JP2002013491A - Scroll compressor and air conditioner using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a scroll compressor for injection of which injection flow is increased by securing a big injection hole and to provide an air conditioner performing improved cycle efficiency by using the compressor. SOLUTION: In this scroll compressor, a fixing scroll and a turning scroll are respectively constituted by a baseplate and a spiral lap integrally formed. The fixing scroll has at least one of an injection hole to inject refrigerant into an intermediate compression chamber constituted by engaging both laps of the fixing scroll and the turning scroll to each other. The injection hole is in an elliptic like shape parallel to a tooth profile of the fixing scroll.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air conditioner which performs a cooling operation and a heating operation by using a refrigeration cycle, and more particularly to a scroll compressor suitable for reducing power consumption or improving cooling and heating capacity and a scroll compressor suitable for the same. It relates to the air conditioner used.

[0002]

2. Description of the Related Art A refrigeration system for performing gas injection to a compressor in a refrigeration cycle is disclosed in, for example, Japanese Patent Application Laid-Open No. 11-1533.
No. 64 is disclosed. A compressor for gas injection is disclosed in, for example, Japanese Patent Application Laid-Open No. H11-93874.

[0003] In the air conditioner disclosed in JP-A-11-153364, a compressor, a four-way valve, a condenser, a first decompression device, a gas-liquid separator, a second decompression device, and an evaporator are connected by piping. Connect in a ring, connect the gas-liquid separator and the compressor with a gas injection pipe, combine the first pressure reducing device, the gas-liquid separator, the second pressure reducing device in a bridge shape with four check valves, A cycle in which the second pressure reducing device is a pressure reducing device with a variable valve opening is described.

On the other hand, in the rotary compressor disclosed in Japanese Patent Application Laid-Open No. H11-93874, the above-described injection hole is opened through a cylinder and one rear head of two head members provided on both axial end surfaces of the cylinder. In a compressor adapted to be supplied to a compression chamber, an injection hole is formed so as to be inclined inward in the radial direction with respect to the axial direction of the rear head, and the compression chamber side opening edge of the injection hole is formed into an elliptical shape. ing.

[0005]

Generally, in order to improve the cycle performance, in particular, to improve the coefficient of performance of the cycle (hereinafter referred to as "COP"), Japanese Patent Application Laid-Open No. H11-1533 has been proposed.
A gas injection cycle as disclosed in Japanese Patent No. 64 is known. Here, COP is a value obtained by dividing the cooling capacity or the heating capacity by the total electric input during each operation.

At this time, factors affecting the performance of the gas injection cycle include injection holes,
There is a position of a compression process for injection determined by an injection flow rate, an injection pressure, and an intermediate pressure. Although the above four factors are closely related, the injection hole is limited by the geometry of the compressor.

To improve the efficiency of the gas injection cycle, it is effective to increase the size of the injection hole from the viewpoint of increasing the injection flow rate. However, when a compression chamber is formed by combining a spiral fixed scroll and a revolving scroll wrap, as in a scroll compressor, if the injection holes are too large, the injection holes communicate between adjacent compression chambers, resulting in high pressure. Refrigerant will leak from the compression chamber to the low-pressure compression chamber, and the performance of the compressor will be reduced.

Therefore, the size of the injection hole is naturally limited. As disclosed in Japanese Patent Application Laid-Open No. H11-93874, a method of forming an injection hole at an angle to form an elliptical shape is effective.
When used in a scroll compressor instead of the rotary compressor disclosed in JP-A-11-93874, a circuit that also bypasses between adjacent compression chambers is formed, causing refrigerant leakage and reducing the performance of the compressor. It is thought to contribute.

An object of the present invention is to improve the efficiency of the gas injection cycle in an air conditioner using a gas injection cycle for a scroll compressor, thereby improving the COP during the cooling operation and the heating operation. Accordingly, it is an object of the present invention to provide a scroll compressor and an air conditioner using the scroll compressor, which can reduce the power consumption required for each operation.

[0010]

In order to achieve the above object, a scroll compressor and an air conditioner using the same according to the present invention are characterized by what is described in the claims. However, the scroll compressor according to the first aspect of the present invention is a fixed scroll comprising a base plate and a spiral wrap integrated therewith, and a orbiting system comprising a base plate and a spiral wrap integral therewith. A scroll and a rotation preventing mechanism for disposing the spiral wraps in mesh with each other and rotating the orbiting scroll without rotating with respect to the fixed scroll, a drive shaft for orbiting the orbiting scroll, and the drive A compression mechanism configured by a frame or the like that supports a shaft, and formed by the fixed scroll and the orbiting scroll; At least one injection hole for injecting the refrigerant into the intermediate compression chamber in the scroll compressor provided in the fixed scroll that,
The injection hole has a pseudo-elliptical shape parallel to the tooth shape of the wrap of the fixed scroll and having a minor axis substantially equal to the tooth width of the wrap.

