OREANDA-NEWS. In the opinion of the Intergovernmental Panel on Climate Change (IPCC), one of the ways to limit our atmosphere’s rise in temperature is by improving energy efficiency – in other words, achieving the same output while using less energy. Bosch research engineers are pursuing this goal for both the largest and the smallest of the company’s products: industrial steam boilers that weigh tons and tiny semiconductor sensors.

Giant industrial steam boilers

Steam boilers are Bosch’s biggest and heaviest energy-supply products. They are over 12 meters long and can weigh more than 130 tons in operation. Every hour, they are capable of delivering around 55 tons of steam – as is the case at Valenzi GmbH & Co. KG, a company based in Suderburg, Germany, that produces some 4,000 tons of mushrooms, 2,000 tons of fruit, and 700 tons of soup vegetables annually. The company employs two efficient Bosch steam boilers.

  • Each produces five tons of steam per hour. First, the boiler feed water passes into the integrated waste heat recovery unit and is pre-heated using hot flue gas. This increases the boiler’s energy efficiency by roughly 5 percent – with a proportionate drop in fuel consumption.

  • The gas burners’ electronic combined control system ensures optimum doses of fuel and combustion air. Compared to the mechanical control used by older combustion systems, this allows for more precise tuning, which further reduces fuel consumption. The burner output is smoothly adjusted to the actual steam requirement, and can be throttled back to approximately 17 percent of rated output. This greatly reduces the switching frequency of the burners, as well as reducing energy losses caused by upstream ventilation of the flue gas channels.

  • The fan’s engine speed is adjusted depending on burner output. In the partial-load range, this leads to significantly lower electrical power input.

  • The boilers are equipped with a heat maintenance device: a heating coil is built into the boiler floor. This allows the boiler in operation to maintain the heat of the second boiler at a low pressure, which saves energy, avoids corrosion, and ensures rapid availability.

  • A boiler system has a service life of between 20 and 40 years. Depending on the situation, it is typically possible to achieve efficiency gains of between 10 and 30 percent by replacing or modernizing older systems. At today’s fuel prices, even the largest facilities will amortize quickly.

  • Valenzi is expecting its investment in the new boiler system to deliver annual energy cost savings of some 40,000 euros. It will bring down CO2 emissions by some 300 tons per year.