Heat Exchanger Operation and Maintenance

Process plants in the oil, gas and petrochemical industries rely on large numbers of heat exchangers for their efficient operation. A single plant may utilise many different heat exchanger types, each with its own specific requirements for operation and maintenance. Site engineers need to be familiar with a wide variety of equipment, processes and techniques in order to ensure safe and reliable operation.

Inefficient operation and unexpected failure of heat exchangers are frequently responsible for significant financial impacts due to lost production, increased energy consumption and costly repair bills. In many cases these losses are exacerbated by failure to identify early indicators of the problem, a lack of understanding of the root causes, and by inappropriate mitigation measures.

This course provides both a broad overview of heat exchanger operation and maintenance in general and a detailed understanding of the critical issues relating to the three main heat exchanger types (shell and tube, air-cooled and plate heat exchangers). The most common problems associated with each type will be presented, and illustrated with case studies drawn from the trainer's own experience. Participants will have the opportunity to work through a range of examples and to discuss their own heat exchanger issues with a highly experienced heat exchanger specialist.

• Broad understanding of heat exchanger technology from an operation and maintenance point of view
• Recognition of the most common causes of failure in each heat exchanger type
• Awareness of early warning signs of heat exchanger problems
• Practice root cause analysis for the investigation of heat exchanger issues
• Understanding of specialized inspection, maintenance and repair techniques for heat Exchangers

The course is specifically designed for professionals with operational or maintenance responsibility for heat exchangers. While other disciplines will also gain benefits from the course, it is specially designed for:

• Maintenance engineers
• Plant engineers
• Inspectors
• Plant operators

DAY 1

Introduction Exercise

• An exercise based on root cause analysis for heat exchangers, designed to encourage participation and to set the scene for the training course.

Introduction to Heat Exchangers

• A session intended to build background knowledge of heat exchangers in general, based on an operations and maintenance perspective. The session will provide the opportunity for the participants to highlight the types of heat exchanger of interest, and the most common issues experienced in day-to-day operation
• Overview of heat exchanger types - advantages, disadvantages and typical applications
• Overview of heat exchanger operation and behavior
• Common problems experienced, by heat exchanger type

Case Study

• An extended case study based on troubleshooting a shell and tube heat exchanger with a history of tube failures. The case study is designed to illustrate the influence of operations, inspection and maintenance actions on the eventual outcomes

DAY 2 & 3

On the first day of the course it will have been established that the majority of problems with heat exchangers are associated in one way or another with leaks. The core of the training course is therefore concerned with the root causes, detection and resolution of heat exchanger leaks.

Types of Leaks and Methods for Detection:

• Tube/plate leaks
• Tube-to-tubesheet joint leaks
• Flange/gasket leaks
• Leak detection and testing
• Tube wall thickness surveys

Case Study

• An extended case study following a tube leakage issue over the 30 year lifetime of a heat exchanger from commissioning through two refurbishment/repair projects. The case study illustrates a wide range of leak-related issues.

Root Causes of Heat Exchanger Leaks

• Corrosion
• Erosion
• Flow-induced vibration
• Flange/gasket issues

Case Study

• A case study based on erosion damage to a set of seawater-cooled heat exchangers in a chemical plant.

Resolving Heat Exchanger Leaks

The techniques available to repair and refurbish heat exchangers will be reviewed, including:

• Tube plugging
• Tube joint re-expansion
• Re-tubing
• Flange/gasket joint repair and bolt tensioning methods

DAY 4

The final day of the course is dedicated to the issues of fouling and cleaning in heat exchangers. Fouling is a major headache in many heat exchangers, and cleaning is a regular maintenance task.

 Case Study

• A case study is used to illustrate that, while fouling is commonly blamed for poor heat exchanger performance, the true cause may lie elsewhere.

Causes of Performance Problems

A review of common causes of performance problems in heat exchangers, including:

• Fouling
• Maldistribution
• Bypassing
• Venting/draining problems
• Fan/air flow issues in air-cooled heat exchangers

Heat Exchanger Fouling

• Types of fouling
• Effect of fouling on thermal performance
• Effect of fouling on hydraulic performance
• Preventing fouling

Heat Exchanger Cleaning

• Mechanical cleaning
• Chemical cleaning
• Online cleaning

Case Study

• Fouling and cleaning in plate-and-frame heat exchangers (sea water/fresh water heat exchangers)