Energy generation from waste heat using the carbon carrier thermodynamic cycle

Abstract

The invention relates to a method is provided which allows the generation of high temperatures, e.g. above 120° C. and maximum 200° C. and low temperatures, e.g. below minimum minus 20° C., from waste heat or geothermal heat or similar heat sources having a temperature of between 20 and 70° C. The method may use essentially pure carbon dioxide as primary working fluid in an essentially closed loop as described in previous disclosures, alternatively low boiling solvents are employed. The common feature of different embodiments is that the system operates at least partly, specifically in the absorber or cold side of the process, below atmospheric pressure (1 bar). In the method a heat pump or heat transformer is realized within the technical boundaries mentioned above. The invention also relates to the use of the method in combination with a district heating system for elevating the temperature of the district heating medium or for electricity production on demand.

Description

FIELD OF THE INVENTION[0001]The present invention relates to a method for generation of energy where a heat source supplies thermal energy in the range 30-80° C. to a Rankine cycle including a desorber on the hot side, an absorber or liquefier on the cold side, heat exchangers and at least one compressor and at least one pump for working fluid, and at least one of the following product streams is obtained:[0002]thermal energy in the range +90, +100, +120 and maximum +200° C.,[0003]thermal energy in the range +15, +10, +5, 0, −5 and minimum −20° C.,[0004]electricity from the decompression of CO2 or a working fluid following the extraction of heat.BACKGROUND OF THE INVENTION[0005]Reference is made to PCT / SE / 2012 / 050319 or WO 2012 / 128715 with priority from SE 1100208-6 (filed Mar. 22, 2011), U.S. application 61 / 468 474 (filed Mar. 28, 2011) and SE 1100596-4 (filed 16.08.2011), these documents are included by way of reference. These documents describe a novel thermodynamic cycle for ene...

AI Technical Summary

Benefits of technology

The invention is a method for generating energy using a Rankine cycle with a heat source, absorber, liquefier, heat exchangers, and compressors and pumps for working fluid. The method can produce thermal energy in the range of 30-80°C and also electricity from the decomposition of CO2 or the working fluid. The process pressure in the absorber or condenser section is always below 1 bar and the temperatures and pressures are within specific ranges. The method can efficiently generate energy from a variety of heat sources.

Problems solved by technology

The improvement needs for heat pumps are evident from the following: a) Lower paraffins as working fluids are flammable and pose therefore risks. b) The often used HFC are expensive, and whilst they are not dangerous for the earth's ozone layer, they contribute to the greenhouse effect.

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