The scroll compressor according to the second aspect of the present invention is a fixed scroll comprising a base plate and a spiral wrap integrated therewith, and a orbiting system comprising a base plate and a spiral wrap integral therewith. A scroll and a rotation preventing mechanism for disposing the spiral wraps in mesh with each other and rotating the orbiting scroll without rotating with respect to the fixed scroll, a drive shaft for orbiting the orbiting scroll, and the drive A scroll having a compression mechanism portion composed of a frame or the like that supports a shaft, and having at least one injection hole for injecting a refrigerant into an intermediate compression chamber formed by the fixed scroll and the orbiting scroll. In the compressor, the center line of the injection hole is forward. Characterized in that it has a pseudo-elliptical shape on an involute curve formed by a base circle having the same dimensions as the base circle of the involute curve forming the tooth profile of the fixed scroll lap and having a minor axis substantially equal to the tooth width of the wrap. It is.

An air conditioner according to a third aspect of the present invention is a compressor, a four-way valve, an outdoor heat exchanger,
In an air conditioner configured by sequentially connecting a first pressure reducing device, a high-pressure vessel, a second pressure reducing device, and at least one indoor heat exchanger with piping to form a heat pump cycle,
The scroll compressor according to claim 1 or 2 is used as the compressor, and the high-pressure container and the injection hole of the compressor are connected by an injection pipe.

An air conditioner according to a fourth aspect of the present invention is a compressor, a four-way valve, an outdoor heat exchanger,
In an air conditioner configured by sequentially connecting a first pressure reducing device, a high-pressure vessel, a second pressure reducing device, and at least one indoor heat exchanger with piping to form a heat pump cycle,
The scroll compressor according to claim 1 or 2 is used as the compressor, on a pipe between the first pressure reducing device and the high-pressure vessel, or on a pipe between a heat exchanger and the high-pressure vessel described later. The branch point provided in the, the injection hole of the compressor is connected by a pipe, or the high-pressure container itself and the injection hole of the compressor is connected by a pipe to provide the injection pipe,
A third decompression device is provided on the pipe near the branch point or the high pressure vessel, and a heat exchanger is further provided between the second pressure reduction device and the pipe on the heat pump cycle from the high pressure vessel. It is characterized by having been provided.

[0014]

According to these means, in a scroll compressor which performs injection, it is possible to provide a scroll compressor capable of performing injection without straddling an adjacent compression chamber, and having a large injection hole cross-sectional area, thereby increasing an injection flow rate. it can.

Further, by using this scroll compressor in a heat pump type air conditioner, the injection work is increased, and the compression work of the scroll compressor can be reduced, so that the COP can be improved. This is for the following reason.

FIG. 12 shows a gas injection cycle on a Mollier diagram. The ideal operating point of the gas injection cycle is that the refrigerant is depressurized by the first decompression device (from point 308 to point 3 in FIG. 12).
The gas-liquid two-phase refrigerant generated in the high-pressure vessel (Fig.
(Corresponding to the point 306 in FIG. 2) at which gas-liquid separation is performed, all the gas refrigerant is injected into the compressor, and only the remaining liquid refrigerant, which is a saturated liquid, flows into the evaporator.

At this time, the enthalpy difference between the inlet and the outlet of the evaporator (between points 303 and 307 in FIG. 12) is maximized. For example, in the cooling operation, if the cooling capacity is the same as when no gas injection is performed. Since the cooling capacity is represented by the product of the refrigerant flow rate and the enthalpy difference, the refrigerant flow rate can be reduced. As a result, the compression work before the injection of the compressor is reduced, and the required electric input can be reduced.

In the heating operation, the capacity increases due to the increase in the enthalpy difference in the evaporator and the flow rate of the refrigerant flowing to the condenser, so that the heating capacity is the same as when no gas injection is performed. Then, since the flow rate of the refrigerant can also be reduced, the compression work of the compressor is reduced, and the required electric input can be reduced. However, if the gas-liquid separation is incomplete and the entire gas refrigerant cannot be injected into the compressor, the refrigerant flows into the evaporator in a gas-liquid two-phase state, and the enthalpy difference is small. Therefore, the increase in capacity is reduced, and the reduction in the electric input of the compressor is also reduced.

Further, since the low-temperature gas refrigerant is injected into the gas refrigerant whose temperature has risen due to the compression of the suction gas, the discharge temperature of the compressor can be lowered. In the superheated gas region, which is the operating region of the compressor, the lower the temperature at the same pressure, the smaller the enthalpy difference between the inlet and the outlet of the compressor, so that the compression work is reduced.

However, theoretically, when a cycle is drawn on a Mollier diagram, the result is as shown in FIG. 12, but in an actual cycle, the injection is performed due to the pressure difference between the high-pressure vessel and the compression chamber of the compressor. As shown in FIG. 13, the injection does not take place instantaneously, but takes a certain period of time during the injection (between points 312 and 313 in FIG. 13). The compression work increases accordingly.

In order to make the actual cycle closer to the theoretical cycle, it is necessary to shorten the injection time. If the injection hole becomes larger,
Injection can be performed in a short time, so that it can be closer to the theoretical cycle, and CO
P improves.

In addition, the air conditioner of the present invention has an HFC-based refrigerant, for example, R407, from the viewpoint of preventing ozone layer destruction.
C, R410A, R32, R404A, and R134a, and from the viewpoint of preventing global warming, HC-based refrigerants and natural-type refrigerants, for example, refrigerants such as propane, isobutane, carbon dioxide, and ammonia are used. The current R
22 can also be used.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

FIG. 3 is a longitudinal sectional view of a scroll compressor according to one embodiment of the present invention. In FIG.
A scroll compression mechanism 105 and an electric motor 108 for driving the scroll compression mechanism 105 are housed in 01. The scroll compression mechanism 105 includes the orbiting scroll 104 and the fixed scroll 10.
2. Drive shaft 1 that forms a crank driven by electric motor 108
09, a frame 111 and a rotation preventing mechanism 112.

The orbiting scroll 104 has a spiral wrap 103 on a base plate 114. The fixed scroll 102 fixed to the frame 111 also has a spiral wrap 126 on the base plate 127.

A suction port 106 is provided at the outer periphery of the wrap, and a discharge port 110 is provided at the center of the wrap. The orbiting scroll 104 and the fixed scroll 102 are combined with the wraps 103 and 126 facing inward, and the fixed scroll 102 and the pedestal 128 of the frame 111 hold the orbiting scroll 104.

At this time, two spaces are formed by the fixed scroll 102 and the orbiting scroll 104, which become the compression chambers 129 and 130. In the scroll compressor of the present invention, injection holes 124 and 125 for injecting refrigerant from outside the scroll compressor in the compression process in each compression chamber are provided.

The injection holes 124 and 125 have high-pressure vessels 2 as gas-liquid separation receivers in FIG.
Injection pipes 122 and 123 connected to 05 are connected. At this time, the injection holes 124, 1
Reference numeral 25 is opened and closed as the orbiting scroll 104 turns.

In order to maximize the efficiency of a scroll compressor that performs injection, it is necessary to inject refrigerant into only one compression chamber. This means that no refrigerant leaks to adjacent compression chambers.

Therefore, the size of the injection hole is limited by the face width W1 of the wrap 103 of the orbiting scroll. In the case of a circular injection hole, if its diameter becomes larger than, for example, the tooth width of the orbiting scroll, FIG.
As shown in FIG. 7, since the openings 55 and 56 are formed across the adjacent compression chambers 53 and 54, refrigerant leakage occurs from the high-pressure side compression chamber 53 to the low-pressure side compression chamber 54,
It will be a big loss.

Therefore, in the case of a circular injection hole, its diameter D3 must be smaller than the tooth width W1 of the orbiting scroll. More precisely, as shown in FIG. 16, since there is generally a chamfered portion 70 at the tip end portion 71 of a workpiece such as an orbiting scroll, the tooth width W1 of the orbiting scroll
The length W2 excluding the chamfered portion is preferably equal to or less than W2.

On the other hand, in order to improve the efficiency of injection, it is necessary to increase the injection flow rate. To that end, it is effective to increase the injection hole cross-sectional area and increase the injection flow rate that can be injected at one time. Therefore, in the present invention, the injection hole shape is not a circular shape but a pseudo-elliptical shape (hereinafter, referred to as “oval”).

FIG. 1 shows a combination of the wrap 126 of the fixed scroll 102 and the wrap 103 of the orbiting scroll 104 in the compressor shown in FIG. 3 and the injection holes 1 and 2 of the shape according to the present invention. Is shown. The wrap 126 of the fixed scroll 102 and the wrap 103 of the orbiting scroll 104 are formed by involute curves using base circles of the same size. The shape of the injection holes 1 and 2 of the present invention is
The second wrap 126 is provided in an oval shape in parallel with the tooth profile curve.

The widths D 1 and D 2 corresponding to the minor diameters of the elliptical injection holes 1 and 2 are determined by the orbiting scroll 104.
Is smaller than the tooth width W1. Also, as shown in FIG.
Considering the width of the chamfered portion 70 of the tip portion 71 of the orbiting scroll wrap 103, the tooth tip width W of the orbiting scroll 104
Desirably less than 2.

FIGS. 6 to 8 show how the injection hole of the present invention is opened and closed as the orbiting scroll 104 rotates. Referring to the position of the wrap 103 of the orbiting scroll shown in FIG. 6, FIG. 7 is 45 degrees, and FIG. 8 is 90 degrees, and is turned from the position shown in FIG.

In FIG. 6, a part of the injection hole 1 is opened to the compression chamber 66 and the injection hole 2 is opened.
Is open to the compression chamber 65, and the other closed portion 6
Reference numerals 2 and 63 are closed by a wrap 103 of the orbiting scroll. In FIG. 7, the entire area of the injection holes 1 and 2 is closed by the wrap 103 of the orbiting scroll. In FIG. 8, a part of the injection holes 1 and 2 is
It is open to the next compression chambers 67, 68, and the other closing parts 62, 63 are closed by the wrap 103 of the orbiting scroll.

In another embodiment of the present invention, as shown in FIG. 2, the longitudinal axes of the injection holes 5 and 6 form the involute curves of the wrap 126 of the fixed scroll 102 and the wrap 103 of the orbiting scroll 104. Exists on an involute curve with a base circle having the same size as the base circle to be formed.

Therefore, the injection hole also has a long oval shape along the involute curve. From these figures, it can be seen that, in the injection hole shape of the present invention, one injection hole is opened to only one compression chamber without straddling adjacent compression chambers.

For this reason, the injection hole can be enlarged without the injection hole straddling the adjacent compression chamber, so that no leakage loss or the like occurs, and the injection efficiency increases with an increase in the injection flow rate.

In the embodiment of the present invention, one injection hole is provided in each compression chamber, but this is for simultaneous injection into two compression chambers.
Therefore, if the injection time of each compression chamber is shifted, it is also possible to inject two compression chambers with one injection hole as shown in FIGS. At this time, the same effect can be obtained with the injection hole shape of the present invention.

FIGS. 9 to 11 show compression chambers a501 and b502 formed simultaneously in the same compression stroke.
FIG. 2 shows opening and closing of the injection hole 503 when one injection hole 503 is injected. FIG. 10 is different from FIG.
FIG. 11 shows a case where the orbiting scroll 104 has been rotated 180 degrees with respect to FIG. At this time, since the intermediate pressures for injection into the respective compression chambers are different, the injection flow rates are also different.

FIG. 4 shows an embodiment of an injection cycle using the compressor of the present invention. The cycle consists of a compressor 201, a four-way valve 202, an outdoor heat exchanger 2
03, a first decompression device 204, a high-pressure vessel 205 as a gas-liquid separation receiver, second decompression devices 206 and 207, and indoor heat exchangers 208 and 209 are connected by piping.

In this embodiment, the air conditioner is configured such that the indoor unit is separated from the outdoor unit 219, and a plurality of indoor units 220 and 221 are connected in parallel. And At the outlet of the outdoor unit 219, blocking valves 210 and 211 for pipe connection are provided. Piping 21 connecting the outdoor unit 219 and the indoor units 220 and 221
7, 218 are called connection piping.

The high-pressure vessel 205 has both functions as a gas-liquid separator and a liquid receiver. A pipe 213 connected to the compressor 201 is connected to the high-pressure container 205. This pipe 213 is for injecting a refrigerant into the compressor.

A third pressure reducing device 222 and a heat exchanger 223 are provided between the pipe 213 and the compressor 201.
The third decompression device 222 reduces the pressure of the liquid refrigerant bypassed from the high-pressure container 205 to a pressure required for injection to generate a gas-liquid two-phase refrigerant and controls the injection flow rate.

The flow of the refrigerant during the cooling operation flows in the direction of the solid line arrow in FIG. In the embodiment of FIG.
Is located at the time of cooling operation. On the other hand, during the heating operation, the four-way valve 202 is switched to flow the refrigerant in the direction of the dashed arrow.

