Combined Heat and Power¶
The cost of the component was explained in component costs or emissions page. The reference size is the nomimal power \(P_{CHP,nom}\). The electrical power of the CHP must remain below the nomimal power.
\[P_{CHP}^t \leq P_{CHP,nom}^{[\frac{t}{l_{yr}}]}\]
The mass flow rate of the burnt liquid is calculated by the electrical efficiency of CHP as follows:
\[M_{CHP}^t = \frac{P_{CHP}^t}{\eta_{el}}\]
The generated heat is calculated with a constant thermal efficiency as follows:
\[\dot{Q}_{CHP}^t = M_{CHP}^t \cdot \eta_{th}\]
The electricity sold must be less than the electricity generated.
\[P_{sell,CHP}^t \leq P_{CHP}^t\]
If a ninimum power considered, the following equations apply:
\[P_{CHP,X}^t = P_{CHP,max}^t - P_{CHP}^t\]
\[P_{CHP,X}^t \leq P_{CHP,max}^t - P_{CHP,min}^t\]
\[P_{CHP,min}^t + P_{CHP,min,tr}^t = f_{min}\cdot P_{CHP,nom}^{[\frac{t}{l_{yr}}]}\]
\[P_{CHP,max}^t + P_{CHP,max,tr}^t = P_{CHP,nom}^{[\frac{t}{l_{yr}}]}\]
\[P_{CHP,min}^t \leq \infty \cdot b_{CHP,min}^t\]
\[P_{CHP,max}^t \leq \infty \cdot b_{CHP,min}^t\]
\[P_{CHP,min,tr}^t + \infty \cdot b_{CHP,min}^t \leq \infty\]
\[P_{CHP,max,tr}^t + \infty \cdot b_{CHP,min}^t \leq \infty\]
If, in addition, a minimum runtime is considered, the following equation applies to guarantee the minimum number of time steps \(N_{min}\).
\[\frac{1}{N_{min}-1} \cdot \sum_{i=t-(N_{min}-1)}^{t-1} b_{CHP,min}^i \leq b_{CHP,min}^t + b_{CHP,min}^{t-N_{min}}\]