JP7345135B2 - scroll compressor - Google Patents

Description

The present invention relates to a scroll compressor having an injection mechanism.

Patent Document 1 discloses a scroll compressor with an injection function. This scroll compressor has a muffler placed on the back of the fixed scroll, and intermediate pressure injection refrigerant passes from the side of the compressor through the intermediate pressure chamber formed by the back of the fixed scroll and the muffler. It flows into the compression chamber during the compression process through the injection port.

In addition, a discharge port for discharging the refrigerant compressed in the compression chamber and a discharge bypass port for discharging the refrigerant that has reached the discharge pressure before the compression chamber communicates with the discharge port are provided in the center of the end plate of the fixed scroll. The refrigerant discharged from the discharge port and the discharge bypass port is discharged into the discharge space in the closed container via the discharge pressure chamber formed by the back surface of the fixed scroll and the muffler.

International Publication No. 2018/150540

The present disclosure suppresses a decrease in the density of the injection refrigerant caused by heat exchange between the injection refrigerant and the fixed scroll and the refrigerant inside the discharge pressure chamber and the discharge space, thereby providing a highly efficient compressor.

In the scroll compressor of the present disclosure, a heat insulating material is provided between the injection refrigerant inside the intermediate pressure chamber, the fixed scroll, and the muffler, and the injection refrigerant inside the intermediate pressure chamber and an adjacent discharge pressure chamber having a higher temperature than this injection refrigerant are provided. , is configured to reduce heat exchange between the refrigerant inside the discharge space and the fixed scroll.

The scroll compressor according to the present disclosure reduces heat exchange between the injection refrigerant inside the intermediate pressure chamber and the adjacent discharge pressure chamber, the refrigerant inside the discharge space, and the fixed scroll, which have a higher temperature than the injection refrigerant. It is possible to suppress a decrease in density due to a rise in temperature, suppress a decrease in refrigerant circulation amount, and provide a highly efficient compressor.

Refrigeration cycle diagram equipped with a scroll compressor according to Embodiment 1 Vertical cross-sectional view of the scroll compressor in Embodiment 1 Enlarged view of main parts of the scroll compressor in Embodiment 1 Enlarged view of main parts showing a modification of the scroll compressor in Embodiment 1

(Findings, etc. that formed the basis of this disclosure)
At the time the inventors came up with the present disclosure, a scroll compressor with an injection mechanism disclosed in Patent Document 1 was known. In this scroll compressor, the temperature of the injection refrigerant inside the intermediate pressure chamber increases as it exchanges heat with the adjacent discharge pressure chamber, the refrigerant inside the discharge space, and the fixed scroll, which have a higher temperature than the injection refrigerant. As a result, there is a problem that the density of the injection refrigerant decreases, the amount of refrigerant circulation decreases, and the efficiency of the compressor decreases. The inventors discovered such a problem, and in order to solve the problem, they came to form the subject matter of the present disclosure.

Therefore, the present disclosure provides a highly efficient compressor by providing a heat insulating material between the injection refrigerant inside the intermediate pressure chamber and the fixed scroll and the muffler to suppress a decrease in density of the injection refrigerant due to a rise in temperature.

Hereinafter, embodiments will be described in detail with reference to the drawings. However, more detailed explanation than necessary may be omitted. For example, detailed explanations of well-known matters or redundant explanations of substantially the same configurations may be omitted. This is to avoid making the following description unnecessarily redundant and to facilitate understanding by those skilled in the art.

The accompanying drawings and the following description are provided to enable those skilled in the art to fully understand the present disclosure, and are not intended to limit the subject matter recited in the claims.

(Embodiment 1)
Embodiment 1 will be described below using FIGS. 1 to 3.

[1-1. composition]
FIG. 1 is a refrigeration cycle diagram including a scroll compressor 100 according to the first embodiment.

As shown in FIG. 1, the refrigeration cycle device includes a scroll compressor 100, a condenser 101, expansion valves 102a, 102b, a gas-liquid separator 103, an evaporator 104, and an injection pipe 105.

