JP2010185350A - Refrigeration system and scroll compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a refrigeration system with high capacity and a high COP (coefficient of performance) sufficiently securing an injection quantity of intermediate-pressure refrigerant gas, and a scroll compressor. <P>SOLUTION: The refrigeration system includes a stepped scroll compressor 2, wherein a gas injection circuit 10 for injecting the intermediate-pressure refrigerant gas extracted from the refrigerant circuit side is arranged in a compression chamber. In the refrigeration system, an injection port 35 for injecting refrigerant gas to the compression chamber is arranged in the position communicating with the inside of the compression chamber 30 on the swirl direction outer circumference edge side beyond a stepped part of a fixed scroll 26, while a heating means heating the refrigerant gas to be injected to the compression chamber 30 is arranged in the gas injection circuit 10. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a refrigeration system with a gas injection circuit having a scroll compressor provided with a stepped portion in a spiral direction, and a stepped scroll compressor suitable for application to the refrigeration system.

  In the scroll compressor, stepped portions are provided at predetermined positions along the spiral direction of the spiral wrap of the fixed scroll and the orbiting scroll, and the distal end surface of the outer peripheral side of the wrap distal end surface with the stepped portion as a boundary. The inner peripheral side tip surface is lowered, the outer peripheral side bottom surface is lower on the bottom surface, and the inner peripheral side bottom surface is increased, so that the wrap height on the outer peripheral side of the spiral wrap is increased to the inner peripheral side. The height in the axial direction of the compression chamber formed between the scrolls is made higher than the height of the inner peripheral side on the outer peripheral side of the spiral wrap, and thereby the circumferential direction of the spiral wrap and A so-called stepped scroll compressor capable of three-dimensional compression capable of compressing gas in both lap height directions is known.

  In refrigeration systems such as various air conditioners and refrigerators in which such a so-called stepped scroll compressor is used, a gas for injecting an intermediate-pressure refrigerant gas extracted from the refrigerant circuit into the compression chamber of the stepped scroll compressor Patent Document 1 proposes a refrigeration system with an injection circuit.

JP 2007-64005 A

  Thus, the stepped scroll compressor generally has a high design compression ratio and a rapid rise in pressure during compression, compared to a normal scroll compressor. For this reason, when applied to a refrigeration system with a gas injection circuit, the pressure on the compression chamber side to be injected is high, and it is difficult to secure a sufficient injection amount due to the relationship with the pressure of the intermediate pressure refrigerant gas.

  In particular, on the gas injection circuit side, the heating heat source of the injection-side refrigerant gas is the main refrigerant circuit side in both the gas-liquid separation method provided with a gas-liquid separator and the intermediate heat exchange method provided with an intermediate heat exchanger. Therefore, it is difficult to secure the degree of superheat of the injection-side refrigerant gas, and gas injection at a low pressure is often caused. For this reason, the injection amount tends to decrease due to the relationship with the pressure in the compression chamber, and a sufficient injection effect has not been obtained.

  In addition, since the degree of superheat of the injection-side refrigerant gas cannot be secured sufficiently, refrigerant gas containing liquid refrigerant may be injected, and the enthalpy difference on the discharge side may be lower than the theoretical value. It was. Furthermore, injection of refrigerant gas containing liquid refrigerant may cause slugging noise and liquid compression.

  The present invention has been made in view of such circumstances, and in a refrigeration system with a gas injection circuit using a stepped scroll compressor, it has a high capability and a high capability capable of sufficiently securing an injection amount of intermediate pressure refrigerant gas. An object of the present invention is to provide a COP (coefficient of performance) refrigeration system and a scroll compressor.

In order to solve the above problems, the refrigeration system and scroll compressor of the present invention employ the following means.
That is, in the refrigeration system according to the present invention, a spiral wrap is erected on the end plate, and a stepped portion is provided in the middle of the spiral direction of the pair of fixed scroll and the orbiting scroll that are engaged with each other to form a compression chamber. And a refrigerant compressor having an intermediate pressure extracted from the refrigerant circuit side into the compression chamber of the scroll compressor. In the refrigeration system provided with the gas injection circuit for injecting the gas, the injection port for injecting the refrigerant gas into the compression chamber communicates with the compression chamber on the outer peripheral end side in the spiral direction with respect to the stepped portion of the fixed scroll. And the gas injection circuit has the pressure applied to the gas injection circuit. Wherein the heating means for heating the refrigerant gas chamber is injected into is provided.

