JP2006220143A - Displacement fluid machine and refrigerating cycle by use of it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a displacement fluid machine having a simple structure and capable of reducing mechanical friction loss of an expander to improve energy efficiency. <P>SOLUTION: In this displacement fluid machine 1, the expander 2 provided with an expansion part 30 for forming an operation chamber 31 by meshing a fixed scroll 6 and a turning scroll 7 mutually, a crank shaft 4 fitting into the turning scroll 7, and a frame 8 is provided in a sealed vessel 5. This displacement fluid machine 1 lets high pressure working fluid flow from the center of the expansion part 30 into the operation chamber 31 and enlarges volume of the operation chamber 31 while moving the operation chamber 31 to the outer periphery to expand the high pressure working fluid. A back pressure chamber 15 is formed between the turning scroll 7 and the frame 8. A back pressure supply mechanism 40 for supplying the high pressure working fluid in the sealed vessel 5 into the back pressure chamber 15 is provided, and a mechanism 50 for adjusting a back pressure in such a way that back pressure in the back pressure chamber 15 becomes predetermined pressure is provided. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a positive displacement fluid machine and a refrigeration cycle using the same, and is particularly suitable for a positive displacement fluid machine having an expander in a sealed container and a refrigeration cycle using the same.

  As a conventional scroll expander, there is one disclosed in JP-A-8-28461 (Patent Document 1). This scroll expander is arranged in a sealed case and has a fixed scroll having a spiral body that rises from the end plate, and rises from the end plate and meshes with the spiral body of the fixed scroll so that the gas taken in from the center portion can be It consists of a orbiting scroll provided with a spiral body that in turn expands toward. That is, the central expansion chamber formed by the scrolls of the fixed scroll and the orbiting scroll is connected to the suction port, and the expansion chamber at the outer peripheral end is connected to the discharge port communicating with the discharge pipe. The gas taken in from the suction port in the central part by the swirling motion is sequentially expanded and discharged outside the discharge pipe through the discharge port on the outer peripheral end side.

  Furthermore, this scroll expander is configured to supply the lubricating oil provided inside the sealed case as a lubrication means to the center of each spiral body from the sliding part of the orbiting scroll and the back of the end plate by a pump. is doing. Specifically, lubricating oil provided in the upper case is supplied to the sliding part of the orbiting scroll and the spiral bodies in mesh with each other by a rotary positive displacement pump. This positive displacement pump is mounted on a shaft coupled to the scroll shaft below the level of the lubricating oil, and is provided with rotational power from the scroll shaft. The lubrication path that communicates with the discharge port of the pump passes through the axis of the scroll shaft and faces the center of each spiral body from the lower side that is the back side of the end plate, and the eccentric shaft portion and each spiral Lubricating oil is supplied to the meshing surface of the body.

JP-A-8-28461

  In the scroll expander disclosed in Patent Document 1 described above, the high pressure lubricant that lubricates the eccentric shaft portion is caused to flow out to the back surface of the end plate of the orbiting scroll so that the high pressure is applied. There is a problem that the mechanical friction loss increases. Further, since the entire back chamber of the end plate of the orbiting scroll is filled with high-pressure lubricating oil, a large amount of this lubricating oil tends to flow out to the outflow side of the expansion chamber, and a large amount of lubricating oil flows out to the external device. This may cause a shortage of lubricating oil in the sealed container.

  An object of the present invention is to obtain a positive displacement fluid machine having a simple structure and capable of improving energy efficiency by reducing mechanical friction loss of an expander.

  Another object of the present invention is to improve the energy efficiency by reducing the mechanical friction loss of the expander with a simple structure, and while also ensuring the high reliability of the sliding portion of the expander, the refrigeration cycle An object of the present invention is to obtain a positive displacement fluid machine capable of improving the coefficient of performance of the refrigeration cycle even when it is used for the above.

  Still another object of the present invention is to improve the energy efficiency by reducing the mechanical friction loss of the expander with a simple structure, and while maintaining high reliability of the sliding portion of the expander, An object of the present invention is to obtain a refrigeration cycle capable of improving the coefficient of performance of the refrigeration cycle because the amount of lubricating oil mixed in the heat exchanger of the cycle can be suppressed.

  In order to achieve the above-mentioned object, the present invention provides an expanding portion that forms a working chamber by meshing a fixed scroll and a orbiting scroll with each other, and fixes the fixed scroll and the orbiting scroll between the fixed scroll and the fixed scroll. An expander including a frame for sandwiching the pressure chamber is installed in a hermetic container, and a high-pressure working fluid is allowed to flow into the working chamber from the center of the inflating portion, and the working chamber is moved to the outer periphery while expanding the volume of the working chamber In the positive displacement fluid machine that expands the high-pressure working fluid, a back pressure chamber is formed between the orbiting scroll and the frame, and the high pressure working fluid in the sealed container is supplied to the back pressure chamber. A supply mechanism is provided, and a back pressure adjusting mechanism for adjusting the back pressure chamber to a predetermined pressure is provided.

