CN1244768C - Urban gas step replacing method - Google Patents

Abstract

The present invention discloses an urban gas step replacing method which uses a new gas source Z to replace an old gas source X and comprises the following steps: (A) using preparation gas Y to directly replace the old gas source X, wherein the operation point of an original cooker using the preparation gas Y is in a stable combustion area (6) of the preparation gas Y which is the mixed gas of the old gas source and the new gas source Z; (B) reforming the cooker so that the operation point of the reformed cooker is in the optimal operation point of a stable combustion area (8) when the new gas source Z is used and the operation point of the reformed cooker using the preparation gas Y is in a stable combustion area (7) of the cooker; (C) using the new gas source Z to directly replace the preparation gas Y. The present invention has the advantages of high conversion speed, high efficiency, little fund input amount, no safety hazard, obvious economical benefit and environmental protection benefit and low influence on users, and can replace gas under the condition of continuous gas supply in the whole city.

Description

Gas step-by-step replacement method

Technical field

The present invention relates to a kind of gas method of replacing, related in particular to gas replacement manufactured gas, manufactured fuel gas or empty method of mixing gas.

Background technology

Country has formulated " gas classification " (GB/T13611-92) according to the kind and the principle of classification of gas.In this standard gas is divided into three classifications, i.e. manufactured gas, manufactured fuel gas, natural gas and liquefied petroleum gas (LPG), and stipulated corresponding index calculating method, index request and safety indexes and interchangeability index.

Natural gas is meant under different geological conditions, generates, migration and preserve a kind of gas in geological structure with certain pressure.It forms because of the gas field different and different with the gas pay position, after the natural gas generation, preserves in hole at subsurface rock, the crack, and by drilling well it is exploited out.Guangdong LNG project is from the liquefied natural gas of Australian import table 1 composed as follows.

Table 1: Guangdong LNG project gas component and combustion characteristics

Methane	Ethane	Propane	Iso-butane	Normal butane	Nitrogen	Higher calorific value	Lower heat value	The white index of China	Combustion potential (CP)	The gas relative density
											CH 4	C 2H 6	C 3H 6	iC 4H 10	nC 6H 10	N 2	MJ/Nm 3(kcal/Nm 3)
(％)
						88.77	7.54	2.59			0.45	0.56	0.07	44.61 (10656)	40.39 (9647)	56.05 (13387)				41.85	0.6335

The manufactured gas, manufactured fuel gas is meant that with raw coal or petroleum product etc. be raw material, adopts the produced gaseous fuel of chemical method.Common manufactured gas, manufactured fuel gas has coke-stove gas, self-support retort gas, moving bed pressurized gasification producer gas, water-gas, producer gas, oil gas, refinery gas, the venting of speeding, natural gas reforming gas, liquefied petroleum gas (LPG) upgrading gas etc., oil gas component such as the following table 2 that use in the area, Guangzhou.

Table 2: Guangzhou area oil gas component and combustion characteristics

H 2	CH 4	C 2H 6	C 2H 6	C 3H 8	C 3H 6	O 2	N 2	CO	CO 2	Higher calorific value	Lower heat value	The white index of China	Combustion potential	The gas relative density
															(％)										MJ/Na 2(kcal/Nm 3)
40.35	20.90	18.3	1.7	0	2.5	0.6	2.35	8.5	4.8	29.68 (7088)	27.09 (6471)	39.58 (9453)																87.15	0.5622

Liquefied petroleum gas (LPG) mainly is made up of hydrocarbons such as propane, butane, because its critical pressure is low, critical-temperature is high, so adopt the mode that reduces temperature or rising pressure to make it to become liquid state, forms so-called liquefied petroleum gas.

By " GB " scheme of classification, the empty gas that mixes claims again that for natural gas (SNG) promptly liquefied petroleum gas and Air mixing gas one " LPG+AIR " gaseous mixture also are included into the natural gas class.Empty gas component such as the following table 3 of mixing of import liquefied petroleum gas (LPG) that use in the area, Guangzhou and typical case.

