How a Dirty or Undersized Heat Exchanger Leads to Hydraulic System Failure?

The heating exchanger hydraulic (or cooler) is the unspoken important component in your entire system. Its primary function is to eliminate the heat waste produced by mechanical inefficiencies as well as resistance. If it isn't able to perform its job, it results in overheating, the unnoticed killer, which rapidly deteriorates the components of your hydraulic system and fluids, which can lead to failure of your system.

The Domino Effect of Heat

Failure of the heat exchanger, caused by dirt or poor sizing, triggers a series of destructive situations:

1. Fluid Degradation (The Direct Threat)

• Oxidation: The hydraulic fluid has been specifically designed to function within a certain temperature range. When temperatures exceed roughly 180^\circ\text (82^\circ\text), the fluid's chemical structure breaks down much faster. This process, also known as "oxidation produces sludge varnish along with acidic by-products.

• Additive Depletion: The essential anti-wear and anti-foaming components within the fluid are swiftly depleted or rendered ineffective due to high temperatures, leaving the components exposed.

• Results: The fluid quickly gets contaminated, reducing its heat transfer and lubrication capabilities, effectively stripping motors and pumps of their protection.

2. Wear of components and Leakage

• Seal Hardening: In excess heat, O-rings and elastomer seals shrink, harden, and break. This causes leakage from the outside and inside in valves, pumps, and cylinders.

• Tolerance Issues: The high temperatures can cause components of metal components to expand. This causes thermal expansion, which alters crucial clearances (tolerances) within precision components such as the piston pump and spool valves, which increases the friction inside and leaking, which ironically creates additional heat..

• The result: Loss of pressure decreased efficiency, total failure of expensive components.

The Two Most Common Reasons for Cooler Failure

1. Clean heat exchanger (Maintenance Failure)

In the case of air-cooled systems, the issue is usually external. For water-cooled systems, the issue is internal.

• External Fouling (Air Coolers): Dust, grease, dirt, and environmental debris cover the fins of the cooler. This layer serves as an insulation and prevents the fins from radiating heat from the internal fluid to the air surrounding it.

  • The Solution: Regular inspection and cleaning of the fins using compressed air or detergent and water.

• Internal fouling (Water/Oil Coolers): Sludge, varnish from oxidized oils, scaling (in water lines), or other particles from wear and tear clog the internal passageways of the cooler's core. This decreases the effective surface area, which can be used to transfer heat and reduces the circulation of fluid.

  • The Solution: Flushing or chemically cleaning the cooler. In extreme cases, replacement may be required.

2. Undersized Heat Exchanger (Design Failure)

A cooler that isn't properly sized is a ticking time bomb - it simply can't handle the full heat load that the system generates at its maximum performance.

• False calculation: This often happens when a system's operating cycle or maximum operating load fluctuates over time, or when the initial cooler was chosen without taking into account what would be the most likely scenario (e.g., the hottest ambient temperature or the longest time of running).

• Insufficient Capacity: Its British Thermal Unit (BTU) or Kilowatt capacity is less than what waste heat that the system generates.

• The result: The system runs hot right from the start. While it is unlikely to fail right away but the heat dramatically reduces the life span of the component and fluid.

Keep your System Cool and keep it running

A little investment in regular maintenance of the cooler and confirming that it is the right size is among the most cost-effective methods to avoid catastrophic system failure. In the event of ignoring a dirty or inadequately sized heat exchanger will mean you'll soon face costly repairs to your valves, pumps, and actuators.