The high-pressure refrigerant flowing out from the condenser 101 is depressurized by the expansion valve 102a provided on the upstream side, and becomes intermediate-pressure gas refrigerant with some liquid refrigerant mixed in. The liquid refrigerant and gas refrigerant are separated in the gas-liquid separator 103. separated into The intermediate-pressure liquid refrigerant separated by the gas-liquid separator 103 is further reduced in pressure by the downstream expansion valve 102b, becomes a low-pressure liquid refrigerant, and flows into the evaporator 104.

In the evaporator 104 , the low-pressure liquid refrigerant is evaporated and flows out as a gas refrigerant or a gas refrigerant partially mixed with liquid refrigerant, and is sucked into the scroll compressor 100 .

Scroll compressor 100 compresses low-pressure refrigerant flowing from evaporator 104. In addition, during the compression process, the intermediate pressure gaseous refrigerant separated by the aforementioned gas-liquid separator 103 is injected into the compression chamber via the injection pipe 105 and compressed, and the high-pressure refrigerant is sent to the condenser 101. send it off to

FIG. 2 is a longitudinal sectional view of the scroll compressor 100 in the same embodiment. FIG. 3 is an enlarged view of the main parts of the scroll compressor 100 in the same embodiment.

In FIG. 2, the scroll compressor 100 includes a compressor main body 110 and a closed container 112 that accommodates the compressor main body 110. Oil 114 is stored at the bottom of the closed container 112. The compressor body 110 includes a motor element 120 and a compression element 130 driven by the motor element 120.

The motor element 120 includes a stator 121 fixed to a closed container 112 by welding or shrink fitting, and a rotor 122 that includes a permanent magnet disposed on the inner circumferential side of the stator 121.

Compression element 130 is located above motor element 120.

The crankshaft 132 includes a main shaft portion 132a into which the rotor 122 is press-fitted and fixed, and an eccentric shaft portion 132b formed eccentrically with respect to the main shaft portion 132a.

Further, the crankshaft 132 is provided with an oil supply hole 132c extending therethrough in the axial direction, and is provided with an oil pump 133 at the lower end. The oil pump 133 is arranged at a position where the suction port can reliably enter the oil 114.

The crankshaft 132 is supported by a main bearing member 134 fixed to the closed container 112 by welding or shrink fitting.

A fixed scroll 135 bolted to the main bearing member 134, an orbiting scroll 136 that meshes with the fixed scroll 135, and a muffler 138 are provided on the main bearing member 134.

Fixed scroll 135 and orbiting scroll 136 can be formed from cast iron or aluminum alloy, and muffler 138 can be formed from carbon steel or cast iron.

A rotation restraining mechanism 137 such as an Oldham ring that prevents rotation of the orbiting scroll 136 is provided between the orbiting scroll 136 and the main bearing member 134.

A compression chamber 139 is formed between the fixed scroll 135 and the orbiting scroll 136.

The fixed scroll 135 has a suction port 140 on its outer periphery and a discharge port 141 in its center.

The suction pipe 142, the discharge pipe 143, and the injection pipe 105 communicate with the refrigeration cycle outside the closed container 112.

Suction pipe 142 communicates with compression chamber 139 via suction port 140 .

The compression chamber 139 communicates with a discharge pressure chamber 145 in the muffler 138 via a discharge port 141 in which a discharge reed valve 144 is provided.

The injection pipe is connected to an intermediate pressure chamber 147 in the muffler 138, and communicates with the compression chamber 139 after closing via an injection port 146 equipped with a check valve 148.

The discharge pressure chamber 145 and the intermediate pressure chamber 147 are formed by being surrounded by the back surface of the fixed scroll 135 and the muffler 138.

As shown in FIG. 3, the inner wall surface of the muffler 138 is covered with a heat insulating material 150. The heat insulating material 150 is a material with excellent oil resistance and heat resistance, and has a thermal conductivity of 0.1 W/(m・K) or less, more preferably a thermal conductivity of 0.05 W/(m・K) or less. For example, hollow ceramic or nitrile foam rubber (NBR) can be used. The method of providing the heat insulating material 150 on the inner wall surface of the muffler 138 includes, for example, applying a paint containing hollow ceramic to the inner wall surface of the muffler 138, or applying nitrile foam rubber (NBR) to the inner wall surface of the muffler 138 with an adhesive. There are methods such as adhering it to the surface.