Table 3: imported L PG that use in the area, Guangzhou and typical empty gas component and the combustion characteristics of mixing

Project	Ethane	Propane	Iso-butane	Normal butane	Pentane	Oxygen	Nitrogen	Higher calorific value	Lower heat value	The white index of China	Combustion potential (CP)	The gas relative density
													C 2H 6	C 3H 8	iC 4H 10	nC 4H 10	C 5H 12	O 2	N 2	MJ/Nm 3(kcal/Nm 3)
	(％)
								Liquefied petroleum gas (LPC)	0.69	44.43			16.77	37.85	0.26	0	0.07	118.81 (28377)	109.59 (26176)				87.47 (20891)	44.17	1.8450
The empty gas that mixes	0.29	18.79	7.03	16.07	0.11	12.12	45.22				50.24 (12000)	46.34 (11069)								43.12 (10300)	39.05	0.5838

The related data of analytical table 1～3, we find: natural gas and manufactured gas, manufactured fuel gas and empty mixed gas are three kinds of combustion gas of different nature, and its calorific value, flame propagation velocity, supply gas pressure, composition etc. all have than big-difference.Natural gas generally is a dry gas, forms based on methane, is substantially free of impurity, and calorific value is higher, and flame propagation velocity is slow, the discharge pressure height; The manufactured gas, manufactured fuel gas is the mixture of multiple gases, contains impurity such as moisture content, tar dirt, ammonia, naphthalene, hydrogen sulfide, and discharge pressure is lower; Empty mixed gas then is liquefied petroleum gas and AIR MIXTURES, and component is based on propane, butane, nitrogen, oxygen, and calorific value is adjustable, but density is bigger, and discharge pressure can not be too high.

Natural gas is extensively adopted by countries in the world as a kind of high-grade fuel efficient, cleaning, and particularly it more and more is subject to people's attention the environmental protection role.Many in the world developed countries since the fifties just the process of artificial coal gas to Natural Gas Conversion, Canada, Britain, France, Holland, Australia, Japan etc. have replaced artificial coal gas with natural gas fully.At present, the source of the gas of National urban combustion gas mainly comprises artificial coal gas, natural gas and liquefied petroleum gas.Along with " West-east Gas, " Russia gas south for " engineering and Guangdong LNG receiving station build up air feed; the source of the gas structure of National urban combustion gas will great changes will take place; natural gas will progressively replace artificial coal gas and liquefied petroleum gas and become the leading source of the gas in city, and the displacement work of gas also will launch throughout the country in succession.

Any burner all is to design according to certain gas component.When source of the gas changes also is that component changes and when causing its calorific value, density and combustion characteristics to change, carbon monoxide content etc. all can change thereupon in the thermic load of burner burner, primary air ratio, combustion stability, flame structure, the flue gas, and causes combustion conditions to change.Little when this variation, can satisfy that burner is original to be provided with when requiring, this variation of source of the gas then allows so, and the source of the gas after promptly changing has interchangeability to the source of the gas before changing, can direct replacement, otherwise do not possess interchangeability.From combustion characteristics, natural gas and artificial coal gas, liquefied petroleum gas are not interchangeable imflammable gas.Concrete difference is as follows: at first, natural gas generally is a dry gas, and is free from foreign meter substantially, discharge pressure is higher, contains moisture content, coal tar wet goods impurity in the artificial coal gas, and discharge pressure is lower, liquefied petroleum gas is with bottled master, some areas employing sub-district gasification centralizedly supply of being supplied as; Secondly, the calorific value of natural gas is than artificial coal gas height, and is lower than liquefied petroleum gas, and Wobbe index is also different with combustion potential, can not two kinds of gases of simultaneous adaptation with a kind of burner.The difference of these characteristics has determined original gas transmission and distribution system and gas appliance when using natural gas as source of the gas, needs through suitable transformation and adjustment.

