In this article, we’re highlighting the maintenance system of heat exchangers used in HVAC and building services applications for both residential as well as commercial properties. We’ll also look at how these types of equipment are applied to system components while going through the working principle of common HVAC heat exchangers.
What is condenser/heat exchanger
A heat exchanger does exactly what its name suggests: exchanges heat. In the context of a chiller, a heat exchanger is a series of tubes or coils that run through the HVAC system. Different models feature different shapes and sizes of tubes based on fuel type but they all perform the same task—the tubes heat up and, in doing so, exchange and transfer the heat to the air. Heat exchangers are either given a hot fluid to provide heating or a cold fluid to provide cooling.
How it works
The way a heat exchanger works is rather simple. Heat exchangers are designed to optimize the temperature as per system needs. Coil heat exchangers in their simplest form use one or more tubes which run back and forth several times. When water flows inside the chiller tubes, heat is transferred from the tube wall via convection, it then conducts through the pipe wall to the other side, thus exchanging the heat from the system.
Why the need for maintenance?
Fouling in heat Exchangers is an undesirable piled deposit formed inside a condenser, sometimes described as a thermal resistance on the heat path in the condenser. Degraded heat exchanger performance from fouling or ageing results in extra operating and energy costs to compensate for gaps in the target temperature.
Product or chemical deposits on heat-transfer surfaces weaken an exchanger’s heat-transfer capacity and must be cleaned away regularly to maintain high performance and prevent disruption of processing. Heat exchanger fouling, or the unwanted accumulation of deposits on heat-transfer surfaces, can result in huge loss.
The maintenance of heat exchangers is therefore important to keep systems running efficiently. Regular maintenance ensures equipment is in working condition and helps prevent emergency repairs. The cost of cleaning a heat exchanger is small compared to the cost of lost production should a heat exchanger require an unscheduled shutdown.
Why Cleaning-In-Place (CIP)
The most common condenser cleaning method is scrubbing propelled through the heat exchanger tubes to remove deposits however this method required shutdown and loss of production hours. However, a proper Cleaning-In-Place (CIP) equipment can automatically clean heat exchangers without the need for a manual shutdown. CIP cleaning of heat exchangers typically includes several goals:
- Cleaning lime deposits
- Passivating surfaces to reduce susceptibility to corrosion
- Neutralizing cleaning chemicals before draining.
How ACCS helps in the maintenance
Most modern technology used today for round-the-clock cleaning of Chiller tubes is Automatic Tube Cleaning System or ACCS. This automatic method of cleaning heat exchanger tubes occurs while the equipment remains in operation and full production.
ACCS is a remarkably simple system in which recycled cleansing balls are flushed through the cooling system via a natural water flow, ensuring that unwanted deposits and residue are cleaned before fouling occurs. A strainer or ball collector is installed at the water piping exiting the condenser that collects the balls for re-circulation in the system.
This system can be controlled online while infusing some slightly oversized elastomer balls periodically to the Condenser tubes and keeps the tubes free of fouling 24×7. There is absolutely no need for system shutdown for descaling and as a result, hence chiller operates at top performance and efficiency.
With the installation of ACCS, the internal surface of the cooling tubes are guaranteed to remain clean, resulting in improved heat transfer and reduced energy consumption. The ACCS is fully automatic and works continuously while the heat exchanger is operational, eliminating the need for inconvenient shutdowns or costly maintenance.
Benefits Of ACCS
To ensure optimum performance from the system, heat exchangers must work with 100% efficiency. For this to happen we must use an automated solution that reduces maintenance cost and increases efficiency. ACCS fulfils these criteria with ease while providing some benefits too:
- Eco-friendly (Save energy up to 30%)
- Optimize heat transfer
- Eliminates downtime
- Extends equipment life
- Zero Ball loss