JPH02269913A - Differential pressure type steam flowmeter - Google Patents

Abstract

PURPOSE:To eliminate the measurement error of a steam flow rate due to variation in wetness and to accurately measure the steam flow rate by arranging a steam separation part on the upstream side of a contraction mechanism and providing a drain valve below the steam separation part. CONSTITUTION:The steam flowmeter consists of the steam separation part 1, drain valve 2, and contraction mechanism 3. Steam to be measured which flowing in through an entrance 10 is swiveled by a swivel blade 24 when passing through an annular space 16 and water is forced outward because it mass is large; and then the water flows down in a drain reservoir chamber 26 along the internal wall of the main body at the periphery, but light steam passes through a straightener 15 in the center of a partition wall member 20 and then passes through an orifice 14 to flow out to an exit 11. Further, a valve float 30 moves up and down according to the water level in the drain water reservoir chamber 26 to open and close a drain water valve outlet 28, thereby discharging a condensate which is reservoired in the drain water reservoir chamber 26 from the system automatically. The detection parts 36 and 37 provided in front of and behind the orifice 14 detect pressure and an arithmetic part 38 calculates the flow rate of the wet steam. Consequently, the measurement error of the steam flow rate due to variation in the wetness is eliminated and the steam flow rate is accurately measured.

Description

【発明の詳細な説明】 産業上の利用分野 本発明は蒸気流れの中にノズル、ベンチュリ、オリフィ
ス等の絞り機構を設け、その上下流部の間に発生する差
圧から流量を測定する、差圧式流量測定装置に関し、特
に蒸気の乾き度を一定にすることにより、測定誤差を少
なくする差圧式蒸気流量計に関する。DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention provides a throttle mechanism such as a nozzle, venturi, orifice in the steam flow, and measures the flow rate from the differential pressure generated between the upstream and downstream parts. The present invention relates to a pressure type flow rate measuring device, and in particular to a differential pressure type steam flow meter that reduces measurement errors by keeping the dryness of steam constant.

差圧式流量計は構造が簡単で稼動部がないために、安価
で故障の少ない流量計として、各種流体に対して幅広く
用いられている。Differential pressure flowmeters have a simple structure and have no moving parts, so they are widely used for various fluids as inexpensive and trouble-free flowmeters.

蒸気配管を流れる蒸気の流量を測定すれば、蒸気使用機
器で消費する蒸気の量が判り、蒸気使用機器の加熱効率
を改善するデータが得られ、有益である。Measuring the flow rate of steam flowing through steam piping is useful because it determines the amount of steam consumed by steam-using equipment and provides data for improving the heating efficiency of steam-using equipment.

従来の技術 従来の一般的な差圧式蒸気流量計は、蒸気配管の途中に
絞り機構を設け、絞り機構の一次側と二次側との差圧、
絞り穴の断面積、及び、蒸気の比重量等より演算して求
めていた。Conventional technology Conventional general differential pressure steam flowmeters have a throttle mechanism installed in the middle of steam piping, and the differential pressure between the primary and secondary sides of the throttle mechanism,
It was calculated from the cross-sectional area of the throttle hole, the specific weight of the steam, etc.

本発明が解決しようとする課題 上記従来技術の場合、実際の蒸気流量と測定値との間で
かなりの誤差を生じる問題があった。これは、蒸気配管
を流れる蒸気が湿り蒸気の場合、その比重量は湿り度（
乾き度）によって変化するのであるが、測定中に湿り度
（乾き度）が変化してしまい、測定流量値に誤差を生じ
るだのである。Problems to be Solved by the Present Invention In the case of the above-mentioned prior art, there was a problem in which a considerable error occurred between the actual steam flow rate and the measured value. This means that if the steam flowing through the steam pipe is wet steam, its specific weight is the wetness (
However, the wetness (dryness) changes during measurement, causing an error in the measured flow rate value.

また、蒸気の湿り度を絶えず測定しなから流量測定をし
たり、湿り蒸気中の水分を取除くセパレータ等を別途設
けると、装置が大型化し且つ高価なものとなってしまう
。Furthermore, if the flow rate is measured without constantly measuring the wetness of the steam, or if a separator or the like is separately provided to remove moisture from the wet steam, the device becomes large and expensive.

従って、本発明の技術的課題は、安価で湿り度（乾き度
〉の変化の影響を受けにくい、測定誤差の少ない差圧式
蒸気流量計を得ることである。Therefore, the technical problem of the present invention is to obtain a differential pressure steam flowmeter that is inexpensive, less susceptible to changes in wetness (dryness), and with less measurement error.

課題を解決するための手段 上記の技術的課題を解決するために講じた本発明の技術
的手段は、絞り機構の一次側と二次側との差圧を検出し
て蒸気流量を測定する流量計において、絞り機構の上流
側に気水分離部を配し、該気水分離部の下方に排水弁を
設け、上記気水分離部と排水弁と絞り機構とを流量計ケ
ーシング内に収容′したものである。Means for Solving the Problems The technical means of the present invention taken to solve the above technical problems is a flow rate system that measures the steam flow rate by detecting the differential pressure between the primary side and the secondary side of the throttle mechanism. In the meter, a steam/water separation section is arranged upstream of the throttle mechanism, a drain valve is provided below the steam/water separation section, and the steam/water separation section, the drain valve, and the throttle mechanism are housed in the flow meter casing. This is what I did.

作用 気水分離部で湿り蒸気中の水分を分離し、排水弁から系
外に排出することにより、絞り機構に至る蒸気の湿り度
（乾き度）は一定のものとなる。By separating the moisture in the wet steam in the working air/water separation section and discharging it from the system through the drain valve, the wetness (dryness) of the steam reaching the throttling mechanism becomes constant.

すなわち、気水分離部で、多量の水分を含んだ湿り蒸気
が流入してさた場合には多量の水分を分離し、少量の水
分しか含んでいない湿り蒸気が流入してきた場合には少
量の水分を分離することにより、絞り機構に至る湿り蒸
気の湿り度（乾き度）はほぼ一定となるのである。In other words, in the steam/water separation section, when wet steam containing a large amount of moisture flows in, a large amount of moisture is separated, and when wet steam containing only a small amount of moisture flows in, a small amount is separated. By separating the water, the wetness (dryness) of the wet steam that reaches the throttle mechanism becomes almost constant.

絞り機構を通じての流体の質量流量は比重量の平方根に
比例する。従って、乾き飽和蒸気の流量は差圧ムｐと比
重量１　／Ｖ″に比例し、となる。The mass flow rate of fluid through the restriction mechanism is proportional to the square root of the specific weight. Therefore, the flow rate of dry saturated steam is proportional to the differential pressure p and the specific weight 1/V''.

湿り蒸気の比容積■は乾ぎ度をＸとすると、■＝Ｖ”ｘ
＋ｖ’（１−ｘ） となり、湿り蒸気の比容積の、乾き飽和蒸気のそれに対
する比は、 Ｖ／Ｖ”＝　Ｘ　＋　Ｖ’（１−Ｘ　）　／Ｖ″となる
。The specific volume of wet steam, ■, where the degree of dryness is X, is: ■=V"x
+v'(1-x), and the ratio of the specific volume of wet steam to that of dry saturated steam is V/V"=X+V'(1-X)/V".

ｖ７Ｖ′は非常に大きな値であるから、／Ｖ”−Ｘ とすることができる。Since v7V' is a very large value, /V"-X It can be done.

従って、湿り度（乾き度）一定の湿り蒸気の流量は、 として演算することができる。Therefore, the flow rate of wet steam with constant wetness (dryness) is It can be calculated as

発明の効果 上記のように本発明では、絞り機構に至る蒸気の湿り度
を一定に維持することにより、湿り度の変化に基因する
蒸気流量の測定誤差をなくすことかでき、蒸気流量を正
確に測定することができる。Effects of the Invention As described above, in the present invention, by maintaining the humidity of the steam reaching the throttling mechanism constant, it is possible to eliminate measurement errors in the steam flow rate due to changes in the humidity, and it is possible to accurately measure the steam flow rate. can be measured.

また、気水分離部と排水弁と絞り機構を１つの流量計ケ
ーシング内に収容したことにより、コンパクトな流量計
となり安価なものとなる。Furthermore, by housing the steam/water separation section, the drain valve, and the throttling mechanism in one flowmeter casing, the flowmeter becomes compact and inexpensive.

実施例 上記の技術的手段の具体例を示す実施例を説明する。（
第１図参照） 本実施例の差圧式蒸気流量計は、気水分離部１と排水弁
２と絞り機構３とで形成する。流量旧本体８に入口１０
．出口１１を形成し、入口１０に連通して円筒形状の隔
壁部材２０を取付け、これを囲む本体８との間に環状空
間１６を形成澱する。Embodiment An embodiment illustrating a specific example of the above technical means will be described. (
(See FIG. 1) The differential pressure type steam flowmeter of this embodiment is formed by a steam/water separator 1, a drain valve 2, and a throttle mechanism 3. Inlet 10 to old main body 8
．． An annular space 16 is formed between the outlet 11, which communicates with the inlet 10, and a cylindrical partition member 20 attached thereto, and the main body 8 surrounding the partition wall member 20.

入口１０と環状空間１６の間にコーン形状のスクリーン
３１を配し、環状空間１６の下部は排水弁２の排水溜り
室２６の上部と連通する。排水溜り室２６の上部は隔壁
部材２０の中央開口を通して絞り機＠３としてのオリフ
ィス１４に連通ずる。A cone-shaped screen 31 is arranged between the inlet 10 and the annular space 16, and the lower part of the annular space 16 communicates with the upper part of the drain chamber 26 of the drain valve 2. The upper part of the drainage sump chamber 26 communicates with the orifice 14 as a diaphragm @3 through the central opening of the partition member 20.

オリフィス１４の下部には流れを整流して測定精度を向
上させるための整流器１５を取付ける。整流器１５は細
い管を多数束ねて形成する。環状空間１６には傾斜壁か
らなる旋回羽根２４を配置する。また隔壁部材２０の下
部は外側へ拡がったフレアー状の水切り部１８を形成す
る。A rectifier 15 is installed at the bottom of the orifice 14 to rectify the flow and improve measurement accuracy. The rectifier 15 is formed by bundling a large number of thin tubes. In the annular space 16, a swirling vane 24 made of an inclined wall is arranged. Further, the lower part of the partition member 20 forms a flared drainage portion 18 that expands outward.

排水溜り室２６の底部には排水弁２としてスチームトラ
ップを形成する。排水溜り室２６の底部に排水口２２に
通じる排水弁口２８を形成し、対向して球形の弁フロー
ト３０を自由状態で収容し、フロー）−カバー３２で覆
う。フロートカバー３２の上部には通気口３４を開ける
。従って入口１０から流入した測定蒸気は環状空間１６
を通過する時に、旋回羽根２４で方向を曲げられて旋回
せしめられ、水分は蒸気より質量が大きいので外側へ搬
出されて周囲の本体内壁に沿って排水溜り室２６に流下
し、軽い蒸気は隔壁部ｖＪ２０の中央の整流器１５を経
てオリフィス１４を通過して出口１１に流出する。弁フ
ロー１へ３０は排水溜り全２６の水位と共に浮上降正し
て排水弁口２８を開閉し、排水溜り室２６に溜る復水を
自動的に系外へ排出する。A steam trap is formed as a drain valve 2 at the bottom of the drain chamber 26. A drain valve port 28 communicating with the drain port 22 is formed at the bottom of the drain chamber 26, and a spherical valve float 30 is accommodated in a free state on the opposite side, and covered with a flow cover 32. A ventilation hole 34 is opened in the upper part of the float cover 32. Therefore, the measuring steam flowing in from the inlet 10 enters the annular space 16.
When passing through the main body, the direction is bent and swirled by the swirling vanes 24, and since the moisture has a larger mass than the steam, it is carried to the outside and flows down along the surrounding inner wall of the main body into the drainage sump chamber 26, while the light steam flows through the partition wall. The liquid flows through the rectifier 15 in the center of the section vJ20, passes through the orifice 14, and flows out to the outlet 11. The valve flow 1 30 ascends and descends with the water level of the drainage basin 26 to open and close the drain valve port 28, and the condensate accumulated in the drainage basin 26 is automatically discharged to the outside of the system.

オリフィス１４の前後に圧力検出部３６．３７を設けて
演算部３８と接続する。演算部３８にて前記した湿り蒸
気の流量式より流量を演算して、表示あるいは記録する
。Pressure detection sections 36 and 37 are provided before and after the orifice 14 and connected to the calculation section 38. The calculation unit 38 calculates the flow rate from the above-mentioned wet steam flow rate formula and displays or records it.

【図面の簡単な説明】[Brief explanation of drawings]

第１図は本発明の差圧式蒸気流量計の１実施例の断面図
である。 １；気水分離部　　　　２：排水弁 ３：絞り機溝　　　　１０：入口FIG. 1 is a sectional view of one embodiment of the differential pressure type steam flow meter of the present invention. 1; Air-water separation section 2: Drain valve 3: Throttle groove 10: Inlet

Claims (1)

【特許請求の範囲】[Claims] １、絞り機構の一次側と二次側との差圧を検出して蒸気
流量を測定する流量計において、絞り機構の上流側に気
水分離部を配し、該気水分離部の下方に排水弁を設け、
上記気水分離部と排水弁と絞り機構とを流量計ケーシン
グ内に収容した差圧式蒸気流量計。1. In a flow meter that measures the steam flow rate by detecting the differential pressure between the primary and secondary sides of the throttle mechanism, a steam/water separation section is placed upstream of the throttle mechanism, and a steam/water separation section is placed below the steam/water separation section. Install a drain valve,
A differential pressure steam flowmeter in which the above-mentioned steam/water separation section, drain valve, and throttling mechanism are housed in a flowmeter casing.