A heat insulating material 152 is interposed between the fixed scroll 135 and the intermediate pressure chamber 147. The heat insulating material 152 can be made of the same material as the heat insulating material 150. When using hollow ceramic, from the viewpoint of sealing performance, it is desirable to interpose it only on the surface of the fixed scroll 135 that forms the intermediate pressure chamber 147 together with the muffler 138, and avoid the portion that will become the fastening surface. When using a highly elastic polymeric material, the heat insulating material 152 can also play the role of a gasket, so by sandwiching and fastening it between the fixed scroll 135 and the muffler 138, sealing performance can be improved at the same time. (not shown).

[1-2. motion]
The operation and effect of the scroll compressor 100 configured as above will be explained below.

When motor element 120 is energized, the magnetic field generated in stator 121 causes rotor 122 to rotate together with crankshaft 132 .

As the crankshaft 132 rotates, the oil pump 133 is driven, and the oil 114 stored at the bottom of the closed container 112 is reliably sucked up regardless of pressure conditions or operating speed. This eliminates the worry of running out of oil. Oil 114 sucked up by oil pump 133 is supplied to compression element 130 through oil supply hole 132c. Note that by removing foreign matter from the oil 114 with an oil filter or the like before and after sucking up the oil 114 with the oil pump 133, it is possible to prevent foreign matter from entering the compression element 130, and improve reliability.

The oil 114 supplied to the compression element 130 has approximately the same pressure as the refrigerant discharged from the scroll compressor 100, and also serves as a source of back pressure for the orbiting scroll 136. Thereby, the orbiting scroll 136 can rotate at a predetermined position without separating from the fixed scroll 135 or hitting the fixed scroll 135 unevenly, so that it can stably perform the compression function.

Further, as the crankshaft 132 rotates, the eccentric shaft portion 132b of the crankshaft 132 rotates eccentrically.

The orbiting scroll 136 is eccentrically driven by the eccentric shaft portion 132b and moved in a circular orbit by the rotation restraint mechanism 137, thereby changing the volume of the compression chamber 139.

Refrigerant sucked from the suction pipe 142 is guided to the compression chamber 139 via the suction port 140. The refrigerant sucked into the compression chamber 139 moves from the outer periphery toward the center while decreasing its volume, and when it reaches a predetermined pressure, it pushes open the discharge reed valve 144 provided at the discharge port 141 and passes through the muffler 138. and the back surface of the fixed scroll 135. The refrigerant discharged into the discharge pressure chamber 145 is discharged from the discharge pipe 143 to the outside of the closed container 112 via the discharge space 149 .

On the other hand, the intermediate pressure refrigerant led from the injection pipe 105 flows into an intermediate pressure chamber 147 surrounded by the muffler 138 and the back surface of the fixed scroll 135, and pushes the check valve 148 provided at the injection port 146. It is injected into the compression chamber 139 after being opened and closed. The injected refrigerant is compressed together with the refrigerant sucked from the suction port 140 and is discharged from the discharge pipe 143 to the outside of the closed container 112 .

In the above compression stroke, inside the compressor, the temperature of the refrigerant in the discharge pressure chamber 145 and the discharge space 149 is higher than that of the refrigerant in the fixed scroll 135 and the intermediate pressure chamber 147. Since the inner wall surface of the muffler 138 is covered with the heat insulating material 150, it is possible to suppress heat from entering the intermediate pressure chamber 147 from the discharge pressure chamber 145 and the discharge space 149, which are at the highest temperature in the compressor. Thereby, the refrigerant flowing into the intermediate pressure chamber 147 from the injection pipe 105 can be prevented from being heated by heat exchange with the high temperature refrigerant in the discharge pressure chamber 145 and the discharge space 149.

Furthermore, in this embodiment, the space between the fixed scroll 135 and the intermediate pressure chamber 147 is also covered with a heat insulating material 152. Therefore, heat intrusion from the fixed scroll 135 into the intermediate pressure chamber 147 can also be suppressed. Thereby, the refrigerant flowing into the intermediate pressure chamber 147 from the injection pipe 105 can be prevented from being heated due to heat exchange with the fixed scroll 135.

As described above, the temperature rise of the refrigerant flowing into the intermediate pressure chamber 147 from the injection pipe 105 is suppressed to a minimum, and a decrease in the refrigerant circulation amount due to a decrease in the density of the refrigerant can be suppressed.