  According to the present invention, in a refrigeration system with a gas injection circuit provided with a so-called stepped scroll compressor having a stepped portion in the middle of the spiral direction and having a high compression ratio and a sudden rise in pressure during compression, An injection port for injecting intermediate-pressure refrigerant gas into the compression chamber of the machine is provided at a position communicating with the compression chamber on the outer peripheral end side in the spiral direction with respect to the stepped portion of the fixed scroll, and the gas injection circuit is connected to the compression chamber. Since the heating means for heating the intermediate pressure refrigerant gas to be injected is provided, it is heated by the heating means in the injection circuit in the compression chamber formed on the outer peripheral end side in the spiral direction with respect to the step portion having a relatively low pressure. Injection of intermediate pressure refrigerant gas with high superheat and high pressure It can be. Therefore, it is possible to inject a sufficient amount of intermediate-pressure refrigerant gas at the time of gas injection even for a stepped scroll compressor with a high compression ratio and a sudden rise in pressure during compression, improving cooling and heating capacity In addition, COP (coefficient of performance) can be improved. In particular, it is possible to improve heating capacity and COP (coefficient of performance) under a high compression ratio condition such as at a very low temperature. In addition, since the intermediate pressure refrigerant gas to be injected can be reliably heated to a superheated gas, the liquid refrigerant is not injected, and the generation of slugging noise and liquid compression can be prevented. .

  Furthermore, the refrigeration system of the present invention is characterized in that, in the refrigeration system, the heating means is constituted by an electric heater.

  According to the present invention, since the heating means is constituted by an electric heater, the most general and simple application electric heater can be used as the heating means for heating the injected intermediate pressure refrigerant gas. Therefore, the present invention can be widely applied to any refrigeration system regardless of use and form.

  Furthermore, the refrigeration system of the present invention is characterized in that, in the above refrigeration system, the heating means is constituted by a heat exchanger using exhaust heat of the engine.

  According to the present invention, since the heating means is constituted by a heat exchanger that uses exhaust heat of the engine, a refrigeration system such as a gas heat pump device, a transport refrigeration device, or a vehicle air conditioner on which the engine is mounted. , By introducing exhaust heat such as engine exhaust gas and cooling water into the heat exchanger, the injection gas can be heated with the heat. Therefore, exhaust heat can be effectively used as a heat source for the heating means, and performance can be further improved.

  Furthermore, the refrigeration system according to the present invention is the refrigeration system according to any one of the above-described refrigeration systems, wherein the scroll compressor is configured such that the spiral wraps are disposed on the outer peripheral end side in the spiral direction with respect to the stepped portion provided with the injection port. It is characterized by being non-contact.

  According to the present invention, in the scroll compressor, since the spiral wraps are not in contact with each other on the outer peripheral end side in the spiral direction with respect to the step portion provided with the injection port, the spiral wrap applied to the spiral wrap. The contact load between each other can be applied only to the inner peripheral end side of the step portion where the wrap height is low and the end plate thickness is thick. Accordingly, it is possible to prevent a decrease in strength due to the notch of the end plate of the fixed scroll or the spiral wrap due to the provision of the injection port.

  Furthermore, in the refrigeration system according to the present invention, in the refrigeration system described above, the spiral wraps are not in contact with each other in a peripheral portion provided at least on the outer peripheral end side in the spiral direction with respect to the stepped portion. It is characterized by.

  According to the present invention, since the spiral wraps are not in contact with each other at least in the peripheral portion where the injection port is provided on the outer peripheral end side in the spiral direction with respect to the stepped portion, the spiral wraps applied to the spiral wraps The contact load can be lowered in the peripheral portion where the injection port is provided. Accordingly, it is possible to suppress a decrease in strength due to the notch of the end plate of the fixed scroll or the spiral wrap resulting from the provision of the injection port.

