JP2000227080A - Scroll type expansion machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To raise efficiency of a scroll type expansion machine as a prime mover. SOLUTION: In this scroll type expansion machine, high pressure fluid is supplied to a suction chamber 11a on the center part, and in a working chamber 10 moving from the center part to the outer circumferential part, fluid expanded into low pressure is discharged from a discharge chamber 17 on the outer circumferential part. Bypass ports 13a, 13b and check valves communicating the moving working chamber 10 to the low pressure part such as the atomspheric space or the discharge chamber are provided on the end plate or the like of a rotor or a shell 9, at excessive expansion when pressure in the working chamber lowers than pressure in the lower pressure part, the check valve is opened to introduce fluid of the low pressure part to the working chamber, the pressure in the working chamber is raised up to the pressure of the low pressure part, and the expansion machine is prevented from being in the driven state. The bypass ports 13a, 13b are formed on the positions returned by angular range less than 360 deg. from the winding end parts 8c, 9b of the outer circumference of the scroll.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scroll type expander as a prime mover which generates rotational power by operating with a compressible fluid such as compressed air.

[0002]

2. Description of the Related Art As described in, for example, Japanese Patent Application Laid-Open No. 8-28461, a scroll type expander is a kind of positive displacement type fluid machine and has the same configuration as a well-known scroll type compressor. However, since the compressed fluid is supplied to generate rotational power, the flow direction of the fluid is opposite to that of the compressor, and the suction side and the discharge side of the fluid are opposite. And the drive shaft is the output shaft. In a scroll-type expander as well as a scroll-type compressor, two scrolls having substantially the same shape of wrap, that is, spiral-shaped blades, are one.
By meshing at phases shifted by 80 °, an even number of crescent-shaped working chambers are formed between each other. Then, the compressed fluid supplied from the central suction chamber to the pair of adjacent working chambers expands in the working chamber, so that the working chamber moves from the center to the outer periphery in the direction in which the volume of the working chamber increases. Since the movable scroll revolves, power can be taken from the orbit. Therefore, in the scroll type expander, the suction and discharge volumes are geometrically determined as the volume of the working chamber.

More specifically, as shown in FIG. 3A, at the center of two meshing scrolls, the start of winding of one wrap contacts the wrap of the other scroll. In the closed working room,
The volume of the working chamber at the moment of fluid such as compressed air drawn from the suction chamber of the central portion is cut off from the suction chamber confined with called the suction volume V _s, as shown in FIG. 3 (c), At the outer peripheral portions of the two scrolls meshing with each other, the end of the wrap of one scroll is separated from the wrap of the other scroll to open the working chamber, and the working chamber at the moment when the working chamber communicates with the discharge chamber at the outer periphery. If will be referred to as volume and ejection volume V _d, these volumes are both determined as a geometrically constant value. Therefore, when the expansion of the compressible fluid is assumed to be adiabatic expansion in the working chamber, since the volume ratio (V _s / V _d) is constant,
the discharge pressure P _d if the κ specific heat ratio may be expressed as follows by the suction pressure P _s.

[0004]

(Equation 1)

Namely, the pressure P _d of the working chamber just before the discharge is determined by the pressure P _s at the time of inhalation. Thus, for example, 1
The suction volume per rotation is 239 cc and the discharge volume is 33
In a 3 cc scroll type expander, as shown in FIG. 4 (a), a supplied compressed fluid is sucked (I) at a predetermined pressure (0.06 MPa) from a suction chamber, expands, and expands into a working chamber. When the working chamber is discharged (II) in communication with the discharge chamber when the pressure becomes equal to a predetermined pressure (0 MPa), an ideal expansion state is obtained.
(A) In the PV diagram shown in the lower part, all the expansion energy of the gas corresponding to the area of the part on the left side of the curve can be recovered as power, so the theoretical efficiency as adiabatic expansion is 100% Becomes

On the other hand, for example, as shown in FIG. 4B, the pressure at the time of inhalation (I) is a predetermined pressure (0.06MPa).
If the pressure is 0.08 MPa, which is higher than a), the pressure in the working chamber is not reduced to the predetermined pressure (0 MPa) at the moment of the start of discharge (II) (underexpanded state).
Therefore, by the time the discharge is completed (III), the lower PV
In the diagram, the power indicated by the hatched portion is not recovered. As a result, the theoretical efficiency is 81.5%.

