CN1035455C

CN1035455C - Combined steam manifold water level sampler

Info

Publication number: CN1035455C
Application number: CN 91100647
Authority: CN
Inventors: 成文章
Original assignee: Individual
Current assignee: Individual
Priority date: 1991-01-30
Filing date: 1991-01-30
Publication date: 1997-07-16
Anticipated expiration: 2006-01-30
Also published as: CN1063936A

Abstract

The present invention relates to a combined water level sampler of steam manifolds, which is formed by scientifically combining two kinds of invention of a three-line double-container electrode measuring barrel and a zero-position reference protective balancing container of constant position bands. The combined water level sampler can be used by matching with an electrode display instrument and various difference pressure meters for measuring theoretical gravity water levels of two-phase pressure containers of gas and water. The combined water level sampler is especially suitable for measuring the theoretical gravity water levels of boiler steam manifolds and automatic regulation signals of the water levels. The combined water level sampler has the advantages of accuracy, reliability, dependability, no room temperature error, no zero-position drift error, obvious effect of saving energy and safety significance, and is suitable for variable parameters of boilers and the operation of all working conditions.

Description

The combined steam manifold water level measurement mechanism

The present invention relates to the electrode type water level gauge that industry, station boiler drum teletransmission level measuring are used, a kind of improved level measurement device that the differential pressure type water level gauge is shared---combined steam manifold water level measurement mechanism.It is applicable to carbonated drink two-phase pressure container water level measuring, is particularly useful for boiler drum water level measurement.

The level measurement device pattern that existing domestic industry, station boiler steam bag level measuring are used has: electrode level meter list container measurement tube, all kinds of high-order benchmark reference equalizing reservoirs of differential pressure type water level gauge etc.There are number of drawbacks in above-mentioned measurement tube and equalizing reservoir: the disclosed a kind of differential pressure water level measuring cylinder of russian patent No. (SU-1536210); its defective is that (1) prover pipe is made up of for 5 two sections chamber on reference water column jecket 15 and the benchmark; measure reference and belong to high-order benchmark; and the indication of custom address steam water-level table is made the reference benchmark with normal " 0 " water level; the two is inconsistent; belong to the measuring principle defective; thereby exist boiler parameter to change to cause gauge glass " 0 " position drift error: (2) room temperature and tubulation 14 play continuous condensate water and return rainbow formula self-equilibrating moisturizing protection permanent position effect under service condition; because room temperature and tubulation 14 cross-sectional areas are approximate consistent with reference water column jecket 15 cross-sectional areas; many times than 5 cross-sectional areas of chamber on the benchmark are little; therefore; when meeting the vapour pressure rapid drawdown; saturation water is when water column is lost in boiling vaporization dehydration in the prover pipe; room temperature and tubulation 14 transient state moisturizing defencive functions are too small; there is transient state, water level misalignment error.The Wu of Nanjing Polytechnical College immortality, can the people compile hydraulic and electric engineering publishing house and publish, institution of higher education's teaching material: the 201st page of Fig. 9-3 one kind of equalizing reservoir of " Thermal Measurement ﹠ Meter " book, its defective is: (1) is measured reference and is belonged to high-order benchmark, the measuring principle defectiveness exists boiler parameter to change and causes water level indicating gauge " 0 " position drift error; (2) prover pipe (L-l) section is the saturation water shell of column, has transient state artifical water height error during the vapour pressure rapid drawdown; (3) benchmark (l) section is subjected to the room temperature variable effect, has the water column density error that causes because of the room temperature variation.As above there is the water column density error that causes because of the room temperature heat radiation in a kind of single container electrode water level measuring cylinder of " Thermal Measurement ﹠ Meter " book 203-205 page or leaf.Two 12 the uniform electrode level measuring tubes of file of external a kind of [Hydrastep7] type twin containers by name, though there is not above-mentioned defective, but exist the electrode measurement inner tube structure unreasonable, two column electrode arrangements are difficult near intensive layout electrode frequent normal " 0 " water level of fluctuation of water table, directly influence near measuring accuracy normal " 0 " water level of drum.The above all kinds of water level gauge is measured tube and general only suitable being arranged in separately on the water level sampling hole of drum diverse location of equalizing reservoir, since boiler operating condition water drum water level vertically each position or transversal section not the homonymy water level be inconsistent, the measurement tube that adds all kinds of water level gauges that measuring principle is different is different with equalizing reservoir error rule, therefore existing many water level gauges of boiler-steam dome are difficult to obtain two covers and can show identical and near the reliable water level gauge of drum real water level, the operations staff is difficult to judge the error or the misalignment state of drum low-water level meter, this differentiates for the boiler operatiopn personnel and the monitoring steam water-level brings blindly and difficulty, it can cause the steam product to worsen, the efficiency of cycle reduces, even the entail dangers to steam turbine, the safety of boiler main equipment.