  Furthermore, in the scroll compressor according to the present invention, a spiral wrap is erected on the end plate, and a step portion is provided in the middle of the spiral direction of the pair of fixed scroll and the orbiting scroll that are engaged with each other to form a compression chamber. In the scroll compressor provided and capable of compressing the refrigerant gas in both the circumferential direction and the axial direction of the spiral wrap, an injection port for injecting the intermediate-pressure refrigerant gas extracted from the refrigerant circuit into the compression chamber is provided The fixed scroll is provided at a position communicating with the compression chamber on the outer peripheral end side in the spiral direction with respect to the stepped portion, and at the outer peripheral end side in the spiral direction with respect to the stepped portion provided with the injection port. The spiral wraps are not in contact with each other.

  According to the present invention, in a so-called stepped scroll compressor in which a step is provided in the middle of the spiral direction, the compression ratio is high, and the rise of pressure during compression is abrupt, the intermediate pressure extracted from the refrigerant circuit into the compression chamber. An injection port for injecting refrigerant gas is provided at a position communicating with the compression chamber on the outer peripheral end side in the spiral direction with respect to the stepped portion of the fixed scroll, and on the outer peripheral end side in the spiral direction with respect to the stepped portion provided with the injection port. Since the spiral wraps are not in contact with each other, the intermediate-pressure refrigerant gas can be injected into the compression chamber formed on the outer peripheral end side in the spiral direction with respect to the step portion having a relatively low pressure. Accordingly, even in a stepped scroll compressor having a high compression ratio and a sudden rise in pressure during compression, it is possible to inject a sufficient amount of intermediate pressure refrigerant gas during gas injection, improving cooling and heating capacity, and COP (Coefficient of performance) can be improved. In addition, since the contact load between the spiral wraps on the spiral wrap can be applied only to the inner peripheral end side of the stepped portion where the wrap height is low and the end plate thickness is thick, the injection port is It is possible to prevent a decrease in strength due to the notch of the end plate of the fixed scroll or the spiral wrap due to the provision.

  Furthermore, the scroll compressor according to the present invention is the above scroll compressor, wherein the spiral wraps are not in contact with each other in a peripheral portion provided at least on the outer peripheral end side in the spiral direction with respect to the stepped portion. It is said that it is said.

  According to the present invention, since the spiral wraps are not in contact with each other at least in the peripheral portion where the injection port is provided on the outer peripheral end side in the spiral direction with respect to the stepped portion, the spiral wraps applied to the spiral wraps The contact load can be reduced in the peripheral portion where the injection port is provided. Accordingly, it is possible to suppress a decrease in strength due to the notch of the end plate of the fixed scroll or the spiral wrap resulting from the provision of the injection port.

  According to the refrigeration system of the present invention, the compression chamber formed on the outer peripheral end side in the spiral direction with respect to the step portion having a relatively low pressure is heated by the heating means in the injection circuit, and the intermediate is heated to a high degree of superheat and the pressure is increased. Since a pressurized refrigerant gas can be injected, a sufficient amount of intermediate-pressure refrigerant gas can be injected during gas injection even for a stepped scroll compressor with a high compression ratio and a sudden rise in pressure during compression. This makes it possible to improve the cooling and heating capacity and the COP (coefficient of performance). In particular, the heating capacity and COP (coefficient of performance) under high compression ratio conditions such as at extremely low temperatures can be improved. In addition, the intermediate pressure refrigerant gas to be injected is heated by the heating means to be sure to Therefore, the liquid refrigerant is not injected, and the generation of slugging noise and liquid compression can be prevented.

  According to the scroll compressor of the present invention, since the intermediate pressure refrigerant gas can be injected into the compression chamber formed on the outer circumferential end side in the spiral direction than the step portion having a relatively low pressure, the compression ratio is high and the compression is performed. Even in a stepped scroll compressor with a steep rise in pressure, it becomes possible to inject a sufficient amount of intermediate pressure refrigerant gas at the time of gas injection, thereby improving cooling and heating capacity and COP (coefficient of performance). be able to. In addition, since the contact load between the spiral wraps on the spiral wrap can be applied only to the inner peripheral end side of the stepped portion where the wrap height is low and the end plate thickness is thick, the injection port is It is possible to prevent a decrease in strength due to the notch of the end plate of the fixed scroll or the spiral wrap due to the provision.

