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  • Every MLR003R MLR003 device contains a “Thermoelectic “Thermoelectric Generator (TEG)” element, that which generates electrical energy when there is a temperature difference.

  • The TEG harvests energy from the temperature difference between the heating flow temperature and the ambient temperature (usually room temperature).

  • The MLR003R MLR003 comes with an Aluminum aluminium housing as a functional part to generate electrical energy.

  • The actuator has a valve-side temperature sensor to determine the flow pipe temperature and an ambient sensor to determine the ambient temperature which is located away from the flow sensor

  • There are two compensations performed on the ambient and the flow sensor respectively

  • The ambient temperature estimation is used to reduce/compensate the temperature difference at the ambient sensor caused by the increased Aluminum housing pipe. Because the ambient sensor is surrounded by the aluminium housing and is still very close to the radiator, when the radiator is heating, the value measured by the ambient sensor is higher than the actual room temperature. Thus an algorithm is applied to estimate the room temperature.

  • A controllable offset for the flow sensor has been added is available to compensate for the temperature drop between the hot water and the sensor element located in the actuator’s aluminum valve adapter.devices which are mounted above exposed hot water pipes. It can be set by sending an FPORT 0x08 Downlink.

  • Valve adapters further increasing the offset between the internal flow sensor and the water temperature must be taken into account

Fluid (water) temperature FSRV

Recommended offset for the flow sensor value FTMP applied in FPORT 0x08

(Offset values derived in climate chamber and without valve adapter)

55°C

10°C

65°C

13°C

70°C

14°C

  • To obtain an estimate of the ambient temperature, the device measures the flow temperature every 5 minutes and performs a moving average across the last 30 minutes. It then performs the following computation

    Orah footnote
    an.spaceKeyMH
    textAmbient Estimate Calculation
    id0cv82peijaks

    grafik-20240529-095530.pngImage Removed

    The offset value for the Flow Temperature can be set via Downlink on FPORT 0x08

Mathblock
anchor
alignmentleft
--uriencoded--\begin%7Balign*%7D

& \text%7BFlow Smoothened %7D F_s = \frac %7B(0.2 F + 1.2F_%7Bt-1%7D + 1F_%7Bt-2%7D + 0.8F_%7Bt-3%7D + 0.6F_%7Bt-4%7D + 0.3F_%7Bt-5%7D + 0.1F_%7Bt-6%7D) %7D %7B4.2%7D + \text%7BFlow Offset%7D
\\
\\
& \text%7Bwhere F = Flow Raw Value%7D
\\
& \text%7Bwhere Flow Offset = 0 (default)%7D
\\
\\
& \text%7Bif %7D \Big(F_s - z  \big( F_s - 0.5(F_%7Bs_%7Bt-3%7D%7D + F_%7Bs_%7Bt-4%7D%7D ) \big) \Big) < \text%7B Ambient Raw Value%7D
\\
& \text%7Bthen%7D
\\
&  \hspace%7B1cm%7D \text%7BFlow Corrected %7D F_c = \text%7BAmbient Raw Value%7D
\\
& \text%7Belse%7D
\\
& \hspace%7B1cm%7D \text%7BFlow Corrected %7D F_c = \Big(F_s - z * \big( F_s - 0.5(F_%7Bs_%7Bt-3%7D%7D + F_%7Bs_%7Bt-4%7D%7D ) \big) \Big) 
\\
\\
& \text%7Bwhere z = 0.1%7D
\\
\\

& \textbf%7BAmbient Temperature Estimate%7D = \textbf%7BAmbient Raw Value%7D * \Bigg( \frac%7B\textbf%7BAmbient Raw Value%7D%7D%7B\textbf%7BFlow Corrected %7D F_c%7D \Bigg) %5e%7B1.2%7D
\end%7Balign*%7D

Byte

Uplink in FPORT #1

Details

Description

2

FSRV

Flow Sensor Raw Value

The uncompensated flow temperature measured at the valve body assemblyside

3

FTMP

Flow Temperature Value

The compensated flow temperature flow moving average, with offset applied

Moving Average of Flow Sensor Raw Value (FSRV) + OFFSET (set via FPORT 0x08)

Default OFFSET = 0

4

ASRV

Ambient Sensor Raw Value

The uncompensated ambient sensor value

5

ATMP

Ambient Temperature Value

Ambient Temperature calculated from

Orah footnotes display

...

  • The Set Point Value “SPV“ is set by the user through Downlink on FPORT 0x01

  • The MLR003 MLR003R uses either uses the ambient temperature coming from an external sensor (“RT“ in FPORT 0x01 Downlink) or the internal Ambient Temperature (“ATMP“) estimate

FPORT 0x01 Downlink Byte 2 Room Temperature (RT) value

Temperature Value

0

Use internal Ambient Temperature (ATMP) estimate

Room Temperature from external sensor

Use the room temperature value from the external sensor

...

In order to achieve a Set Point Value

...

(SPV) Ambient Temperature, the device applies a PID control algorithm.

...