JPS585114Y2 - gas compression equipment - Google Patents

Description

[Detailed description of the invention] The present invention uses two screw rotating machines, one of which is a non-contact type, and the other screw rotating machine is an oil injection type. It is designed to also function as a timing gear for a rotating machine.

. When two screw rotating machines are used in two stages, high and low, and the tilting is also used as an oil injection type screw compressor, the oil injection type injects cold oil during the gas compression process of the compressor to compress the gas. It is extremely effective for obtaining a high compression ratio because it seals, cools the gas, and lubricates the rotor, but it not only requires an oil separator and oil cooler to separate and cool the oil, but also takes up a large amount of space. When the device is used in a cryogenic system, the cryogenic temperature ranges from 0℃ to -6.
There is a disadvantage that it becomes extremely difficult to separate liquid and oil at temperatures around 0°C, and when the device is used in a heat pump system, oil aging occurs due to the shared use of refrigerant gas such as freon and oil at high temperatures. This has the disadvantage that the temperature of the discharged gas from the compressor cannot be raised much.

In addition, if both screw rotating machines are non-contact type and a timing gear is installed to link the female and male rotors, a high compression ratio cannot be obtained because the oil cannot seal the gas, resulting in high speed rotation. This requires a speed increaser.

The present invention was developed in order to eliminate such drawbacks of the conventional technology, and it uses two screw rotating machines that can change the volume of fluid using screw-type male and female rotors that rotate in mesh with each other in the axial direction. The male rotors are connected coaxially to each other, and the female rotors are also coaxially connected to each other, and the two screw rotating machines are inserted into separate fluid circulation cycles, so that a part of the condensate of the compressed gas is The male and female rotors of one screw rotating machine, where oil is injected during the gas compression process, are brought into contactless engagement, and the male and female rotors of the other screw rotating machine, where oil is injected during the gas compression process, are brought into contact engagement. The present invention relates to a gas compression device characterized in that a screw rotating machine also functions as a timing gear for the one screw rotating machine.

Next, two aspects of implementing the present invention will be explained with reference to FIGS. 1 and 2.

Screw-type four-toothed male rotors 3, 5 and large-toothed female rotors 4, 6 are respectively mounted in the front and rear chambers of shafts 8, 9, which are mounted on a case body 7, separated by a partition wall 10.
, 4 in contact meshing with each other, and a screw rotating machine 2 in which rotors 5 and 6 are meshed with each other without contact.

The male rotors 3 and 5 are coaxially connected by a shaft 9, and the female rotors 4 and 6 are coaxially connected by a shaft 8.

Most of the tooth profile of the male rotors 3 and 5 is formed by the addenda outside the pitch circle, and the female rotor 4
, 6, most of the tooth profile is formed by the dedendum inside the pitch circle.

And the electric motor 11 is attached to the male rotor 3 of the screw rotating machine 1.
A drive shaft 12 from the above is connected.

Note that the drive shaft 12 may be connected to the female rotor 4 or to either the male or female rotor 5 or 6 of the screw rotating machine 2.

In the drawing, 13 is a bearing metal, and 14 is a mechanical seal.

FIG. 1 shows an example of a refrigeration cycle, including a screw rotating machine 1 serving as a compressor, a discharge port 15, a discharge gas pipe 16, an oil separator 17, a condenser 18, a liquid receiver 19, a liquid pipe 20, and an expansion valve 2.
1. A refrigeration cycle A is constituted by the evaporator pipe 22, the suction gas pipe 23, and the suction port 24, and an oil pump 26 and an oil cooler 27 are inserted into the oil pipe 25 led out from the oil separator 17. A cooling oil pipe 28 led out from the screw rotary machine 1 is connected to the discharge port 15 of the screw rotating machine 1 and to an oil injection hole 29 located on the high pressure side during the gas compression process.

A cooling pipe 30 such as a cold water pipe is inserted into the oil cooler 27 .

The rotor 5.6 of the screw rotating machine 2, which serves as a compressor, is driven without contact with the coaxial rotors 3 and 4 serving as timing gears. Discharge gas pipe 32, condenser 33, liquid pipe 34,
Expansion valve 35, evaporator 36, suction gas pipe 37, suction port 38
The refrigeration cycle B is configured by:

Further, a condensing pipe 39 and the evaporation sound 22 of the refrigeration cycle A are inserted into the condenser 33 to exchange heat.

