JPS6036537B2 - Refrigeration equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a refrigeration system using a centrifugal compressor with a single-stage or multiple-stage impeller.

[Conventional technology]

In a centrifugal chiller, depending on operating conditions, the temperature of the cold soot gas discharged from the compressor becomes high and may rise above the liner decomposition temperature.

To prevent this, conventionally, for example, in a single-stage compressor, a spray nozzle was installed in the soot gas suction pipe, and the condensed refrigerant liquid was injected from the float valve chamber using the differential pressure between the condenser and the suction pipe. Alternatively, a spray nozzle is installed in the refrigerant gas discharge pipe and a refrigerant pump is used to inject condensed refrigerant liquid from the float valve chamber to lower the discharge temperature. [Problems to be solved by the invention] However, in the former case, the soot liquid is sucked in, resulting in wet compression, which causes wear and tear on the impeller, and in the latter case, a refrigerant pump is required. There were drawbacks such as.

The present invention utilizes the fact that the inside of the casing near the impeller outlet exhibits a static pressure that is considerably lower than the reaction rate 1 (lower than the discharge pressure), and by guiding a refrigerant liquid introduction path near the impeller outlet, cooling is achieved. It is an object of the present invention to provide a refrigeration system that can mix soot into a discharge fluid without bringing it into a wet compressed state and without particularly requiring a pump. [Means for Solving the Problems] As a means for solving the problems, the present invention introduces cold soot liquid into the casing portion (including the vicinity of the exit from the impeller outlet to the volute chamber and the volute chamber itself). A centrifugal compressor, a condenser, an evaporator, and a refrigerant path connecting these devices are provided with a closed end of the path, and a part of the refrigerant liquid condensed in the condenser is transferred to the refrigerant liquid introduction path. It is an object of the present invention to provide a refrigeration system characterized in that the refrigeration system is configured such that the refrigeration system is guided into the inside of the casing.

〔Example〕

To explain the present invention with reference to the drawings, 1 is an evaporator, 2 is a compressor, a single-stage impeller 3 is driven by an electric motor 4, 5 is a condenser, and 6 is a float. A valve chamber, 9 a cold water pipe, and 10 a cooling water pipe.

The respective devices are connected by pipes 13, 15, 16 and a refrigerant liquid introduction pipe 11 as a soot liquid introduction path, and a float valve 8 is provided in the float valve chamber 6. FIG. 2 is a detailed view of the vicinity of the impeller 3, in which the casing 17 has a swirl chamber 18 and a diffuser 12.

The tip end of the introduction pipe 11 opens into the inside of the casing 17 near the outlet of the impeller 3. When the refrigeration system with such a configuration is operated, the liner medium compressed by the impeller 3 enters the condenser 5, is cooled and condensed, becomes liner liquid, enters the float valve chamber 6, and flows below the float valve 8. A part of the water flows down into the introduction pipe 11.

Most of the remaining refrigerant liquid is further led to the evaporator 1 and evaporated, and the refrigerant vapor is sucked into the suction port of the compressor 2, and the impeller 3
is compressed again. The medium liquid that has entered the introduction pipe 11 is guided near the outlet of the impeller 3 and near the inlet of the diffuser 12, as shown in FIG. In a single-speed centrifugal compressor, the degree of reaction is generally much lower than 1 and 0.5 to 0.0 at the impeller outlet and diffuser inlet. It is disguised holiness,
Since the static pressure is low (between the suction pressure and the discharge pressure), the refrigerant liquid from the float valve chamber 6 can be sucked out, and the pipe line 16
The refrigeration cycle is repeated by mixing with the steam from the refrigeration tank and entering the condenser 5 again. Since the present embodiment is configured and operates in this way, the refrigerant liquid in the float valve chamber is injected to the impeller outlet, and the refrigerant gas discharge temperature can be lowered, but at this time, the turbulent force is not increased, and In particular, there is no need to use a cold soot pump. FIG. 3 shows another embodiment, in which a conduit 13 and an impeller are used as a circulation path connecting the high-pressure fluid path after the discharge of the centrifugal compressor and the casing section from near the impeller outlet to the volute chamber. Circulation path 19 runs between the vicinity of the exit of 3.
, two rivers are connected, and an ejector 21 is provided between them, and the introduction pipe 11 is connected to the low pressure part of the ejector 21.
A fluid introduction path is formed from the introduction pipe 11, the ejector 21, and the circulation path 201, and cold soot liquid is introduced by the suction effect of the ejector 21.