Further, contrary to the case of insufficient expansion, FIG.
As shown in (c), when the suction pressure is lower than the predetermined suction pressure and is, for example, 0.04 MPa, the pressure in the working chamber becomes a negative pressure (over-expanded state) at the time of the discharge start (II). Until the discharge is completed after the negative pressure is reached (III), the expander is driven to rotate from the outside instead of generating a driving force. Power is lost and the theoretical efficiency drops to 62.9%.

Japanese Patent Application Laid-Open No. 10-266980 discloses a scroll-type expander in which a control passage through which a working chamber and the inside of a case can communicate is formed in a fixed scroll in order to prevent over-expansion. However, according to FIG. 9 of the publication showing the position where the control passage is provided, since the control passage is located at a position which is returned to the center side by more than 360 ° from the end of the winding on the outer periphery of the scroll, the overexpansion still occurs. There is an area to do.

[0009]

SUMMARY OF THE INVENTION As described above, the present invention solves the problem of a decrease in efficiency caused by excessive or insufficient expansion of a compressed fluid in a conventional scroll type expander by simple means. It is another object of the present invention to provide an improved scroll-type expander that can achieve high efficiency close to an ideal expansion state.

[0010]

According to the present invention, there is provided a method for solving the above-mentioned problems.
And a scroll-type expander described in (1).

According to the present invention, in the scroll type expander, a bypass port capable of communicating at least a part of the working chamber with the low pressure portion is provided. This bypass port, in the movable scroll and the fixed scroll, from the winding end portion of the outer peripheral portion toward the winding start portion of the central portion,
Each is arranged at a position returned by an angle range of 360 ° or less along the lap. By providing a check valve in the bypass port, when the pressure in the working chamber becomes lower than the pressure in the low pressure section, the check valve is opened by the differential pressure, and the fluid is discharged from the low pressure section through the bypass port. It is introduced into the working chamber and increases the pressure in the working chamber to the pressure in the low pressure section.

Therefore, even in a so-called over-expansion state in which the pressure in the working chamber becomes lower than the pressure in the low-pressure section, the check valve is opened, and the fluid from the low-pressure section passes through the bypass port from the working chamber. To prevent the pressure in the working chamber from becoming lower than the pressure in the low-pressure section, so that in any case, the state is not over-expanded, and the scroll-type expander is driven by external power. Since no state occurs, the efficiency of the scroll-type expander does not decrease, and power loss can be avoided.

In this case, the low-pressure section may be a discharge chamber or a space at an arbitrary atmospheric pressure. If the discharge chamber is used as a low-pressure part, a closed cycle is formed by being cut off from the atmosphere, so that any gas other than air can be used as a working fluid.

If necessary, four or more bypass ports may be provided. A plurality of the bypass ports may be simultaneously opened to the same working chamber, or all of the bypass ports may be opened to different working chambers. You may make it. In the case where a large number of bypass ports are provided in this manner, the one located near the center is returned from the position of the one located near the outer periphery toward the winding start part in the center by an angle range of 360 ° or less along the wrap. It is preferable to arrange them at positions.

The bypass port provided with the check valve which is a feature of the present invention can be provided on the end plate of the movable scroll. In this case, the movable scroll may be of a double-tooth type, whereby the whole size can be reduced and the capacity of the scroll type expander can be doubled. The bypass port can be provided on the end plate of the fixed scroll.

The scroll type expander of the present invention is attached to a compressor provided with another drive unit, and drives the scroll type expander by discharging exhaust gas discharged from a device supplied with fluid compressed from the compressor. It can also be configured to receive the compressed fluid into the suction chamber as a working fluid and operate by the exhaust gas. In this case, a one-way clutch is provided between the output shaft of the scroll type expander and the shaft of the compressor, and only when the rotational speed of the expander exceeds the rotational speed of another drive unit, the one-way clutch of the scroll type expander is used. If the output is transmitted to the compressor, wasteful energy can be recovered without loss of power.

As a specific application, the scroll type expander of the present invention can be used, for example, in a system for supplying oxygen to a fuel cell. The fuel cell in this case is a device that directly generates electric power by a chemical reaction between oxygen and hydrogen. A fuel cell has an oxygen supply system and a hydrogen supply system.
Two pressure circuits are provided. The scroll type expander of the present invention is supposed to be used for this oxygen supply system, but of course, it can be used for a hydrogen supply system.

