A major pharmaceutical company has a large facility in the greater Philadelphia area. This facility consumes as much as 300 million BTUs of thermal energy per day to cool its labs, equipment, offices, and other facilities. The chiller distribution network runs across several buildings over long distance and throughout underground tunnels. The pipe sizes at this facility range from a few inches up to 24 inches.

The chiller system is managed by a facility management company. In order for the facility management company to bill its client properly, it was necessary to install an energy metering system to accurately measure the energy consumption of each compound. In addition, due to the long pipe lines, it was crucial to know if leakage of water or energy occurred on a real-time basis.

Challenges of Energy, Uptime & Pipe Size

24-Inch Chiller
A 24-inch chiller (center) transports a large amount of energy daily. (Photo courtesy of Spire Metering Technology)
Clamp-On Ultrasonic BTU Meter
A clamp-on BTU ultrasonic meter installation. (Photo courtesy of Spire Metering Technology)

This application presented major challenges for traditional BTU meters, such as turbine-, orifice- or even electromagnetic-based BTU meters. The end-customer did not want to stop the flow and energy supply. It also prohibited the drilling of holes or cutting the pipe. In addition, as the water may not be clean after many years of operation, any meter with moving parts could be problematic.

Another challenge was the measurement of the large 24-inch pipe size. An insertion flowmeter would not be accurate due to a limitation in the sampling area, i.e., the energy is not uniform along the entire pipe cross-section. Also, an inline type flowmeter was too costly to consider.

Energy leakage is another issue to consider due to the large amount of thermal energy transported throughout this network. Any bad insulation could cause a large monetary loss without warning.

A Non-Intrusive Solution
Spire Metering specializes in energy and flow monitoring. Its TP10 ultrasonic thermal energy meter is a non-intrusive instrument, which is used to accurately measure flow, temperature and thermal energy consumption (BTU). The transducer can be clamped onto any pipe size without cutting the pipe or shutting down the flow. The TP10 does not have any moving parts to wear and tear, thus, saving in maintenance costs. The cost of the TP10 does not increase with pipe size, as it uses the same transducers for both small and large pipes.

The ultrasonic thermal energy meter utilizes transit-time technology and a patented digital signal processing algorithm. It is able to conduct flow and energy measurement with precision. This allows it to detect small flow and energy consumption, which is critical for locating leakage in a complicated pipeline network. Therefore, a number of TP10 units can be installed on the chiller distribution pipelines. All of the TP10s send data to the BMS system for data collection and data analysis.

Considering the Results
The entire thermal energy measurement system was observed for a test period of 38 days. Figures 1 and 2 illustrate the performance of the TP10 energy meters during this timeframe.

As indicated in Figure 1, the blue curve represents the energy rate histogram of the meter on the 24-inch pipe (the main pipe); the other three curves represent the energy rate histograms of the meters on three branch pipes—18 inches, 12 inches and 4 inches. The energy rate in this graph is in million BTU per hour. The energy variation pattern of the branch pipes follow exactly that of the main pipe, showing the energy meters within the system are providing consistent results.

The data for the 4-inch pipe is very small in comparison with the other noted pipes. The energy pattern on this pipe is not obvious, which may be due in part to the nature of the energy consumption pattern of that particular building. In this facility, there are still several pipes, which are not yet in service; therefore, the data is not available.

Energy Rate Histogram
Figure 1. Energy Rate Histogram (Image courtesy of Spire Metering Technology)

Figure 2 compares the energy rate of the main pipe and the sum of all the branch pipes. The two curves match very well, and the data shows the total error is about 1.2 percent and the meters are providing accurate readings.

Energy Rate Histogram Comparison
Figure 2. Energy Rate Histogram Comparison (Image courtesy of Spire Metering Technology)

The clamp-on ultrasonic energy meter has been successful in a large pharmaceutical facility to monitor the thermal energy distribution system. The observation of 38 days data demonstrates the performance of the TP10 energy meter. It also provides the facility manager with strong confidence that his distribution system is in excellent health.

The entire installation and system tuning was completed within two days. This is only possible with non-intrusive, clamp-on ultrasonic technology. The fact that the size of the pipe was as large as 24 inches, allowed for a less expensive and less labor-intensive installation than if another type of technology, i.e., mechanical flowmeter or magnetic flowmeter was used. The BTU meter saved the customer major installation costs and quickly delivered results.

John Shen holds a Ph.D. from Swiss Federal Institute of Technology Lausanne (EPFL), Switzerland, and a master’s degree from Sichuan University, China. Mr. Shen has been developing ultrasonic flow measurement technology, metering devices, and smart sensing solutions for more than 25 years. Ten years ago, he founded Shenitech, now Spire Metering Technology, a supplier of premium flow measurement and energy metering solutions for commercial and residential applications.