A more preferable specific configuration example in the present invention is as follows.
(1) The back pressure adjusting mechanism communicates the back pressure chamber to the low pressure side of the inflating portion and adjusts the back pressure chamber to a predetermined pressure.
(2) The back pressure supply mechanism includes a back pressure supply passage formed in the fixed scroll and communicated with a high pressure side in the sealed container, and the back pressure supply passage and the back pressure chamber by a turning motion of the orbiting scroll. And a working fluid supply pocket formed in the orbiting scroll so as to repeat communication and interruption alternately and intermittently.
(3) The back pressure adjustment mechanism includes a back pressure control valve that opens a back pressure adjustment passage when a pressure difference between the pressure in the back pressure chamber and the pressure on the low pressure side of the expansion portion becomes a predetermined pressure difference.
(4) In addition to the above (3), the back pressure control valve has predetermined values for a valve body that opens and closes a passage of the back pressure adjustment mechanism, a pressure of the back pressure chamber, and a pressure on a low pressure side of the expansion portion. An elastic member that applies an elastic force to the valve body so as to maintain the pressure difference.
(5) The back pressure adjusting mechanism communicates the back pressure chamber with the low pressure side of the evaporator outlet in the external refrigeration cycle so as to adjust the back pressure chamber to a predetermined pressure.

  In order to achieve the above-mentioned another object, the present invention is capable of rotating freely on an inflating portion that meshes with the fixed scroll and the orbiting scroll to form an operation chamber, and a bearing portion on the back side of the orbiting scroll. An expander having a crankshaft to be fitted and a frame holding the orbiting scroll and fixing the fixed scroll is installed in a sealed container, and a high-pressure working fluid is allowed to flow into the working chamber from the center of the expanding portion. Then, while moving the working chamber to the outer periphery, the volume of the working chamber is expanded to expand the high-pressure working fluid, and lubricating oil is supplied to the sliding portion of the expander via the oil supply passage of the crankshaft. In the positive displacement fluid machine, a back pressure chamber is formed between the orbiting scroll and the frame, and the front is passed through the bearing portion on the back side of the orbiting scroll from the oil supply passage of the crankshaft. A lubricating oil supply mechanism that allows the lubricating oil to flow into the back pressure chamber and a back pressure supply mechanism that supplies the high pressure working fluid in the sealed container to the back pressure chamber are provided in parallel, and the back pressure chamber has a predetermined pressure. Thus, a back pressure adjusting mechanism is provided.

  Further, as another means for achieving the above-described further object, the present invention expands the radiated working fluid, a compressor that compresses the working fluid, a radiator that radiates the compressed working fluid, and A positive displacement fluid machine and an evaporator for evaporating the expanded working fluid are connected by a pipe, and the positive displacement fluid machine meshes the fixed scroll and the orbiting scroll with each other to form the working chamber. And an expander including a frame for fixing the fixed scroll and sandwiching the orbiting scroll between the fixed scroll and a high-pressure working fluid from the center of the expansion portion to the working chamber. In the refrigeration cycle configured to expand the high-pressure working fluid by inflowing and expanding the volume of the working chamber while moving the working chamber to the outer periphery, the volume The fluid machine includes a back pressure chamber that forms a back pressure chamber between the orbiting scroll and the frame, and supplies a high pressure working fluid in the sealed container to the back pressure chamber. A back pressure adjusting mechanism is provided in communication with the low pressure side of the evaporator outlet so as to adjust the back pressure chamber to a predetermined pressure.

A more preferable specific configuration example in the present invention is as follows.
(1) The back pressure adjusting mechanism includes a back pressure control valve that opens a back pressure adjusting passage when a pressure difference between the pressure in the back pressure chamber and the pressure on the low pressure side of the evaporator outlet becomes a predetermined pressure difference.
(2) The back pressure control valve maintains a predetermined pressure difference between the valve body that opens and closes the passage of the back pressure adjustment mechanism, the pressure of the back pressure chamber, and the pressure on the low pressure side of the evaporator outlet. And an elastic member for applying an elastic force to the valve body.