[0018] In a fuel cell, in order to increase the density of supplied oxygen, oxygen pressurized by an attached compressor is supplied. Further, the pressure on the outlet side of the fuel cell is also increased to a constant pressure for the same reason. Therefore, the scroll-type expander of the present invention can be used to recover the energy remaining in the gas discharged from the fuel cell and utilize it as power.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The structure of a scroll type expander as a first embodiment of the present invention will be described with reference to FIGS. In the figure, 1 is a housing, 2 is a main bearing, 3 is a shaft seal, and 4 is a shaft that is supported by the main bearing 2, one end of which is a housing 1 so that generated rotational power can be transmitted to the outside.
From the outside. Reference numeral 5 denotes a drive boss formed integrally and eccentrically at the other end (inner end) of the shaft 4.
The revolution of the rotor described later is converted into a rotational motion. 6 is a balance weight attached to the shaft 4, 7 is a rotor bearing attached to the drive boss 5, 8 is a rotor (movable scroll) that is supported by the drive boss 5 via the rotor bearing 7, and is a spiral type. It comprises a wrap 8a as a blade and an end plate 8b supported by a rotor bearing 7. Although not shown, the end plate 8b of the rotor 8 has a rotation preventing mechanism that prevents the rotation of the rotor 8 and allows only the revolution.

Reference numeral 9 denotes a shell (fixed scroll) fixed so as to constitute another part of the housing connected to the housing 1, and is fixed at a position facing the rotor 8 described above. Phase 1 for lap 8a
A spiral wrap 9a having substantially the same shape as the wrap 8a meshing with an offset of 80 °, and an end plate 9 serving also as an end wall of a shell 9 constituting an extension of the housing 1.
e. Reference numeral 10 denotes an even number of movable chambers formed as a pair of movable spaces between the meshed wraps 8a and 9a, and has a substantially crescent shape when viewed in the axial direction.

Reference numeral 11 denotes a suction port provided at the center of the end plate 9e of the shell 9, and introduces pressurized air as a compressed fluid. 11a is formed at the center of the two wraps 8a and 9a,
The suction chamber 12 communicates with the suction port 12 and is a discharge port provided so as to open to a part of the outer periphery of the shell 9. The discharge port 12 is always in communication with a discharge chamber 17 as a space on the outer peripheral portion of the two meshed wraps 8a and 9a. As described above, the volume at the moment when the working chamber 10 is shut off from the suction chamber 11a by the revolution of the rotor 8 is defined as the suction volume V.
_s, along with the the suction pressure P _s pressure, working chamber 10 is the ejection volume V _d the volume of moment it is opened to the discharge chamber 17 by the revolution of the rotor 8, it will be referred to as pressure and the discharge pressure P _d.

In accordance with the feature of the present invention, the scroll type expander of the first embodiment has, as shown in FIG. 2, a winding end portion 8c, 9 on the outer peripheral portion of each of the two wraps 8a, 9a.
b, toward the center of the winding start, each wrap 8a,
At positions returned by an angle range of 360 ° or less along 9a, bypass plates 13a and 13b communicating with the outside are provided on an end plate 9e which is the bottom surface of the shell 9. The bypass ports 13a and 13b have
A check valve 14 is provided to allow only a fluid flow from the outside atmospheric pressure space into the working chamber 10. In this case, the check valve 14 is spherical, and is supported by a stopper 15 attached to the end plate 9e. The stopper 15 is provided with a bypass port 15a through which a fluid passes.

In the illustrated embodiment, the discharge volume _Vd is set at the time of the ideal expansion in order to avoid the state of insufficient expansion and to always obtain the function and effect characteristic of the present invention. 2 so that it is larger than the discharge volume, that is, slightly overexpanded as in the case of FIG.
One lap 8a, determine the spiral shape of 9a, the suction volume V _s, and sets the ejection volume V _d, the suction pressure and the target P _s and the discharge pressure P _d is set.

Since the scroll-type expander of the first embodiment has such a structure, a compressed fluid, for example, pressurized air is supplied to the suction chamber 11a through the suction port 11 and is turned on as shown in FIG. As described above, when the working chamber 10 flows into the working chamber 10 when the working chamber 10 is open toward the suction chamber 11a, and then the working chamber 10 is closed and pressurized air is trapped therein, the pressurized air is pressurized. Since the air expands in the working chamber 10 so as to increase the volume of the working chamber 10, the working chamber 10 is divided into two wraps 8 in order to respond thereto.
a, 9a move from the center to the outer periphery. As a result, the rotor 8 having the wrap 8a revolves around the axis of the shaft 4.

