[HRA] Heating release algorithm
Function block HRA permits heating based on heat duration, outside temperature, and wind speed.
HRA permits winter operation based on heat duration (start and stop date), outside temperature, and wind speed (optional). If winter operation is enabled, the function block decides whether to enable Comfort or Economy mode for heat distribution.
The following functions are integrated in HRA:
- Enable winter operation
- Enable heat distribution
- Move heating limit (based on wind speed)
- Filter outside temperature
- Filter wind speed
HCRV requires the values of the effective outside temperature and the filtered wind speed to calculate the flow temperature setpoint.
Enable winter operation
Winter operation is enabled if the following switching conditions are met:
Condition | Result |
|---|---|
| [EnWinOp] = Yes |
Enable heat distribution
Heat distribution is enabled if the following switching conditions are met:
Condition | Result |
|---|---|
| [EnHDstr] = Comfort |
| [EnHDstr] = Comfort and Eco |
Present heating limit
HRA shifts the present heating limit for Comfort or Economy in dependence of the filtered wind speed [WdSpdFil].
[WdSpd] is interconnected | [WdSpd] <= 0.8 m/s | No increase of the heating limits (no wind). |
[WdSpd] = 20 m/s | The heating limits Comfort [HLmCmf] and Economy [HLmEco] are increased by [ShHLmWds]. | |
Intermediate values | Linear interpolation on straight line having two sample points (0.8 / 0) and (20 / [ShHLmWds]). | |
[WdSpd] = 0 | Wind speed does not impact calculation of the present heating limits. | |
Filtering outside air temperature and wind speed
HRA filters the input values for outside air temperature [TOa] and wind speed [WdSpd] to attenuate their fluctuations.
[EnFil] = No | Filtering is disabled. The block processes the unfiltered outside air temperature [TOa] and wind speed [WdSpd]. | |
[EnFil] = Yes | Filtering is enabled. | |
[TOaFil] | The filtered outside temperature [TOaFil] is calculated as a strongly filtered value for outside temperature [TOa] from [TcnBldg] and [TcnOw]. | |
[TOaEf] | The effective outside temperature [TOaEf] is calculated as a combination of weak to medium filtered outside temperature [TOa] from [TcnOw] and [WndProp]. | |
[WdSpdFil] | The filtered wind speed [WdSpdFil] is calculated as a slightly filtered value from wind speed value [WdSpd]. | |
Release heating mode
Input [HraMod] sets outputs for heating mode with fixed or automatically calculated values. Input [EnFil] specifies whether the input values for temperature and wind are filtered in the calculations of the function block:
HraMod | EnFil | EnWinOp | EnHDstr | EnCmf | EnCmfEco |
Off | - | No | No | No | No |
EnWinOp | - | Yes | No | No | No |
EnHDstrCmf | - | Yes | Comfort | Yes | No |
EnHDDstrCmfAndEco | - | Yes | Comfort and Eco | Yes | Yes |
Auto | Yes | Release occurs in dependence of the heating period [SttHPrd], [StpHPrd], the effective outside air temperature [TOaEf], and the filtered wind speed [WdSpdFil]. | |||
No | Release occurs in dependence of the heating period [SttHPrd], [StpHPrd], outside air temperature [TOa], and wind speed [WdSpd]. | ||||
Input | Description | Data type | Default value |
|---|---|---|---|
TOa | Outside temperature | Real | 0.0 [°C] -100.0…50.0 [°C] |
WdSpd | Wind speed | Real | 0.0 0.0…20.0 [m/s] |
SttHMth | Start of heating period month of year | Integer | 1 1…12 |
1: January | |||
SttHDay | Start of heating period day of month | Integer | 1 1…31 |
StpHMth | Stop of the heating period month of year | Integer | 1 1…12 |
StpHDay | Stop of the heating period day of month | Integer | 1 1…31 |
EnFil | Enable filtering | Boolean | 1 |
0 - No filtering. | |||
HraMod | HRA mode (heating release algorithm) | Integer | 5: Auto |
1: Off | |||
HLmCmf | Heating limit comfort | Real | 15.0 5.0…35.0 [°C] |
HLmEco | Heating limit economy | Real | 5.0 5.0…35.0 [°C] |
TcnBldg | Time constant of building | Time | 2d_2h 0…200h |
WndProp | Proportion of windows Reference value for percentage of heat loss from windows. | Real | 50.0 0.0…100.0 [%] |
TcnOw | Time constant for outside wall | Time | 10h |
ShHLmWds | Shift of heating limit for nominal wind speed | Real | 5.0 0.0…10.0 [deltaK] |
Output | Description | Data type | Default value |
|---|---|---|---|
EnWinOp | Enable winter operation Indicates if winter operation is enabled. | Boolean | 0 |
0 - Winter operation disabled. | |||
EnCmf | Enable comfort for heat distribution | Boolean | 0 |
EnCmfEco | Enable comfort and economy for heat distribution | Boolean | 0 |
EnHDstr | Enable heat distribution | Integer | 1: No |
1: No | |||
TOaEf | Effective outside temperature | Real | 0.0 -50.0…150.0 [°C] |
TOaFil | Filtered outside temperature | Real | 0.0 -50.0…150.0 [°C] |
WdSpdFil | Filtered wind speed | Real | 0.0 [m/s] 0.0…20.0 [m/s] |
|
SysUnits | System of units Indicates the system of units used by the block. | Integer | 1: International system of units (SI) (fallback) 1...5 |
1: International system of units (SI) (fallback) | |||
ErrCode | Error code indication | Integer | 0: No error |
= 0 - No error | |||
Filtered values are lost during a power outage. At start up, all filters are initialized with the present input values.
Invalid input values are adjusted according to the limit values.
Input | Valid range | Correction |
|---|---|---|
TOa | [-100…50] | -100 or 50 |
WdSpd | [0…20] | 0 or 20 |
HraMod | [Aus…Auto] | Off |
HLmCmf | [5…35] | 5 or 35 |
HLmEco | [5…HLmCmf] | 5 or HLmCmf |
TcnBldg | [0…200h] | 0 or 200h (0 filter disabled) |
TcnOw | [0…200h] | 0 or 200h (0 filter disabled) |
ShHLmWds | [0…10] | 0 or 10 |
WndProp | [0…100] | 0 or 100 |
SttHMthStpHMth | [1…12] | Correction impossible. If outside the valid range, the heating period is considered active. |
SttHDayStpHDay | [1…31] | 1 or max. day of relative month. |