During the cooling operation, the heat exchanger 223 exchanges heat between the gas-liquid two-phase refrigerant to be injected and the refrigerant exiting from the high-pressure vessel 205 to completely gasify the injected refrigerant. On the other hand, during the heating operation, the heat exchanger 223 exchanges heat with the refrigerant entering the high-pressure vessel 205. In any case, the refrigerant of the main cycle is cooled by the heat exchanger 223. At this time, for example, the high pressure vessel 2
When a gas-liquid two-phase or saturated liquid refrigerant is taken out from the compressor 05 and injected into the compressor, gas injection occurs. In addition, since the refrigerant at the inlet of the indoor heat exchanger is cooled, the enthalpy difference between the indoor heat exchangers 208 and 209 is large. Therefore, the flow rate of the refrigerant required to obtain the same cooling capacity is reduced. Therefore, in order to obtain the same performance with a constant speed compressor, the theoretical discharge flow rate of the compressor can be reduced, and the compressor can be downsized.In the case of a variable speed compressor, the operating speed of the compressor can be reduced. Therefore, the power consumption of the compressor can be reduced.

FIGS. 14 and 15 show the gas injection cycle of FIG. 4 on a Mollier diagram. Figure 1
4 shows a case where this cycle is in a cooling operation, and FIG. 15 shows a case where this cycle is in a heating operation.

In FIG. 14, during the cooling operation, the point 40
0 is the compressor inlet or evaporator outlet, point 403 is the compressor outlet or condenser inlet, point 404 is the condenser outlet, point 4
The section from 04 to point 405 is the first pressure reducing device 204, point 4
05 is the high-pressure vessel 205, points 405 to 406 are the third decompression device 222, the section from point 406 to point 409 and the point 40
The section from point 5 to point 407 is the heat exchanger 223, and the section from point 407 to point 408 is the second decompressor 206, 207, point 40.
The point 400 from 8 corresponds to the part of the evaporator.

On the other hand, in FIG. 15, during the heating operation,
14, only the section from point 405 to point 410 and the section from point 411 to point 409 are the heat exchanger 223, the section from point 410 to point 411 is the third decompression device 222, and the section from point 410 to point 412. Corresponds to the first decompression device 204. The cycle when the gas injection cycle is not performed includes the points 400, 413, 404, and 414.
Is a diagram that connects.

Therefore, in both FIG. 14 and FIG. 15, the enthalpy difference of the evaporator in the gas injection (the section between points 408 and 400 in the cooling operation, and the point 4 in the heating operation)
Since the enthalpy difference (section from point 12 to point 400) is larger than the enthalpy difference when not performing gas injection (section from point 414 to point 400), it is possible to reduce the flow rate of the refrigerant with the same capacity. Therefore, the compression work of the compressor can be reduced,
Power consumption is reduced and COP is improved.

Theoretically, the refrigerant is instantaneously injected into the compression chamber of the compressor at a certain injection pressure. However, in practice, the driving force of the refrigerant to be injected is due to the pressure difference between the high-pressure container and the compression chamber, and the resistance of the injection circuit prevents instantaneous injection of an ideal flow rate.

For this reason, in order to approach an ideal gas injection cycle as much as possible, it is necessary to secure a large injection flow rate in a short time. To that end, it is effective to increase the size of the injection hole. Therefore, when the compressor of the present invention is used for the compressor in the gas injection cycle, the injection hole can be made larger than that in the case of a circular shape, so that a sufficient injection flow rate can be secured,
Further, the cycle efficiency is improved.

The branch point from the main cycle to which the third pressure reducing device 222 is connected is not limited to the high pressure vessel 205 and may be at any point on the piping from the heat exchanger 223 to the first pressure reducing device 204. Good. At this time, when the branch point is on the pipe, the refrigerant flows into the third pressure reducing device in a gas-liquid two-phase refrigerant state. When there is a branch point in the high-pressure vessel 205,
It is also possible to take out only the saturated liquid refrigerant from the container. At that time, the heat exchanger 22 on the gas injection circuit
The enthalpy difference between the inlet and outlet of No. 3 is maximum, and the cycle efficiency is also highest.

FIG. 5 shows another embodiment of the injection cycle of the present invention. In the present invention, for example, the gas refrigerant separated by the high-pressure container 205 having the functions of a gas-liquid separator and a liquid receiver is injected into the compression chamber of the compressor. FIG.
The heat exchanger 223 shown in (3) is not provided, and the third pressure reducing device 222 is used as the on-off valve 212, thereby simplifying the cycle.