Further, as yet another means for achieving the above-mentioned further object, the present invention expands the compressor that compresses the working fluid, a radiator that radiates the compressed working fluid, and the radiated working fluid. It is constructed by connecting a positive displacement fluid machine and an evaporator that evaporates the expanded working fluid with piping,
The positive displacement fluid machine includes an inflating portion that forms a working chamber by meshing a fixed scroll and a turning scroll, and a frame that fixes the fixed scroll and sandwiches the turning scroll between the fixed scroll and the fixed scroll. An expander provided in a sealed container, a high-pressure working fluid is allowed to flow into the working chamber from the center of the inflating section, and the volume of the working chamber is expanded while moving the working chamber to the outer periphery. In the refrigeration cycle configured to expand the positive displacement fluid machine, the positive displacement fluid machine forms a back pressure chamber between the orbiting scroll and the frame, and the back side of the orbiting scroll from the oil supply passage of the crankshaft. A lubricating oil supply mechanism that allows the lubricating oil to flow into the back pressure chamber through a bearing portion of the back, and a back that supplies high pressure working fluid in the sealed container to the back pressure chamber. It provided the supply mechanism in parallel, in which the back pressure chamber communicates with the back pressure chamber to the low pressure side of the evaporator outlet is provided back pressure adjusting mechanism for adjusting to a predetermined pressure

  According to the positive displacement fluid machine of the present invention, the back pressure chamber is formed between the orbiting scroll and the frame, and the back pressure chamber is provided to supply the high pressure working fluid in the sealed container to the back pressure chamber. Since the back pressure adjusting mechanism for adjusting the pressure so that the pressure becomes a predetermined pressure is provided, the mechanical friction loss of the expander can be reduced and the energy efficiency can be improved with a simple structure.

  Further, according to the positive displacement fluid machine of the present invention, the back pressure chamber is formed between the orbiting scroll and the frame, and the lubricating oil supply mechanism allows the lubricant to flow into the back pressure chamber through the bearing on the back side of the orbiting scroll. And a back pressure supply mechanism for supplying the high pressure working fluid in the sealed container to the back pressure chamber in parallel and a back pressure adjusting mechanism for adjusting the back pressure chamber to a predetermined pressure. With a simple structure, the mechanical friction loss of the expander can be reduced and energy efficiency can be improved, and the refrigeration cycle even when used in the refrigeration cycle while ensuring high reliability of the sliding part of the expander It is possible to improve the coefficient of performance.

  Furthermore, according to the refrigeration cycle of the present invention, a lubricating oil supply mechanism that forms a back pressure chamber between the orbiting scroll and the frame, and allows the lubricating oil to flow into the back pressure chamber through the bearing on the back side of the orbiting scroll; A back pressure supply mechanism for supplying the high pressure working fluid in the hermetic container to the back pressure chamber is provided in parallel, and the back pressure chamber communicates with the low pressure side of the evaporator outlet in the external refrigeration cycle so that the back pressure chamber becomes a predetermined pressure. Since the back pressure adjustment mechanism for adjusting the pressure is adjusted in this way, it is possible to improve the energy efficiency by reducing the mechanical friction loss of the expander with a simple structure and to increase the sliding portion of the expander. Since the amount of lubricating oil mixed in the heat exchanger of the refrigeration cycle can be suppressed while ensuring reliability, the coefficient of performance of the refrigeration cycle can be improved.

  Hereinafter, a positive displacement fluid machine according to an embodiment of the present invention will be described with reference to FIGS.

  The entire positive displacement fluid machine 1 of the present embodiment will be described with reference to FIGS. 1 and 2. FIG. 1 is a longitudinal sectional view of a positive displacement fluid machine 1 according to an embodiment of the present invention, and FIG. 2 is a sectional view taken along line AA of FIG.

  The positive displacement fluid machine 1 includes an expander 2 that converts fluid energy of a high-pressure working fluid into mechanical energy, and a power generation element 3 that converts the converted mechanical energy into electrical energy. The expander 2 and the power generation element 3 are stacked one above the other and connected via a crankshaft 4 and stored in a sealed container 5.

  The expander 2 is a scroll type expander including an expansion unit 30 having the fixed scroll 6 and the orbiting scroll 7 as main components. The expander 2 includes an expansion section 30, a frame 8, an Oldham ring 9, and a crankshaft 4 as main components.

  The fixed scroll 6 includes a spiral fixed scroll wrap 6a and a fixed scroll end plate 6b on which the fixed scroll wrap 6a stands upright. An inflow port 6c is formed at the center of the fixed scroll end plate 6b. The inflow port 6c communicates with the inflow passage 6d. The inflow passage 6d is supplied with a high-pressure working fluid from an external device. An outflow port 6e is formed on the outer periphery of the fixed scroll end plate 6b. The outflow port 6e communicates with the outflow channel 6f. The outflow passage 6f extends to the outside of the positive displacement fluid machine 1 and is connected to an external device. The expanded working fluid is discharged to an external device through the outflow port 6e and the outflow channel 6f.

