KR100840048B1 - Displacement fluid machine - Google Patents

Abstract

An object of the present invention is to realize stable startup without using an auxiliary motor in a fluid machine having an inflator section and a compressor section.

A volumetric fluid machine having a scroll-type inflator portion that forms an operating chamber with fixed scrolls and swing scrolls, and a rolling piston-type compression mechanism portion having a vane portion that partitions a space formed by cylinders, rollers, and occlusion plates, and the rotation of the swing scroll. The position was made into the range from -45 degree from this rotation position to the limit of the rotation position which maximizes the volume of the operation chamber which communicates with the inflow port of a fixed scroll center part.

Inflator section, compressor section, fixed scroll, pivoting scroll, suction port, crankshaft

Description

Volumetric Fluid Machine {DISPLACEMENT FLUID MACHINE}

1 is a cross-sectional view of a fluid machine made by applying the present invention.

2 is a schematic diagram of a refrigeration cycle with a fluid machine according to the present invention.

3 is a Moriel diagram of a refrigeration cycle with a fluid machine made in accordance with the present invention.

4 is a cross-sectional view of the inflator and compressor sections of a fluid machine in accordance with the present invention.

Fig. 5 is an operation diagram of an inflator portion and a compressor portion for each crank angle of a fluid machine according to the present invention.

<Explanation of symbols for the main parts of the drawings>

1: Inflator part

3: compressor unit

5: fixed scroll

7: turning scroll

13: inlet

21: crankshaft

21a: Inflator Eccentric Shaft

21b: compressor eccentric shaft

31: cylinder

33: roller

35: vane

43: spring

[Document 1] Japanese Unexamined Patent Publication No. Hei 8-82296

The present invention relates to a volumetric fluid machine, and more particularly to a fluid machine having a function of expanding and compressing a refrigerant in a refrigeration cycle.

Background Art Conventionally, a fluid machine including an expander section and a compressor section has been known, for example, as a fluid machine used in connection with a refrigeration cycle.

For example, the rolling piston type inflator portion and the compressor portion are accommodated in the same container, and the main shaft is coaxially coupled to the inflator portion and the compressor portion, and the main shaft is rotated by using the expansion energy of the refrigerant flowing into the expander portion. The technique which drives a compressor part by this is disclosed (refer patent document 1).

In this way, the COP of the refrigeration cycle can be improved by recovering power in the expansion process of the refrigeration cycle and using it for the compression process.

By the way, in the fluid machine of patent document 1, an auxiliary motor is provided between an expander part and a compressor part, and the auxiliary motor, the expander part, and the main shaft of a compressor part are comprised mutually. These main shafts are provided with a phase difference so that the rotational position at the time of generating the maximum torque of the expander portion coincides with the rotational position at the time of generating the maximum load torque of the compressor portion.

As described above, in Patent Document 1, since the rotational torque is applied to the main shaft from the auxiliary motor at the start of the fluid machine, the starting torque of the fluid machine can be sufficiently secured.

However, in such a configuration in which the auxiliary motor is accommodated in the container, there is a problem that the structure of the fluid machine is complicated, for example, the manufacturing cost is high, and the apparatus itself is enlarged.

On the other hand, in the case of a fluid machine that is not equipped with a power source such as an auxiliary motor, if the starter torque having a magnitude greater than the load torque (stop frictional force) of the inflator section and the compressor section cannot be generated from the expander section, You cannot start it.

An object of the present invention is to realize stable startup without using an auxiliary motor in a fluid machine having an expander section and a compressor section.

The fluid machine of the present invention accommodates the expander section and the compressor section in a container, expands the fluid flowing into the expander section to drive the expander section, and drives the compressor section by the driving force.

Here, the inflator portion is formed by vortex wings standing upright on the plate, respectively, the fixed scroll and the swing scroll which are engaged with each other to form a plurality of operating chambers, the inlet of the fluid opening in the center of the fixed scroll, and the fixed scroll It is a scroll type expander part provided with the discharge port of the fluid opening to an outer peripheral part, and the 1st eccentric shaft part connected with a turning scroll, The compressor part is a cylinder, the blocking plate which closes the both ends of this cylinder, and an eccentric inside the cylinder. A rotating cylindrical roller, a vane portion contacting the outer circumferential surface of the roller and partitioning a space formed by the cylinder, the roller and the closing plate, a spring for pressing the vane portion against the roller and a second eccentricity connected to the roller It is assumed that it is a rolling piston type compressor part provided with a shaft part.

