Smart Hot Water Monitoring system

A large project concerned R&D in thermophysics embedded algorithms, mechanical and electronics design with multiple on-site tests. The final product is a tool that regulates, measures and monitors thermal energy supply for centralised hot water supply in the industrial and residential system.

With the RnD goal to increase hot water supply efficiency and to lower operational costs for calibration, a water/heat management company EnCata several years ago.

Hot water consumption is characterised by significant irregularity. Circulation in residential hot water piping system is provided to compensate heat losses. While data on heat losses in residential hot water systems are intrinsically missing due to metering complexity.

It was estimated that 10% of hot water consumption associated with additional necessary circulation. The real value of the circulation flow rate in the pipelines of hot water supply systems significantly exceeds the estimated value and totals 40-90% of the flow in the delivery pipe and 70-500% of water consumption of the residential house hot water supply system.

With the R&D goals set in place, the project was identified to be at TRL-1..2. EnCata started to develop the new measurement technology, that would enable both precision metering, temperature sensing with efficient feedback to the valve system. The research was executed in stages, starting from the applied thermophysical research and algorithms development.

We further lifted up a number of test PCBs to verify these algorithms with the firmware. In total there were 6 algorithms developed in order to fit the control and monitoring system into existing infrastructure. The system electronics is based on the MCUs of the STM family. This enabled the regulators to works in tandem with the heat meter through the heat communication channel.

First tests (TRL-6) suggested further refinements in the algorithms which took several months of further R&D. I.e. the challenge was in achieving precision in regulating the release of hot water based on consumption data (obtained through the communication with a heat meter).

All together there are 4 PCBs  are part of this project. The electronics and the firmware implemented the following features:

  • adjustable PID control loops
  • calendar control of heating modes
  • data archiving on the controller board
  • integration with SCADA system

The electronics architecture gained:

  • the operator interface (LCD screen)
  • remote control via RS-485 / Modbus ASCII interfaces
  • PCBs were reduced in size to become two-layer.

Overall, this large project was moved from TRL-2 to TRL-8 and the project currently goes into the mass-production phase and sales (TRL-9). Newer generation design is already planned where newer (optimised) PCBs, enclosures and custom valve regulator will be used.

The R&D program and the product achieved several essential milestones:

  1. The ability to automatically adjust the heat/hot water flow and balance the energy consumption (which are not allowed by any existing analogue temperature regulators).
  2. The system can detect inaccuracies in the operation of monitoring devices (meters) without dismantling the device and shutting down the entire system, unavailable for other regulators.
  3. Reduced maintenance costs for system monitoring at-loci.
  4. The system can integrate other existing heating automation protocols.
  5. The system is now certified as well as data readings, which saves a fortune for the heat/water supply company.