Method of operating a solar thermal process heat plant and solar thermal process heat plant

Solar thermal process heat plant, comprising:

• a heating section, in which a heat carrier medium is heatable by solar radiation;
• wherein the heating section comprises a plurality of heating branches connected in parallel;
• wherein at the heating branches or a majority of the heating branches a mass flow control valve is disposed, respectively;
• one or more state variable sensors for measuring a state variable of flowing heat carrier medium associated with the heating branches, respectively;
• a control device, by means of which the mass flow control valves are controllable;
• and
• a mean-value generating device, by means of which a mean value of measured state variables over heating branches is calculable;
• wherein the control of the mass flow control valve of a respective heating branch is dependent upon the state variable deviation between the respective measured state variable of the heat carrier medium in the respective heating branch and the calculated mean value over the heating branches.