With injection type atmospheric combustion device burner common in the pipeline network of fuel gas in city is example, promptly uses the theory of combustion of partly-premixed flame (flame own) to come the burner combustion pattern is analyzed: Fig. 1 changes the back operation point of gas appliance for source of the gas and combustion pattern changes schematic diagram with source of the gas.To a certain burner, after source of the gas changes (become the B source of the gas by the A source of the gas, become the C source of the gas again), the former operating point (a of its burner ₁) and former combustion pattern figure T ₁Can change thereupon, thereby produce new operating point (a ₂And a ₃) and new combustion pattern T ₂, T ₃But no matter how operation point of gas appliance and combustion pattern change, new operating point must be in the areal extent that comprises from flame limit curve 1, tempering limit curve 2, yellow flame limit curve 3 and CO limit curve 4, it is stable combustion region, the change of thermic load, primary air ratio and flame characteristics just can not surpass a certain limit, could guarantee that like this burner still can keep gratifying duty, become the situation of B source of the gas as the A source of the gas.If new operating point moves to outside the combustion characteristics limit curve, as the C source of the gas, the new operating point a that it produces on burner ₃Depart from from the upper right side of flame limit curve, thereby can produce from the flame phenomenon during this source of the gas burning, it can not smooth combustion on above-mentioned burner, and promptly the C source of the gas can not be replaced the smooth combustion on original burner of A source of the gas.

The operating condition of burner depends on combustion characteristics, thermal intensity of fire port and the primary air ratio of combustion gas, for a certain burner, when combustion gas character (gas component) changes, fuel gas buring characteristic and Hua Bai index change simultaneously, the change of fuel gas buring characteristic will cause the change of characteristic curve position, and the change of Wobbe index will cause the change of operation point of gas appliance.

Specific to by gas replacement manufactured gas, manufactured fuel gas or empty when mixing gas, from the interchangeability angle, after should guaranteeing that source of the gas becomes natural gas by manufactured gas, manufactured fuel gas or empty mixed gas, when natural gas burnt on original manufactured gas, manufactured fuel gas's burner or empty mixed gas burner, the new operating point that produces was still within the new features curve ranges.Regrettably, because natural gas and manufactured gas, manufactured fuel gas's nature difference are too big, after natural gas was replaced the manufactured gas, manufactured fuel gas, combustion pattern figure will be by the T among Fig. 1 ₁Become T ₃, new operating point is also by a ₁Point moves to a ₃Point departs from outside new combustion pattern scope.Be after former artificial combustion gas burner is used natural air-air source instead, new operating point a ₃Point illustrates that two kinds of sources of the gas can not directly change not within the combustion pattern scope.

Natural gas also is like this when some sky mixes gas shift, so some empty gas that mixes can not connect conversion by natural gas straight equally.

Gas replacement manufactured gas, manufactured fuel gas or the empty gas that mixes generally have two kinds of schemes.The one, under the situation that does not influence the non-conversion area air feed, the pipe network system of cutting off transition region and manufactured gas, manufactured fuel gas or empty gas mixing pipe net system get in touch, and reduce the pressure of manufactured gas, manufactured fuel gas in the transition region (empty mixed gas) pipe network then.After pressure reduced, beginning was to transition region input natural gas, manufactured gas, manufactured fuel gas's (empty gas that mixes) predefined diffuse a little to diffuse until gas sampling concentration reach requirement.The advantage of this scheme is that replacing velocity is fast, and user security is good.But a large amount of giving out of gas arranged, and waste is big, pollution is to a certain degree arranged, and stopping the supple of gas or steam the time of a few hours arranged.Another kind of scheme is that the combustion gas of low-pressure pipe network is not being diffused an emission coal gas after cutting off manufactured gas, manufactured fuel gas's supply, burnouts on the kitchen range after user's conversion and change into, and is normal until combustion gas.This scheme is long conversion time, and user security is poor, but can continuous air feed.

Certainly, before the source of the gas displacement, must or be replaced with the natural gas burner, then, just can carry out the source of the gas conversion work all burner transformations of transition region.Because manufactured gas, manufactured fuel gas or empty mixed gas and natural gas burning property difference are bigger, so the above two combustion gas tool must change the natural gas burner into, that is: nozzle, the fire hole cover of replacing family expenses kitchen range are changed system into the natural gas kitchen range with it; The nozzle of replacing pot-type boiler (main fire, ever-burning flame etc.), burner etc. are changed system into the natural gas water heater with it.