When the inflator portion of such a fluid machine is connected to, for example, the downstream side of the compressor of the refrigeration cycle to start the compressor, the high-pressure refrigerant flows into the innermost operating chamber through the inlet port in the center of the fixed scroll. At this time, since the operation chamber on the discharge port side of the inflator portion has a lower pressure than the operation chamber on the inlet side, the turning scroll acts as a radial force from the rotational center of the main shaft due to this pressure difference, thereby generating a rotational torque.

Here, in the operation chamber communicating with the inlet, the radial force by the coolant acts most effectively when the volume thereof is maximum. However, the volume of the operating chamber changes with the revolution of the revolving scroll, and decreases immediately after the volume becomes maximum. For this reason, the rotational position of the revolving scroll is set to the rotational position at which the volume of the operating chamber communicating with the inlet is maximized, and this position is limited to the range of -45 deg. Or the rotation torque close to it can be generated.

On the other hand, the compressor part is connected between the discharge port side of the expander part and the suction port side of the compressor, for example. For this reason, the pressure of the operation chamber on the discharge port side is lower than that of the operation chamber on the suction port side partitioned by vanes in the cylinder. That is, the refrigerant flowing into the cylinder from the suction port moves the roller to the position where the operating chamber on the suction port side becomes the maximum volume with the pressure difference between the operating chambers, and generates a rotational torque on the main shaft at this time. The starting torque generated from the expander section and the compressor section coincides with the rotation direction.

Therefore, by forming a predetermined phase difference between the first eccentric shaft portion of the expander portion and the second eccentric shaft portion of the compressor portion, it is possible to simultaneously extract the starting torque from the expander portion and the compressor portion. However, in order to rotate the main shaft by this starting torque, the turning scroll and the roller must be stopped at a position where these starting torques always exceed the load torques (stop frictional force) of the expander section and the compressor section.

Therefore, in the present invention, the roller is focused on the compressor to always stop at the rotational position at which the entire length of the spring is maximized by the pressing force of the vane, and pivots about the rotational position of the roller when the spring is most extended. The rotational position of the scroll is between the first eccentric shaft portion and the second eccentric shaft portion so as to limit the rotational position at which the volume of the operating chamber communicating with the inlet is maximized, and to be within a range from -45 degrees from this rotational position. It is characterized by forming a phase difference.

According to this, the rotational positions of the first eccentric shaft portion and the second eccentric shaft portion can be made substantially the same at the time of stopping the fluid machine. Therefore, the starting torque generated from the inflator portion and the compressor portion at the time of starting is almost maximized. It can take out and a stable start can be achieved, without using an auxiliary motor.

In addition, the fluid machine of the present invention can realize a significant improvement in COP by recovering the power of the expansion process when the working refrigerant of the refrigeration cycle is carbon dioxide, for example.

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of this invention is described based on drawing. 1 is a cross-sectional view of a fluid machine according to the present invention. 2 is a schematic diagram of a refrigeration cycle with a fluid machine according to the present invention. Fig. 3 is a Moriel diagram of a refrigeration cycle with a fluid machine according to the present invention. 4 is a cross-sectional view of an inflator section and a compressor section of the fluid machine according to the present invention. Fig. 5 is an operation diagram of the inflator portion and the compressor portion for each crank angle of the fluid machine according to the present invention.

The refrigeration cycle of this embodiment uses carbon dioxide R744 as the working fluid (hereinafter, appropriately referred to as refrigerant). Carbon dioxide (R744) as a refrigerant has an excellent global warming coefficient (GWP) of only a few thousandths of a prone-based refrigerant, and is excellent in terms of global environmental conservation. On the other hand, although the theoretical COP (coefficient of performance) on the Moriel diagram of the high pressure refrigerant is low, the R744 has a large energy loss in the expansion process compared to the pron refrigerant, and thus greatly reduces the COP by recovering the power of the expansion process. It can be improved.