Task of the present invention is that different electrode type water level gauge, the differential pressure type water level gauges of using for boiler-steam dome teletransmission level measuring of measuring principle provides a kind of shared room temperature heat radiation that exists hardly to cause the water column density error, there is not the zero shift error, the combined steam manifold water level measurement mechanism of instrument misalignment error when not having the vapour pressure rapid drawdown.

Solution of the present invention is as follows: the main measurement is full of in the tube from cutting down the 15 drum saturated vapors that import vapour side communicating pipe, condensing water vapor causes downtake 19, become the water column in the inner barrel 4 of water connected state to be can be considered saturation water with drum liquid to the space by heating continuously, it becomes statics weight equipotential equilibrium state with the interior saturated water level of theoretical severe of drum, stretch between the conducting end of electrode 18 in inner barrel 4 spaces and barrel wall and differentiate vapour phase or liquid phase according to the difference of carbonated drink conductance, output does not exist the room temperature heat radiation to cause the electrode level of water column density error.Be arranged in main zero reference pipe 5 water columns of measuring tube 1 and also be heated to form state of saturation, it is to keep permanent position state for supposition earlier, then it with inner barrel 4 in the theoretical severe water table ratio that changing, export the differential pressure water level, it exports differential pressure and the water level conversion relational expression has:

ΔP＝-(Ho－H)(γw－γs)……(-)

Δ P---output differential pressure

Ho---lateral water sampling tube center to " 0 " height of water level

Theoretical severe water level in H---the state of saturation water drum

γ w---saturation water severe (not containing steam bubble)

γ s---saturated vapor unit weight

1, the end variable of room temperature influence occurs being subjected to (γ a) shows that Δ P is not subjected to room temperature influence in the formula.

2, when H＞Ho, Δ P be on the occasion of, H (Δ P is a negative value during Ho, Δ P=0 when H=Ho, this is positive and negative with the steam water-level that we are accustomed to calling, zero level is consistent and show that vapour pressure changes: indicating gauge " 0 " not drift of position when " 0 " water level.

3, when H be definite value, Δ P=f (γ w-γ s) then shows that vapour pressure changes and only causes that the gauge glass amplitude changes that differential pressure (Δ P) obtains water level value (H-Ho) through the vapour pressure compensation.

For this reason, a kind of measure that the present invention takes is: measure tube 1 side and show a pair wide vessel 2 main, paying wide vessel 2 connects benchmark head efferent duct 7 through water communication short tube 10 and communicates with zero reference pipe 5, vapour communication pipe 8 will be led measurement tube 1 and be communicated with pair wide vessel 2 steam chests, pay wide vessel 2 tops the U trap 3 that communicates with inner barrel 4 is arranged, pay wide vessel 2 cross-sectional areas and be multiple times than zero reference pipe 5 cross-sectional areas, its water storage height has downwards from normal " 0 " water level of drum and is no less than 2/3 of zero reference pipe 5 length, normal " 0 " water level of prover pipe 5 height flat drums.

After taking above-mentioned measure, there is the protection automatically of three covers zero reference pipe of the present invention 5 permanent positions, and its protection philosophy is summarized as follows:

1) paying wide vessel 2 has garden week and the bigger room temperature film-cooled heat in bottom, and its top steam chest is measured tube 1 with the master and is communicated with, the continuous therein condensation of saturated vapor, and condensate water can replenish pays wide vessel 2, zero reference pipe 5, and Yu Shui overflows certainly through zero reference pipe 5 upper ends permanent.