Conversion for resident's kitchen range generally has two kinds of methods, and the one, each professional kitchen range replacement personnel is responsible for some residents' kitchen range and replaces, and several replace composition of personnel group, finish the replacement work of certain sub-district kitchen range.Send out a turnover kitchen range for resident's each household, treat to regain again after the former kitchen range transformation of user is finished, be used for next conversion sub-district.The 2nd, before the supply natural gas, finish the transformation of side kitchen range in resident's eyes kitchen range, keep the opposite side kitchen range and still use manufactured gas, manufactured fuel gas or the empty gas that mixes, transform this side behind the natural gas to be used again, require one-sided kitchen range to be no more than for two weeks service time.The characteristics of the method are that conversion speed is fast, and it is many once to change amount, but before and after conversion in a period of time, and the user can only one-sided use kitchen range, make troubles to the user.Should formulate special conversion plan in advance for industry, Gongjian user, take corresponding measure with vaporous condition, shorten conversion time as far as possible, reduce user's economic loss at difference.

The Natural Gas Conversion work of Osaka, Japan Gas Company was carried out with the speed at 250,000 families every year on average since 1975, and nineteen ninety just all finishes, whole 15 years consuming time.Its job step: the one, original transmission and distribution network is carried out across-the-board regulation, comprise the serviceability that guarantees translate phase, what the conversion natural gas was set in the suitable place of pipe network diffuses hole and pressure tap, and in time adjusts pressure regulator outlet pressure etc. when conversion.The 2nd, original manufactured gas, manufactured fuel gas's burner is carried out across-the-board regulation, test and propose adjustment measure and way after various burners are used natural gas instead.Equally, the gas replacement scheme of Osaka, Japan has also been carried out the modernization overlay work to pipe network pipeline and user's burner, and its implementation process then is inevitable to the influence of stopping the supple of gas or steam that the user causes.

Oil field, North China in 1987 begins the transport gas to Beijing, form two zones that natural gas and manufactured gas, manufactured fuel gas supply simultaneously, Pekinese's Natural Gas Conversion work mainly comprises formulates conversion plan, door-to-door survey, the brush coating of registering one's residence, replacing sheepskin film table, the preceding user's rectification of conversion, on-the-spot consulting, gas appliance transformation etc., and each equipment producer participates in the transformation of equipment directly.Before the pipe network displacement, nozzle and the kitchen range lid with user's kitchen range left side pinkeye is replaced with the natural gas part earlier, and the coal gas tube connector of the water heater of dismantling simultaneously installs plug additional.The same day was changed right pinkeye part in the pipe network displacement, and finished the water heater transformation in two weeks.As seen, during the gas replacement of Beijing, user's two all heater insides can not use, and kitchen range also can only use one-sidedly in a period of time, and what this replacement scenario brought to the user is not conspicuous.320 yuan/family of user is collected in displacement expense aspect, Beijing, and wherein House Property unit pays 280 yuan, and 40 yuan of displacement expenses are paid by resident family.

PVG Natural Gas Conversion engineering in April, 99, the burner transformation mainly comprises the transposing of switch, nozzle, burner.The division of transition region then is 2000～15000 family/districts, and the cell switch cycle is 7 days, conversion every other week, and pipe network gas replacement day is Saturday.Except that the user's of unit specific (special) requirements, civil kitchen range, water heater conversion are from pipe network conversion day, and two burners of kitchen range are finished repacking simultaneously, and the repacking time was generally 3～4 days.For not influencing resident's normal life, have the simple eye kitchen range of natural gas and lease for the user, the water heater down time still is 3～7 days.Pudong District's Natural Gas Conversion has been spent time a year and a half, and corotation changes resident 329729 families, and 23,737 ten thousand yuan of gross investments are amounted to and are about 800 yuan/family.

