{"id":5014,"date":"2015-01-22T18:36:31","date_gmt":"2015-01-22T16:36:31","guid":{"rendered":"https:\/\/www.tempco.it\/blog\/?p=5014"},"modified":"2015-01-22T18:36:31","modified_gmt":"2015-01-22T16:36:31","slug":"cold-from-heat-energy-saving-with-absorption-chillers","status":"publish","type":"post","link":"https:\/\/www.tempco.it\/blog\/en\/5014\/cold-from-heat-energy-saving-with-absorption-chillers\/","title":{"rendered":"Cold from heat: energy saving with absorption chillers"},"content":{"rendered":"

Heat recovery for cooling<\/strong>. In spite of the appearing contradiction – how can it be possible to obtain cold from heat? -, absorption chillers<\/a><\/strong> are an excellent energy saving alternative to traditional compressor chillers<\/strong>, requiring on the opposite big amounts of electricity.<\/p>\n

It consists of energy efficiency cooling and conditioning systems<\/strong>, working on capitalization of waste heat<\/strong> flows, coming from other industrial processes or from solar panels<\/strong>, also called solar air conditioning<\/a>. Those are conditioning and refrigerating green solutions, also environmentally friendly not even using CFC<\/strong>, chlorofluorocarbons<\/a>, but low ambient impact fluids: an ideal solution for lowering pollution and Co2 emissions<\/strong>, with a more intelligent employ of energy, containing energy demand for conditioning and cooling, both for residential and industrial utilities.<\/p>\n

\"Tempco<\/a><\/p>\n

But let\u2019s see how this is achieved and how it works, with an engineering example of an absorption chiller<\/strong>.
\n<\/p>\n

First of all, the absorption<\/strong> is a physical process that happens when a liquid grab heat from the environment while evaporating. This is the fundamental principle on which works any chiller and cooling machine<\/strong>. That being said, let\u2019s remember that water evaporates at the temperature of 100\u00b0 C at normal atmospheric pressure (760 mm Hg), but with decreasing pressure levels, and in vacuum conditions, water evaporates at much lower temperatures: for example, in an airtight tank with a pressure of approximately 6 mm Hg, water starts evaporating at 4\u00b0 C.<\/p>\n

Absorption refrigerators<\/strong> mostly employ a mix of water and lithium bromide<\/strong> as primary working thermal fluid: the two components of the solution, thanks to their peculiar physical properties, are in charge of two different functions in the cooling cycle. Water is the cooling and heat dissipation fluid during the thermal cycle, while the lithium bromide works as absorber: lithium bromide solution is indeed an excellent absorber, being able to capture all of the ambient steam, also creating and maintaining low pressure conditions.<\/p>\n

An absorption refrigerator is then composed by multiple steps using different interconnected thermal machines<\/strong>, supplying the fluids at the right temperature and pressure conditions in order to enhance the several physical processes required for the absorption refrigeration cycle<\/strong>. These are essentially four:<\/p>\n