JPS611895A - Method of preventing condensation in multiple stage compressor - Google Patents

Abstract

PURPOSE:To prevent the condensation of specified mixed components by detecting a ratio of the gas partial of specified mixed components in compressed gas to saturated pressure in the outlet side of an intermediate cooler to adjust heat removed from the compressed gas so that the ratio approaches 1. CONSTITUTION:Gas absorbed in a first compressor 2 through a filter 1 is compressed and discharged therefrom to be cooled by an intermediate cooler 3. Also, the relative humidity of compressed gas existing the intermediate cooler 3 is detected by a relative humidity detector 6, and a flow regulating valve 8 is opened and closed through a setter 9 to regulate cooling water amount in a water conduit 7 such that the relative humidity approaches as close as possible to 1. As a result, the compressed gas leaving the intermediate cooler 3 is cooled as low as possible, so long as it is not accompanied by drain, to be sent to a second compressor 4. Thus, the condensation of specified mixed components on and after the intermediate cooler 3 can be prevented to avoid corrosion of piping and each portion of the machine.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for preventing condensation in a multi-stage compressor such as a refrigerator.

(Prior art) Conventionally, in a multi-stage compressor equipped with an intercooler, when gas containing water vapor (including air) was compressed and then cooled, the water vapor often became supersaturated and condensed (condensed). . If this gas contains components that are easily soluble in water and corrode metals, these components will dissolve into the drain, causing significant corrosion of piping and other parts of the 8% machine.

Therefore, in order to prevent this, the cooling water supplied to the intercooler can be adjusted manually (1) or automatically by using a temperature controller to adjust the control valve, throttle valve, etc. to prevent the water vapor from becoming supersaturated. A method is used to maintain the temperature and pressure.

However, in the case of manual cooling, it is troublesome to frequently adjust the cooling water according to changes in operating conditions, water temperature, etc., and the current situation is that the cooling water is often not adjusted.

In addition, when using a temperature controller, you can set a temperature in advance at which it is thought that no condensation will occur, and simply adjust the amount of cooling water to reach this temperature, regardless of whether or not condensation actually occurs. Adjustments are made to For this reason,
For example, even though it can normally be cooled to 80°C, the temperature is actually adjusted to 90°C, and it is difficult to cool the compressed gas as much as possible using an intercooler without generating condensation, which is desirable for energy saving. In compressors, this method has a problem in that the optimum operating force cannot be achieved.

Problems similar to those described above occur not only when water vapor contains a corrosive gas but also when a mixed gas consisting of a plurality of components mixed at a fixed ratio is handled. In other words, when compressed gas is cooled in an intercooler, only a specific power component becomes supersaturated and condenses, resulting in a change in the ratio of the mixed power component afterward, which poses a problem that hinders the use of the compressed gas. was.

(Object of the Invention) The present invention has been made in view of the above-mentioned conventional problems, and is designed to prevent the generation of condensate, that is, condensation, from the mid-open cooler to the piping while performing optimal operation for energy saving. The present invention aims to provide a method for preventing condensation in a multistage expansion compressor, which eliminates corrosion of the mechanical parts and makes it possible to maintain a constant mixing ratio of mixed gases.

(Means for Solving the Problems) In order to solve the above conventional problems, the present invention has at least two compressor bodies, and each compressor body is connected in series via an intercooler. In the combined multi-stage expansion compressor, the ratio of the gas partial pressure of a specific mixture component in the compressed gas at the outlet side of the intercooler to the saturation pressure is detected, and the ratio is adjusted so that the ratio becomes close to the power curve. The amount of heat removed from the compressed gas by the intercooler is adjusted.

(Function) According to the method according to the present invention, the range of decrease in the compressed gas temperature on the outlet side of the intercooler with respect to the inlet side is appropriately adjusted, and the occurrence of condensation of a specific mixed component after the intercooler is prevented.