It is a refrigerant circuit figure of the refrigerating system concerning a 1st embodiment of the present invention. It is sectional drawing of the scroll compressor applied to the refrigeration system shown in FIG. It is a top view which shows the meshing state of the fixed scroll and turning scroll of the scroll compressor shown in FIG. It is the elements on larger scale in the vicinity of the step part in the fixed scroll shown in FIG.

Embodiments according to the present invention will be described below with reference to the drawings.
[First Embodiment]
Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. 1 to 4.
As shown in FIG. 1, the refrigeration system 1 includes a scroll compressor 2 that compresses a refrigerant, a condenser (condenser) 3 that cools and compresses the compressed refrigerant, and a pressure of the condensed liquid refrigerant. The pressure is reduced via the first expansion valve 4 for reducing the pressure to an intermediate pressure, the gas-liquid separator 5 for gas-liquid separation of the reduced pressure refrigerant, the second expansion valve 6 for further reducing the pressure of the liquid refrigerant, and the second expansion valve 6. A closed-cycle refrigerant circuit 9 is provided which is connected to an evaporator (evaporator) 7 for evaporating the refrigerant through a refrigerant pipe 8.

  The refrigeration system 1 also includes a gas injection circuit 10 that injects an intermediate-pressure refrigerant gas separated by the gas-liquid separator 5 into a compression chamber 30 (to be described later) of the scroll compressor 1. The gas injection circuit 10 is provided with an electromagnetic valve 11, and the operation and non-operation of the gas injection circuit 10 can be switched by opening and closing thereof.

  Further, the gas injection circuit 10 heats the intermediate-pressure refrigerant gas extracted from the gas-liquid separator 5 and injected into the compression chamber 30 of the scroll compressor 1, thereby increasing the degree of superheat and increasing the pressure. A heating means 12 is provided. As the heating means 12, an electric heater such as a PTC heater can be used.

  As shown in FIG. 2, the scroll compressor 2 is disposed in a housing 21 that is a sealed container, an electric motor 22 that is fixedly installed in a lower portion of the housing 21, and an upper portion of the electric motor 22. The scroll compression mechanism 24 is driven by an electric motor 22 via a crankshaft 23. The scroll compression mechanism 24 is supported on the thrust surface of the main bearing 25, the main bearing 25 fixedly installed in the housing 21, the fixed scroll 26 fixedly installed on the main bearing 25, and the crank An orbiting scroll 27 that is connected to a crankpin 23A provided at the end of the shaft 23 via a drive bush 28 and is orbitally driven by the rotation of the crankshaft 23, and an Oldham ring that prevents the orbiting scroll 27 from rotating. A rotation prevention mechanism 29 is provided.

  The fixed scroll 26 includes an end plate 26A and a spiral wrap 26B standing from the end plate 26A, and the orbiting scroll 27 includes an end plate 27A and a spiral wrap 27B standing from the end plate 27A. It is composed of The fixed scroll 26 and the orbiting scroll 27 are provided with step portions 26C and 26D and 27C and 27D, respectively, at positions along the spiral direction of the front and bottom surfaces of the spiral wraps 26B and 27B. The stepped portions 26C and 27C are preferably provided between the outer peripheral ends of the spiral wraps 26B and 27B with a traveling angle between π radians and 2π radians.

  With the stepped portions 26C, 26D and 27C, 27D as a boundary, at the lap tip surface, the tip surface on the outer peripheral side is high in the axial direction of the crankshaft 23, the tip surface on the inner peripheral side is lowered, and on the bottom surface In the axial direction, the bottom surface on the outer peripheral side is low and the bottom surface on the inner peripheral side is high. Accordingly, the spiral wraps 26B and 27B have a wrap height on the outer peripheral side higher than a wrap height on the inner peripheral side.