As the pressurized air in the working chamber 10 expands as described above, the working chamber 10 expands in volume while moving from the center to the outer periphery.
The pressure of the air in the working chamber 10 also gradually decreases. Since the illustrated embodiment is set larger than the discharge volume in the case of the ideal expansion shown in FIG. 4 (a) the ejection volume V _d, shortly before the working chamber 10 is opened toward the discharge chamber 17, The pressure in the working chamber 10 becomes equal to the pressure in the discharge chamber 17. If the pressure in the working chamber 10 further decreases, it is necessary to rotate the shaft 4 from outside through the shaft 4 in order to maintain the rotation of the shaft 4, so that the power loss as shown in FIG. However, in the first embodiment, the working chamber 1
The check valve 14 opens when the pressure in the chamber 0 is about to drop below that of the outside, and outside air is introduced into the working chamber 10 from the atmospheric pressure space, which is a low-pressure section, through the bypass ports 13a and 13b. In addition, the pressure in the working chamber 10 is prevented from lowering to 0 MPa or less.

In this manner, since the inside of the working chamber 10 is prevented from becoming negative pressure, a state in which the shaft 4 is driven from the outside does not occur. Therefore, as in the case of the ideal expansion shown in FIG. 4A, all the energy of the pressurized air is theoretically converted into rotational power. When the working chamber 10 opens toward the discharge chamber 17, the air completely expanded in the working chamber 10 and further equalized to the pressure of the outside air by sucking the outside air through the check valve 14. It flows out to the discharge port 12.

Next, a second embodiment of the present invention will be described with reference to FIG. The same components as those in the above-described first embodiment are denoted by the same reference numerals, and redundant description will be omitted. In the first embodiment, a check valve 14 provided to prevent the efficiency from being reduced due to overexpansion when the pressure in the working chamber 10 is reduced more than necessary is opened to the outside air in the first embodiment. The second embodiment is configured to receive the atmospheric pressure air through the bypass port 15a, but does not receive the outside air but bypasses the low pressure air discharged into the discharge chamber 17 in the second embodiment. The difference is that the port is adapted to be received through ports 16a and 16b. As a result, a closed cycle that is shut off from the outside air is configured, so valuable gases other than air as a working fluid and gases harmful if released into the atmosphere
It is also possible to use any compressible fluid.

Similarly, FIG. 6 shows a third embodiment of the present invention. In this case, the check valve 14 is provided not on the end plate 9e of the shell 9 but on the end plate 8b of the rotor 8. When the pressure in the working chamber 10 becomes lower than necessary and the check valve 14 is opened, fluid is received from the space 18 formed in the housing 1 to prevent the pressure in the working chamber 10 from dropping. The feature is that it is. The space 18 is formed around the drive boss 5, and communicates with the discharge chamber 17 and the discharge port 12 through a passage such as a perforation or a groove (not shown), so that a low-pressure discharge fluid is constantly introduced into the space 18. Have been. Therefore, also in the third embodiment, since a closed cycle is formed from the outside air as in the second embodiment, any working fluid other than air can be used. Reference numerals 13a 'and 13b' denote bypass ports that communicate the check valve 14 and the working chamber 10.

FIG. 7 shows a fourth embodiment of the present invention.
In this case, the two bypass ports 13a and 13
It is characterized in that two bypass ports 13c and 13d are provided in addition to b. Bypass port 13c,
13d is opened at a position that is returned by an angle range of 360 ° or less toward the center winding portion along the wraps 8a and 9a from the position where the bypass ports 13a and 13b are open. I have. These bypass ports 13
Needless to say, check valves 14 are also provided in c and 13d. In the fourth embodiment, the bypass ports 13a, 13b and the bypass ports 13c, 13d are respectively opened to different working chambers 10. However, the present invention is not limited to this. The ports may be provided so as to open at the same time, and these bypass ports may be provided on either the end plate 8b of the rotor 8 or the end plate 9e of the shell 9, and the number thereof is four. More than the above may be used.

In the fourth embodiment shown in FIG. 7, by providing a large number of four or more bypass ports, it is ensured that the internal pressure is unnecessarily reduced in all the working chambers 10 in which they are provided. Therefore, the range in which operation can be effectively performed with respect to the fluctuation of the suction pressure is widened, and the decrease in efficiency due to overexpansion can be more reliably prevented. Further, when a plurality of bypass ports communicate with one working chamber 10 at the same time, the pressure loss of the fluid passing through the bypass port can be reduced.

