JPH068789U - Multi-stage water-cooled oil-free positive displacement compressor - Google Patents

Abstract

(57) [Summary] [Purpose] To provide a multi-stage water-cooled oil-free positive displacement compressor capable of preventing device failure due to drainage caused by supercooling of suction gas in the compressor body of the second and subsequent stages. To do. [Structure] The first and second compressor bodies 11 and 12 are arranged in two stages in series, and the first and second compressor bodies 11 and 12 are arranged.
A parallel flow type water-cooled intercooler 1 is provided in the intermediate flow passage 16 between the two, and two first and second cooling water outlets 3a, 3b are provided in the intercooler 1 along the cooling water flow direction. First and second cooling water outlets 3a and 3b are connected to first and second drainage flow paths 6a and 6b provided with first and second flow rate adjusting valves 5a and 5b, respectively, and are connected to the downstream side of the intercooler 1. The gas temperature of the portion of the intermediate flow path 16 in the portion is detected, and the lower the detected temperature, the drainage flow connected to the cooling water outlet located on the more upstream side with respect to the cooling water flow direction of each cooling water outlet. It is formed by providing a temperature sensor 7 that opens the flow rate adjusting valve of the passage and closes the other flow rate adjusting valves.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a multi-stage water-cooled oil-free storage type compressor in which two or more stages of compressor bodies are arranged in series and at least a water-cooled intercooler is provided in an intermediate flow path between the compressor bodies. .

[0002]

[Prior art]

 Conventionally, a two-stage water-cooled oil-free screw compressor shown in FIG. 3 is known. This compressor includes a first compressor body 11 and a second compressor body 12 arranged in two stages in series, and a suction silencer 14 and a suction filter 15 are provided in a suction passage 13 of the first compressor body 11. An intercooler 17 and a first drain separator 18 are provided in the intermediate flow passage 16 between the two compressor main bodies, and a discharge silencer 20, a check valve 21, an aftercooler 22, and a discharge silencer 20 are provided in the discharge flow passage 19 of the second compressor main body 12. A second drain separator 23 is provided. Further, to the intercooler 17 and the aftercooler 22, water supply passages 24 and 25 and drain passages 28 and 29 provided with manual flow rate adjusting valves 26 and 27 are connected, respectively.

Then, the air sucked by the first compressor body 11 via the suction silencer 14 and the suction filter 15 is compressed and discharged, and the compressed air heated by the compression is cooled by the intercooler 17. The drain generated from the compressed air is separated from the compressed air by the first drain separator 18 and discharged. The compressed air discharged from the first drain separator 18 is further compressed by the second compressor body 12, passed through the discharge silencer 20 and the check valve 21, and then cooled by the aftercooler 22. The generated drain is separated from the compressed air by the second drain separator 23, and then the compressed air is sent to the user side. Further, the temperature of the intake air of the second compressor body 12 and the temperature of the compressed air sent to the user side can be adjusted by adjusting the flow rate of the cooling water in the intercooler 17 and the aftercooler 22 by the flow rate adjusting valves 26 and 27. Has become.

[0004]

[Problems to be solved by the device]

 In the above conventional device, the suction temperature of the second compressor body 12 is set to the suction temperature of the first compressor body 11 plus 15 to 20 ° C in order to prevent the drain from being brought into the second compressor body 12. It is necessary to set the temperature to 50 ° C. or lower due to the discharge temperature limitation of the second compressor body 12. By the way, when the opening of the flow rate adjusting valve 26 is constant, the suction temperature of the second compressor body 12 is controlled by the cooling water temperature. Further, when the suction temperature of the second compressor body 12 is kept constant, it is necessary to adjust the opening degree of the flow rate adjusting valve 26.

However, there are various types of cooling water used by users. For example, when using well water, suction air of the second-stage compressor body 12 is supercooled to generate drainage, and this drainage water is used. Therefore, there is a problem that the second stage compressor body 12 is likely to fail. The present invention has been made to solve the above-mentioned conventional problems, and a multi-stage water-cooling system capable of preventing a device failure due to a drain caused by supercooling of suction gas in the compressor body of the second and subsequent stages. An oil-free positive displacement compressor is provided.

