This buffer macro works only in discharging control mode.
Discharging control means, that the buffer will not be charged by the controlled heat generators. It will be charged only by uncontrolled heat sources like solar panels, heat pumps, solid fuel boilers, combined heat and power plants (CHPs).The buffer lower sensor “BufLowerTemp” is optional in all cases.
The buffer configuration depends on the number of connected sensors.
The buffer supply and the buffer upper sensors are always mandatory.
You can find the valid configurations in the table below.
Table 1. Buffer configuration depending on the number of connected sensors
Valid stages |
BufUpperTemp BufSupplyTemp |
BufLowerTemp |
BufMid1Temp |
BufMid2Temp |
BufMid2Temp |
Comments |
One stage |
mandatory |
999 |
999 |
doesn’t care used for monitoring |
doesn’t care used for monitoring |
1 charging valve |
<> 999 |
||||||
Two stage |
mandatory |
999 |
mandatory |
999 |
doesn’t care used for monitoring |
2 charging valves |
<> 999 |
||||||
Three stage |
mandatory |
999 |
mandatory |
mandatory |
999 |
3 charging valves |
<> 999 |
||||||
Four stage |
mandatory |
999 |
mandatory |
mandatory |
mandatory |
4 charging valves |
<> 999 |
The total possible number of charging levels is displayed at the output „MaxChgLevels“.
The actual charging level is shown at the output „ActLoadLevel“.
Simple configuration |
3 sensors and |
Maximum configuration 5 sensors and 4 bypass valves |
Configuration for simple solar or heat pump buffer, where the buffer is always charged down to the lowest sensor. |
Buffer with two stages charging. Depending on the input “BufLoadLevel” the buffer can be charged only in the upper part or completely. For this configuration you need two bypass valves |
Can be used in complex buffer strategies, where the charging level depends on weather or other external energy forecasts. The higher the expected external energy for the next day will be, the less conventional energy has to be spent for buffer charging. |
Fig. 1. Buffer configurations for charging control