FIG. 8 shows a fifth embodiment of the present invention. The rotor 8 'used in this embodiment is what is called a double-toothed scroll, and its end plate 8b' has spiral wraps 8a 'and 8b' on both sides. The fixed scroll corresponding to these wraps also has the same wrap 9a 'and end plate 9 as in the other embodiments.
In addition to the shell 9 'made of e', a shell made of a spiral wrap 1a and an end plate 1b formed on the housing 1 is provided. In this case, the check valve 14 is provided on the end plate 8b 'of the rotor 8'. However, since the rotor 8 'is a double-toothed scroll, the radial bypass port 13e connected to the check valve 14 has an end. It is connected to the middle of a bypass port 13f which penetrates the plate 8b 'and communicates the working chambers 10 on both sides. The bypass port of the stopper 15 ′ is open to the discharge chamber 17.

Since the rotor 8 'is a double-toothed scroll, a suction chamber 11b is also formed around the drive boss 5 in addition to the suction chamber 11a'. Connected to the suction port 11. Further, as for the working chambers, an even number of working chambers 1 formed on one side are provided.
In addition to Oa, an even number of working chambers 10b having the same shape are formed on the other side. As described above, in the scroll type expander of the fifth embodiment, the working chambers 10a and 10b are formed on both sides of the end plate 8b 'of the single rotor 8' to provide about twice the capacity of each of the above-described embodiments. Nevertheless, there is a feature that the size is reduced as a whole by merging.

FIG. 9 shows a sixth embodiment of the present invention.
In this case, the scroll type expander of the present invention is provided in addition to the compressor to recover exhaust energy. In FIG. 9, a left end portion 20 shows a scroll compressor, and a central portion 21 shows a motor for driving the compressor 20. The compressor 20 and the motor 21 are operatively connected by a common shaft 22. The scroll type expander 23 of the present invention is also connected to them by the shaft 22, and the rotational power generated by the expander 23 is supplied to the compressor 20 via the crank 24 attached to the shaft 22. Expander 23 in this case
Has a configuration similar to that of the first embodiment described above, except that the compressed fluid supplied to drive the expander 23 is supplied from the compressor 20. Exhaust gas discharged from equipment not shown is used.

Therefore, the compressor 20 is not only driven by the motor 21, but also converts the exhaust energy of the compressed fluid generated by itself and supplied to other devices into rotational power by the expander 23. Since the auxiliary driving is performed, the energy consumption of the entire system is reduced, and the operation efficiency is improved.

The seventh embodiment shown in FIG. 10 corresponds to a modification of the sixth embodiment shown in FIG. 9, and differs from the sixth embodiment in that the common shaft 22 and the crank 24 of the expander 23 are different.
Do not directly connect with, one way clutch 2 between them
5 is provided. The one-way clutch 25 is engaged only when the rotation speed of the expander 23 is higher than the rotation speed of the shaft 22, that is, the rotation speeds of the motor 21 and the compressor 20, so that the expander 23 assists the driving force of the motor 21. When the rotational speed of the expander 23 is low, the engagement relationship is released, and the expander 23
And the compressor 20 so as not to hinder the rotation.

In the seventh embodiment, only the usable portion of the energy discarded in this way is regenerated as rotational power and is effectively used for driving the compressor 20, so that the entire system is Not only does the efficiency of the motor 21 improve, but also in a transient state where the expander 23 cannot drive the compressor 20 sufficiently, such as during start-up and stop, the expander 23 operates with the brake of the motor 21. Since it is possible to avoid such a situation, it is possible to reduce the mechanical loss caused due to the idle rotation of the expander 23 meaninglessly, so that higher efficiency can be obtained as compared with the sixth embodiment.

[Brief description of the drawings]

FIG. 1 is a vertical sectional side view showing a scroll type expander as a first embodiment of the present invention.

FIG. 2 is a cross-sectional front view of the first embodiment.

FIG. 3 is an operation explanatory view showing an expansion process of an operation chamber formed by two scrolls.

FIG. 4 is a diagram for explaining the operation and effect of the present invention in comparison with a comparative example.

FIG. 5 is a vertical sectional side view showing a scroll type expander of a second embodiment.

FIG. 6 is a longitudinal sectional side view showing a scroll type expander of a third embodiment.