The fluid machine of this embodiment accommodates the scroll type expander part 1 and the rolling piston type compressor part 3 in the same airtight container 9, and the inflator part 1 and the compressor part 3 are each, respectively. By coaxially coupling the drive shafts (main shafts), the power generated when the refrigerant expands in the expander section 1 is recovered, and the compressor section 3 is driven to form an expansion / compressor for performing a compression operation.

The inflator part 1 arrange | positions the fixed scroll 5 and the revolving scroll 7 which are formed by making a spiral wrap upright on the disk-shaped hard board, respectively, in a posture facing each other, and fixed scroll 5 And the swinging scroll 7 are engaged to form a plurality of operating chambers therebetween. The fixed scroll 5 is fixed to the frame 11 fixed to the closed container 9.

Inlet pipes 15 are perforated in the inlet 13 opening in the center of the fixed scroll 5, while outlet pipes 19 are perforated in the outlet 17 opening in the outer periphery of the fixed scroll 5. . The revolving scroll 7 is formed with a bearing 23 in the center of the surface opposite to the wrap. The bearing 23 is slidably fitted with an inflator eccentric shaft 21a connected to one end of the crankshaft 21 rotatable about the central axis L1, and the swinging scroll 7 is inflator eccentric. It is supported by the shaft 21a. As a result, the swing scroll 7 idles with respect to the fixed scroll 5 at a predetermined eccentricity about the center axis L1, moves the operating chamber to the outer circumferential side and enlarges the volume of the operating chamber. Let's do it. In addition, the orbiting movement of the turning scroll 7 is controlled by the Oldham ring 25.

The compressor unit 3 includes an cylinder 31 having a cylindrical inner circumferential surface, an end plate 27 and a frame 11 that block both end surfaces of the cylinder 31, and an eccentric rotational movement in the cylinder 31. The cylindrical roller 33 and the outer circumferential surface of the roller 33 are reciprocated in the grooves 37 formed in the cylinder 31 while being in contact with the end surface thereof, and formed by the cylinder 31 and the roller 33. Plate-shaped vanes 35 for dividing the space into the suction chamber 39 and the compression chamber 41, and springs provided on the rear end of the vanes 35 to press the vanes 35 on the outer circumferential surface of the roller 33. It consists of 43. In addition, the compressor eccentric shaft 21b connected to the other end of the crankshaft 21 is rotatably fitted in the roller 33.

The cylinder 31 is formed with a suction port 45 and a discharge port 47 of the refrigerant, and a suction pipe 49 is perforated in the suction port 45, while the discharge plate 47 and the discharge pipe 51 are formed in the discharge port 47. 53 is connected.

In this way, the turning scroll 7 of the expander section 1 and the roller 33 of the compressor section 3 are defined by the expander eccentric shaft 21a, the compressor eccentric shaft 21b, and the crank shaft 21. It is connected to the rotation angle.

Next, an operation when a working fluid flows into the fluid machine will be described.

First, when a high-pressure working fluid flows into the operating chamber formed at the innermost circumference through the inlet pipe 15 of the inflator part 1, the turning scroll 7 moves the central axis L1 by the reduced pressure expansion of the working fluid. Orbit around the center. By the revolving movement of the revolving scroll 7, the operating chamber moves to the outer circumferential side while enlarging the volume, and flows out from the outlet pipe 19 in a reduced pressure state. In addition, when the orbiting scroll 7 orbits, the crankshaft 21 which rotates the inflator eccentric shaft 21a one end rotates.

On the other hand, in the compressor part 3 arrange | positioned at the other end of the crankshaft 21, when the crankshaft 21 rotates by the expander part 1, the roller 33 through the compressor eccentric shaft 21b. Rotates eccentrically in the cylinder 31. With the eccentric rotation of the roller 33, the vane 35 reciprocates in the groove 37 while being pressed against the outer circumferential surface of the roller 33 by the spring 43.