  The orbiting scroll 7 includes a spiral orbiting scroll wrap 7a and an orbiting scroll end plate 7b on which the orbiting scroll wrap 7a stands upright. An orbiting bearing 7c is provided at the center of the surface of the orbiting scroll end plate 7b on the side opposite to the orbiting scroll wrap. The orbiting scroll 7 is driven by the eccentric portion 4a of the crankshaft 4 via the orbiting bearing 7c. The expansion part 30 has a working chamber 31 formed by meshing the fixed scroll 6 and the orbiting scroll 7 with each other.

  The crankshaft 4 includes a main shaft portion 4c, an eccentric portion 4b extending upward from the main shaft portion 4c, and an oil supply passage 4c penetrating vertically through the main shaft portion 4c and the eccentric portion 4b. The main shaft portion 4c is composed of an upper large diameter portion and a lower thin diameter portion. The space in the hermetic container 5 is communicated with the high pressure side of the inflating part 30, and the pressure is kept high. Lubricating oil 11 is stored at the bottom of the sealed container 5. In order to supply oil to the bearing sliding portion of the expander 2, an oil supply piece 20 is attached to the lower end portion of the crankshaft 4. The lubricating oil 11 is supplied to each bearing sliding portion through the oil supply passage 4b by the centrifugal pump action of the oil supply piece 20 by the rotation of the crankshaft 4. As one of the supply paths of the lubricating oil 11, a lubricating oil supply path for allowing the lubricating oil 11 to flow into the back pressure chamber 15 through the bearing portion 7 c on the back side of the orbiting scroll 7 is formed.

  The frame 8 includes a main shaft support portion provided at the center, a turning scroll support portion provided on the outside thereof, and a fixed scroll support portion provided on the outside thereof. A through hole is provided in the main shaft support portion of the frame 8, and a main bearing 8a is provided in the through hole. The large diameter portion of the main shaft portion 4c is supported by the center portion of the frame 8 via the main bearing 8a. A fixed scroll 6 is fixed to the upper surface of the frame 8 via fastening bolts 10. The outer periphery of the frame 8 is fixed to the sealed container 5. A turning scroll 7 is sandwiched between the fixed scroll 6 and the frame 8 so as to be turnable. A back pressure chamber 15 is formed between the orbiting scroll 7 and the frame 8. The Oldham ring 9 is provided between the orbiting scroll 7 and the frame 8 so as to prevent the orbiting scroll 7 from rotating.

  The power generation element 3 includes a rotor 3 a fixed to the crankshaft 4 and a stator 3 b fixed to the sealed container 5. The rotor 3 a is fixed to the small diameter portion of the main shaft portion 4 c and is rotated together with the crankshaft 4. The stator 3b is disposed around the rotor 3a and has a coil.

  In such a configuration, when a high-pressure working fluid is supplied from an external device to the inflow passage 6d, the high-pressure working fluid passes through the inflow port 6c from the inflow passage 6d and is formed between the fixed scroll wrap 6a and the orbiting scroll wrap 7a. Into the working chamber 31. The high-pressure working fluid that has flowed into the working chamber 31 is expanded by expanding the volume of the working chamber 31 by operating the orbiting scroll 7 due to a pressure difference with the low-pressure working fluid formed on the outer peripheral side. The expanded working fluid flows out of the sealed container 5 through the outflow passage 6f through the outflow port 6e in the outer peripheral portion. At this time, since the orbiting scroll 7 is prevented from rotating by the Oldham ring 9, the center of the orbiting scroll 7 undergoes a revolving motion with a constant radius by the eccentric portion 4a of the crankshaft 4, so that the expansion energy of the working fluid is increased. Is converted into mechanical energy called rotation of the crankshaft 4. When the crankshaft 4 is rotated, the rotor 3a is rotated, a current is induced in the coil of the stator 3b, and the power generation element 3 is caused to generate power.

  Next, the back pressure control mechanism of the positive displacement fluid machine 1 will be described with reference to FIGS. FIG. 3 is an enlarged view of a main part for explaining a back pressure supply mechanism 40 for supplying a high-pressure working fluid to the back pressure chamber in the positive displacement fluid machine 1 of the present embodiment, and FIG. 4 is a back view of the positive displacement fluid machine 1 of the present embodiment. It is a principal part enlarged view explaining the back pressure adjustment mechanism 50 which makes a pressure chamber into predetermined pressure. FIG. 3A shows a high-pressure working fluid in the sealed container 5 through a back pressure supply passage 12 formed in the fixed scroll 6 and into a back pressure supply pocket 13 formed on the sliding surface of the end plate 7 b of the orbiting scroll 7. FIG. 3B shows a state in which the crankshaft 4 is rotated about 180 degrees from the state shown in FIG.

