Expander and heat pump using the expander

Abstract

An expander of the invention includes: n-number of rotary type fluid mechanisms (where n is an integer equal to or greater than 2), a first suction port ( 41 b ) for sucking a working fluid into a suction-side space ( 55 a ) of a first fluid mechanism ( 41 ), a communication port ( 43 a ) connecting a discharge-side space ( 55 b ) of a k-th fluid mechanism (where k is an integer from 1 to n−1) and a (k+1)-th suction-side space ( 56 a ) to form a single space, and a discharge port ( 51 a ) for discharging the working fluid from the discharge-side space of an n-th fluid mechanism. The expander further includes a second suction port ( 72 f ) being capable of changing its connecting position to the suction-side space ( 55 a ) of the first fluid mechanism ( 41 ), for sucking the working fluid into the suction-side space ( 55 a ).

1 . An expander comprising:
 n-number of rotary type expansion mechanisms (where “n” is an integer equal to or greater than 2) each having a cylinder, a shaft with an eccentric portion, a piston fitted to the eccentric portion and rotating eccentrically in the cylinder, and a partition member partitioning a space between the cylinder and the piston into a suction-side space and a discharge-side space;   a first suction port for sucking a working fluid into the suction-side space of the first expansion mechanism;   a communication port connecting the discharge-side space of the k-th expansion mechanism (where “k” is an integer from 1 to n−1) and the suction-side space of the (k+1)-th expansion mechanism to form a single space;   a discharge port for discharging the working fluid from the discharge-side space of the n-th expansion mechanism; and   a second suction port for sucking the working fluid into the suction-side space of the first expansion mechanism, the second suction port being capable of changing its connecting position to the suction-side space of the first expansion mechanism.   
     
     
         2 . The expander according to  claim 1 , further comprising:
 an intermediate plate disposed between the cylinder of the k-th expansion mechanism and the cylinder of the (k+1)-th expansion mechanism, for separating the cylinders, and wherein   the first suction port is provided in the cylinder of the first expansion mechanism, the communication port is provided in the intermediate plate, and the discharge port is provided in the cylinder of the n-th expansion mechanism and/or in a closing member for closing the cylinder of the n-th expansion mechanism.   
     
     
         3 . The expander according to  claim 1 , further comprising:
 a closing member for closing the cylinder of the first expansion mechanism at an end face thereof, and wherein   the second suction port is provided in the closing member.   
     
     
         4 . The expander according to  claim 3 , wherein:
 the closing member includes a movable portion capable of rotating, taking the shaft as the center of rotation, and   the second suction port is provided in the movable portion.   
     
     
         5 . The expander according to  claim 4 , wherein the movable portion includes a cylindrical bearing surface for supporting the shaft. 
     
     
         6 . The expander according to  claim 4 , further comprising a drive mechanism for rotating the movable portion. 
     
     
         7 . The expander according to  claim 6 , wherein the drive mechanism includes an electric actuator. 
     
     
         8 . The expander according to  claim 4 , wherein the closing member further includes an annular stationary portion to which the movable portion is united rotatably, the annular stationary portion having therein a first inlet passage for supplying the working fluid from outside of the expander to the second suction port provided in the movable portion, and a second inlet passage branched from the first inlet passage, for supplying the working fluid to the first suction port. 
     
     
         9 . An expander-compressor unit comprising: an expander section comprising an expander according to  claim 1 ; and a compressor section coupled integrally with the expander section by the shaft. 
     
     
         10 . A heat pump comprising an expander according to  claim 1 . 
     
     
         11 . A heat pump comprising an expander-compressor unit according to  claim 9 . 
     
     
         12 . The expander according to  claim 1 , further comprising:
 a movable member that closes the cylinder of the first expansion mechanism and that is capable of rotating independently of the shaft, taking the shaft as the center of rotation; and   an actuator imparting a rotational force having a magnitude corresponding to a pressure difference between a high pressure fluid and a low pressure fluid to the movable member, wherein   the second suction port is provided in the movable member.   
     
