Chilled and superheated water: advantages and applications of microturbines

Capstone Green Energy microturbines have a number of advantages, one of which is their high production capacity for heat carriers such as chilled water and superheated water, making them ideal for applications in various sectors such as food and beverage, hospitals and pharmaceuticals. Here’s what to know about them.

Advantages and specifications of microturbines

Capstone Green Energy is a Californian company, world leader in turbine technology with over 100 registered patents for cogeneration, that is, the combined production of electrical and thermal energy, of which IBT Group is the exclusive partner for the Italian market. Capstone’s most important patent, of aeronautical origin, is the one concerning the “oil-free” technology: this refers to the complete absence of lubricating oil thanks to the use of air bearings (air-bearings) that support the turbine shaft in rotation without mechanical contact. There are many advantages to this application: first and foremost, the modulation of electricity and heat production according to the instantaneous needs of users from 0 to 100%. Another advantage is that microturbines have the lowest atmospheric pollutant emissions available today: NOx < 18 mg/Nm3; CO < 50 mg/Nm3 (at 15% oxygen), well below legal limits. In addition, the absence of lubricating oil means less need for maintenance. Other noteworthy features are the absence of vibrations, low noise emissions and remote control software, which make this technology absolutely innovative.

The application of microturbines to produce chilled and superheated water

Capstone Green Energy microturbines can be used for the combined production of electricity and sub-zero glycol water. This solution is perfect for the logistics and food industries where refrigeration at low temperatures is widespread.
Thanks to a specific application with an oil-free Capstone Turbine built and operating on multiple sites, it is possible to produce sub-zero cooling energy at a controlled temperature, without the use of electric chillers, thus saving electricity.

This allows superheated water to be produced to feed a specific ammonia absorption unit for the production of glycol water from -6°C to -60°C. The system ensures primary energy savings of over 30%, with overall efficiency peaks of over 85%. Microturbines are also used for the combined production of electrical and thermal energy. The system allows the use of a Capstone gas turbine and a specific heat recovery module (HRM), sized for the production of superheated water at the required in-out temperature, guaranteeing savings of over 30% of primary energy, with a combined production of electricity and over 80% of the heat recovered from the exhaust gases in the form of superheated water.

Case studies: Surgital and Coati

As already mentioned, these applications are ideal for the logistics and food industry, and the following case studies refer to this sector, starting with Surgital, leader in the production of frozen convenience foods. At its Lavezzola site, the IBT Group has installed a system for the simultaneous production of electricity, steam and sub-zero cooling energy for its futuristic storage warehouse. The system consists of a Capstone C600 oil-free gas turbine and a recovery steam generator equipped with an air vein burner for post-combustion of the exhaust gases, which produces the saturated steam used for the production process and the cooling energy required by the storage warehouse.

The second example takes us to Valpolicella, where the Salumificio Fratelli Coati is based: here, the IBT Group has installed a CCHP (Combined Cooling Heat and Power) system based on Capstone technology. The first of its kind in the meat processing sector in Italy, the new system allows the company to meet its efficiency targets by providing reliable power, significant cost savings and environmental benefits. The use of this technology allows the three energy carriers to be produced autonomously, even during maintenance periods. The CCHP system provides around 80% overall energy efficiency. This equates to significant energy savings of around 9,600 MWh per year, while also avoiding the emission of 2,400 tonnes of CO2.