FIG. 4 shows another embodiment, in which the tip of the introduction pipe 11 becomes the nozzle 22, which is provided at the inlet of the diffuser 12 at the outlet of the impeller 3, facing in the direction of flow, similar to the previous example. It has a great effect.

Note that FIG. 5 shows another embodiment, in which the velocity of the fluid in the swirl chamber 18 is considerably reduced compared to the velocity at the impeller outlet and is close to the velocity in the discharge pipe 25.
Since there is usually an expansion tube 23 in the discharge section of the compressor, the speed is slower than the velocity inside the discharge tube. Therefore, the pressure in the swirl chamber 18 is lower than the pressure in the float valve chamber 6. Therefore, it is also possible to provide a closed part of the pipe 11 in the volute chamber 18. Further, when the liquid refrigerant is introduced into the casing, it is preferable to use a spray nozzle 24 as shown in FIG. 5 to atomize the liquid refrigerant so that it mixes well with the cold soot gas. The above examples have been described for single-stage impellers, and since it was difficult to obtain an intermediate pressure part with a single-stage compressor, the effect is particularly large, but multi-stage impellers are suitable. Of course, it has the same effect even when used for things.

Further, similar effects can be obtained not only when used in a refrigeration cycle but also when used in a heat pump cycle that pumps up heat.

According to the present invention, there is no increase in power, there is no need to specifically install a pump, and the refrigerant liquid can be jetted near the impeller outlet to cool the impeller without causing wear and tear due to wet compression, and to prevent refrigerant decomposition. can provide equipment,
This has an extremely large practical effect.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIG. 1 is a flow sheet;
FIG. 2 is a detailed sectional view of the vicinity of the impeller, FIGS. 3 and 4 are detailed sectional views of the vicinity of the impeller of another embodiment, and FIG. 5 is a sectional side view of another embodiment. 1...Evaporator, 2...Compressor, 3...
... Impeller, 4 ... Electric motor, 5 ...
・Condenser, 6...Float valve chamber, 8...
Waroth valve, 9...Cold water piping, 10...
・Cooling water piping, 11...Introduction pipe, 12...
... Diffuser, 13, 15, 16... Pipeline, 17...
...Casing, 18... Vortex chamber, 19, 20.
... Circulation path, 21 ... Ejector, 22
...Nozzle, 23... Enlargement tube, 24.
...Spray nozzle, 25...Discharge pipe. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5

Claims (1)

[Scope of Claims] 1. A centrifugal compressor, a condenser, and a condenser having an opening at the end of a refrigerant liquid introduction path in a casing portion from near the impeller outlet to the vortex chamber;
A refrigeration device comprising an evaporator and a refrigerant path connecting these devices, and configured to introduce a part of the refrigerant liquid condensed in the condenser to the casing part through the refrigerant liquid introduction path. . 2. The refrigeration system according to claim 1, wherein the casing has a differential user, and the end opening is provided at the inlet of the differential user. 3. An ejector in which the refrigerant liquid introduction path is provided in a circulation path connecting a high-pressure fluid path after the discharge port of the centrifugal compressor and the casing section from near the impeller exit to the swirl chamber. 2. The refrigeration system according to claim 1, wherein the refrigeration system is connected to a suction part and configured to make the circulation path after the ejector part of the refrigerant introduction path. 4. The refrigeration system according to claim 1, wherein the end opening is a nozzle facing in the direction of flow near the blade outlet. 5. The refrigeration system according to claim 1, wherein a spray nozzle is attached to the end opening of the refrigerant liquid introduction path.