  As shown in FIG. 3, the back pressure supply mechanism 40 includes a back pressure supply path 12 formed in the fixed scroll 6, a back pressure chamber 15 formed in the orbiting scroll 7, and a back pressure formed in the fixed scroll 6. And a supply groove 14. The back pressure supply path 12 is formed so as to penetrate vertically through the peripheral edge of the fixed scroll 6. One side of the back pressure supply path 12 communicates with a space in the sealed container 5 where the high-pressure working fluid exists, and the other side of the back pressure supply path 12 is opened to face the orbiting scroll 7. The back pressure supply pocket 13 is formed by denting the peripheral upper surface of the orbiting scroll 7. The back pressure supply pocket 13 is provided at a position where the back pressure supply passage 12 and the back pressure supply groove 14 communicating with the back pressure chamber 11 are alternately and intermittently communicated and interrupted by the orbiting scroll 7. It has been.

  In the back pressure supply mechanism 40, when the orbiting scroll 7 is turned, the back pressure supply path 12 and the back pressure supply pocket 13 are communicated with each other as shown in FIG. As a result, the high-pressure working fluid in the sealed container 5 is supplied into the back pressure supply pocket 13 through the back pressure supply path 12 as indicated by an arrow. When the orbiting scroll 7 further turns from this state, the back pressure supply path 12 and the back pressure supply pocket 13 are shut off, and then the back pressure supply pocket 13 and the back pressure supply groove 14 as shown in FIG. Is communicated. As a result, the high-pressure working fluid in the back pressure supply pocket 13 is supplied to the back pressure chamber 15 via the back pressure supply groove 14. That is, the pressure in the back pressure supply groove 14 and the back pressure chamber 15 is lower than the pressure of the high-pressure working fluid in the back pressure supply pocket 13 due to the function of the back pressure adjustment mechanism 50, so The high pressure working fluid is supplied to the back pressure chamber 15 through the back pressure supply groove 14 due to the pressure difference. Then, the back pressure supply pocket 13 is filled with the working fluid having the same pressure as the back pressure supply groove 14 and the back pressure chamber 15, and the orbiting scroll 7 is further swung to make the above-described FIG. Return to the state. The supply amount of the high-pressure working fluid can be arbitrarily changed by changing the internal volume of the back pressure supply pocket 13. Further, the supply amount of the high-pressure working fluid can be further increased by configuring the back pressure supply passage 12 and the back pressure chamber 15 to directly communicate with each other. In this way, the back pressure chamber 15 is alternately and intermittently communicated and interrupted with the back pressure supply passage 12 and the back pressure chamber 11 by the orbiting motion of the orbiting scroll 7. An appropriate amount of high-pressure working fluid can be supplied to the back pressure chamber 15 intermittently from the side.

  According to the back pressure supply mechanism 40, an appropriate amount of high-pressure working fluid can be easily supplied into the back pressure chamber 15 with a simple structure in which passages, pockets, and grooves are provided in the fixed scroll 6 and the orbiting scroll 7. Can do. In addition, since the lubricating oil 11 is supplied to the back chamber 15 through the main bearing 8a and the slewing bearing 7c, the main bearing 8a and the slewing bearing 7c can be reliably lubricated. In that case, since the high-pressure working fluid is also supplied to the back pressure chamber 15, it is possible to prevent the lubricating oil 11 from flowing out through the back pressure chamber 15. Thereby, the outflow of the lubricating oil 11 to the external device can be suppressed, and the shortage of the lubricating oil 11 in the sealed container can be prevented.

  The back pressure adjusting mechanism 50 includes a back pressure control valve 16, a valve storage portion 6h, an outflow side communication passage 6j, and an outflow side communication groove 6i. The back pressure adjustment mechanism 50 is provided on the fixed scroll 6. The back pressure control valve 16 communicates or shuts off the back pressure chamber 15 and the low pressure side of the expansion portion 30, and the pressure of the back pressure chamber 15 and the low pressure side pressure of the expansion portion 30 are a predetermined pressure. It comprises an elastic member 18 that elastically supports the valve body 17 so as to control the difference, and a pin 19 having a back pressure chamber communication passage 19a. Although the low pressure side of the expansion part 30 is the outflow port 6e in this embodiment, the low pressure side of the working chamber 31 may be sufficient. The valve body 17 is formed of a circular metal plate. The elastic member 18 is formed of a spiral metal spring. The valve body 17 and the elastic member 18 are housed in the valve housing portion 6h, and the pin 19 is fixed to the fixed scroll 6 with the elastic member 18 being pressed through the valve body 17. As a result, the elastic member 18 is given an elastic force that presses the valve body 17 toward the pin 19. The communication path that connects the back pressure chamber 15 and the low pressure side of the expansion part 30 is the back pressure chamber communication path 19a that communicates the back pressure chamber 15 and the valve housing 6h, and the outflow side communication groove that communicates with the outflow port 6e. 6i and an outflow side communication passage 6j that communicates the outflow side communication groove 6i and the valve storage portion 6h.