(Other embodiments)
As mentioned above, Embodiment 1 has been described as an example of the technology disclosed in this application. However, the technology in the present disclosure is not limited to this, and can also be applied to embodiments in which changes, replacements, additions, omissions, etc. are made. Furthermore, it is also possible to create a new embodiment by combining the components described in the first embodiment.

Therefore, one of the other embodiments will be illustrated below.

In the first embodiment, the intermediate pressure chamber 147 and the discharge pressure chamber 145 are formed in one muffler 138 as an example. However, the intermediate pressure chamber 147 and the discharge pressure chamber 145 may be formed by separate mufflers.

For example, as shown in FIG. 4, the intermediate pressure chamber 147 may be formed by a first muffler 238, and the discharge pressure chamber 145 may be formed by a second muffler 240 different from the first muffler 238.

In this way, the first muffler 238 forming the intermediate pressure chamber 147 can be formed of a material having a lower thermal conductivity than the muffler 138 of the embodiment or the second muffler 240 of the present embodiment, and the discharge Heat infiltration from the pressure chamber 145 and the discharge space 149 to the intermediate pressure chamber 147 can be more strongly suppressed, and the heating suppression effect due to heat exchange with the high temperature refrigerant in the discharge pressure chamber 145 and the discharge space 149 can be enhanced.

Specifically, the first muffler 238 is made of a material with excellent oil resistance and heat resistance, and a thermal conductivity of 0.5 W/(m·K) or less, such as hollow ceramic or polytetrafluoroethylene ( PTFE) or polybutylene terephthalate (PBT) can be molded and used.

Note that a heat insulating material 152 is interposed between the fixed scroll 135 and the intermediate pressure chamber 147, as in the first embodiment. This heat insulating material 152 can be made of the same material as the heat insulating material 150 of the first embodiment. When using hollow ceramic, from the viewpoint of sealing performance, it is desirable to interpose it only on the surface of the fixed scroll 135 that forms the intermediate pressure chamber 147 together with the first muffler 238, and avoid the portion that will become the fastening surface. When using a highly elastic polymer material, the heat insulating material 152 can also play the role of a gasket, so by sandwiching and fastening it between the fixed scroll 135 and the first muffler 238, sealing performance can be improved at the same time. I can do it.

Note that the above-described embodiments are for illustrating the technology of the present disclosure, and therefore various changes, substitutions, additions, omissions, etc. can be made within the scope of the claims or equivalents thereof.

[1-3. Effects, etc.]
As described above, the scroll compressor in this embodiment includes a fixed scroll and an orbiting scroll having a spiral wrap rising from an end plate, and by meshing the wraps of the fixed scroll and the orbiting scroll, the fixed scroll and the orbiting scroll are A compression chamber is formed in between, and a muffler is disposed on the back surface of the fixed scroll to partition a discharge pressure chamber and an intermediate pressure chamber, and an injection port is provided in the intermediate pressure chamber to inject refrigerant into the compression chamber. and a discharge space connected from the discharge pressure chamber to the discharge pipe above the muffler, in which a heat insulating material is provided between the injection refrigerant inside the intermediate pressure chamber and the fixed scroll and the muffler. There is a structure.

This suppresses heat exchange between the injection refrigerant inside the intermediate pressure chamber and the adjacent discharge pressure chamber, the refrigerant inside the discharge space, and the fixed scroll, which are hotter than the injection refrigerant, and increases the temperature of the injection refrigerant. It is possible to suppress a decrease in density due to the rise, suppress a decrease in the amount of refrigerant circulation, and provide a highly efficient compressor.

Further, the heat insulating material is formed by covering the inner wall of the muffler forming the intermediate pressure chamber with a material having a lower thermal conductivity than the muffler.

Thereby, heat conduction from the discharge pressure chamber and the discharge space to the intermediate pressure chamber can be suppressed, and a decrease in density due to a rise in temperature of the injection refrigerant can be suppressed.

Further, the heat insulating material is formed by interposing a material having a lower thermal conductivity than the fixed scroll between the fixed scroll and the intermediate pressure chamber.

Thereby, heat conduction from the fixed scroll to the intermediate pressure chamber can be suppressed, and a decrease in the density of the injection refrigerant due to a rise in temperature can be suppressed.