2) in meeting vapour pressure by a small margin during rapid drawdown, in the zero reference pipe 5 water column with pay wide vessel 2 in water column become the free equilibrium state of statics weight, decuple zero reference pipe 5 cross-sectional areas owing to pay the cross-sectional area number of wide vessel 2, the water column amount that saturated water column self-boiled in the zero reference pipe 5 is risen vaporization loss obtains paying wide vessel 2 and reduces a trace and highly take advantage of the water yield of its cross-sectional area to replenish, the water surface in the zero reference pipe 5 after the balance is than the also low approximate trace height paying wide vessel 4 reductions of permanent plane, through the permanent position of process condensate water recovery after replenishing.

3) when meeting vapour pressure significantly during rapid drawdown, when repeating above-mentioned moisturizing process, because vapour pressure rapid drawdown significantly, must cause steam water-level to rise to high water stage rapidly, saturated water level rises synchronously rapidly with steam water-level in the inner barrel 4, when water level surpassed U trap top curved pipe elevation, U trap 3 enforcements siphon water transfer from inner barrel 4 replenishes paid a wide vessel 2, and then makes zero-bit parent tube 5 water columns obtain additional rapidly permanent position.16 internal diameters are little to many times because U trap 3 internal diameters are than cut down water side communicating pipe, the siphon water transfer does not influence the height that inner barrel 4 middle water levels should rise to, when the vapour pressure rapid drawdown stops, water level begins to descend, U trap 3 postpones to stop water transfer when moisturizing to water levels are lower than the siphon import, so the siphon moisturizing not only reliably but also inexcessive.

For improving the electrode measurement precision, the another kind of measure that the present invention takes is that inner barrel 4 is improved, inner barrel 4 is made the transversal section to be bent polygon and to become converting pipe at the bottom of the band that three files contact with main tube 1 inwall of measuring, or measure tube 1 inwall by a kind of three Guan Yuzhu and become combination shape cylindrical shell at the bottom of the parallel band that is arranged in juxtaposition and is interconnected of three files contact, this cylindrical shell bottom is communicated with drum water side, contact periphery at inside and outside cylindrical shell has stretched into three file potential electrode 18, the minimum vertical spacing of each potential electrode of file reaches 15 millimeters, therefore, shortened the distance of each measurement point of potential electrode 18, measuring accuracy is improved.

After taking above-mentioned measure, the present invention's output electrode water level, differential pressure water level simultaneously can have four kinds of purposes; Optional one does not all influence accuracy, reliability, and its four kinds of purposes are: electrode type water level gauge, differential pressure type water level gauge are united use; Pure electrode level meter; Pure differential pressure type water level gauge; Belt electrode is reported to the police, protection differential pressure type water level gauge.

Advantage of the present invention is that electrode, differential pressure two cover water level gauges can record theoretical severe water level in the drum synchronously, accurately and reliably, the water column density error that exists the room temperature heat radiation to cause hardly, there is not the zero shift error, instrument misalignment error when not having the vapour pressure rapid drawdown, have significant steam quality and the energy-saving effect of improving, can guarantee boiler turbine main equipment safety.

Embodiments of the invention are as shown in drawings:

Accompanying drawing 1 is a structural representation.

Accompanying drawing 2 is A--A views.

Accompanying drawing 3 is B--B views.

The present invention has main measurement tube 1, zero reference pipe 5, changes head efferent duct 9, vapour side communicating pipe cuts down 15, cut down 16 water side communicating pipe, waste pipe cuts down 20, potential electrode 18, comprise a kind of differential pressure equalizing reservoir, measure tube 1 side and show a pair wide vessel 2 main, pay wide vessel 2 and connect benchmark head efferent duct 7 through water communication short tube 10, vapour communication pipe 8 will be led measurement tube 1 and communicate with paying wide vessel 2 steam chests, pay the U trap of ining succession and communicate with inner barrel 4 in wide device 2 tops 3.Normal " 0 " water level of zero reference pipe 5 height flat drums, its underpart is positioned to be cut down 16 centre-heights water side communicating pipe and connects benchmark head efferent duct 7 and be switched to benchmark head pulse tube 12, at its sustained height, connect variation head efferent duct 9 from inner barrel 4 bottoms and be switched to variation head pulse tube 11.The cross-sectional area of paying wide vessel 2 is multiple times than the cross-sectional area of zero reference pipe 5, base water storage height has downwards from normal " 0 " water level of drum and is no less than 2/3 of zero reference pipe 5 length, pay U trap 3 that wide vessel 2 communicates with inner barrel 4 and be to draw from inner barrel 4 middle and upper parts to pass through and mainly measure tin 1, be bent upwards the back and cause the top steam chest of paying wide vessel 2 down, the siphon height of U trap 3 is no more than the highest alarm water level, and the height of U trap 3 and inner barrel 4 junctions is near alarm water level.Vapour communication pipe 8 is to be communicated with more than the water level in normal " 0 " to pay wide device 2 steam chests and the main tube 1 of measuring.