FIG. 12 shows the gas injection cycle of FIG. 5 on a Mollier diagram. In FIG. 12, point 303 is the compressor inlet or evaporator outlet, point 30
5 is the compressor outlet or condenser inlet, point 308 is the condenser outlet, and the section from point 308 to point 306 is the first pressure reducing device 2
04, point 306 is the high pressure vessel 205, points 309 to 30
Section 7 corresponds to the second decompression devices 206 and 207, and points 307 to 303 correspond to the evaporator. Cycles without gas injection are points 303 and 31
It is a diagram connecting 0, point 308, and point 600.

Therefore, the enthalpy difference (points 307 to 303) of the evaporator when performing the gas injection shown in FIG.
Is larger than the enthalpy difference (the section from point 600 to point 303) when gas injection is not performed, so that the refrigerant flow rate can be reduced with the same capacity. Therefore, the compression work of the compressor can be reduced, the power consumption is reduced, and the COP is improved. As the effect of the cycle incorporating the compressor of the present invention, the same effect as the cycle shown in FIG. 4 can be obtained.

In the present embodiment shown in FIGS. 4 and 5, the second decompression devices 206 and 207 are installed in the indoor units 220 and 221. However, this may be installed in the outdoor unit 219. The blocking valves 210 and 211 may be provided in the indoor units 220 and 221 or may not be provided. However, in order to perform the cycle operation at the highest efficiency point, the first, second, third
It is preferable to use an expansion valve, particularly an electronic expansion valve, for the pressure reducing device. However, the first decompression device may be replaced by a resistance such as a capillary tube or an orifice. In the second decompression device, a resistance such as a capillary tube or an orifice may be used instead.

The compressor 201 may be a compressor operated at a constant speed or a compressor operated at a variable speed by an inverter. In the present invention, the high-pressure container 205 is used as a gas-liquid separation receiver, and has both functions of a gas-liquid separator and a liquid receiver. However, the gas-liquid separator and the receiver may be provided separately. Further, in the embodiment of the present invention, there is no low-pressure vessel (hereinafter, referred to as “accumulator”) at the inlet of the compressor, but an accumulator may be provided, and the effect of the present invention is not changed.

If there is no four-way valve, it is only for cooling or only for heating, but the same effect is obtained. Further, in the present invention, the outdoor unit and the indoor unit are shown as being separated from each other, but may be integrated. In the present invention, a case is shown in which a plurality of indoor units are installed, but similarly, a plurality of outdoor units may be provided, or each may be one.

In the embodiment of the present invention, the scroll compressor is shown in the high-pressure chamber system, but the same effect can be obtained in the low-pressure chamber system. The refrigerant to be used is not only Freon R22 but also HFC-based refrigerant such as R407C, R
The same effect can be obtained with refrigerants such as 410A, R32, R134a, and R404A, and with HC-based refrigerants and natural-based refrigerants such as propane, isobutane, carbon dioxide, and ammonia. Therefore, it can contribute to prevention of ozone layer depletion and prevention of global warming.

[0062]

As described above in detail, according to the air conditioner of the present invention, in the gas injection cycle using the scroll compressor, the air conditioner is parallel to the fixed scroll of the scroll compressor and the tooth shape of the wrap of the fixed scroll. Make the long axis of the elliptical injection hole on the involute curve using a base circle that is the same as the base circle of the fixed scroll involute curve. By doing so, the injection hole can be enlarged, and by using a scroll compressor having this injection hole for a heat pump type air conditioner,
By increasing the injection flow rate, the compression work of the compressor can be reduced, so that the COP can be improved.

This is for the following reason. It is assumed that all gas refrigerant generated by decompressing the refrigerant by the first decompression device is injected into the compressor by the high-pressure container, and only the liquid refrigerant, which is the remaining saturated liquid, flows into the evaporator. At this time, the enthalpy difference between the inlet and the outlet of the evaporator becomes maximum.For example, in the cooling operation, when the cooling capacity is the same as when no injection is performed, the cooling capacity is represented by the product of the refrigerant flow rate and the previous enthalpy difference. Therefore, the flow rate of the refrigerant can be reduced. As a result, the compression work before the scroll compressor is injected is reduced, and the required electric input can be reduced. In the heating operation, the capacity increases due to the increase in the enthalpy difference in the evaporator and the increase in the flow rate of the refrigerant flowing to the condenser. As a result, the compression work of the compressor is reduced, and the required electric input can be reduced.