[0006]

[Means for Solving the Problems]

 In order to solve the above problems, the present invention is a multi-stage water-cooled oil-free positive displacement type in which two or more stages of compressor bodies are arranged in series and at least a water-cooled intercooler is provided in an intermediate passage between the compressor bodies. In the compressor, the intercooler is of a parallel flow type, and a plurality of cooling water outlets are provided in the intercooler along the cooling water flow direction, and a drainage valve is provided at each cooling water outlet. By connecting the flow paths and detecting the gas temperature in the intermediate flow path in the downstream side of the intercooler, the lower the detected temperature, the higher the upstream side in the flow direction of the cooling water in the outlet. It was formed by providing a temperature sensor that opens the flow rate adjustment valve of the drainage flow path connected to the cooling water outlet located and closes the other flow rate adjustment valves.

[0007]

With the configuration as described above, the cooling capacity of the intercooler can be adjusted according to the temperature in the downstream portion of the intercooler.

[0008]

【Example】

 Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows a two-stage water-cooled oil-free screw compressor according to the present invention, and parts common to the compressor shown in FIG. 3 are designated by the same reference numerals. In this embodiment, a so-called parallel flow type intercooler 1 is provided in the intermediate flow passage 16, in which cooling water is caused to flow in the same direction as the flow direction of the compressed gas. The intercooler 1 is provided with one cooling water inlet 2 and two cooling water outlets along the flow direction of the cooling water, that is, a first cooling water outlet 3a and a second cooling water outlet 3b. A first drainage flow path in which a water supply flow path 4 is provided in the cooling water inlet 2, and a first flow rate adjusting valve 5a and a second flow rate adjusting valve 5b are provided in the first cooling water outlet 3a and the second cooling water outlet 3b, respectively. 6a and the second drainage channel 6b are connected.

Further, a temperature sensor 7 is provided in a portion of the intermediate flow passage 16 located on the downstream side of the first drain separator 18, and the inside of the intermediate flow passage 16 detected by the temperature sensor 7 is described below. It is formed so as to control the first flow path adjusting valve 5a and the second flow rate adjusting valve 5b based on the compressed gas temperature. In FIG. 2, the horizontal axis represents the distance L at each position in the intercooler 1 along the flow direction of the cooling water when the position indicated by A in FIG. 1 is the starting point, and the vertical axis represents the temperature T. The solid line I in Fig. 2 shows the temperature change of the compressed gas, and the broken line II shows the change of the cooling water temperature. Further, LA, LB, LC and LD on the horizontal axis of FIG. 2 correspond to the respective positions of A, B, C and D in FIG. As shown in the figure, as the distance L increases, the temperature of the compressed gas decreases and the temperature of the cooling water increases.

Then, usually, the first flow rate adjusting valve 5a is closed by the temperature sensor 7 based on the detected temperature, and the flow rate in the second drainage channel 6b is adjusted by the second flow rate adjusting valve 5b. The gas temperature in the intermediate passage 16, that is, the suction temperature of the second compressor body 12 is kept constant. On the other hand, when the cooling water temperature is low, for example, in winter or when well water is used as cooling water, the compressed gas is supercooled by the intercooler 1 and the temperature detected by the temperature sensor 7 is detected. As a result, the signal from the temperature sensor 7 causes the second flow rate adjusting valve 5b to close and the first flow rate adjusting valve 5a to open. As a result, the supercooling of the suction gas of the second compressor body 12 and the occurrence of drain are prevented, and the failure of the second compressor body 12 due to drain is also prevented.

In addition, as described above, the temperature sensor 7 controls the first and second flow rate adjusting valves 5a and 5b in accordance with the suction gas temperature of the second compressor main body 12, so that the second compression The suction gas temperature of the machine body 12 can be automatically adjusted. Furthermore, the intercooler 1 of the parallel flow type improves the responsiveness of the temperature control of the suction gas of the second compressor body 12, and the cooling water flow rate is improved by providing multiple cooling water outlets. There is no need to use a throttle valve for adjustment, and there is no need to worry about the scale adhering to the inside of the valve when using a throttle valve.

