System and method for controlling a fluid vector temperature in order to heat a building

A system for heating a building comprising:

• a heat generator to heat a carrier fluid,
• at least one radiating element for transferring heat to a thermal load included in a building,
• a delivery conduit for transferring the carrier fluid from the heat generator to the radiating element,
• a return conduit for transferring the carrier fluid from the radiating element to the heat generator,
• a three-way valve arranged along the delivery conduit and connected to the return conduit, the three-way valve operable to mix the carrier fluid in the delivery conduit to the carrier fluid in the return conduit,
• a plurality of temperature sensors arranged to measure the temperature of the carrier fluid and a temperature of the environment outside the building, and
• a control unit operatively connected to the heat generator, the three-way valve and the temperature sensors,
• wherein the control unit is configured for:
• a) acquiring a temperature of the carrier fluid in the delivery conduit downstream of the three-way valve with respect to the direction of the flow of the carrier fluid in the delivery conduit,
• b) acquiring a temperature of the carrier fluid in the return conduit upstream of the three-way valve with respect to the direction of the flow of the carrier fluid in the return conduit,
• c) acquiring a temperature of the environment outside the building,
• d) estimating a first target temperature of the carrier fluid in the delivery conduit downstream of the three-way valve, based on a simplified model of the system calculated as a function of the temperature of the external environment,
• e) actuating at least one among the heat generator and the three-way valve to generate a periodic perturbation in the temperature of the carrier fluid downstream of the three-way valve,
• f) determining a second target temperature of the carrier fluid in the delivery conduit downstream of the three-way valve based on a temperature difference between the temperature of the carrier fluid in the delivery conduit and the temperature of the carrier fluid in the return conduit based on said perturbation,
• g) combining the first target temperature and the second target temperature to obtain a total target temperature,
• h) actuating at least one among the heat generator and the three-way valve to bring the carrier fluid in the delivery conduit downstream of the three-way valve to the total target temperature, and
• i) reiterating steps e) to h) until reaching a target temperature difference between the temperature of the carrier fluid in the delivery conduit and the temperature of the carrier fluid in the return conduit.