Steam trap monitoring devices, systems, and related techniques
Devices, systems, and techniques relating to steam trap monitoring are described. These include battery-less steam trap monitors that run on power harvested from their environments, systems for acquiring steam trap monitor data for the traps in a facility or across multiple facilities, and techniques for processing steam trap monitor data to reliably determine the status of individual steam traps and potentially other system parameters.
1. A sensing device, comprising:
one or more temperature sensors configured to generate sensor signals representing one or more temperatures;
one or more transmitters configured to wirelessly transmit sensor data representing the sensor signals to a remote device;
control circuitry configured to control operation of the one or more transmitters, and to convert the sensor signals to the sensor data, the sensor data comprising time series data representing the one or more temperatures;
a thermo-electric generator configured to harvest heat energy from an environment in which the sensing device is deployed;
an energy harvesting device configured to harvest a different type of energy than heat energy from the environment;
an energy storage device configured to store energy derived from a combination of the heat energy and the different type of energy; and
power management circuitry configured to control the storing of the energy derived from the combination of the heat energy and the different type of energy by the energy storage device.
2. The sensing device of claim 1 , wherein the power management circuitry is configured to receive first power from the thermo-electric generator and second power from the energy harvesting device, and provide third power generated from the stored energy to the one or more transmitters and the control circuitry.
3. The sensing device of claim 2 , wherein the power management circuitry is further configured to operate in a first mode in which the stored energy is derived only from the first power, in a second mode in which the stored energy is derived only from the second power, and in a third mode in which the stored energy is derived from a combination of the first power and the second power.
4. The sensing device of claim 3 , further comprising selection circuitry configured to selectively enable the power management circuitry to operate in the first, second, or third modes.
5. The sensing device of claim 2 , wherein the power management circuitry includes power-point-tracking circuitry configured to track either or both of the first power and the second power.
6. The sensing device of claim 2 , wherein the power management circuitry includes at least one of a DC-DC converter, an AC-DC converter, a buck converter, a boost converter, a buck-boost converter, or a single inductor multiple output (SIMO) converter.
7. The sensing device of claim 1 , wherein the different type of energy is one of light energy, mechanical energy, vibrational energy, acoustic energy, ultrasonic energy, radio frequency energy, electromagnetic energy, or magnetic energy.
8. The sensing device of claim 1 , wherein the energy harvesting device comprises one or more photovoltaic cells.
9. The sensing device of claim 1 , wherein the energy storage device is either a capacitor or a battery.
10. The sensing device of claim 1 , wherein the sensing device is configured to monitor a steam trap, wherein the one or more temperature sensors include a first temperature sensor and a second temperature sensor, and wherein the sensor data represent steam temperature and condensate temperature.
11. The sensing device of claim 10 , wherein the sensor data include first time series data representing the steam temperature and second time series data representing the condensate temperature.
12. The sensing device of claim 1 , wherein the sensor data also represent either or both of an ambient temperature or a humidity of the environment in which the sensing device is deployed.
13. The sensing device of claim 1 , wherein the sensor data also represent one or more of light energy, mechanical energy, vibrational energy, acoustic energy, ultrasonic energy, radio frequency energy, electromagnetic energy, or magnetic energy.
14. The sensing device of claim 1 , wherein the control circuitry is configured to wake up from a low-power mode to take readings of the sensor signals, control operation of the one or more transmitters, and convert the sensor signals to the sensor data.
15. The sensing device of claim 14 , further comprising a wakeup timer configured to generate a wakeup message, or a wakeup receiver configured to receive a wakeup message from the remote device.
16. The sensing device of claim 1 , wherein the control circuitry is configured to packetize the sensor data for transmission to the remote device, each packet of the sensor data identifying the sensing device and having a timestamp for associated sensor data.
17. The sensing device of claim 16 , wherein the one or more temperature sensors comprise a plurality of temperature sensors, and wherein each packet includes information correlating portions of the associated sensor data with corresponding ones of the plurality of temperature sensors.
18. A steam trap monitor, comprising:
a plurality of temperature sensors configured to generate sensor signals representing a steam temperature and a condensate temperature associated with a steam trap;
one or more transmitters configured to wirelessly transmit sensor data representing the sensor signals to a remote device;
a wakeup receiver configured to receive a wakeup message from the remote device;
control circuitry configured to control operation of the one or more transmitters, and to convert the sensor signals to the sensor data, the sensor data comprising first time series data representing the steam temperature and second time series data representing the condensate temperature, wherein the control circuitry is further configured to wake up from a low-power mode in response to the wakeup message to take readings of the sensor signals, control operation of the one or more transmitters, and convert the sensor signals to the sensor data;
a thermo-electric generator configured to harvest heat energy from an environment in which the steam trap monitor is deployed;
an energy harvesting device configured to harvest a different type of energy than heat energy from the environment;
an energy storage device configured to store energy derived from a combination of the heat energy and the different type of energy; and
power management circuitry configured to control the storing of the energy derived from the combination of the heat energy and the different type of energy by the energy storage device.
19. The steam trap monitor of claim 18 , wherein the control circuitry is configured to packetize the sensor data for transmission to the remote device, each packet of the sensor data identifying the steam trap monitor, including a timestamp for associated sensor data, and including information correlating portions of the associated sensor data with corresponding ones of the plurality of temperature sensors.
20. The steam trap monitor of claim 18 , wherein the power management circuitry is configured to receive first power from the thermo-electric generator and second power from the energy harvesting device, and operate in a first mode in which the stored energy is derived only from the first power, in a second mode in which the stored energy is derived only from the second power, and in a third mode in which the stored energy is derived from a combination of the first power and the second power.
21. The steam trap monitor of claim 18 , wherein the energy harvesting device includes one or more photovoltaic cells.