Further, an evaporation sound 40 and a load-side cooling pipe 41 are inserted into the evaporator 36 for heat exchange.

In the condenser 33 and evaporator 36, the evaporator tube 22, the condenser tube 39, the evaporator tube 4.0, and the cooling tube 41 are inserted separately as heat exchange tubes, but in reality, the condenser 3
A heat exchange tube is inserted into the evaporator 36 and the evaporator 36, so that heat exchange is performed between the inside and outside of the tube.

Further, a branch liquid pipe 42 branched from the liquid pipe 34 midway is opened to a position near the discharge port 31 of the screw rotating machine 2 during the gas compression process on the high pressure side through a flow rate adjustment valve 43 midway for liquid injection. It communicates with the hole 44.

Note that a branch oil pipe 46 branched midway from the tip of the oil amount adjustment valve 45 of the cooling oil pipe 28 is connected to the metal 13 of the screw rotating machines 1 and 2, the mechanical seal 14, the thrust bearing, and the unloader hydraulic pressure through a throttle adjustment hole 47 midway. The oil suction pipe 49, in which the return oil pipes 48 led out from these introduction parts are merged, is used for oil suction during the gas compression process on the lower pressure side than the oil injection hole 29 of the oil injection side screw rotating machine 1. It communicates with the hole 50 to suck oil into the screw rotating machine 1.

Next, the operation of this embodiment will be explained.

The screw rotating machine 1 of the refrigeration cycle A has 7 cylinders (R2
2) Rotors 3 that contact and mesh with each other using a refrigerant such as NH3
The condenser 33 of the refrigeration cycle B is cooled by injecting oil to lubricate the rotors 3 and 4, sealing the gas, and cooling the rotors 3 and 4.

In the refrigeration cycle B, the rotors 5 and 6 of the screw rotating machine 2 are operated without contact using the coaxial rotors 3 and 4 as timing gears, and condensed liquid is injected from the liquid injection hole 44.
Gas sealing and gas cooling are performed.

When propane, freon, etc. are used as the compressed gas in refrigeration cycle B, these gases tend to dissolve in oil, but according to this example, there is no need to inject oil, so the separation between liquid and oil is reduced. The difficult problem of separation does not arise.

Also, in this embodiment, the evaporator 36 of the refrigeration cycle B
A load-side cooling pipe 41 is inserted into the refrigeration cycle B, and the liquid pipe 34 led out from the condenser 33 of the refrigeration cycle B is connected to, for example, a liquid propane tank via an expansion valve 35, so that the evaporated gas from the liquid propane tank is frozen. If the suction gas pipe 37 of cycle B is sucked into the screw rotating machine 2, the screw rotating machine 2 will operate as an oil-free refrigerator, performing liquefaction circulation without oil intervention, and deep cooling the tank. can.

In the embodiment shown in FIG. 3, the oil injected into the screw rotating machine 1 serving as a compressor is cooled by injection of refrigerant liquid without using an oil cooler 27. A liquid pipe 34 is connected to the high pressure side of the gas compression process in step 2, and the refrigerant liquid whose pressure has decreased due to the sealing effect is drawn out from the low pressure side during the gas compression process and is led out to the evaporator 36. , this structure will be explained with reference to the drawings.

In the refrigeration cycle A, an oil pipe 25 led out from the oil separator 17 is communicated with an oil injection hole 29 provided on the high pressure side of the screw rotary machine 1 via an oil pump 26 midway, and from the liquid receiver 19 to the evaporator 22. The introduced liquid pipe 20 is branched in the middle, and this branched liquid pipe 51 is communicated with a liquid injection hole 53 provided on the lower pressure side than the oil injection hole 29 of the screw rotating machine 1 via a flow rate adjustment valve 52 in the middle. .

Furthermore, a liquid pipe 34 led out from the condenser 33 of the refrigeration cycle B
The high pressure side 1 of the screw rotating machine 2: The liquid injection hole 5 provided here
Gas on the low-pressure side of the screw rotating machine 2: A low-pressure liquid pipe 56 led out from a liquid discharge hole 55 provided at a position after confinement is connected to the evaporator 36 through a flow rate adjustment valve 57 in the middle. Introduce.

Next, the operation of this embodiment will be explained.