Further, since the low-temperature gas refrigerant is injected into the gas refrigerant whose temperature has risen due to the compression of the suction gas, the discharge temperature of the compressor can be lowered. In the superheated gas region, the lower the temperature at the same pressure, the smaller the enthalpy difference between the inlet and the outlet of the compressor, so that the compression work is reduced. However, in the actual cycle, the injection is performed by the pressure difference between the high-pressure vessel and the compression chamber of the compressor, so the injection is not performed instantaneously.
The injection takes some time, and the compression work increases accordingly. Therefore, in order to make the actual cycle closer to the theoretical cycle, it is necessary to shorten the injection time. If the injection hole becomes large, the injection can be performed in a short time, so that it can be made closer to the theoretical cycle, and the cycle COP is improved.

Further, since the hole width corresponding to the minor diameter of the oval injection hole of the present invention is smaller than the tooth width of the wrap of the orbiting scroll, the adjacent compression chambers having different pressures do not communicate with each other. Since no refrigerant leaks from the high-pressure side compression chamber to the low-pressure side compression chamber, no leakage loss occurs and high efficiency can be maintained. In addition, by performing high-efficiency injection, the enthalpy difference on the evaporator side can be made large, the amount of refrigerant circulating required to obtain the same capacity is reduced, and the theoretical discharge capacity can be further reduced. For this reason, the compressor is also reduced in size and the mechanical loss is reduced, so that the COP can be further improved.

The effect of the present invention can be obtained in the use of an HFC-based refrigerant, which contributes to the prevention of ozone layer destruction. In addition, the effect of the present invention can be similarly achieved in the use of an HC-based refrigerant and a natural-based refrigerant. As a result, it can contribute to the prevention of global warming.

[Brief description of the drawings]

FIG. 1 is a sectional view taken along line AA of FIG. 3, showing a combination of an injection hole shape, a fixed scroll wrap, and an orbiting scroll wrap according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view taken along line AA of FIG. 3 showing a combination of an injection hole shape, a fixed scroll wrap, and an orbiting scroll wrap according to another embodiment of the present invention.

FIG. 3 is a longitudinal sectional view of a scroll compressor having an injection hole according to the present invention in a fixed scroll.

FIG. 4 is an injection cycle diagram of one embodiment using the scroll compressor of the present invention.

FIG. 5 is an injection cycle diagram of another embodiment using the scroll compressor of the present invention.

FIG. 6 is a diagram showing a relationship between an oval injection hole and a wrap position of an orbiting scroll according to one embodiment of the present invention.

FIG. 7 is a diagram showing a relationship between an oval injection hole and a wrap position of the orbiting scroll when the orbiting scroll is turned by 45 degrees with reference to FIG. 6;

FIG. 8 is a diagram showing a relationship between an oval injection hole and a wrap position of the orbiting scroll when the orbiting scroll is turned by 90 degrees with reference to FIG. 6;

FIG. 9 is a view showing the relationship between the injection hole and the wrap position of the orbiting scroll in the case of one oval injection hole according to the present invention.

FIG. 10 is a diagram showing a relationship between an oval injection hole and a wrap position of the orbiting scroll when the orbiting scroll is turned by 90 degrees with reference to FIG. 9;

FIG. 11 is a diagram showing a relationship between an oval injection hole and a wrap position of the orbiting scroll when the orbiting scroll is turned by 180 degrees with reference to FIG. 9;

FIG. 12 is a Mollier diagram showing the gas injection cycle of FIG. 5;

FIG. 13 is a Mollier diagram showing the actual gas injection cycle of FIG. 5;

FIG. 14 is a Mollier diagram during a cooling operation of the gas injection cycle of FIG. 4;

FIG. 15 is a Mollier diagram during a heating operation of the gas injection cycle of FIG. 4;

FIG. 16 is a sectional view of a wrap of an orbiting scroll of the scroll compressor.

FIG. 17 is a diagram showing the relationship between the injection hole and the wrap position of the orbiting scroll when the injection hole is a circle having a diameter larger than the tooth width of the wrap of the orbiting scroll.