  Here, when the pressure in the back pressure chamber 15 becomes larger than the sum of the expander outflow pressure and the elastic force of the elastic member 18, the valve body 17 is pushed up, and the low pressure side of the back pressure chamber 15 and the expansion portion 30 communicates with each other. The pressure in the chamber 15 decreases. When the pressure in the back pressure chamber 15 decreases, the sum of the expander low pressure side working chamber 6g and the elastic force of the elastic member 18 exceeds the force on the back pressure chamber side. Shut off from the low pressure side.

  According to the back pressure adjusting mechanism 50, the pressure in the back pressure chamber 15 can be easily set to an appropriate pressure by adjusting the elastic force of the elastic member 18.

  By the back pressure control mechanism as described above, the high pressure working fluid can be supplied from the back pressure supply passage 12 to the back pressure chamber 15, and the pressure of the back pressure chamber 15 can be appropriately held by the back pressure control valve 16. As a result, a back pressure is applied to the end plate 7b of the orbiting scroll 7 to press the orbiting scroll 7 against the fixed scroll 6, and this pressing force cancels the axial thrust load due to the pressure in the working chamber to reduce the mechanical friction loss. In addition, the positive displacement fluid machine 1 can be provided in which the clearance between the scroll wrap tip portions is reduced to ensure sealing performance and enable highly efficient operation.

  Next, a positive displacement fluid machine according to another embodiment of the present invention will be described with reference to FIGS. 5 and 6, the same reference numerals as those in FIGS. 1 to 4 denote the same parts and perform the same functions. FIG. 5 is a longitudinal sectional view of a positive displacement fluid machine 1 according to another embodiment of the present invention, and FIG. 6 is a refrigeration cycle configuration diagram including the positive displacement fluid machine 1 according to another embodiment of the present invention. In the figure, 6k is an external outflow port of the back pressure adjusting mechanism 50 and is connected from the external outflow passage 51 to the external refrigeration cycle through the back pressure relief pipe 51a. Reference numeral 52 denotes a compressor constituting a refrigeration cycle, and includes a compression element 52a and an electric element 52b for driving the compression element 52a. 53 is an oil separator that separates oil in the discharge gas, and the separated oil is returned to the sealed container 5 of the positive displacement fluid machine 1 of the present invention through an oil return pipe 53a (shown by a broken line). 54 is a radiator, and 55 is an evaporator. 60 is an inverter for controlling the rotational speed of the electric element 52b, and 61 is a commercial power source. Reference numeral 62 denotes a controller that directs electric power generated by the power generation element 3 to the inverter 60. The power consumption of the commercial power source 61 is reduced by the amount of generated power, and the coefficient of performance of the refrigeration cycle can be improved. In the case where the inverter 60 is not provided, the recovered electric energy can be used by directly returning to the commercial power source by AC power generation.

  The operation of the refrigeration cycle is performed as follows. The high-temperature and high-pressure refrigerant discharged from the compression element 52a of the compressor 52 driven by the electric element 52b enters the radiator 54 and dissipates heat, thereby lowering the temperature. The refrigerant discharged from the radiator 54 flows into the expander 2 of the positive displacement fluid machine 1 of the present invention through the inflow passage 6d, performs the above-described expansion operation, converts the fluid energy into mechanical energy, and generates power. 3 is rotated and recovered as electric energy to become a low-temperature and low-pressure refrigerant. The refrigerant that has flowed out of the expander 2 through the outflow passage 6f returns to the compressor 52 and is compressed again to become a high-temperature and high-pressure refrigerant. The above cycle is repeated to produce a freezing action.

  In the positive displacement fluid machine 1 according to another embodiment of the present invention, the back pressure chamber 15 communicates with the low pressure side of the outlet of the evaporator 55 in the external refrigeration cycle so as to adjust the back pressure chamber 15 to a predetermined pressure. Since the pressure adjustment mechanism 50 is provided, the back pressure chamber 15 communicates with the low pressure side of the expansion portion 30 and the back pressure adjustment mechanism 50 that adjusts the back pressure chamber 15 to a predetermined pressure is provided. In comparison, since the basic function of the back pressure adjusting mechanism 50 is not changed and the amount of lubricating oil mixed into the evaporator 55 of the refrigeration cycle can be suppressed, the heat transfer performance degradation and pressure loss increase due to the oil are eliminated. The coefficient of performance of the refrigeration cycle can be improved.