     
         13 . The expander according to  claim 12 , wherein the working fluid is used as the high pressure fluid and the low pressure fluid. 
     
     
         14 . The expander according to  claim 12 , wherein the actuator, the movable member, and the first expansion mechanism are disposed in that order along a direction parallel to the central axis line of the shaft. 
     
     
         15 . The expander according to  claim 12 , further comprising:
 a suction passage connected to the first suction port, for sending the working fluid to the cylinder of the first expansion mechanism; and   a branch passage branched from the suction passage, and wherein:   a high pressure chamber of the actuator and the branch passage are connected to each other, and a high pressure working fluid supplied to the actuator through the branch passage is utilized as the high pressure fluid;   the actuator and the movable member are disposed adjacent to each other so that one end of the second suction port is connected to the high pressure chamber of the actuator; and   the working fluid supplied to the actuator as the high pressure fluid is supplied through the second suction port provided in the movable member to the suction-side space of the first fluid mechanism.   
     
     
         16 . The expander according to  claim 12 , wherein the actuator comprises:
 a cylinder for driving the movable member;   a piston for driving the movable member, the piston forming a pressure chamber between the piston and the cylinder for driving the movable member and rotating the movable member by swinging eccentrically in the cylinder for driving the movable member; and   a partition member for driving the movable member, that partitions the pressure chamber into a high pressure chamber in which the high pressure fluid flows, and a low pressure chamber in which the low pressure fluid flows.   
     
     
         17 . The expander according to  claim 16 , wherein:
 the movable member is in a substantially disk-shaped configuration;   one of main surfaces of the movable member closes the cylinder of the first expansion mechanism while the other one of the main surfaces closes the cylinder for driving the movable member; and   on the other one of the main surfaces side, the movable member is coupled or united with the piston for driving the movable member or an eccentric portion disposed in the piston for driving the movable member.   
     
     
         18 . The expander according to  claim 16 , further comprising a stopper provided on an inner circumferential surface of the cylinder for driving the movable member and having a protruding shape toward the central axis line of the shaft, for restricting a movable range of the piston for driving the movable member in the cylinder for driving the movable member. 
     
     
         19 . The expander according to  claim 16 , further comprising pushing means for pushing the movable member in a predetermined direction of rotation. 
     
     
         20 . The expander according to  claim 19 , wherein:
 the pushing means is configured to vary the magnitude of the rotational force imparted to the movable member according to the position taken by the movable member around the central axis line of the shaft; and   the position of the movable member around the central axis line of the shaft is controlled by counterbalancing a rotational force in a forward direction, imparted to the piston for driving the movable member by the pressure difference between the high pressure fluid and the low pressure fluid, and a rotational force in a reverse direction, imparted to the movable member by the pushing means.   
     
     
         21 . An expander-compressor unit comprising: an expander section comprising an expander according to  claim 12 ; and a compressor section integrally coupled to the expander section by the shaft. 
     
     
         22 . A heat pump comprising an expander according to  claim 12 . 
     
     
         23 . The heat pump according to  claim 22 , further comprising a pressure regulator for regulating a pressure difference between the high pressure fluid and the low pressure fluid to be supplied to the actuator. 
     
     
         24 . The heat pump according to  claim 23 , wherein the pressure regulator acquires a portion of the working fluid to be sent to the first suction port and decompresses the acquired working fluid to produce a low pressure fluid, and by adjusting the degree of the decompression, the pressure regulator controls the position of the second suction port around the central axis line of the shaft. 
     
     
         25 . The heat pump according to  claim 23 , further comprising:
 a first pressure pipe having one end connected to a main pipe for sending the working fluid to the first suction port and another end connected to the pressure regulator and supplying a portion of a high pressure working fluid to be expanded to a first chamber of the pressure regulator; and   a second pressure pipe having one end connected to a second chamber of the pressure regulator and another end connected to the actuator and supplying, to the low pressure chamber of the actuator, the working fluid that has been decompressed to a low pressure by the pressure regulator.