Ejector

Abstract

An ejector includes a nozzle for decompressing a fluid in any one state of a gas-liquid state, a liquid state and a super-critical state, and a body portion having a fluid suction port and a mixing and pressurizing portion. The ejector is provided with a suction passage through which a fluid drawn from the fluid suction port flows into the mixing and pressurizing portion. The suction passage is changed such that the fluid drawn from the fluid suction port is decompressed in the suction passage in iso-entropy. Alternatively, the suction passage is changed such that a flow velocity of the fluid flowing into the mixing and pressurizing portion from the suction passage is substantially equal to a flow velocity of the fluid flowing from a jet port of the nozzle into the mixing and pressurizing portion, or is equal to or larger than the sound velocity.

1 . An ejector comprising:
 a nozzle configured to decompress and expand a fluid in any one state of a gas-liquid two-phase state, a liquid state and a super-critical state;   a body portion in which the nozzle is disposed, the body portion having a fluid suction port from which a fluid is drawn by a jet flow of the fluid jetted from a jet port of the nozzle, and a mixing and pressurizing portion in which the fluid jetted from the jet port of the nozzle and the fluid drawn from the fluid suction port are mixed and kinetic energy of the mixed fluid in a gas-liquid two-phase state is converted to pressure energy thereof; and   a suction passage through which the fluid drawn from the fluid suction port flows into an inlet of the mixing and pressurizing portion,   wherein a fluid passage area of the suction passage is configured to be changed such that the fluid drawn from the fluid suction port is decompressed in the suction passage substantially in iso-entropy.   
   
   
       2 . An ejector comprising:
 a nozzle configured to decompress and expand a fluid in any one state of a gas-liquid two-phase state, a liquid state and a super-critical state;   a body portion in which the nozzle is disposed, the body portion having a fluid suction port from which a fluid is drawn by a jet flow of the fluid jetted from a jet port of the nozzle, and a mixing and pressurizing portion in which the fluid jetted from the jet port of the nozzle and the fluid drawn from the fluid suction port are mixed and kinetic energy of the mixed fluid in a gas-liquid two-phase state is converted to pressure energy thereof; and   a suction passage through which the fluid drawn from the fluid suction port flows into an inlet of the mixing and pressurizing portion,   wherein a fluid passage area of the suction passage is configured to be changed such that a flow velocity of the fluid flowing into the mixing and pressurizing portion from the suction passage is substantially equal to a flow velocity of the fluid flowing from the jet port of the nozzle into the mixing and pressurizing portion.   
   
   
       3 . An ejector comprising:
 a nozzle configured to decompress and expand a fluid in any one state of a gas-liquid two-phase state, a liquid state and a super-critical state;   a body portion in which the nozzle is disposed, the body portion having a fluid suction port from which a fluid is drawn by a jet flow of the fluid jetted from a jet port of the nozzle, and a mixing and pressurizing portion in which the fluid jetted from the jet port of the nozzle and the fluid drawn from the fluid suction port are mixed and kinetic energy of the mixed fluid in a gas-liquid two-phase state is converted to pressure energy thereof; and   a suction passage through which the fluid drawn from the fluid suction port flows into an inlet of the mixing and pressurizing portion,   wherein a fluid passage area of the suction passage is configured to be changed such that a flow velocity of the fluid flowing into the mixing and pressurizing portion from the suction passage is equal to or larger than a sound velocity.   
   
   
       4 . The ejector according to  claim 1 , wherein the fluid passage area of the suction passage is gradually reduced toward downstream in a flow direction of the fluid flowing in the suction passage. 
   
   
       5 . The ejector according to  claim 4 , wherein a reduce degree of the fluid passage area at an inlet side of the suction passage is larger than a reduce degree of the fluid passage area at an outlet side of the suction passage. 
   
