JP2012037485A - Steam quality measurement apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a steam quality measurement apparatus capable of calculating steam quality correctly without detecting dynamic pressure.SOLUTION: Branched from a steam pipe 1, a steam extraction pipe 2 for extracting steam whose quality is to be measured is connected. A blow valve 13, a needle valve 3, an electric heater 5 and a needle valve 4 are successively connected to the steam extraction pipe 2. A pressure sensor 15 and a temperature sensor 16 are mounted on the electric heater 5. The electric heater 5 is electrically connected to an operation control part 17. The steam flow rate of decompressed steam supplied to the electric heater 5 is calculated based on the calorie supplied to the electric heater 5 and the steam quality of the decompressed steam is calculated based on the steam flow rate.

Description

The present invention relates to a steam dryness measuring apparatus for measuring so-called dryness: X, which indicates the moisture content in steam, that is, the ratio of the mass of dry saturated steam to the total mass per unit volume of steam. When the dryness of steam is X, the wetness is represented by (1-X). In various boilers, equipment using steam power, drying equipment, etc., it is necessary to measure the dryness of steam for heat management. This is because, for example, the dry state changes depending on the moisture content in the steam.

In the steam dryness measuring apparatus, a flow rate sensor 6, a pressure sensor 5, and a Pitot tube 1 are sequentially attached to the steam pipe 2, and the dynamic pressure of the steam to be measured is detected by the Pitot tube 1, and the steam is determined from the dynamic pressure and the flow rate. Then, the dryness or wetness of the steam to be measured can be calculated from the relational expression between the obtained specific weight or specific volume and the dryness or wetness.

  In this steam dryness measuring device, the dynamic pressure of the steam to be measured is detected by the Pitot tube and the dryness of the steam is calculated, but it is difficult to accurately detect the dynamic pressure by the Pitot tube. Further, there is a problem that the calculated dryness of steam becomes an inaccurate value.

JP 2002-243611 A

  The problem to be solved is to provide a steam dryness measuring device capable of accurately calculating the steam dryness without detecting dynamic pressure.

The present invention is to measure the dryness of steam flowing down a steam pipe, a steam pipe pressure detecting means for detecting the steam pressure of the steam pipe, and a dryness measurement steam extraction for taking out the steam for measuring the dryness from the steam pipe. A throttle means for connecting the pipe to depressurize the steam flowing down the dryness measurement steam take-out pipe, a decompressed steam pressure detecting means for detecting the pressure of the steam decompressed by the throttle means, and the temperature of the decompressed steam A depressurized steam temperature detecting means for detecting the amount of heat, a heat quantity supplying means for supplying a predetermined amount of heat to the depressurized steam, and a degree of steam flowing down the dryness measuring steam take-out pipe based on the amount of heat supplied from the heat quantity supplying means. A calculation control unit for calculating the flow rate and the dryness of the steam is provided.

  The steam dryness measuring apparatus of the present invention can accurately calculate the steam dryness by calculating the steam dryness based on the amount of heat supplied to the steam from the heat quantity supply means.

The block diagram which shows the Example of the dryness measuring apparatus of the vapor | steam of this invention.

  The present invention supplies heat to the steam from the heat supply means, but the heat supply means is preferably an electric heater that can easily control or measure the heat supplied to the steam.

In FIG. 1, a steam pipe 1 through which steam flows, a dryness measurement steam takeout pipe 2 for taking out steam for measuring dryness from the steam pipe 1, valves 3 and 4 as throttling means for decompressing steam, and decompression The steam dryness measuring device is constituted by the heat amount supply means 5 for supplying a predetermined amount of heat to the generated steam.

  A dryness adjusting means 6 capable of adjusting the dryness of the flowing steam is attached to the steam pipe 1. The dryness adjusting means 6 includes a heater 7 for heating the flowing steam to increase the dryness, and conversely, a cooler 8 for supplying water droplets to the flowing steam to lower the dryness. .

