Buffer Control Configurations

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


  1. One stage charging happens if the “BufMid1Temp” is not connected. The other mid temperature sensors do not care in this case. They will be used for monitoring only.
    The buffer charging will be done based on the buffer upper and/ or buffer lower sensors.
  2. Two staged charging happens if the “BufMid1Temp” is connected and “BufMid2Temp” is not connected. “BufMid3Temp” does not care in this case. It will be used for monitoring if it is connected.
    The two staged buffer charging will be done based on the buffer upper, “BufMid1Temp” and/ or buffer lower sensors.
  3. Three staged charging happens if the “BufMid1Temp” and “BufMid3Temp” are connected and “BufMid3Temp” is not connected.
    The three staged buffer charging will be done based on the buffer upper, “BufMid1Temp”, “BufMid2Temp” and/ or buffer lower sensors.
  4. Four stage charging can happen only if the upper and all the mid temperature sensors are connected.

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
two bypass valves

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