   
       6 . The ejector according to  claim 1 , wherein
 the fluid passage area of the suction passage at an inlet side of the suction passage is gradually reduced toward downstream in a flow direction of the fluid flowing in the suction passage, and   the fluid passage area of the suction passage at an outlet side of the suction passage is gradually increased toward downstream in the flow direction of the fluid flowing in the suction passage.   
   
   
       7 . The ejector according to  claim 1 , wherein the suction passage is provided between an outer peripheral surface of the nozzle and an inner peripheral surface of the body portion. 
   
   
       8 . The ejector according to  claim 1 , wherein the suction passage is configured by another nozzle to be provided therein. 
   
   
       9 . The ejector according to  claim 1 , wherein the nozzle and the suction passage are configured, such that an enthalpy difference (ΔH) between enthalpy of the fluid at an inlet of the nozzle and enthalpy of the fluid at the jet port of the nozzle is equal to or larger than an enthalpy difference (Δh) between enthalpy of the fluid at the inlet of the suction passage and enthalpy of the fluid at the outlet of the suction passage. 
   
   
       10 . The ejector according to  claim 1 , wherein
 the mixing and pressurizing portion is configured by a straight portion extending from the inlet of the mixing and pressurizing portion in a range, and an expanding portion extending from a downstream end of the straight portion to the outlet of the mixing and pressurizing portion,   the straight portion is cylindrical passage having a constant passage area in its entire range, and   the expending portion is configured such that a passage sectional area of the expanding portion is gradually increased toward downstream in a flow direction of the fluid.   
   
   
       11 . The ejector according to  claim 10 , wherein the range of the straight portion is set such that the flow velocities of gas fluid and liquid fluid within the fluid flowing into the mixing and pressurizing portion become equal to each other in the range. 
   
   
       12 . The ejector according to  claim 10 , wherein
 when a length of the straight portion in an axial direction of the nozzle is L 1  and a length from the inlet of the mixing and pressurizing portion to the outlet of the mixing and pressurizing portion in the axial direction is L 2 , the mixing and pressurizing portion is configured such that 0<L 1 /L 2 ≦0.4.   
   
   
       13 . The ejector according to  claim 10 , wherein the mixing and pressurizing portion is configured such that the fluid is pressurized in iso-entropy. 
   
   
       14 . An ejector comprising:
 a nozzle configured to decompress and expand a fluid in any one state of a gas-liquid two-phase state, a liquid state and a super-critical state; and   a body portion in which the nozzle is disposed, the body portion having a fluid suction port from which a fluid is drawn by a jet flow of the fluid jetted from a jet port of the nozzle, and a mixing and pressurizing portion in which the fluid jetted from the jet port of the nozzle and the fluid drawn from the fluid suction port are mixed and kinetic energy of the mixed fluid in a gas-liquid two-phase state is converted to pressure energy thereof, wherein   the mixing and pressurizing portion is configured by a straight portion extending from the inlet of the mixing and pressurizing portion in a range, and an expanding portion extending from a downstream end of the straight portion to the outlet of the mixing and pressurizing portion,   the straight portion is a cylindrical passage having a constant passage area in its entire range, and   the expending portion is configured such that a passage sectional area of the expanding portion is gradually increased toward downstream in a flow direction of the fluid.   
   
   
       15 . The ejector according to  claim 14 , wherein the range of the straight portion is set such that the flow velocities of gas fluid and liquid fluid within the fluid flowing into the mixing and pressurizing portion become equal to each other in the range. 
   
   
       16 . The ejector according to  claim 14 , wherein
 when a length of the straight portion in an axial direction of the nozzle is L 1  and a length from the inlet of the mixing and pressurizing portion to the outlet of the mixing and pressurizing portion in the axial direction is L 2 , the mixing and pressurizing portion is configured such that 0<L 1 /L 2 ≦0.4.   
   
   
       17 . The ejector according to  claim 14 , wherein the mixing and pressurizing portion is configured such that the fluid is pressurized in iso-entropy in the mixing and pressurizing portion. 
   