The two working chambers defined by the vanes 35 in the cylinder 31, that is, the suction chamber 39 and the compression chamber 41, change in volume with eccentric rotation of the roller 33. When a low pressure working fluid is sucked into the suction chamber 39 through the suction pipe 49, the suction chamber 39 is compressed to a predetermined pressure with a decrease in volume. The compressed working fluid is discharged from the discharge pipe 53 to the outside through the discharge plate 51.

The fluid machine of this embodiment drives the compressor part 3 using the expansion energy which arises when the working fluid expands in the expander part 1, and operates the working fluid in the compressor part 3 which drives this. The working fluid can be expanded and compressed without using an electric motor or the like to compress it.

Next, the configuration and operation of the refrigeration cycle with the fluid machine described above will be described with reference to Figs.

The refrigeration cycle of this embodiment is comprised by connecting the compression apparatus 61, the radiator (gas cooler) 63, the fluid machine 65, the evaporator 67, and the expansion valve 69, respectively, with refrigerant piping. The compression apparatus 61 is comprised by accommodating the main compressor 71 and the electric motor 73 in a sealed container. In the fluid machine 65, an evaporator 67 is connected between the expander section 1 and the compressor section 3 (also called a subcompressor). The expansion valve 69 is disposed in a bypass path that bypasses the path connecting the inflator portion 1 and the evaporator 67. In addition, the expansion valve 69 is closed except for adjusting flow rate (pressure) when the operating condition of the cycle changes.

After the high temperature / high pressure refrigerant (state of point C in FIG. 3) compressed in the main compressor 71 is discharged from the discharge port of the compression device 61, passes through the radiator 63, and is cooled by heat radiation (FIG. 3). Point D), enters the inflator portion 1 of the fluid machine 65 via the inlet pipe 15. The refrigerant introduced into the expander section 1 converts the expansion energy into mechanical energy in the expansion process to drive the compressor section 3, and the low-temperature / low pressure gas-liquid refrigerant from the outlet pipe 19 (dotted point in Fig. 3). E) and discharged.

The refrigerant discharged from the expander section 1 enters the evaporator 67 and gasifies by endotherm, and is then sucked into the compressor section 3 of the fluid machine 65 through the suction pipe 49 (dot in Fig. 3). A). The refrigerant flowing into the compressor section 3 is slightly boosted and discharged through the discharge pipe 53 (point B in Fig. 3). The gas refrigerant discharged from the compressor unit 3 is returned to the main compressor 71 and compressed again to become a high temperature and high pressure gas refrigerant. The above cycle is repeated to achieve the freezing action.

Thus, when the fluid machine 65 of this embodiment is used for a refrigeration cycle, the expansion energy of the inflator part 1 is recovered as a power, and this recovered power is used as a driving source of the compressor part 3 to form part of the compression process. Since it can be used for (between AB in FIG. 3), the amount of work in the main compressor 71 can be reduced by that amount, and the COP of the refrigerating cycle can be improved.

In addition, although carbon dioxide is used as a refrigerant | coolant of a refrigerating cycle in this embodiment, even if it is not about the improvement rate of carbon dioxide in a fron system refrigerant | coolant, COP can be improved.

Next, the operation at the start of the above-mentioned refrigeration cycle will be described in detail.

Just before the start of the refrigeration cycle, the pressure in the cycle is at a substantially constant balance pressure, and the operation of the main compressor 71 is started from this pressure balanced state to start the refrigeration cycle.

First, the expansion valve 69 is closed simultaneously with the start of the operation of the main compressor 71. As a result, the suction side pressure of the main compressor 71 decreases with the increase in the rotational speed of the main compressor 71, and the discharge side pressure increases. Then, the high-pressure refrigerant having risen in pressure passes through the radiator 63 and reaches the innermost inner working chamber (reference numeral 71a in FIG. 4) through the inflow pipe 15. At this time, since the operating chamber around the innermost operating chamber is maintained at the state of the balance pressure at the time of stopping, the turning scroll 7 is connected to the central axis L1 of the crank shaft 21 due to the pressure difference between the operating chambers. Radial force is generated, and rotational torque is generated.