FIG. 7 is a cross-sectional front view showing a scroll type expander of a fourth embodiment.

FIG. 8 is a longitudinal sectional side view showing a scroll type expander of a fifth embodiment.

FIG. 9 is a vertical sectional side view showing the entire configuration of the sixth embodiment.

FIG. 10 is a vertical sectional side view showing the entire configuration of the seventh embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 4 ... Shaft 5 ... Drive boss 8 ... Rotor (movable scroll) 8a ... Rotor wrap (spiral-shaped blade) 8b ... Rotor end plate 8c ... Rotor wrap winding end part 9 ... Shell (fixed scroll) 9a ... Shell 9b ... End of winding of shell wrap 9e ... End plate of shell 10 ... Working chamber 11 ... Suction port 11a ... Suction chamber 12 ... Discharge port 13a, ..., 13f ... Bypass port 14 ... Reverse Stop valve 15 Stopper 16a, 16b Bypass port 17 Discharge chamber 18 Space 20 Scroll compressor 21 Motor 22 Common shaft 23 Scroll expander 24 Crank 25 One-way clutch

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Shinji Knife 14 Iwatani, Shimowakaku-cho, Nishio-shi, Aichi Prefecture Inside Japan Automotive Parts Research Institute, Inc. (72) Inventor Motoki Harada 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Motor Corporation F-term (reference) 3H039 AA02 AA04 AA12 BB28 CC02 CC03 CC07 CC26 CC30 CC34 CC40

Claims (11)

[Claims] An orbiting scroll having a spiral wrap and an end plate and supported for revolving about a rotatable shaft; and a spiral wrap and an end plate; A fixed scroll fixed to face the movable scroll so as to form a plurality of working chambers therebetween by engaging with the movable scroll, and a high pressure is applied to the working chamber at the center of the movable scroll and the fixed scroll. And a discharge chamber that receives a low-pressure fluid discharged from the working chamber at an outer peripheral portion of the movable scroll and the fixed scroll, and supplies the low-pressure fluid from the suction chamber to the working chamber. The high-pressure fluid expanded in the working chamber causes the working chamber to move from the central portion to the outer peripheral portion. A scroll type expander configured to be discharged to the discharge chamber after the volume of the working chamber increases while the pressure of the fluid in the working chamber is reduced, and at least a part of the working chamber. A low-pressure part provided with the low-pressure part through the bypass port, the valve being opened when the pressure in the working chamber is lower than the pressure in the low-pressure part. And a check valve that operates to increase the pressure in the working chamber to the pressure in the low-pressure section, and the bypass port includes:
The movable scroll and the fixed scroll are arranged at positions returned by an angle range of 360 ° or less along the wrap from the winding end portion of the outer peripheral portion to the winding start portion of the central portion, respectively. A scroll type expander characterized by: 2. The scroll type expander according to claim 1, wherein the low-pressure section is the discharge chamber. 3. The scroll-type expander according to claim 1, wherein the low-pressure section is a space of an atmospheric pressure. 4. The method according to claim 1, wherein
A scroll-type expander, wherein four or more bypass ports are provided, and all of them are configured to open to the working chambers different from each other. 5. The method according to claim 1, wherein
A scroll-type expander, wherein four or more bypass ports are provided, and a plurality of the bypass ports are simultaneously opened in the same working chamber. 6. The bypass port according to claim 4, wherein, among the plurality of bypass ports that can be sequentially opened in the same working chamber by moving the working chamber, one of the bypass ports that is closer to the center is the outer periphery. Along the wrap from the position of the nearer part to the beginning of winding at the center
A scroll-type expander, wherein the scroll-type expander is disposed at a position returned by an angle range of 60 ° or less. 7. The method according to claim 1, wherein
The scroll type expander, wherein the bypass port is provided in the end plate of the movable scroll. 8. The scroll type expander according to claim 7, wherein the movable scroll is a double tooth type. 9. The method according to claim 1, wherein
The scroll-type expander, wherein the bypass port is provided on the end plate of the fixed scroll. 10. The apparatus according to claim 1, which is attached to a compressor provided with a drive unit, receives exhaust gas of a device supplied with fluid compressed from the compressor into the suction chamber, and receives the exhaust gas. A scroll-type expander configured to be operated by exhaust gas. 11. The scroll-type expander according to claim 10, wherein an output shaft is connected to a shaft of the compressor via a one-way clutch.