1 is a longitudinal sectional view of a positive displacement fluid machine according to an embodiment of the present invention. It is AA sectional drawing of FIG. It is a principal part enlarged view explaining the back pressure supply mechanism which supplies a high pressure working fluid to the back pressure chamber in the positive displacement fluid machine of this embodiment. It is a principal part enlarged view explaining the back pressure adjustment mechanism which makes the back pressure chamber the predetermined pressure in the positive displacement fluid machine of this embodiment. It is a longitudinal cross-sectional view of the positive displacement fluid machine concerning other embodiment of this invention. It is a refrigerating cycle block diagram provided with the positive displacement fluid machine concerning other embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Positive displacement fluid machine, 2 ... Expander, 3 ... Power generation element, 4 ... Crankshaft, 4a ... Eccentric part, 4b ... Oil supply passage, 4c ... Main shaft part, 5 ... Sealed container, 6 ... Fixed scroll, 6a ... Fixed Scroll wrap, 6b ... fixed scroll end plate, 6c ... inflow port, 6d ... inflow passage, 6e ... outflow port, 6f ... outflow passage, 6h ... valve storage, 6i ... outflow side communication groove, 6j ... outflow side communication passage, 6k ... External outlet port, 7 ... Orbiting scroll, 7a ... Orbiting scroll wrap, 7b ... Orbiting scroll end plate, 7c ... Orbiting bearing, 8 ... Frame, 8a ... Expansion machine main bearing, 9 ... Oldham ring, 10 ... Tightening bolt, DESCRIPTION OF SYMBOLS 11 ... Lubricating oil, 12 ... Back pressure supply passage, 13 ... Back pressure supply pocket, 14 ... Back pressure supply groove, 15 ... Back pressure chamber, 16 ... Back pressure control valve, 17 ... Valve body, 18 ... Elastic member, 19 ... pin, 19a ... back pressure chamber Communicating passage, 20 ... refueling piece, 30 ... expansion part, 31 ... working chamber, 40 ... back pressure supply mechanism, 50 ... back pressure adjusting mechanism, 51 ... external outflow passage, 51a ... back pressure relief pipe, 52 ... compressor, 52a ... compression element, 52b ... electric element, 53 ... oil separator, 53a ... oil return pipe, 54 ... radiator, 55 ... evaporator, 60 ... inverter, 61 ... commercial power supply, 62 ... controller.

Claims (11)