   
       18 . The ejector according to  claim 14 , wherein a sectional shape of a wall surface of the expanding portion in a section including an axial line of the nozzle is a straight line. 
   
   
       19 . The ejector according to  claim 14 , wherein a sectional shape of a wall surface of the expanding portion in a section including an axial line of the nozzle is a curved line. 
   
   
       20 . The ejector according to  claim 14 , wherein a sectional shape of a wall surface of the expanding portion in a section including an axial line of the nozzle is formed by combining plural straight lines. 
   
   
       21 . The ejector according to  claim 14 , wherein a sectional shape of a wall surface of the expanding portion in a section including an axial line of the nozzle is formed by combining at least a straight line and a curved line. 
   
   
       22 . The ejector according to  claim 14 , wherein an expanding degree of the expanding portion at an inlet side of the expanding portion is larger than an expanding degree of the expanding portion at an outlet side of the expanding portion. 
   
   
       23 . The ejector according to  claim 2 , wherein the fluid passage area of the suction passage is gradually reduced toward downstream in a flow direction of the fluid flowing in the suction passage. 
   
   
       24 . The ejector according to  claim 23 , wherein a reduce degree of the fluid passage area at an inlet side of the suction passage is larger than a reduce degree of the fluid passage area at an outlet side of the suction passage. 
   
   
       25 . The ejector according to  claim 2 , wherein
 the fluid passage area of the suction passage at an inlet side of the suction passage is gradually reduced toward downstream in a flow direction of the fluid flowing in the suction passage, and   the fluid passage area of the suction passage at an outlet side of the suction passage is gradually increased toward downstream in the flow direction of the fluid flowing in the suction passage.   
   
   
       26 . The ejector according to  claim 2 , wherein the suction passage is provided between an outer peripheral surface of the nozzle and an inner peripheral surface of the body portion. 
   
   
       27 . The ejector according to  claim 2 , wherein the suction passage is configured by another nozzle to be provided therein. 
   
   
       28 . The ejector according to  claim 2 , wherein the nozzle and the suction passage are configured, such that an enthalpy difference (ΔH) between enthalpy of the fluid at an inlet of the nozzle and enthalpy of the fluid at the jet port of the nozzle is equal to or larger than an enthalpy difference (Δh) between enthalpy of the fluid at the inlet of the suction passage and enthalpy of the fluid at the outlet of the suction passage. 
   
   
       29 . The ejector according to  claim 3 , wherein the fluid passage area of the suction passage is gradually reduced toward downstream in a flow direction of the fluid flowing in the suction passage. 
   
   
       30 . The ejector according to  claim 29 , wherein a reduce degree of the fluid passage area at an inlet side of the suction passage is larger than a reduce degree of the fluid passage area at an outlet side of the suction passage. 
   
   
       31 . The ejector according to  claim 3 , wherein
 the fluid passage area of the suction passage at an inlet side of the suction passage is gradually reduced toward downstream in a flow direction of the fluid flowing in the suction passage, and   the fluid passage area of the suction passage at an outlet side of the suction passage is gradually increased toward downstream in the flow direction of the fluid flowing in the suction passage.   
   
   
       32 . The ejector according to  claim 3 , wherein the suction passage is provided between an outer peripheral surface of the nozzle and an inner peripheral surface of the body portion. 
   
   
       33 . The ejector according to  claim 3 , wherein the suction passage is configured by another nozzle to be provided therein. 
   
   
       34 . The ejector according to  claim 3 , wherein the nozzle and the suction passage are configured, such that an enthalpy difference (ΔH) between enthalpy of the fluid at an inlet of the nozzle and enthalpy of the fluid at the jet port of the nozzle is equal to or larger than an enthalpy difference (Δh) between enthalpy of the fluid at the inlet of the suction passage and enthalpy of the fluid at the outlet of the suction passage.