Thermal energy recovery device

Abstract

Provided is a thermal energy recovery device in which poor lubrication of a bearing can be inhibited when an expander is driven. The thermal energy recovery device includes an evaporator ( 10 ), an expander ( 20 ), a power recovery machine ( 30 ), a condenser ( 40 ), a pump ( 50 ), a circulation flow path ( 60 ), a cooling flow path ( 70 ) for supplying working fluid from the pump ( 50 ) partially to the power recovery machine ( 30 ), an on-off valve (V 1 ) provided in the cooling flow path ( 70 ), and a control unit ( 80 ), in which the expander ( 20 ) has a rotor ( 21 ), a bearing ( 22 ), and a primary casing ( 23 ), and in which the power recovery machine ( 30 ) has a power recovery unit ( 31 ) and a secondary casing ( 35 ), and in which upon reception of a stop signal for stopping power recovery by the power recovery machine ( 30 ), the control unit ( 80 ) closes the on-off valve (V 1 ).

What is claimed is: 
     
       1. A thermal energy recovery device comprising:
 an evaporator for evaporating working medium through heat exchange between heating medium and the working medium; 
 an expander for expanding working medium flowing out of the evaporator; 
 a power recovery machine connected to the expander; 
 a condenser for condensing working medium flowing out of the expander; 
 a pump for delivering working medium flowing out of the condenser to the evaporator; 
 a circulation flow path connecting the evaporator, the expander, the condenser, and the pump in this order; 
 a cooling flow path for supplying working medium of liquid phase flowing out of the pump partially to the power recovery machine; 
 an on-off valve provided in the cooling flow path; and 
 a control unit, 
 wherein the expander has: 
 a rotor to be rotationally driven by the expansion energy of the working medium; 
 a bearing that bears the rotor such that the rotor is rotatable; and 
 a primary casing housing the rotor and the bearing therein, 
 and wherein the power recovery machine has: 
 a power recovery unit connected to the rotor to rotate together with the rotor and thereby recover power; and 
 a secondary casing housing the power recovery unit therein and having a shape in communication with the interior of the primary casing, 
 and wherein upon reception of a stop signal for stopping power recovery by the power recovery machine, the control unit closes the on-off valve. 
 
     
     
       2. The thermal energy recovery device according to  claim 1 ,
 wherein the secondary casing has an introducing portion connectable to the cooling flow path and capable of introducing working medium of liquid phase supplied through the cooling flow path into the secondary casing. 
 
     
     
       3. The thermal energy recovery device according to  claim 1 ,
 wherein the power recovery machine further has a jacket provided in the secondary casing to form a cooling space that allows working medium of liquid phase to flow between the jacket and the secondary casing, 
 and wherein the jacket has an introducing portion connectable to the cooling flow path and capable of introducing working medium of liquid phase supplied through the cooling flow path into the cooling space. 
 
     
     
       4. A thermal energy recovery device comprising:
 an evaporator for evaporating working medium through heat exchange between heating medium and the working medium; 
 an expander for expanding working medium flowing out of the evaporator; 
 a power recovery machine connected to the expander; 
 a condenser for condensing working medium flowing out of the expander; 
 a pump for delivering working medium flowing out of the condenser to the evaporator; 
 a circulation flow path connecting the evaporator, the expander, the condenser, and the pump in this order; 
 a cooling flow path for supplying cooling medium different from the working medium to the power recovery machine to cool the power recovery machine; 
 an on-off valve provided in the cooling flow path; and 
 a control unit, 
 wherein the expander has: 
 a rotor to be rotationally driven by the expansion energy of the working medium; 
 a bearing that bears the rotor such that the rotor is rotatable; and 
 a primary casing housing the rotor and the bearing therein, 
 and wherein the power recovery machine has: 
 a power recovery unit connected to the rotor to rotate together with the rotor and thereby recover power; and 
 a secondary casing housing the power recovery unit therein and having a shape in communication with the interior of the primary casing, 
 and wherein upon reception of a stop signal for stopping power recovery by the power recovery machine, the control unit closes the on-off valve. 
 
     
     
       5. The thermal energy recovery device according to  claim 1 , further comprising
 a liquid draining flow path for returning working medium of liquid phase within the primary casing or the secondary casing to the downstream side of the expander and the upstream side of the pump. 
 
     
     
       6. The thermal energy recovery device according to  claim 5 , further comprising:
 a liquid draining valve provided in the liquid draining flow path; 
 a bypass flow path for bypassing the expander; 
 a bypass valve provided in the bypass flow path; and 
 a shutoff valve provided at a site of the circulation flow path between a portion where the circulation flow path and an upstream end portion of the bypass flow path are connected and the expander, 
 wherein upon reception of a stop signal for stopping power recovery by the power recovery machine, the control unit reduces the rotational speed of the pump, closes the shutoff valve and opens the bypass valve, and closes the on-off valve and, after the pump is stopped, opens the liquid draining valve. 
 
     
     
       7. The thermal energy recovery device according to  claim 2 , further comprising
 a liquid draining flow path for returning working medium of liquid phase within the primary casing or the secondary casing to the downstream side of the expander and the upstream side of the pump. 
 
     
     
       8. The thermal energy recovery device according to  claim 3 , further comprising
 a liquid draining flow path for returning working medium of liquid phase within the primary casing or the secondary casing to the downstream side of the expander and the upstream side of the pump. 
 
     
     
       9. The thermal energy recovery device according to  claim 4 , further comprising
 a liquid draining flow path for returning working medium of liquid phase within the primary casing or the secondary casing to the downstream side of the expander and the upstream side of the pump.