How can a heat exchanger be fouled, and how would you troubleshoot a decline in heat transfer efficiency?

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Multiple Choice

How can a heat exchanger be fouled, and how would you troubleshoot a decline in heat transfer efficiency?

Fouling creates an insulating layer on heat exchanger surfaces, increasing thermal resistance and reducing the actual heat transfer for the same flow and driving temperature difference. When performance drops, the deposits blocking heat transfer are the likely culprit, so cleaning is the appropriate initial remedy. Troubleshooting starts with confirming the heat transfer driving force and flow conditions. Measure the delta-T across the exchanger to see if the temperature difference driving the transfer has diminished. Check flow rates on both sides to ensure there’s no restriction or pump issue limiting circulation. Look for air locks or trapped gases that can disrupt flow and reduce effective heat transfer. Inspect for signs of fouling such as deposits, scaling, or sludge on surfaces. After cleaning, recheck the heat transfer rate and delta-T to verify improvement; if performance remains low, you’d repeat cleaning or pursue further diagnostics. Other options aren’t consistent with how heat exchangers behave. Fouling does not improve heat transfer, and simply replacing the exchanger without testing neglects a fundamental maintenance step.

Fouling creates an insulating layer on heat exchanger surfaces, increasing thermal resistance and reducing the actual heat transfer for the same flow and driving temperature difference. When performance drops, the deposits blocking heat transfer are the likely culprit, so cleaning is the appropriate initial remedy.

Troubleshooting starts with confirming the heat transfer driving force and flow conditions. Measure the delta-T across the exchanger to see if the temperature difference driving the transfer has diminished. Check flow rates on both sides to ensure there’s no restriction or pump issue limiting circulation. Look for air locks or trapped gases that can disrupt flow and reduce effective heat transfer. Inspect for signs of fouling such as deposits, scaling, or sludge on surfaces. After cleaning, recheck the heat transfer rate and delta-T to verify improvement; if performance remains low, you’d repeat cleaning or pursue further diagnostics.

Other options aren’t consistent with how heat exchangers behave. Fouling does not improve heat transfer, and simply replacing the exchanger without testing neglects a fundamental maintenance step.

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