Liquid pump of screw expander

Abstract

A liquid pump of a screw expander is disclosed, applicable to an Organic Rankin Cycle (ORC). The liquid pump of a screw expander includes a semi-sealed or fully sealed shell. An expander unit and a liquid pump unit are disposed in the shell. The expander unit includes a screw rotor, and the liquid pump unit includes a screw rotor. The rotor of the expander unit is fixedly connected to the rotor of the liquid pump unit. The rotor of the liquid pump unit rotates under driving of the rotor of the expander unit. In the liquid pump of a screw expander applied to the ORC, since a resistance torque of the female rotor is small, the liquid pump does not wear even when the liquid viscosity is low, contributing to high reliability of the liquid pump. Meanwhile, the liquid pump is driven by the screw expander, thereby further improving power generation efficiency of the ORC. In addition, the semi-sealed or fully sealed shell can effectively prevent leakage of a refrigerant

1 . A liquid pump of a screw expander, comprising a semi-sealed or fully sealed shell, wherein an expander unit and a liquid pump unit are disposed in the shell;
 the expander unit comprises a screw rotor, and the liquid pump unit comprises a screw rotor;   the rotor of the expander unit is fixedly connected to the rotor of the liquid pump unit, and the rotor of the liquid pump unit rotates under driving of the rotor of the expander unit.   
     
     
         2 . The liquid pump of a screw expander as in  claim 1 , wherein
 the expander unit comprises an expander male rotor and an expander female rotor, and the liquid pump unit comprises a liquid pump male rotor and a liquid pump female rotor;   an end of the expander male rotor is fixedly connected to the liquid pump male rotor, and the liquid pump male rotor rotates under driving of the expander male rotor.   
     
     
         3 . The liquid pump of a screw expander as in  claim 2 , wherein
 the shell comprises an expander cavity and a liquid pump cavity isolated from each other; all or a main body part of the expander male rotor, and the expander female rotor are disposed in the expander cavity; and all or a main body part of the liquid pump male rotor, and the liquid pump female rotor are disposed in the liquid pump cavity;   an expander suction inlet, an expander exhaust outlet, a liquid pump inlet and a liquid pump outlet are disposed on the shell.   
     
     
         4 . The liquid pump of a screw expander as in  claim 3 , wherein
 the expander male rotor comprises a first rotor part and a first connection part which are integrally designed;   the first rotor part is disposed in the expander cavity and coordinates with the expander female rotor; and the first connection part extends into the liquid pump male rotor in the liquid pump cavity.   
     
     
         5 . The liquid pump of a screw expander as in  claim 3 , wherein
 the liquid pump male rotor comprises a second rotor part and a second connection part which are integrally designed;   the second rotor part is disposed in the liquid pump cavity and coordinates with the liquid pump female rotor; and the second connection part extends into the expander male rotor in the expander cavity.   
     
     
         6 . The liquid pump of a screw expander as in  claim 4 , wherein
 expander female rotor bearings are separately disposed at two ends of the expander female rotor, and liquid pump female rotor bearings are separately disposed at two ends of the liquid pump female rotor;   a first male rotor bearing is disposed at an end of the expander male rotor away from the liquid pump male rotor, and a second male rotor bearing is disposed at the first connection part and between the first rotor part of the expander and the second rotor part of the liquid pump.   
     
     
         7 . The liquid pump of a screw expander as in  claim 6 , wherein
 the expander cavity and the liquid pump cavity are isolated from each other through an isolation mechanism, so that a hole is formed between the expander cavity and the liquid pump cavity, and the first connection part passes through the hole and enters the liquid pump cavity.   
     
     
         8 . A liquid pump of a screw expander, applied to an Organic Rankin Cycle (ORC), comprising a semi-sealed or fully sealed shell, wherein an expander male rotor, an expander female rotor, a liquid pump male rotor and a liquid pump female rotor are disposed in the shell; an end of the expander male rotor is fixedly connected to the liquid pump male rotor, and the liquid pump male rotor rotates under driving of the expander male rotor;
 the shell comprises an expander cavity and a liquid pump cavity isolated from each other; all or a main body part of the expander male rotor, and the expander female rotor are disposed in the expander cavity; all or a main body part of the liquid pump male rotor, and the liquid pump female rotor are disposed in the liquid pump cavity; an expander suction inlet, an expander exhaust outlet, a liquid pump inlet and a liquid pump outlet are disposed on the shell;   the expander male rotor comprises a first rotor part and a first connection part which are integrally designed; the first rotor part is disposed in the expander cavity and coordinates with the expander female rotor; and the first connection part extends into the liquid pump male rotor in the liquid pump cavity;   expander female rotor bearings are separately disposed at two ends of the expander female rotor, and liquid pump female rotor bearings are separately disposed at two ends of the liquid pump female rotor; a first male rotor bearing is disposed at an end of the expander male rotor away from the liquid pump male rotor; a second male rotor bearing is disposed at the first connection part and between the first rotor part of the expander and the second rotor part of the liquid pump; and   the expander cavity and the liquid pump cavity are isolated from each other through an isolation mechanism, so that a hole is formed between the expander cavity and the liquid pump cavity, and the first connection part passes through the hole and enters the liquid pump cavity