The present invention also comprises a kind of double container three column electrode water level measuring tube, and inner barrel 4 section of interconnecting transversal section are bent polygon, is three files with main measurement tube 1 inwall and contacts.Inner barrel 4 can be made into two kinds in the present embodiment, and first kind is that the transversal section is bent polygon, is converting pipe at the bottom of the band that three files contact with main tube 1 inwall of measuring, and adopts a converting pipe to make as shown in Figure 2.Another kind is to measure tube 1 inwall by three Guan Yuzhu to be parallel being arranged in juxtaposition of three files contact, and as shown in Figure 3, the section of interconnecting transversal section as shown in Figure 2 is bent polygon, and combination shape cylindrical shell is formed at the bottom of a kind of band.Potential electrode 18 stretches into inner barrel 4 spaces along the file of inside and outside cylindrical shell contact, and each staggered potential electrode minimum vertical of file is apart from reaching 15 millimeters.Potential electrode 18 is fixed on the electrode tip holder 17 that is installed in main measurement tube 1 periphery, pass through by electrode tip holder 17, main measure the space that inner barrel 4 is stretched in tubular duct, concentric closed garden that tube 1 wall, inner barrel 4 walls form, electrode file and electrode are provided with number and look measuring accuracy and decide.

In the accompanying drawing: 1, main measuring cylinder, 2, pay tolerant device, 3, siphon pipe, 4, in Cylindrical shell, 5, the zero-bit prover pipe, 6, main measuring cylinder base plate, 7, the output of benchmark head Pipe, 8, the vapour communication pipe, 9, change the head efferent duct, 10, water communication short tube, 11, Change the head pulse tube, 12, benchmark head pulse tube, 13, drain the mouth of pipe, 14, Interior tube end plate, 15, cut down vapour side communicating pipe, 16, cut down water side communicating pipe, 17, electrode Seat, 18, measure electrode, 19, down-comer, 20, excretory duct cuts down, 21, drum.

Claims

1, a kind of combined steam manifold water level measurement mechanism; Master graduated cylinder (1) is arranged, change head efferent duct (9), potential electrode (18), its feature comprises:

1) a kind of differential pressure equalizing reservoir, the zero reference pipe (5), the benchmark head efferent duct (7) that comprise normal " 0 " water level of height flat drum, vapour communication short tube (8), and the cross-sectional area of paying wide vessel (2) is multiple times than the cross-sectional area of zero reference pipe (5), the water storage height of paying wide vessel (2) has downwards from normal " 0 " water level of drum and is no less than 2/3 of zero reference pipe (5) length, pay wide vessel (2) bottom and connect benchmark head efferent duct (7) by the water short tube (10) of communicating, paying wide vessel (a 2) top steam chest has the U trap (3) that communicates with inner barrel (4);

2) a kind of double container three column electrode water level measuring tube, comprise electrode tip holder (17), and inner barrel (4) section of interconnecting transversal section is bent polygon, is three files and contact with main tube (1) inwall of measuring, and potential electrode (18) contacts file along inside and outside cylindrical shell and stretches into inner barrel (4) space.

2, a kind of combined steam manifold water level measurement mechanism according to claim 1, it is characterized in that: inner barrel (4) stretches into potential electrode (18), and the bottom connects and changes head efferent duct (9), and U trap (3) is drawn in the position, middle and upper part.