  The fixed scroll 26 and the orbiting scroll 27 are separated from each other by the orbiting radius, and the spiral wraps 26B and 27B are engaged with each other by shifting the phase by 180 degrees. It is assembled so as to have a slight gap in the lap height direction at room temperature. Accordingly, a pair of compression chambers 30 limited by the end plates 26A and 27A and the spiral wraps 26B and 27B are formed between the scrolls 26 and 27 symmetrically with respect to the scroll center, and the orbiting scroll 27 Is configured to be smoothly driven to revolve around the fixed scroll 26.

  The compression chamber 30 compresses the gas in the circumferential direction of the spiral wraps 26B and 27B and the wrap height direction by making the height in the axial direction higher than the height on the outer peripheral side of the spiral wraps 26B and 27B. A scroll compression mechanism 24 capable of three-dimensional compression is configured. In addition, tip seals (not shown) for sealing the tip seal surface formed between the bottom surfaces of the other scrolls are provided on the front end surfaces of the spiral wraps 25B and 27B of the fixed scroll 26 and the orbiting scroll 27. be able to.

  A discharge port 31 for discharging the compressed refrigerant gas is opened at the center position of the end plate 26 </ b> A of the fixed scroll 26. The discharge port 31 is provided with a discharge valve (not shown), and the discharge port 31 is communicated with a discharge chamber 33 defined in the housing 21 via a discharge cover 32 via the discharge valve. Yes. The high-temperature and high-pressure refrigerant gas discharged into the discharge chamber 33 is sent out from the scroll compressor 2 through the discharge pipe 34.

  Further, the fixed scroll 26 has an injection port 35 for injecting the intermediate pressure refrigerant gas introduced by the gas injection circuit 10 into the compression chamber 30 at a position communicating with the compression chamber 30. As shown in FIG. 4, the injection port 35 is provided so as to communicate with the compression chamber 30 on the outer peripheral end side in the spiral direction with respect to the stepped portion 26 </ b> C of the spiral wrap 26 </ b> B of the fixed scroll 26.

  Furthermore, at least the spiral wrap 26B of the fixed scroll 26 forms the spiral wrap 26B as shown in FIG. 4 on the outer peripheral end side in the spiral direction with respect to the step portion 26C where the injection port 35 is provided. The outer curved line 26E and the ventral side curve 26F are shaved as shown by the solid line from the two-dot chain line in units of several tens of microns so that they are not in contact with the spiral wrap 27B of the other orbiting scroll 27. The thickness of 26B is reduced.

With the configuration described above, according to the present embodiment, the following operational effects can be obtained.
In the refrigeration system 1, the high-temperature and high-pressure refrigerant gas compressed by the scroll compressor 2 is condensed by the condenser 3 and reduced to an intermediate pressure by the first expansion valve, and then led to the gas-liquid separator 5. Gas-liquid separation. The liquid refrigerant cooled by the refrigerant separation of the gas phase is decompressed by the second expansion valve, evaporated by the evaporator 7, and again sucked into the scroll compressor 2 and compressed. Thereafter, the same operation is repeated.

  The intermediate-pressure refrigerant gas separated by the gas-liquid separator 5 is injected into the compression chamber 30 of the scroll compressor 2 through the gas injection circuit 10. This intermediate pressure refrigerant gas is heated by the heating means 12 when being injected, and is injected in a state where the degree of superheat is large and the pressure is increased. On the other hand, on the scroll compressor 2 side, the injection port 35 for injecting the intermediate pressure refrigerant gas into the compression chamber 30 is located at a position communicating with the inside of the compression chamber 30 on the outer peripheral end side in the spiral direction with respect to the stepped portion 26C of the fixed scroll 26. The intermediate-pressure refrigerant gas that is provided is injected into the compression chamber 30 that is formed on the outer circumferential end side in the spiral direction with respect to the step portion 26C having a relatively low pressure.

  As a result, the step portions 26C and 27C are provided in the spiral direction, and three-dimensional compression is possible in which gas is compressed in both the circumferential direction and the wrap height direction of the spiral wraps 26B and 27B. A sufficient amount of intermediate pressure refrigerant gas can be injected even into the so-called stepped scroll compressor 2 where the rise of the pressure is abrupt.

