An energy converter

Abstract

An energy converter includes an electrical turbo-machine ( 101 ) for converting energy contained by vaporized working fluid into electrical energy, a feed pump ( 105 ) for pumping the working fluid in a condensed form to a vaporizer ( 115 ), a pre-feed pump ( 106 ) for pumping the condensed working fluid to the suction side of the feed pump, and an ejector-pump ( 108 ) for pumping the condensed working fluid to the suction side of the pre-feed pump. The energy converter can be based on for example the Organic Rankine Cycle. The feed pump is operated by the electrical turbo-machine, the pre-feed pump is operated by a separate motor ( 107 ), and the ejector-pump is operated by a part of the output flow of the pre-feed pump. The ejector-pump facilitates generating sufficient pre-supply pressure for the pre-feed pump during also a starting phase and other situations where the electrical turbo-machine and feed pump are not fully operating.

1 - 14 . (canceled) 
     
     
         15 . An energy converter comprising:
 an electrical turbo-machine for converting energy contained by vaporized working fluid into electrical energy, the electrical turbo-machine comprising a turbine section and a generator section,   a feed pump for pumping the working fluid in a condensed form to a vaporizer, the feed pump being arranged to be operated by the electrical turbo-machine,   a pre-feed pump for pumping the working fluid in the condensed form to a suction side of the feed pump, the pre-feed pump being arranged to be operated by a motor capable of running independently of operation of the electrical turbo-machine, and   an ejector-pump for pumping the working fluid in the condensed form to a suction side of the pre-feed pump, wherein the ejector-pump is arranged to be operated by a part of an output flow of the pre-feed pump.   
     
     
         16 . An energy converter according to  claim 15 , wherein the feed-pump comprises an impeller connected directly to an end of a rotor of the generator section. 
     
     
         17 . An energy converter according to  claim 16 , wherein the impeller of the feed pump is provided with a screw-type inducer for reducing a risk of cavitation on vanes of the impeller of the feed pump. 
     
     
         18 . An energy converter according to  claim 15 , wherein the motor for operating the pre-feed pump is an electrical motor. 
     
     
         19 . An energy converter according to  claim 15 , wherein the energy converter comprises:
 first cooling ducts for conducting cooling fluid to and from the generator section so as to cool the generator section, and   second cooling ducts for conducting the cooling fluid to and from a condenser for condensing the vaporized working fluid outputted by the electrical turbo-machine, the first and second cooling ducts constituting mutually parallel flowing paths for the cooling fluid.   
     
     
         20 . An energy converter according to  claim 15 , wherein the energy converter comprises ducts for conducting the working fluid to bearings of the electrical turbo-machine so as to lubricate the bearings of the electrical turbo-machine with the working fluid, the ducts being connected to a delivery side of the pre-feed pump. 
     
     
         21 . An energy converter according to  claim 15 , wherein the energy converter comprises ducts for conducting the working fluid to bearings of the electrical turbo-machine so as to lubricate the bearings of the electrical turbo-machine with the working fluid, the ducts being connected to a delivery side of the feed pump. 
     
     
         22 . An energy converter according to  claim 15 , wherein the energy converter further comprises the vaporizer. 
     
     
         23 . An energy converter according to  claim 15 , wherein the energy converter comprises a piping interface for connecting to the vaporizer. 
     
     
         24 . An energy converter according to  claim 15 , wherein the energy converter further comprises a recuperator for transferring heat energy from the vaporized working fluid outputted by the electrical turbo-machine to the condensed working fluid outputted by the feed pump. 
     
     
         25 . An energy converter according to  claim 15 , wherein the functional elements further comprise a frequency converter for supplying the electrical energy outputted by the electrical turbo-machine to an external electrical system. 
     
     
         26 . An energy converter according to  claim 15 , wherein the energy converter further comprises a condenser for condensing the vaporized working fluid outputted by the electrical turbo-machine. 
     
     
         27 . An energy converter according to  claim 15 , wherein the energy converter further comprises a controller arranged to start the pre-feed pump so that the rotational speed of the pre-feed pump is increased gradually according to a pre-determined speed profile. 
     
     
         28 . An energy converter according to  claim 15 , wherein the working fluid is organic working fluid. 
     
     
         29 . An energy converter according to  claim 19 , wherein the energy converter comprises ducts for conducting the working fluid to bearings of the electrical turbo-machine so as to lubricate the bearings of the electrical turbo-machine with the working fluid, the ducts being connected to a delivery side of the pre-feed pump. 
     
     
         30 . An energy converter according to  claim 19 , wherein the energy converter comprises ducts for conducting the working fluid to bearings of the electrical turbo-machine so as to lubricate the bearings of the electrical turbo-machine with the working fluid, the ducts being connected to a delivery side of the feed pump.