The high vacuum inside the condenser is what keeps a thermal power plant efficient. A "vacuum leak" that lowers it doesn't blow air outward — it draws outside air in, which makes it hard to find by sight or experience alone. This case study shows how a thermal power plant used the acoustic camera "CRYSOUND CRY8120" to visualize vacuum leaks on screen, without stopping the equipment.
Key Takeaways
- Captures the ultrasound created as outside air is drawn in, visualizing hard-to-spot vacuum leaks on screen
- Inspects without stopping the equipment — fewer people, less time, and fewer approaches to high, cramped or high-temperature areas
- Useful beyond the condenser (high-pressure feedwater heater too), cutting manpower and on-site workload
Struggling with air or vacuum leaks at your site?
Get a free consultation →- Industry
- Thermal power plant (name withheld)
- Equipment
- Steam condenser / high-pressure feedwater heater
- Objective
- Locate vacuum leaks (inward air ingress)
- Product
- Acoustic camera "CRYSOUND CRY8120" (200 MEMS microphones)
What Is a Condenser Vacuum Leak? The "Inward Air" That Cuts Efficiency
At a thermal power plant, steam that has finished its work in the turbine is condensed back into water in the condenser. Keeping the condenser under a high vacuum is what sustains generating efficiency. But when a "vacuum leak" develops — outside air being drawn in through pipe joints, flanges or seals — non-condensable gases build up inside the condenser, lowering the vacuum and raising turbine back pressure.
The consequences include reduced generating efficiency, higher fuel costs and increased CO₂ emissions, as well as a corrosion risk to pipes and equipment from rising dissolved oxygen.
Challenges: Why Vacuum Leaks Are Hard to Find the Old Way
Traditionally, vacuum leaks were hunted one spot at a time using soapy water, incense smoke or tracer gas. But a power plant covers a vast area with a huge number of pipes and joints, so this takes a great deal of time and manpower.
On top of that, a vacuum leak is harder to find than an ordinary air leak:
- It draws air inward instead of blowing it out — because no gas escapes outward as it would with a normal air leak, the location is hard to pinpoint by sight or experience alone.
- The search area is large and labor-intensive — with so many pipes and joints, soapy water and incense can only check one point at a time.
- The plant must stay running — what was needed was a way to safely narrow down leaks in a short time while the equipment kept operating.
Solution: Visualizing Ultrasound with the "CRYSOUND CRY8120" Acoustic Camera
The solution we proposed was the acoustic camera "CRY8120". Using 200 MEMS microphones, it captures the ultrasound generated by a leak and visualizes the sound-source location on the camera screen.
Even for a vacuum leak, by capturing the turbulence noise and ultrasound produced as outside air is drawn in, the CRY8120 lets you pinpoint suspect spots on screen instead of searching a wide area by hand.
- Visualizes vacuum (inward) leaks too — it detects the ultrasound of air being sucked in, so it can locate leaks that never blow out to the surface.
- Non-contact checks from a distance — inspections can be done without approaching high, cramped or high-temperature areas, improving safety.
- Fewer people, less time — because the position shows on screen, the painstaking spot-by-spot search is no longer needed.
| Comparison | Conventional methods (soapy water, incense, tracer gas) |
CRY8120 acoustic camera |
|---|---|---|
| Finding a vacuum (inward) leak | Nothing blows outward, so it is hard to locate by sight or experience | Captures the turbulence/ultrasound of inrushing air and shows it on screen |
| Search area & effort | Checks a wide area one spot at a time — time- and labor-intensive | Narrows down suspect spots on screen — fewer people, less time |
| High / cramped / hot areas | Must get close to check | Checks from a distance, reducing the number of approaches |
Results: Less Manpower and Faster Inspections — Without Shutdown
With the equipment still running, the team used the CRY8120 to inspect around the condenser and the high-pressure feedwater heater. Because the sound-source location appears on screen, operators could intuitively grasp where leaks were suspected, and the old routine of checking spot by spot with incense and soapy water became far easier.
- Less manpower, shorter inspections — the large plant could be checked by fewer people in less time.
- Fewer approaches to hazardous spots — checking from a distance reduced the number of times workers had to get close to high, cramped or high-temperature areas.
- Results recorded and shared as images — inspection findings can be saved as images, making it easy to share on site and report repair locations.
- Expanded beyond the condenser — it was useful not only for the condenser vacuum leaks but also for checking leaks around the high-pressure feedwater heater.
As a result, plant inspections became more labor-efficient, faster and less physically demanding. By turning a vacuum-leak survey that once relied on sight and experience into something you can see on screen, the CRY8120 let the team pinpoint exactly where a leak is — without ever stopping the equipment.