Introduction

As global demand for renewable energy continues to increase, Concentrated Solar Power (CSP) technology is gaining renewed attention for its ability to deliver stable, dispatchable clean electricity. In this context, non-intrusive flow measurement technologies are becoming increasingly important for improving system efficiency and operational reliability.

The FLEXIM™ clamp-on ultrasonic flowmeter developed by Emerson is emerging as a key instrumentation solution for CSP applications, particularly in high-temperature heat transfer fluid (HTF) and molten salt circulation systems.

CSP Industry Measurement Challenges

Concentrated solar power plants rely on complex thermal energy transfer systems, typically involving:

• Molten salt storage loops
• Heat transfer fluid (HTF) circulation pipelines
• High-temperature pressurized piping systems
• Thermal energy storage and heat exchange units

These systems present significant measurement challenges, including:

• Extremely high operating temperatures
• Corrosive or opaque fluids (molten salts, synthetic oils)
• Large-diameter pipelines
• Requirement for zero pressure loss measurement
• Maintenance constraints in harsh outdoor environments

Traditional inline flowmeters often struggle under these conditions due to wear, fouling, and installation complexity.

FLEXIM™ Clamp-On Ultrasonic Flowmeter Technology

The FLEXIM™ series by Emerson uses advanced ultrasonic transit-time technology to measure flow externally, without direct contact with the fluid.

Key technical advantages:

• Non-intrusive clamp-on installation (no pipe cutting required)
• Suitable for extreme temperature applications
• No pressure drop in the pipeline
• High accuracy in conductive and non-conductive fluids
• Minimal maintenance requirements
• Long-term stable performance in harsh environments

This makes it particularly suitable for CSP plants where system downtime must be minimized.

Application in Concentrated Solar Power Systems

Heat Transfer Fluid (HTF) Monitoring

In CSP plants, HTF systems require precise flow control to ensure efficient thermal energy transfer from solar collectors to storage systems.

Clamp-on ultrasonic flowmeters enable:

• Real-time monitoring of HTF circulation efficiency
• Detection of flow imbalance in solar field loops
• Optimization of thermal energy transfer performance

Molten Salt Thermal Storage Systems

Molten salt is widely used in CSP thermal storage due to its high heat capacity and stability.

FLEXIM™ technology supports:

• Accurate flow measurement in high-temperature salt loops
• Monitoring charge/discharge cycles in storage tanks
• Improved thermal energy dispatch efficiency

Solar Field and Balance of Plant (BOP) Systems

Beyond core thermal loops, ultrasonic flow measurement is also valuable in auxiliary systems such as cooling water and secondary circulation circuits.

Benefits include:

• Enhanced operational visibility across the plant
• Reduced risk of flow-related inefficiencies
• Improved predictive maintenance capability

Industry Advantages and Operational Value

The adoption of clamp-on ultrasonic flow measurement in CSP plants provides several long-term benefits:

Improved Reliability

Non-contact measurement eliminates wear and mechanical failure points.

Reduced Maintenance Costs

No need for periodic replacement of wetted parts.

Higher System Efficiency

Real-time flow optimization improves energy conversion efficiency.

Safer Operation

Minimizes leakage risk in high-temperature and high-pressure environments.

Market Outlook for CSP and Flow Measurement Technology

As governments and utilities expand renewable energy portfolios, CSP technology is expected to regain momentum, especially in regions with high solar irradiance such as the Middle East, North Africa, and parts of Asia.

Advanced instrumentation solutions like Emerson FLEXIM™ clamp-on ultrasonic flowmeters are expected to play a critical role in:

• Large-scale solar thermal power plants
• Hybrid renewable energy systems
• Industrial heat recovery applications
• Next-generation energy storage systems

Conclusion

The FLEXIM™ clamp-on ultrasonic flowmeter from Emerson offers a highly suitable solution for the demanding operating conditions of Concentrated Solar Power plants. Its non-intrusive design, high accuracy, and reliability make it an important enabling technology for improving efficiency and operational stability in CSP systems.

As the renewable energy sector continues to expand, demand for advanced flow measurement technologies is expected to grow significantly, positioning clamp-on ultrasonic solutions as a key component of future energy infrastructure.