Generally, in a water-cooled cooler, if the water temperature becomes high, the pipe forming the internal cooling water flow path is likely to be corroded or scale is likely to be generated in the pipe. In the present invention, since the intercooler 1 is of the parallel flow type, the part where the flow of cooling water stops and the temperature of the water is likely to rise is the low temperature side (right side in Fig. 1) of the intercooler 1 and the high temperature side. On the left side in FIG. 1, the cooling water flows regardless of whether the suction gas temperature is high or low, and in this respect as well, corrosion and scale generation are suppressed. In addition, although the two-stage compressor has been described in the above embodiment, the present invention is not limited to this, and includes compressors having three or more stages arranged in series, and the intercooler 1 also has a cooling water outlet. It may have three or more along the flow direction of the cooling water. Further, the present invention is not limited to the screw type compressor, and includes all multi-stage water-cooled oil-free positive displacement type compressors.

[0013]

[Effect of device]

 As is apparent from the above description, according to the present invention, a multi-stage water-cooled type is provided in which two or more stages of compressor bodies are arranged in series and at least a water-cooled intercooler is provided in the intermediate flow path between the compressor bodies. Type oil-free positive displacement compressor, the intercooler is of parallel flow type, and a plurality of cooling water outlets are provided in the intercooler along the cooling water flow direction. By connecting the drainage flow path provided with a regulating valve and detecting the gas temperature of the intermediate flow path in the downstream side part of the intercooler, the lower the detected temperature, the more the flow direction of the cooling water in the outlet. Then, a temperature sensor is provided to open the flow rate adjusting valve of the drainage flow path connected to the cooling water outlet located on the more upstream side and close the other flow rate adjusting valves. For this reason, the cooling capacity of the intercooler can be adjusted according to the temperature in the downstream side of the intercooler, and the drainage of the device caused by the supercooling of the suction gas of the compressor body of the second and subsequent stages Failure can be prevented. Further, the temperature sensor controls the flow rate adjusting valve according to the suction gas temperature of the compressor body at the second stage or thereafter, so that the suction gas temperature can be automatically adjusted. Furthermore, by using a parallel flow type intercooler, the responsiveness of the temperature control of the suction gas is improved, and by providing multiple cooling water outlets, a throttle valve is used to adjust the flow rate of cooling water. There is no need for it, and when using a throttle valve, there is no need to worry about the scale adhering to the inside of the valve. Furthermore, since the intercooler is a parallel flow type, the part where the flow of cooling water stops and the water temperature is likely to rise is on the low temperature side of the intercooler, and the high temperature side is concerned with the high and low suction gas temperature. Instead, the cooling water is flowing, which also has the effect of suppressing corrosion and scale generation.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of a two-stage water-cooled oil-free screw compressor according to the present invention.

FIG. 2 is a diagram showing temperatures of cooling water and compressed gas at respective positions in an intercooler of the compressor shown in FIG.

FIG. 3 is an overall configuration diagram of a conventional two-stage water-cooled oil-free screw compressor.

[Explanation of symbols]

 1 Intercooler 3a, 3b 1st, 2nd cooling water outlet 5a, 5b 1st, 2nd flow rate adjusting valve 6a, 6b 1st, 2nd drainage flow path 7 Temperature sensor 11, 12 1st, 2nd compressor main body 16 Intermediate channel

Claims (1)

[Scope of utility model registration request] 1. A multi-stage water-cooled oil-free positive displacement compressor in which two or more stages of compressor bodies are arranged in series and at least a water-cooled intercooler is provided in an intermediate passage between the compressor bodies. Is a parallel flow type, and a plurality of cooling water outlets are provided in the intercooler along the cooling water flow direction, and a drainage flow path provided with a flow rate adjusting valve is connected to each of the cooling water outlets. The temperature of the gas in the intermediate flow passage in the downstream portion of the intercooler is detected, and the lower the detected temperature, the more the outlet is connected to the cooling water outlet located on the upstream side with respect to the cooling water flow direction. A multi-stage water-cooled oil-free positive displacement compressor characterized in that a temperature sensor for opening the flow rate adjusting valve of the drainage flow path and closing the other flow rate adjusting valve is provided.