When the starting torque (starting torque) exceeds the static frictional force in the inflator 1 of the fluid machine 65 and the sliding parts of the compressor 3, the crankshaft 21 stops rotating. To start. Here, the size of the operating chamber is determined according to the rotational position of the swinging scroll 7 at the time of stopping, and in particular, the innermost operating chamber 71a communicating with the suction port 13 has a larger volume, which is in the radial direction of the refrigerant. The applied force increases, and as a result, the starting torque increases. For this reason, in order to generate | occur | produce starting torque sufficient to communicate with the suction port 13, and to exceed the static frictional force of each sliding part, the predetermined | prescribed volume may be ensured at the time of stop. There is a need.

On the other hand, when the suction side pressure of the main compressor 71 decreases, the pressure of the compression chamber 41 of the compressor part 3 of the fluid machine 65 and the space which communicates with this falls. At this time, since the suction chamber 39 of the compressor part 3 is maintained in the state of the balance pressure at the time of stop, the pressure difference generate | occur | produces between both the operation chambers of the suction chamber 39 and the compression chamber 41. FIG. Due to this pressure difference, the roller 33 moves to the rotation position where the volume of the suction chamber 39 becomes the maximum, and rotational torque is generated in the crankshaft 21 at the same time. Since the direction in which this rotation torque is applied is the same as the rotation direction of the expander part 1, the rotation torque at the time of starting of the fluid machine 65 will increase.

In this way, the fluid machine 65 of the present refrigeration cycle, when the turning scroll 7 and the roller 33 are stopped at a predetermined rotational position at the time of starting, respectively, the inflator portion 1 and the compressor portion 3, respectively. Starting torque is generated. That is, the fluid machine 65 should be provided at the next start-up at the time of its stop, and should always stop the turning scroll 7 and the roller 33 at a position where the starting torque exceeds the static frictional force. . Therefore, in this embodiment, in order to define the rotation angle between the inflator part 1 and the compressor part 3, the inflator eccentric shaft 21a and the compressor with respect to the central axis L1 of the crankshaft 21 are therefore. The rotational phase of the eccentric shaft 21b is defined.

Here, when focusing on the compressor part 3 at the time of the stop of the fluid machine 65, the roller 33 of the compressor part 3 always receives the pressing force by the spring 43 via the vane 35. As shown in FIG. For this reason, when the fluid machine 65 stops, the roller 33 moves to the rotation position (vane bottom dead center) which becomes the maximum length of a spring by the press of the spring 43, and stops. That is, the roller 33 stops at the position where the suction chamber 39 and the compression chamber 41 become substantially the same volume. For this reason, when the roller 33 starts a refrigerating cycle from the position of vane bottom dead center, the discharge side pressure of the compressor part 3 will fall, and a pressure difference will generate | occur | produce between the suction chamber 39 and the compression chamber 41. FIG. Then, the roller 33 moves to the rotational position where the volume of the suction chamber 39 is maximized, so that starting torque can be obtained at the time of movement of the roller 33.

In view of the above, in this embodiment, when the compressor part 3 is the rotation position of the roller 33 which becomes a vane bottom dead center, the turning scroll 7 so that the rotation torque which the inflator part 1 may raise may become the maximum. ), And specifically, the rotational position of the inflator eccentric shaft 21a is determined so that the volume of the innermost working chamber 71a communicating with the inlet of the inflator 1 is maximized. .

Although an example of the relationship between the turning scroll 7 for each crank angle, vane position, and starting torque is shown in FIG. 5, in the inflator part 1, the volume of the innermost working chamber 71a which communicated with the suction port 13 is shown. The larger the starting torque is, the easier the fluid machine is to start. Therefore, in the fluid machine of this embodiment, the crank angle when the volume of the innermost circumference operation chamber 71a which communicates with the suction port 13 of the inflator part 1 becomes the maximum, and the vane lower thread of the compressor part 3 is lowered. The expander eccentric shaft 21a and the compressor eccentric shaft 21b are arranged in a predetermined phase with respect to the central axis L1 of the crank shaft 21 so that the crank angle at the point becomes the point. As a result, the turning scroll 7 stops at the rotational position at which the volume of the innermost operating chamber 71a which always communicates with the suction port 13 at the time of stopping the fluid machine 65 becomes the maximum, and the main compressor 71 ), The high-pressure refrigerant is introduced into the operating chamber of the innermost circumference communicating with the suction port 13, so that the maximum starting torque that the inflator section 1 can generate can be obtained.

Further, generally, the innermost operating chamber 71a of the scroll expander portion continuously increases in volume while starting to communicate with the inlet 13 and closing the operating chamber to the end, but closes the operating chamber to the end. Immediately after this, the innermost working chamber moves to the working chamber formed on the inner circumferential side, so that the volume is drastically small. Therefore, when the rotational position of the turning scroll 7 at the time of stop | deviation produces a shift | deviation with respect to the position of the maximum spring length by the press of the roller 33, there exists a possibility that it may be in the state just after the operation chamber is closed to the end. . In this case, the starting torque generated by the inflator section 1 is in the smallest state, and there is a fear that the fluid machine cannot be driven.

In order to prevent this, the rotational position (crank angle) at the time of the stop of the turning scroll 7 may have shifted slightly forward than the rotational position at which the operation chamber is closed at the end, for example, inflation with respect to the vane bottom dead center. It is preferable to arrange the inflator eccentric shaft 21a in an angular range from this rotation position to -45 degrees to the limit of the rotational position at which the volume of the operating chamber communicating with the suction port 13 of the base 1 is the maximum. desirable. Thereby, even if the rotation position of the crankshaft 21 at the time of a shift | deviates from the vane bottom dead center, the fall of starting torque can be prevented and a stable starting can be performed.

As mentioned above, according to the fluid machine of this embodiment, the expander part 1 is equipped with the scroll type expander, and the compressor part 3 is provided with the rolling piston type rotary compressor, and the roller 33 of the rolling piston type compressor part is provided. ) By pressing the spring 43 through the vanes 35, the rotational position of the crankshaft 21 at the time of stationary can always be substantially the same, and also by the inflator section 1 at that rotational position. Since the generated starting torque can be made almost maximum, stable starting can always be realized, for example, without providing an auxiliary motor, thereby improving the reliability of the refrigerating cycle and achieving efficient expansion energy recovery. In addition, since it is not necessary to particularly provide starting means such as an auxiliary motor in a fluid machine, it can contribute to the cost reduction of an apparatus.

According to the present invention, it is possible to realize stable startup without using an auxiliary motor in a fluid machine having an inflator section and a compressor section.

Claims (3)

An inflator portion and a compressor portion housed in a container, inflating fluid in the inflator portion to drive the inflator portion, and the volumetric fluid machine for driving the compressor portion by a driving force of the inflator portion, Each of the inflator is formed by a spiral wing is upright in the plate, the fixed scroll and the swing scroll to form a plurality of operating chambers to interlock with each other, the inlet of the fluid opening in the center of the fixed scroll, and the fixed A scroll expander portion having a discharge port of the fluid opening to an outer circumference of a scroll, and a first eccentric shaft portion connected to the swing scroll; The compressor unit is formed by a cylinder, a blocking plate for closing both ends of the cylinder, a cylindrical roller eccentrically rotating inside the cylinder, and the cylinder, the roller and the blocking plate in contact with an outer circumferential surface of the roller. It is a rolling piston type compressor part which has the vane part which partitions a space, the spring which presses the said vane part, and presses it to the said roller, and the 2nd eccentric shaft part connected to the said roller, The first eccentric shaft portion and the second eccentric shaft portion are connected to the main shaft, and with respect to the rotational position of the roller when the spring is most extended, the rotational position of the pivoting scroll of the operating chamber communicates with the inlet. A volumetric fluid characterized by forming a phase difference between the first eccentric shaft portion and the second eccentric shaft portion so that the volume is in a range from the rotation position to -45 degrees with the maximum rotational position as a limit. machine. The phase difference between the first eccentric shaft portion and the second eccentric shaft portion is such that the rotational position of the pivoting scroll communicates with the inlet port with respect to the rotational position of the roller when the spring is most extended. A volumetric fluid machine, characterized in that it is set such that the volume of said operating chamber is at the maximum rotational position. 3. The volumetric fluid machine of claim 1 or 2, wherein the fluid is carbon dioxide.

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