchanger at the opposite end of the shellside fluid. Typically, a countercurrent pattern in a shell and tube heat exchanger is the most thermally efficient option.
Pros & Cons
- The temperature difference in counter flow configurations is more uniform throughout the entire exchanger.
- The counter flow pattern allows for the greatest temperature change between fluids.
Crossflow
The design of a crossflow heat exchanger allows for two fluids to flow perpendicularly. Crossflow exchangers are common in steam condensers, in which a liquid transforms into a gas by the end of the process.
Combining Flow Patterns
In practice, shell and tube heat exchangers typically include multiple flow patterns to meet the various process needs. A common combination is counter flow and parallel flow, as seen in most multipass shell and tube heat exchangers.
Optimize Your Heat Exchanger Efficiency With Enerquip
Ready to enhance your system’s performance with the ideal parallel flow, counter flow, or crossflow heat exchanger? Enerquip’s team of experts is here to guide you through selecting the perfect solution tailored to your specific needs. Connect with us today for personalized advice or request a custom quote that aligns with your project requirements. Trust Enerquip to elevate your operation’s thermal efficiency to new heights.