  As a result, during heating or heating, since the intermediate pressure refrigerant gas-injected is added to the refrigerant flowing through the condenser 3, the amount of refrigerant circulation is increased, and the heating or heating performed by using the heat radiation from the condenser 3 accordingly. Heating capacity can be improved. Further, during cooling or cooling, the enthalpy difference of the refrigerant introduced into the evaporator 7 increases, so the amount of heat of the refrigerant evaporated in the evaporator 7 increases, and the cooling or cooling capacity can be improved accordingly.

  Therefore, according to the present embodiment, even when the stepped scroll compressor 2 having a high compression ratio and a sudden rise in pressure during compression is used for the compressor of the refrigeration system 1, a sufficient amount at the time of gas injection is used. The intermediate pressure refrigerant gas can be injected, and the cooling and heating ability can be improved and the COP (coefficient of performance) can be improved. In particular, it is possible to improve heating capacity and COP (coefficient of performance) under a high compression ratio condition such as at a very low temperature. Furthermore, since the intermediate pressure refrigerant gas to be injected can be heated by the heating means 12 to be surely used as a superheated gas, generation of slagging sound and liquid compression due to the liquid refrigerant being injected can be prevented.

  Moreover, since the heating means 12 is composed of an electric heater such as a PTC heater, the most general and simple application electric heater can be used as the heating means 12 for heating the intermediate pressure refrigerant gas to be injected. . Accordingly, the present invention can be widely applied to any refrigeration system 1 regardless of use and form.

  Further, in the stepped scroll compressor 2 described above, the injection port 35 for injecting the intermediate-pressure refrigerant gas extracted from the refrigerant circuit 9 into the compression chamber 30 is on the outer peripheral end side in the spiral direction with respect to the step portion 26C of the fixed scroll 26. The outer side curve 26E and the ventral side curve 26F of the spiral wrap 26B are several on the outer peripheral end side in the spiral direction with respect to the stepped portion 26C where the injection port 35 is provided. Since the spiral wraps 26B and 27B are cut out in units of 10 microns and are not in contact with each other, the compression chamber 30 formed on the outer peripheral end side in the spiral direction than the step portion 26C having a relatively low pressure, Intermediate pressure refrigerant gas will be injected.

  Accordingly, the compression capacity of the scroll compressor 2 and the COP (coefficient of performance) can be improved, and at the same time, the contact load between the spiral wraps 26B and 27B can be reduced with a low wrap height. Since the load can be applied only to the inner peripheral end side of the stepped portions 26C and 27C having a thick plate thickness, the fixed scroll 26 of the fixed scroll 26 caused by the injection port 35 being provided on the outer peripheral end side in the spiral direction. It is possible to prevent a decrease in strength due to the notch of the end plate 26A or the spiral wrap 26B.

[Other Embodiments]
Next, another embodiment of the present invention will be described.
Instead of a part of the first embodiment described above, the following forms can be adopted.
(1) In the first embodiment, the embodiment using the hermetic electric scroll compressor 2 including the electric motor 22 as the scroll compressor 2 has been described. However, the scroll compressor 2 has a drive source. A so-called open-type scroll compressor that is not built-in and is driven via a clutch or the like by an external drive source such as an engine can be used, and this also achieves the same effects as the first embodiment. it can.

  (2) In the first embodiment, the gas-liquid separation type refrigeration system 1 with the gas-injection circuit 10 using the gas-liquid separator 5 is shown, but instead of the gas-liquid separator 5, the main refrigerant circuit is used. An intermediate-pressure refrigerant gas evaporated from the intermediate heat exchanger is provided by branching a part of the liquid refrigerant and reducing the pressure of the branched refrigerant to an intermediate pressure and then exchanging heat with the refrigerant flowing through the main refrigerant circuit 9. It is good also as the refrigeration system 1 with the gas injection circuit of the intermediate heat exchange system comprised so that injection may be carried out. Also by this, the same effect as 1st Embodiment can be acquired.