An expander comprising: an inflating portion that engages a fixed scroll and an orbiting scroll to form a working chamber; and a frame that fixes the fixed scroll and sandwiches the orbiting scroll between the fixed scroll and an expander. Installed in
In the positive displacement fluid machine that causes the high-pressure working fluid to flow from the center of the expansion portion into the working chamber, expands the volume of the working chamber while moving the working chamber to the outer periphery, and expands the high-pressure working fluid.
Forming a back pressure chamber between the orbiting scroll and the frame;
A back pressure supply mechanism for supplying the high pressure working fluid in the sealed container to the back pressure chamber;
A positive displacement fluid machine provided with a back pressure adjusting mechanism for adjusting the back pressure chamber so as to have a predetermined pressure.   2. The positive displacement fluid machine according to claim 1, wherein the back pressure adjusting mechanism communicates the back pressure chamber to a low pressure side of the expansion portion and adjusts the back pressure chamber to a predetermined pressure. A positive displacement fluid machine.   3. The positive displacement fluid machine according to claim 1, wherein the back pressure supply mechanism includes a back pressure supply passage formed in the fixed scroll and communicated with a high pressure side in the sealed container, and a turning motion of the orbiting scroll. The positive displacement fluid machine is provided with a working fluid supply pocket formed in the orbiting scroll so as to alternately and intermittently communicate and block between the back pressure supply passage and the back pressure chamber.   4. The positive displacement fluid machine according to claim 1, wherein the back pressure adjusting mechanism has a back pressure adjusting passage when a pressure difference between the pressure in the back pressure chamber and the pressure on the low pressure side of the expansion portion becomes a predetermined pressure difference. 5. A positive displacement fluid machine comprising a back pressure control valve for opening the circuit.   5. The positive displacement fluid machine according to claim 4, wherein the back pressure control valve includes a valve body that opens and closes a passage of the back pressure adjusting mechanism, a pressure of the back pressure chamber, and a pressure on a low pressure side of the expansion portion. A positive displacement fluid machine comprising: an elastic member that applies an elastic force to the valve body so as to maintain a predetermined pressure difference.   2. The positive displacement fluid machine according to claim 1, wherein the back pressure adjusting mechanism communicates the back pressure chamber with a low pressure side of an evaporator outlet in an external refrigeration cycle so as to adjust the back pressure chamber to a predetermined pressure. A positive displacement fluid machine. The fixed scroll and the orbiting scroll are meshed with each other to form an operating chamber, the crankshaft that is rotatably fitted to the bearing portion on the back side of the orbiting scroll, and the fixed scroll by sandwiching the orbiting scroll An expander equipped with a frame fixed to the inside of the sealed container,
A high-pressure working fluid is caused to flow into the working chamber from the center of the expansion portion, and the working chamber is moved to the outer periphery, the volume of the working chamber is expanded to expand the high-pressure working fluid, and the expander slides. In a positive displacement fluid machine that supplies lubricating oil to a part via an oil supply passage of the crankshaft,
Forming a back pressure chamber between the orbiting scroll and the frame;
A lubricating oil supply mechanism for flowing lubricating oil into the back pressure chamber from the oil supply passage of the crankshaft through the bearing portion on the back side of the orbiting scroll, and a back for supplying high pressure working fluid in the sealed container to the back pressure chamber. A pressure supply mechanism is provided in parallel,
A positive displacement fluid machine comprising a back pressure adjusting mechanism that communicates the back pressure chamber with a low pressure side of the expansion portion so as to adjust the back pressure chamber to a predetermined pressure. Piping connects a compressor that compresses the working fluid, a radiator that dissipates the compressed working fluid, a positive displacement fluid machine that expands the dissipated working fluid, and an evaporator that evaporates the expanded working fluid. Configured
The positive displacement fluid machine includes an inflating portion that forms a working chamber by meshing a fixed scroll and a turning scroll, and a frame that fixes the fixed scroll and sandwiches the turning scroll between the fixed scroll and the fixed scroll. An expander provided in a sealed container, a high-pressure working fluid is allowed to flow into the working chamber from the center of the inflating section, and the volume of the working chamber is expanded while moving the working chamber to the outer periphery. In a refrigeration cycle configured to expand
The positive displacement fluid machine includes a back pressure supply mechanism that forms a back pressure chamber between the orbiting scroll and the frame, and supplies a high pressure working fluid in the sealed container to the back pressure chamber. A refrigeration cycle, characterized in that a back pressure adjusting mechanism is provided for adjusting the back pressure chamber to a predetermined pressure by communicating the chamber to the low pressure side of the evaporator outlet.   9. The refrigeration cycle according to claim 8, wherein the back pressure adjustment mechanism opens a back pressure adjustment passage when a pressure difference between the pressure in the back pressure chamber and the pressure on the low pressure side of the evaporator outlet becomes a predetermined pressure difference. A refrigeration cycle comprising a valve.   10. The refrigeration cycle according to claim 9, wherein the back pressure control valve has predetermined values for a valve body that opens and closes a passage of the back pressure adjusting mechanism, a pressure of the back pressure chamber, and a pressure on a low pressure side of the evaporator outlet. A refrigeration cycle comprising: an elastic member that applies an elastic force to the valve body so as to maintain a pressure difference between the two. Piping connects a compressor that compresses the working fluid, a radiator that dissipates the compressed working fluid, a positive displacement fluid machine that expands the dissipated working fluid, and an evaporator that evaporates the expanded working fluid. Configured
The positive displacement fluid machine includes an inflating portion that forms a working chamber by meshing a fixed scroll and a turning scroll, and a frame that fixes the fixed scroll and sandwiches the turning scroll between the fixed scroll and the fixed scroll. An expander provided in a sealed container, a high-pressure working fluid is allowed to flow into the working chamber from the center of the inflating section, and the volume of the working chamber is expanded while moving the working chamber to the outer periphery. In a refrigeration cycle configured to expand
The positive displacement fluid machine forms a back pressure chamber between the orbiting scroll and the frame,
A lubricating oil supply mechanism for flowing lubricating oil into the back pressure chamber from the oil supply passage of the crankshaft through the bearing portion on the back side of the orbiting scroll, and a back for supplying high pressure working fluid in the sealed container to the back pressure chamber. A pressure supply mechanism is provided in parallel, and the back pressure chamber is connected to the low pressure side of the evaporator outlet to provide a back pressure adjustment mechanism that adjusts the back pressure chamber to a predetermined pressure. A positive displacement fluid machine.

Images