[Explanation of symbols]

 1,2,5,6 oval injection hole 3,4 ... compression chamber 7,8 ... long axis of injection hole 50,51 ... injection hole 52,53,54 ... compression chamber 55,56,57, 60, 61 ... Opening 58, 59, 62, 63 ... Closed 65, 66, 67, 68 ... Compression chamber 70 ... Chamfer 71 ... Tip 101 ... Closed container 102 ... Fixed scroll 103 ... Lapping 104 ... Revolving scroll 105 … Scroll compression mechanism 106… suction port 107… discharge pipe 108… electric motor 109… drive shaft 110… discharge port 111… frame 112… rotation prevention mechanism 114… orbiting scroll base plate 122, 123… injection pipe 124, 125… injection hole 126 ... wrap 127 ... fixed scroll base plate 128 ... base 129, 130 ... compression chamber 201 ... compressor 202 ... four-way valve 203 ... outdoor heat exchanger 204 ... first pressure reducing device 205 ... high pressure vessel 206,207 ... second pressure reducing device 208,209 ... indoor heat exchanger 210,211 ... blocking Valve 212 ... On-off valve 213 ... Injection piping 214, 215, 216 ... Fan 217, 218 ... Connection piping 219 ... Outdoor unit 220, 221 ... Indoor unit 222 ... Third decompression device 223 ... Heat exchanger 501 ... Compression room a 502 ... compression chamber b 503 ... injection hole

Continued on the front page (72) Inventor Masanao Kotani 502 Kandate-cho, Tsuchiura-city, Ibaraki Pref. Machinery Research Laboratory, Hitachi, Ltd. (72) Inventor Susumu Nakayama 390 Muramatsu, Shimizu-shi, Shizuoka Pref. (72) Inventor Go Tsuchiya 502, Kandachi-cho, Tsuchiura-shi, Ibaraki F-term in Machinery Research Laboratories, Hitachi, Ltd. (Reference) CC33 CC48

Claims (5)

[Claims] 1. A fixed scroll comprising a base plate and a spiral wrap integral therewith, and a orbiting scroll comprising a base plate and a spiral wrap integral therewith are arranged by mutually engaging the spiral wraps. A rotation preventing mechanism for rotating the orbiting scroll without rotating with respect to the fixed scroll, a driving shaft for orbiting the orbiting scroll, and a compression mechanism including a frame supporting the driving shaft. A scroll compressor in which at least one injection hole for injecting refrigerant into an intermediate compression chamber formed by the fixed scroll and the orbiting scroll is provided in the fixed scroll, wherein the injection hole has a tooth shape of a wrap of the fixed scroll. Pseudo-ellipse whose parallel diameter is approximately equal to the width of the lap A scroll compressor characterized by a circular shape. 2. A fixed scroll consisting of a base plate and a spiral wrap integral therewith, and a orbiting scroll consisting of a base plate and a spiral wrap integral therewith are arranged by mutually engaging the spiral wraps. A rotation preventing mechanism for rotating the orbiting scroll without rotating with respect to the fixed scroll, a driving shaft for orbiting the orbiting scroll, and a compression mechanism including a frame supporting the driving shaft. A scroll compressor in which at least one injection hole for injecting refrigerant into an intermediate compression chamber formed by the fixed scroll and the orbiting scroll is provided in the fixed scroll, wherein a center line of the injection hole is a wrap of the fixed scroll; Of Involute Curve Forming Tooth Profile A scroll compressor having a pseudo-elliptical shape on an involute curve formed by a base circle having the same size as a circle and having a minor axis substantially equal to a tooth width of a wrap. 3. A heat pump cycle is constituted by sequentially connecting a compressor, a four-way valve, an outdoor heat exchanger, a first decompression device, a high-pressure vessel, a second decompression device, and at least one indoor heat exchanger by piping. In the air conditioner, the scroll compressor according to claim 1 or 2 is used as the compressor, and the high-pressure container and the injection hole of the compressor are connected by an injection pipe. Air conditioner. 4. A heat pump cycle is constituted by sequentially connecting a compressor, a four-way valve, an outdoor heat exchanger, a first pressure reducing device, a high pressure vessel, a second pressure reducing device, and at least one indoor heat exchanger by piping. An air conditioner comprising: the scroll compressor according to claim 1 or 2 as the compressor, a pipe between the first pressure reducing device and the high-pressure vessel, or a heat exchanger and the high-pressure Whether the branch point provided on the pipe between the vessel and the injection hole of the compressor is connected by a pipe, or whether the high-pressure vessel itself and the injection hole of the compressor are connected by a pipe. To provide the injection pipe,
A third decompression device is provided on the pipe near the branch point or the high pressure vessel, and a heat exchanger is further provided between the second pressure reduction device and the pipe on the heat pump cycle from the high pressure vessel. An air conditioner characterized by being installed. 5. The scroll compressor according to claim 1, wherein the refrigerant is any one of R22, HFC-based refrigerant, HC-based refrigerant, and natural-based refrigerant as the refrigerant. A scroll compressor or an air conditioner using the same.