(Embodiment) FIG. 1 shows a first embodiment of a multi-stage expansion compressor to which the method according to the present invention is applied, in which a filter 1. First compressed rock body 2. Intercooler 3. The second compressor main body 4 and the post-cooler 5 are connected in series. In addition, a relative humidity detector 6 for detecting the relative humidity of compressed gas is connected between the intercooler 3 and the second compressor main body 4, and a water flow pipe 7 for cooling water passing through the intercooler 3 is connected to a relative humidity detector 6 for detecting the relative humidity of the compressed gas. By providing a muscle adjusting valve 8 and interposing a setting device 9 between the two, the valve opening degree of the flow rate regulating valve 8 can be adjusted as appropriate based on the detected value by the relative humidity detector 6. There is.

The gas sucked into the first compressor main body 2 via the filter 1 is compressed, discharged from the compressor, cooled by the intercooler 3, and then reaches the second compressor main body 4. on the other hand,
The relative humidity of the compressed gas exiting the intercooler 3 is detected by the relative humidity detector 6, and the flow rate control valve 8 is opened and closed via the setting device 9 to bring the relative humidity as close to j as possible in the water pipe 7. The amount of cooling water is adjusted.

As a result, the amount of heat removed from the compressed gas in the intercooler 3 is adjusted, and the compressed gas leaving the intercooler 3 is cooled to as low a temperature as possible without generating drain, and then transferred to the second Pressure #1 is sent to the rock main body 4.

If the suction gas is at a high temperature, there will be a large energy loss during compression, but since the compressed gas has been cooled to a state just before condensate is generated, it reaches the second compression rock main body 4 with good efficiency, and is suctioned, compressed, After being discharged and cooled by the post-cooler 5, it is discharged. Next, FIG. 2 shows a second embodiment of a multistage expansion compressor to which the method according to the present invention is applied. , except that a flow rate control valve 8a is provided in the bypass line 10 that directly connects the inlet and outlet sides of the intercooler 3, the other parts are substantially the same, and corresponding parts are given the same numbers. The explanation will be omitted. In this multistage expansion-compressor, the flow adjustment valve 8a is opened and closed based on the signal from the relative humidity detector 6 via the setting device 9 as described above, and the flow rate is passed through the bypass line 10 and the intercooler 3. By appropriately adjusting the ratio of the amounts of compressed gas, the amount of heat removed from the compressed gas by the intercooler 3 is adjusted. Although the second embodiment is applied to a case where water vapor is contained in the compressed gas, the present invention is not limited to this, and can be applied to a case where a mixed gas consisting of multiple components mixed at a fixed ratio is handled. , it can be applied to prevent condensation of specific components in the mixed gas after the intercooler.

Furthermore, the present invention is not limited to the two-stage compressor as described above, but can of course be applied to compressors with three or more stages, and in this case, the intercooler 3 is used instead of the post-cooler 5. use

(Effects of the Invention) According to the above explanation, according to the present invention, compression by the intercooler is performed so that the ratio of the gas partial pressure of the specific mixed component in the compressed gas at the outlet side of the intercooler to the saturation pressure approaches 1. The amount of heat removed from the gas is regulated. Therefore, the compressed gas can be cooled to a state just before condensation of the specific mixed components starts to occur on the outlet side of the intercooler, so that compression efficiency is improved and energy-saving operation becomes possible.

In addition, if the compressed gas contains water vapor, corrosion caused by condensate is reduced, thereby extending the life of the equipment. It becomes possible to prevent accidents.

Furthermore, even when handling mixed gases where the mixing ratio is important, energy-saving operation is possible without causing fluctuations in the mixing ratio.

[Brief explanation of drawings]

1 and 2 show the first part of a multi-stage compressor to which the method according to the present invention is applied. FIG. 3 is an equipment configuration diagram of a second embodiment. 2... First compression rock main body, 3... Intercooler, 4...
・Second compressed rock main body, 6... relative humidity detector, 7...
Water pipe. 8.8a...Flow control valve, 9...Setter, 10...
・Bypass line.

Claims (1)

[Claims] (1) In a multi-stage compressor that has at least two compressor bodies and is formed by connecting each compressor body in series via an intercooler, identification of the compressed gas on the outlet side of the intercooler A multi-stage device characterized in that the ratio of the gas partial pressure of the mixed component to the saturation pressure is detected, and the amount of heat removed from the compressed gas by the intercooler is adjusted so that this ratio becomes a value close to 1. Method for preventing condensation in compressors.