In the refrigeration cycle A, two parts of the liquid are injected from the branch liquid pipe 51 to the screw rotating machine 1, which expands endothermically within the screw rotating machine 1 and cools it while mixing gas and oil, so that the oil and gas are at the same temperature. It is discharged with compression close to compression.

This cools the inside of the screw rotating machine 1, so
The oil injected from the oil injection hole 29 does not need to be cooled, and an oil cooler becomes unnecessary.

In addition, in the refrigeration cycle B, the liquid pipe 34 is connected to the liquid injection hole 54 on the high pressure side of the screw rotary machine 2, and a relatively large amount of condensed liquid is injected to achieve gas sealing and cooling of the rotor 5. case body 7 due to centrifugal force
The screw rotating machine 2 also acts as an expander in this respect because the pressure is reduced as it moves to the inner circumferential surface of the rotor, flows through the gap between the inner circumferential surface and the tips of the male and female rotor blades, and moves to the low pressure side. This eliminates the need for an expansion valve, and it is sufficient to simply attach the flow rate regulating valve 57 to the low pressure liquid pipe 56.

The structure and operation of other parts are similar to the embodiment shown in FIGS. 1 and 2.

Also, as is well known, the bearing metal 13 of the screw rotating machine 2
A mechanical seal 14 or the like is provided on the end face of the rotor 5.6 to prevent oil from leaking.

Further, the drive shaft 12 may be connected to the female rotor 4.

Furthermore, during manufacturing, the case body 7 of the screw rotary machines 1 and 2 is divided into two along the partition wall 10 in the axial direction, and the shafts 8 and 9 are sandwiched between them, and then the case body 7 is assembled with the rotors 3, 4, 5, and 6. Once inserted, processing of the case body 7 becomes easy.

According to the present invention, the male rotors and the female rotors of two screw rotating machines arranged in parallel in the axial direction are coaxially connected, so that a part of the condensate of the gas to be compressed is absorbed during the gas compression process. The male and female rotors of one screw rotating machine that is to be injected are meshed without contact (as an oil-free screw compressor), and the male and female rotors of the other screw rotating machine that is injected during the gas compression process are brought into contact meshing. (An oil injection type screw compressor) This oil injection type screw rotating machine was used for compressing gas and at the same time was used as the timing gear of the non-contact meshing screw rotating machine, so the non-contact meshing screw rotating machine However, the timing gear can be omitted to save space.

Since the non-contact meshing screw rotary machine is oil-free and does not use oil, when the present invention is used as a system for cryogenic temperatures, if the rotary machine is used on the lower stage side, the refrigerant liquid can be used as in the conventional technology. On the other hand, when the present invention is used as a heat pump system, if the rotary machine is used on the high stage side, it is possible to prevent oil from being separated due to high temperatures as in the conventional technology. It is therefore possible to increase the temperature of the discharged gas (condensation temperature 5) without causing aging, and to obtain a heat pump system that operates at high temperatures.

In addition, in a non-contact meshing screw rotating machine, a part of the condensed liquid of the compressed gas is injected during the compression process, and this liquid can seal and cool the gas. A high compression ratio can be obtained even if the

Furthermore, even if oil is not used in non-contact meshing screw rotating machines and the present invention is not used in cryogenic systems such as those mentioned above, it is difficult to use oil in refrigeration cycles that use refrigerants that are difficult to separate from oil. It is of course suitable for use in compressing gases where intervention is particularly avoided.

[Brief explanation of the drawing]

FIG. 1 is a flow sheet diagram showing an example of the implementation of the present invention, FIG. 2 is a cross-sectional plan view of the same compressor, and FIG. 3 is a flow sheet diaphragm of another embodiment. 1.2... Screw rotating machine, 3.5...
...Male rota, 4,6...Female rota, A,
B: Refrigeration cycle as a fluid circulation cycle.

Claims (1)

[Scope of utility model registration request] Two screw rotating machines that can change the volume of fluid with screw-type male and female rotors that mesh with each other and rotate are installed in parallel in the axial direction, and the male rotors are connected coaxially to each other, and the female rotors are also connected coaxially to each other. Then, the two screw rotating machines are inserted into separate fluid circulation cycles, and a part of the condensate of the compressed gas is injected during the gas compression process. The male and female rotors of the other screw rotating machine, which are in mesh with each other and oil is injected during the gas compression process, are brought into contact mesh with each other, so that this screw rotating machine also functions as a timing gear for the one screw rotating machine. A gas compression device featuring: