CN1085831C

CN1085831C - Pressure difference balance container

Info

Publication number: CN1085831C
Application number: CN 97118174
Authority: CN
Inventors: 成文章
Original assignee: Individual
Current assignee: Cheng Wenzhang
Priority date: 1997-11-05
Filing date: 1997-11-05
Publication date: 2002-05-29
Anticipated expiration: 2017-11-05
Also published as: CN1216351A

Abstract

The present invention relates to a pressure difference balance container which is composed of a reference tube with the height of KH10, K=1-0.75, and the saturated water column of the reference tube, wherein the constant level of the saturated water column has different protection. The present invention can provide the true water-level signals of entrained steam bubbles in a boiler drum when a boiler is in a rated working condition, and can be matched with various pressure difference transmitters to measure the true water level in the boiler drum.

Description

A kind of differential pressure equalizing reservoir

The present invention relates to felt piece of a kind of improved water level gauge of differential pressure type water level gauge---a kind of differential pressure equalizing reservoir that industry, station boiler drum teletransmission level measuring are used.It is applicable to carbonated drink two-phase pressure vessel and the real water level measuring of boiler drum under declared working condition, is particularly useful for large-sized boiler tube real water level measuring.

The disclosed a kind of combined steam manifold water level sampler of Chinese invention patent publication number: CN1063936A, wherein the defective of differential pressure equalizing reservoir is with respect to the lateral water sampling tube center reference, the prover pipe of differential pressure equalizing reservoir " 0 " ordinary water level height is unreasonable, differential pressure method is surveyed water level and is realized by specific head, under declared working condition, normally the theoretical severe water column of " 0 " water level benchmark pressure head is greater than normal " 0 " real water level pressure head of carrying steam bubble in the drum secretly, thereby the differential pressure of above-mentioned equalizing reservoir output can not make differential pressure transmitter detect " 0 " differential pressure, and water level gauge shows the purpose of normal " 0 " water level.For large-sized boiler, the theoretical severe water level that records with above-mentioned water level gauge under declared working condition, can not satisfy manufacturing technique requirent far below the real water level of carrying steam bubble in the drum secretly, can cause and reduce main steam temperature and reheat steam temperature, influence the thermal efficiency and jeopardize boiler safety production.

Task of the present invention is to provide a kind of water column density error that the room temperature heat radiation causes of both having eliminated for differential pressure type water level gauge that boiler teletransmission level measuring is used under declared working condition, can eliminate again and carry steam bubble in the saturation water secretly and influence density error, can be accurately, carry secretly in the reliable measurements drum steam bubble real water level by a kind of KH ₀A kind of differential pressure equalizing reservoir that the permanent bit strip kinds of protect of prover pipe water column is formed.

Solution of the present invention is as follows: cause on the low level downtake of insulation with uninsulated steam tapping pipe that coagulates, the water column density difference that utilizes the two water column temperature difference under service condition to cause, make the main tube 1 of measuring be full of the saturated vapor that imports from vapour side stopple coupon 11, main measure tube 1 can be compared to one with the interior identical little drum of vapour pressure steam temperature condition of drum, be arranged in main reason tube 1 inner core 4 water columns that are communicated with drum water side of surveying and can be considered the saturated water level of not carrying steam bubble secretly by the continuous heating of saturated vapor, claim theoretical severe water level again, under different load or different vapour pressure, the a certain real water level of carrying steam bubble secretly in the drum, many highly theoretical severe water levels weight balancing is with it arranged in the inner core 4, under declared working condition, a real water level of carrying steam bubble secretly of measured position in the drum, the theoretical severe water level that a height only arranged in the inner core 4 is weight balancing with it, carries the real water level H of steam bubble in the drum secretly _ZExpression, theoretical severe water level H in the inner core 4 _LExpression.Be arranged in main prover pipe 5 water columns of measuring tube and also can be considered the saturated water column of theoretical severe of not carrying steam bubble secretly, when the prover pipe height is KH by the continuous heating of saturated vapor ₀The time, water column H in its prover pipe 5 _LT0Expression claims theoretical severe equivalent " 0 " real water level under the declared working condition, carries normal " 0 " real water level H of steam bubble in it and drum secretly _Z0When having identical pressure head, equalizing reservoir output differential pressure be " 0 ", and gauge glass demonstration " 0 " ordinary water level under declared working condition, is worked as H _ZWith H _LDuring weight balancing, make KH _Z=H _L, again because H _Z0With H _LT0Also be in balance when weighing, thereby KH _Z0=H _LT0Set up; K be one less than 1 coefficient, 1＞K＞0.75, boiler capacity is big more; it is big more to load; vapour pressure is high more, and it is big more that carbonated drink is separated steam loss, and the K value is more little; vapour communication pipe 6; swan-neck 3, cross-sectional area are multiple times than the storage subcooled water of prover pipe 5 cross-sectional areas and pay tube 2, pay piping and prover pipe upper port spilling water function composition prover pipe 5 permanent automatically position protection system under dynamic condition that tube 2 bottoms and prover pipe 5 waters are passage.Vapour communication pipe 6 is used for to paying the continuous filling that tube 2 causes vapour to reduce because of the vapour condensation, swan-neck 3 is used for when the rapid drawdown significantly of drum vapour pressure, the vaporization of prover pipe 5 saturation waters is lost in a large number, follow boiler drum water level to rise suddenly this moment, water level rises suddenly in the inner core 4, when water level surpasses swan-neck 3 tops, swan-neck 3 is implemented siphon and is transferred inner core 4 interior water to replenish pair tube 2 and then keep permanent of prover pipe 5 water columns, saturated water level is kept not equipotential weight balancing in following pair of tube of service condition 2 interior subcooled waters and the prover pipe 5, meet rapid drawdown by a small margin in the vapour pressure, the saturation waters moderate dehydration of vaporizing in the prover pipe 5, pay tube 2 " wide " container prover pipe 5 " narrow " container is kept the approximate permanent position of water level in the prover pipe 5 by the water column weight balancing, pay tube 2 continuous condensate waters and replenish prover pipe 5 to return the rainbow mode, unnecessary water column is through the excessive certainly permanent position of prover pipe 5 upper port.Inner core 4 bottoms are drawn and are changed head efferent duct 8, an output differential pressure (Δ P) between the benchmark head efferent duct 7 that draw prover pipe 5 bottoms, and differential pressure water level conversion relational expression has:

Δ P=-(H _LT0-H _L) (γ w-γ s) ... (1)

Δ P in the formula---output differential pressure

K _LT0---theoretical severe equivalent " 0 " water level under the declared working condition,

H _L---change theoretical severe water level

The theoretical severe of γ w---saturation water

γ s=---saturated vapor severe

Use KH _Z0Replace H _LT0, use KH _ZReplace K _L

Then formula () is write as:

Δ P=-(KH _Z0-KH _Z) (γ w-γ s) ... (2)

Δ P=-K (H _Z0-H _Z) (γ w-γ s) ... (3)

H in the formula _Z0---normal " 0 " real water level under the declared working condition,

H _Z---real change water level under the declared working condition

Investigation formula (three) is as can be known: by measuring differential pressure (Δ P) and vapour pressure (P) and making

Vapour pressure (P) function to indicate gets γ w-γ s=f (p), by to the mensuration of various boilers at true " 0 " water level of declared working condition lower drum and theoretical severe equivalent " 0 " height of water level related coefficient K, only remains next unknown number (H in formula (three) equation again _Z)---real change water level, the visible KH that sets up ₀The permanent bit strip kinds of protect of prover pipe water column equalizing reservoir physical model and this physical mathematic(al) representation (three) can be found the solution the real change water level (H that carries steam bubble in the declared working condition lower drum secretly with differential pressure method _Z).

Advantage of the present invention is: under declared working condition, both eliminated the water column density error that the room temperature heat radiation causes, eliminated water level steam quality influence in the drum again, make the differential pressure type water level gauge can be accurately, carry the real water level of steam bubble in the reliable measurements drum secretly, for large-sized boiler high energy-conservation and safe meaning is arranged.

Embodiments of the invention are as shown in drawings:

Accompanying drawing 1 is a structural representation

Accompanying drawing 2 is to pay tube 2 and benchmark head efferent duct 7 threeway connected modes.

The present invention has the main tube 1 of measuring; be positioned at the main tube 1 of measuring inner core 4, prover pipe 5 are arranged; a vapour side stopple coupon 11 will be led measurement tube 1 a top steam chest and be communicated with drum 16; a lateral water sampling tube 12 is communicated with inner core 4 following sides with drum 16; main tube 1 bottom of measuring has a waste pipe 14 to be communicated with downtake 15; protect a kind of differential pressure equalizing reservoir of forming by a kind of prover pipe 5 water columns perseverance bit strip kind, the KH of a pair end of 2, swan-necks 3 of tube from inner core 4 also shown in main measurement tube 1 side ₀Draw near the height, the other end advances to pay tube 2 tops and inserts into the inner, it stretches into height will be lower than exit on the inner core 4, the top height of swan-neck 3 is near the high alarm water level of drum, a vapour communication pipe 6 will be led measurement tube 1 and be communicated with pair tube 2 steam chests, pay the cross-sectional area that tube 2 cross-sectional areas are multiple times than prover pipe 5, prover pipe 5 bottoms be positioned at lateral water sampling tube 12 centre-heights must have a horizontal communication pipe to draw to connect short tube 13 or directly with pay tube 2 and be communicated with, being positioned at main tin 1 dried up side stopple coupon 12 centre-heights of the prover pipe 5 upper end mouths of pipe measured is normal " 0 " height of water level H ₀K doubly, the KH of tube 2 inner space height and prover pipe 5 is paid in 1＞K＞0.75 ₀Highly approximate identical, or slightly long or lower slightly can, change head efferent duct 8, benchmark head efferent duct 7 is respectively together vertical the drawing in the bottom of inner core 4 and prover pipe 5, also can draw by a same level, when vertically drawing, with a horizontal communication pipe, height will be paid tube 2 in lateral water sampling tube 12 centre-heights and be communicated with prover pipe 5, shown in accompanying drawing 1 dotted line, when benchmark head efferent duct 7 variation head efferent ducts 8 one same levels are drawn, draw height in lateral water sampling tube 12 centre-heights, the connected mode that pay tube 2 and horizontal benchmark head efferent duct 7 this moment can have two kinds, a kind of is that benchmark head efferent duct was done two sections in 7 minutes, pay tube 2 and be serially connected on the benchmark head efferent duct 7, as the connected mode of Fig. 1, another kind is to pay tube 2 bottoms to be communicated with benchmark head efferent duct 7 threeway modes with a short tube 13, as shown in Figure 2, change head efferent duct 8 and connect variation head pulse tube 10, benchmark head output 7 connects the output of benchmark head pulse tube 9, two pulse tubes and connects differential pressure transmitter or differential pressure water level gauge.Inner core 4 can be a tube at the bottom of the tubulose band, and the internal diameter of swan-neck 3 generally is about 1/3 of a lateral water sampling tube internal diameter.

In the accompanying drawing; 1, main measuring cylinder 2, pair tube 3, swan-neck 4, inner core

5, prover pipe 6, vapour communication pipe 7, benchmark head efferent duct

8, change head efferent duct 9, benchmark head pulse tube

10, change head pulse tube 11, vapour side stopple coupon 12, lateral water sampling tube

13, short tube 14, waste pipe 15, downtake 16, drum

Claims

A kind of differential pressure equalizing reservoir, the main tube (1) of measuring is arranged, be positioned at the main tube (1) of measuring inner core (4) is arranged, prover pipe (5), a vapour side stopple coupon (11) will be led measurement tube (1) top steam chest and be communicated with drum (16), a lateral water sampling tube (12) is communicated with inner core (4) following side with drum (16), main tube (1) bottom of measuring has a waste pipe (14) to be communicated with downtake (15), main measurement tube (1) side is also shown and is paid tube (2), one end of a swan-neck (3) is drawn from inner core (4), the other end advances to pay tube (2) top and inserts into the inner, the top height of swan-neck (3) is near the high alarm water level of drum, a vapour communication pipe (6) will be led measurement tube (1) and be communicated with pair tube (a 2) steam chest, pay the cross-sectional area that tube (2) cross-sectional area is multiple times than prover pipe (5), prover pipe (5) bottom be positioned at lateral water sampling tube (12) centre-height must have a horizontal communication pipe draw through short tube (13) or directly with pay tin (2) and be communicated with, change head efferent duct (8), benchmark head efferent duct (7) is drawn with the bottom of prover pipe (5) is together vertical at inner core (4) respectively, also can draw by a same level, it is characterized in that:

Prover pipe (5) the upper end dried up side stopple coupon of the mouth of pipe (12) centre-height is normal " 0 " height of water level H ₀K doubly.One end of swan-neck (3) is from the KH of inner core (4) ₀Draw 1＞K＞0.75 near the height.