  By connecting the heating fluid supply pipe 9 and the discharge pipe 10 to the heater 7 and controlling the supply amount of the heating fluid to the heater 7, the steam flowing down the steam pipe 1 is appropriately heated to dry the steam. The degree can be increased arbitrarily. On the other hand, by connecting the cooling water supply pipe 11 to the cooler 8 and controlling the supply amount of the cooling water to the cooler 8, the dryness of the steam can be arbitrarily reduced.

  The steam pipe 1 is provided with a pressure sensor 12 as steam pipe pressure detecting means for detecting the pressure of the flowing steam. The steam pipe 1 is branched and two dryness measuring steam take-out pipes 2 are connected. Although not shown, one dryness measurement steam take-out pipe 2 is connected to the upper side of the steam pipe 1, and the other take-out pipe 2 is connected to the lower side of the steam pipe 1.

The dryness measurement steam take-out pipe 2 is joined at the lower end portion and a blow valve 13 is attached. The blow valve 13 is configured to open and close so that the dryness measurement steam take-out pipe 2 and the blow passage 14 communicate with each other, and the dryness measurement steam flowing down the take-out pipe 2 can be discharged to the outside. is there.

  On the downstream side of the blow valve 13, valves 3 and 4 as throttle means and a heat quantity supply means 5 for supplying a predetermined heat quantity are connected. The valves 3 and 4 may be any valves that can arbitrarily reduce the steam pressure by narrowing the passage of the steam flowing down the dryness measuring steam take-out pipe 2. An example using 4 is shown.

  An example in which an electric heater 5 is used as the heat supply means 5 will be shown. The electric heater 5 is provided with a pressure sensor 15 as a reduced pressure steam pressure detecting means for detecting the pressure of the steam flowing down the dryness measuring steam take-out pipe 2 and a temperature sensor 16 as a reduced pressure steam temperature detecting means. The arithmetic control unit 17 is connected.

  The steam flowing down from the steam pipe 1 through the dryness measuring steam take-out pipe 2 is depressurized to a predetermined pressure by the needle valves 3 and 4 and reaches the electric heater 5. In response to the two types of superheated steam, the electric heater 5 is changed from the detected values from the pressure sensors 12 and 15 and the temperature sensor 16 and the respective amounts of heat supplied from the electric heater 5 to form two types of superheated steam. The flow rate of the reduced-pressure steam that flows down can be calculated, and further, the dryness of the reduced-pressure steam can be calculated from this flow rate value. The reduced-pressure steam flowing down the electric heater 5 is discharged out of the system from the needle valve 4 and the discharge pipe 18.

  Depending on the detected value of the steam dryness at 5 parts of the electric heater, the dryness of the steam flowing down the steam pipe 1 is arbitrarily adjusted by the dryness adjusting means 6 according to the detected value of steam dryness from the right end 19 of the steam pipe 1. It is possible to arbitrarily control the dryness of the steam supplied to the use location.

  INDUSTRIAL APPLICABILITY The present invention can be used for the case where the performance of the steam using device changes depending on the dryness of the steam used in various steam using devices.

DESCRIPTION OF SYMBOLS 1 Steam piping 2 Dryness measurement steam taking-out pipe 3 Throttling means 4 Throttling means 5 Calorie supply means 6 Dryness adjustment means 7 Heater 8 Cooler 12 Steam piping pressure detection means 13 Blow valve 15 Decompression steam pressure detection means 16 Decompression steam temperature Detection means 17 Calculation control unit

Claims (1)

When measuring the dryness of the steam flowing down the steam pipe, connect the steam pipe pressure detection means that detects the steam pressure of the steam pipe and the dryness measurement steam take-out pipe that takes out the steam that measures the dryness from the steam pipe. A depressurizing means for depressurizing the steam flowing down the dryness measuring steam take-out pipe, a depressurizing steam pressure detecting means for detecting the pressure of the steam depressurized by the throttling means, and a depressurizing for detecting the temperature of the depressurized steam A steam temperature detecting means, a heat quantity supplying means for supplying a predetermined amount of heat to the decompressed steam, a flow rate of steam and a flow rate of the steam flowing down the dryness measuring steam take-out pipe based on the heat quantity supplied from the heat quantity supplying means An apparatus for measuring dryness of steam, comprising a calculation control unit for calculating dryness.

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