Air source heat pump system and method of use for industrial steam generation

Abstract

A system for generating steam for industrial heat. The system may include a plurality of heat pump cycles in thermal communication with each other and in thermal communication with a steam generation cycle. The plurality of heat pump cycles may include first and second heat pump cycles. The first heat pump circulates a first a working fluid and includes a first heat exchanger. The second heat pump cycle circulates a second working fluid and includes a second heat exchanger. The first heat exchanger transfers heat from the first to the second working fluid. The second heat exchanger transfers heat to a third working fluid in the steam generation cycle.

What is claimed is: 
     
         1 . A system for generating steam, said system comprising:
 one or more heat pump cycles configured to transfer heat from an ambient air source via one or more working fluids, to add energy to a feed stream comprising water to generate an output stream comprising said steam at a saturation temperature of at least 120 degrees Celsius.   
     
     
         2 . The system of  claim 1 , further comprising a heat exchanger located within a heat pump cycle of said one or more heat pump cycles, wherein said heat exchanger is configured to preheat a working fluid of said one or more working fluids prior to compressing said working fluid downstream of a condenser. 
     
     
         3 . The system of  claim 2 , wherein said heat exchanger is a suction-line heat exchanger in fluid communication between at least two sections of said heat pump cycle, wherein said at least two sections are at different temperatures. 
     
     
         4 . The system of  claim 1 , further comprising said one or more working fluids, wherein said one or more working fluids comprises at least one of a fluorocarbon, a hydrofluoroolefin, a hydrofluoroether, a hydrocarbon, carbon dioxide, ammonia, or water. 
     
     
         5 . The system of  claim 1 , wherein at least one heat pump cycle of said one or more heat pump cycles comprises one or more compressors. 
     
     
         6 . The system of  claim 5 , wherein said one or more compressors comprises a centrifugal compressor. 
     
     
         7 . The system of  claim 5 , wherein at least one compressor of said one or more compressors is electrically powered. 
     
     
         8 . The system of  claim 5 , wherein at least one compressor of said one or more compressors is a double ended compressor with one or more compressor wheels on each side of said double ended compressor. 
     
     
         9 . The system of  claim 1 , wherein at least one heat pump cycle of said one or more heat pump cycles comprises an economizer. 
     
     
         10 . The system of  claim 1 , wherein said temperature of said steam is at least 150 degrees Celsius. 
     
     
         11 . The system of  claim 1 , wherein said temperature of said steam is between 120 degrees Celsius and 150 degrees Celsius. 
     
     
         12 . The system of  claim 1 , wherein a heat pump cycle of said one or more heat pump cycles comprises at least two compressors in series. 
     
     
         13 . The system of  claim 1 , wherein a heat pump cycle of said one or more heat pump cycles comprises at least two compressors in parallel. 
     
     
         14 . The system of  claim 1 , wherein a heat pump cycle of said one or more heat pump cycles comprises at least two compressors that are rotatably coupled together on a shaft. 
     
     
         15 . The system of  claim 1 , wherein a temperature of said ambient air source is less than or equal to 40 degrees Celsius. 
     
     
         16 . The system of  claim 1 , wherein said system comprises at least two heat pump cycles thermally coupled via at least a first heat exchanger, wherein a bottom heat pump cycle of said at least two heat pump cycles circulates a first working fluid through said first heat exchanger that condenses the first working fluid, a second heat exchanger, to transfer heat from an ambient air stream to a bottom cycle of said at least two heat pump cycles that evaporates the first working fluid, and wherein said top cycle circulates a second working fluid through said first heat exchanger to evaporate said second working fluid, a second compressor, and a third heat exchanger that condenses the second working fluid to transfer heat to a stream comprising water. 
     
     
         17 . The system of  claim 1 , further comprising a steam compressor to compress said stream comprising water downstream of said one or more heat pump cycles, wherein said steam compressor outputs superheated or saturated steam. 
     
     
         18 . The system of  claim 17 , wherein said steam exiting said one or more heat pump cycles has a saturation temperature less than 120 degrees Celsius, and said steam compressor increases said saturation temperature of said steam to at least 120 degrees Celsius. 
     
     
         19 . The system of  claim 17 , wherein said steam compressor is electrically powered. 
     
     
         20 . The system of  claim 17 , further comprising a second steam compressor in series with said steam compressor.