  (3) In the first embodiment, an example in which an electric heater is used as the heating unit 12 has been described. However, a refrigeration system applied to a gas heat pump apparatus, a transport refrigeration apparatus, a vehicle air conditioner, and the like on which an engine is mounted. 1, a heat exchanger configured to allow exhaust heat such as engine exhaust gas and cooling water to circulate is provided as the heating means 12, and exhaust heat such as exhaust gas and cooling water is introduced into the heat exchanger. Thus, the injection gas may be heated with the heat. According to this, in addition to the same effects as those in the first embodiment, exhaust heat can be effectively used as a heat source for the heating means 12, so that it is possible to further improve performance.

  (4) In the first embodiment, the spiral wraps 26B and 27B are not in contact with each other on the outer peripheral end side in the spiral direction with respect to the stepped portion 26C where the injection port 35 is provided. The spiral wraps 26B and 27B may be configured to be in non-contact with each other only in the peripheral portion. Also by this, the contact load between the spiral wraps on the spiral wraps 26 </ b> B and 27 </ b> B can be reduced in the peripheral portion where the injection port 35 is provided, and this is because the injection port 35 is provided. The strength reduction due to the notch of the end plate 26A or the spiral wrap 26B of the fixed scroll 26 can be suppressed.

  The present invention is not limited to the invention according to the above-described embodiment, and it goes without saying that modifications can be made as appropriate without departing from the scope of the invention.

DESCRIPTION OF SYMBOLS 1 Refrigeration system 2 Scroll compressor 5 Gas-liquid separator 9 Refrigerant circuit 10 Gas injection circuit 12 Heating means 26 Fixed scroll 26A End plate 26B Spiral wrap 26C, 26D Step part 26E Outer curve 26F of spiral wrap Belly of spiral wrap Side curve 27 Orbiting scroll 27A End plate 27B Spiral wrap 27C, 26D Step 30 Compression chamber 35 Injection port

Claims (7)

A spiral wrap is erected on the end plate, and a step portion is provided in the middle of the spiral direction of the pair of fixed scroll and the orbiting scroll that form a compression chamber by meshing with each other, and allows refrigerant gas to flow around the spiral wrap. A scroll compressor that is compressible in both the axial direction and the axial direction, and a gas injection circuit that injects an intermediate-pressure refrigerant gas extracted from the refrigerant circuit side into the compression chamber of the scroll compressor. In the refrigeration system
An injection port for injecting the refrigerant gas into the compression chamber is provided at a position communicating with the compression chamber on the outer peripheral end side in a spiral direction with respect to the stepped portion of the fixed scroll, and the gas injection circuit includes the A refrigeration system comprising heating means for heating the refrigerant gas injected into the compression chamber.   The refrigeration system according to claim 1, wherein the heating unit includes an electric heater.   The refrigeration system according to claim 1, wherein the heating unit includes a heat exchanger using exhaust heat of the engine.   4. The scroll compressor according to claim 1, wherein the spiral wraps are not in contact with each other on the outer peripheral end side in the spiral direction with respect to the stepped portion provided with the injection port. A refrigeration system according to crab.   5. The refrigeration system according to claim 4, wherein the spiral wraps are not in contact with each other in at least a peripheral portion provided with the injection port on the outer peripheral end side in the spiral direction with respect to the stepped portion. . A spiral wrap is erected on the end plate, and a step portion is provided in the middle of the spiral direction of the pair of fixed scroll and the orbiting scroll that form a compression chamber by meshing with each other, and allows refrigerant gas to flow around the spiral wrap. In a scroll compressor that is compressible in both direction and axial direction,
An injection port for injecting an intermediate pressure refrigerant gas extracted from the refrigerant circuit into the compression chamber is provided at a position communicating with the compression chamber on the outer peripheral end side in the spiral direction with respect to the stepped portion of the fixed scroll. The scroll compressor is characterized in that the spiral wraps are not in contact with each other on the outer peripheral end side in the spiral direction with respect to the stepped portion provided with the injection port. The scroll compression according to claim 6, wherein the spiral wraps are not in contact with each other at least in a peripheral portion provided with the injection port on the outer peripheral end side in the spiral direction with respect to the stepped portion. Machine.

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