Further, the material with low thermal conductivity is made of a polymer material.

Thereby, the heat insulation effect between the discharge pressure chamber, the discharge space, and the fixed scroll and the intermediate pressure chamber can be enhanced, and a decrease in density due to a rise in the temperature of the injection refrigerant can be more effectively suppressed.

In addition, the material with low thermal conductivity is made of hollow ceramic.

Thereby, the heat insulation effect between the discharge pressure chamber, the discharge space, and the fixed scroll and the intermediate pressure chamber can be enhanced, and a decrease in density due to a rise in the temperature of the injection refrigerant can be more effectively suppressed.

Further, it is preferable to adopt a structure in which the intermediate pressure chamber is formed by the first muffler and the discharge pressure chamber is formed by the second muffler, and the first muffler is formed of a material having a lower thermal conductivity than the second muffler.

This more strongly suppresses the heat exchange that occurs between the injection refrigerant inside the intermediate pressure chamber and the refrigerant inside the adjacent discharge pressure chamber and discharge space, which is hotter than the injection refrigerant, and prevents the temperature of the injection refrigerant from rising. A highly efficient compressor can be provided by suppressing the accompanying decrease in density and suppressing a decrease in the amount of refrigerant circulation.

Further, in a configuration in which the intermediate pressure chamber is formed by the first muffler and the discharge pressure chamber is formed by the second muffler, the first muffler is made of a polymeric material.

As a result, the insulation effect between the discharge pressure chamber, the discharge space, the fixed scroll, and the intermediate pressure chamber can be further enhanced, and the reduction in density caused by the temperature rise of the injection refrigerant can be suppressed, increasing efficiency. The weight of the compressor can be reduced.

The scroll compressor according to the present disclosure can suppress a decrease in density due to an increase in the temperature of the injection refrigerant, and can be a highly efficient compressor. Therefore, it is useful as a scroll compressor for water heaters, hot water heaters, air conditioners, and refrigeration cycle devices such as refrigerators.

100 Scroll compressor 101 Condenser 102a, 102b Expansion valve 103 Gas-liquid separator 104 Evaporator 105 Injection pipe 110 Compressor body 112 Sealed container 114 Oil 120 Motor element 121 Stator 122 Rotor 130 Compression element 132 Crankshaft 132a Main shaft portion 132B eccentric axis part 132C 132c liner hole 133 oil pump 134 main axis receiver receiving material 135 fixed scrolling scrolls 136 Contracted scrolls 138 Muffra 139 Muffla 139 Muffra 139 Muffra 139 Muffra 139 Muffra 139 Mufflae 139 Mufflass 139 出 Inhalation port 142 Discount 143 discharge 145 discharge Pressure chamber 146 Injection port 147 Intermediate pressure chamber 148 Check valve 149 Discharge space 150 Heat insulator 152 Heat insulator 238 First muffler 240 Second muffler

Claims (7)

In a scroll compressor, a muffler is arranged on the back side of a fixed scroll to partition a discharge pressure chamber and an intermediate pressure chamber, and the intermediate pressure chamber is equipped with an injection port for injecting refrigerant.
The discharge pressure chamber and the intermediate pressure chamber are formed by being surrounded by the back surface of the fixed scroll and the muffler,
A scroll compressor characterized in that a heat insulating material is interposed between the fixed scroll and the intermediate pressure chamber . The scroll compressor according to claim 1 , wherein the inner wall surface forming the intermediate pressure chamber is coated with a material having a lower thermal conductivity than the muffler. The scroll compressor according to claim 1, wherein the heat insulating material is made of a material having a lower thermal conductivity than the fixed scroll. The scroll compressor according to claim 2 or 3, wherein the material having low thermal conductivity is made of a polymeric material. 4. The scroll compressor according to claim 2, wherein the material having low thermal conductivity is made of hollow ceramic. The muffler is formed of a first muffler forming the intermediate pressure chamber and a second muffler forming the discharge pressure chamber, and the first muffler is formed of a material having a lower thermal conductivity than the second muffler. The scroll compressor according to claim 1 or 3, characterized in that: The scroll compressor according to claim 6, wherein the first muffler is made of a polymeric material.

Images