The commissioning phase of the solar thermal system for Martini & Rossi was carried out during the week of February 8 to 12, 2021.

Figure 1 Solar field based on the High Vacuum Flat Panels (HVFPs) of TVP.

The whole activity was divided into three main steps:

1. Operating status assessment

First, detailed checks were carried out on the operating status of the main instruments linked to the protection equipment of the solar field. The electronic connection and the consequent mechanical/electrical activation of the main valves were verified through changes to the operating settings of the PLC (Programmable Logic Controller).

2. Operating and regulation parameters analysis

The next phase was characterized by the study related to the operating and regulation parameters according to the different characteristics that the heat carrier can assume. Temperature and pressure ranges have been defined based on the different operating functions. At the same time, the software for monitoring and regulation for the entire plant was checked and implemented.

3. Training session

Once the commissioning was completed, a basic training activity was provided to Martini & Rossi operators. This activity addressed both theoretical and practical aspects to ensure the possibility to act quickly and effectively in case of failures.

‘Winter’ mode ON

The plant has been operating in ‘Winter’ mode since Monday, February 15th. This function involves the operation of two-unit heaters to heat up the environment of the production department below the solar field.

How it works

Currently, the circulating pumps are activated with an irradiation higher than 200 𝑊⁄𝑚2. Once this level of solar radiation is reached, the circulation phase begins, allowing the glycol water in the system to increase its temperature up to the minimum level that opens the flow in the direction of the unit heaters. This

temperature is set at 110°C to date. The flow to the unit heaters will be interrupted if the temperature drops below 60°C, in which case the system switches back to “recirculation” mode, or if it rises above 134°C, a temperature above which the dry cooler is activated to dissipate excess energy. These will turn off below 120°C.

Figure 2 Control panel of the solar system displaying the main operating parameters

The ‘Summer’ mode

On the other hand, the ‘Summer’ mode will be used in the hot period of the year. Under this mode and , thanks to a heat exchanger, it will be possible to bring the heat produced to a second circuit of water and glycol that will end up in an indirect steam generator to produce steam.

From the control panel, it is possible to set the “Winter” or “Summer” mode regardless of the actual season of the year.

Figure 3 Piping and Instrumentation Diagram (P&ID) of the solar system

Next Steps

Now it is time to start the implementation of the monitoring and storage system of the most significant energy quantities. Martini & Rossi are also starting the testing and commissioning of circuit 2 which will be able to produce steam in the summer season. It has been preferred to wait for the spring season to be able to make more accurate tests on safety settings.

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