At present, Guangzhou has manufactured gas, manufactured fuel gas user 66.5 ten thousand families, when liquefied natural gas supported fringe in 2006, estimates to have user 800,000 families.By " Guangzhou gas utilization project feasibility study report ", " Guangzhou gas utilization project Preliminary design book " and " Guangzhou gas replacement tentative programme " plan, after natural gas supports fringe, subregion burst substitute mode will be adopted in the Guangzhou, scheme is divided into 103 sections with the existing gas ductwork in Guangzhou, each displacement section number of users is 5000～9000 families, divides the displacement work of finishing in 5 years.Need augment 42 on valve, augment 9885 meters in pipeline, about 41,600 ten thousand yuan of gross investment.

Common practice according to domestic and international Natural Gas Conversion, in the process with gas replacement manufactured gas, manufactured fuel gas or empty mixed gas, at least must carry out three aspect work: the one, gas transmission pipeline net work is transformed, make it to be broken down into some independently zonules, progressively replace so that implement subregion by the replacement scenario requirement; It two is that user's burner is transformed or changed; The 3rd is giving out of gas when switching.

First content can reduce influence to user's air feed to greatest extent by adopting rational construction operation scheme, and as the operation etc. of stopping the supple of gas or steam night, but in any case, concerning gas enterprise, cost great amount of manpower and material resources, financial resources then are inevitable.Need in addition to expend a large amount of time generally investigate the underground pipe network data, formulate work element construction program, set up valve line, establishment is overall and the subregion replacement scenario, the difficulty of construction operation is well imagined especially: implementing this content needs one long period, this directly has influence on the process that entire city is used natural gas comprehensively, having influence on the image of government and enterprise, is all can bring tremendous influence to economic benefit, social benefit, environmental benefit.The work of Osaka, Japan Natural Gas Conversion spent for 15 years, the time that Beijing is used to replace also has 15 years, does not also finish at present, and the gas replacement work in Shanghai was from beginning in 99 years, estimate transit time and also will surpass 15 years, be 5 years the locomorphic stage that estimate the Guangzhou.As seen, the Natural Gas Conversion engineering is a hard engineering consuming time.Formulate science, economic replacement scenario is how important! Shorten time swap as possible, of far-reaching significance and great.

Second content also is that the work of difficulty maximum is transformed user's burner exactly, is not the technical difficulty of burner transformation itself, but exists two big factors directly to influence finishing smoothly of retrofit work.The firstth, it is pressed for time, in the shortest time, all user's burner transformations or replacing in the zone to be converted are finished, can not miss single household, as much as possible reduce influence degree to the user, this just needs to be equipped with great amount of manpower and material resources; The secondth, work of organization and coordination, how to adopt effective and efficient manner that the diversiform combustion gas user in the transition region is organized at short notice, the constituent parts staff who participates in retrofit work is organized, and with these two parts personnel effective coordination, make it close fit, finish the displacement task jointly, this involves the problem of every aspects such as replacement scenario, employing mechanism.The characteristics that distinctive unmanned family as the area, Guangdong (indoor nothing hang up one's hat people) is many, the difficulty of registering one's residence is big have determined the trifling and hard of regional burner retrofit works such as Guangzhou especially.

The 3rd content is that natural gas switches the preceding problem of diffusing to manufactured gas, manufactured fuel gas and natural gas in the desire replacement areas, and this will directly constitute potential safety hazard and the pollution that causes environment, the big and medium-sized cities that the density of population is bigger, and this problem is particularly outstanding.There is an energy waste problem in addition.Experience shows that in the gas replacement process, for middle compression ignite gas B level pipe network, the combustion gas of diffusing or burning is 2.8～3.5 times of replacement areas pipe network pipeline storage volumes.

There is a common drawback in conventional replacement scenario, and that need repeatedly enter in the user family exactly, brings unhappyly to the user, even causes that the user dislikes.Pipeline network of fuel gas in city as hundreds of thousands and even users up to a million, pipe network pipeline modification scheme no matter, burner modification scheme and replacement scenario be science how, how rigorous, final result always unavoidably can cause bigger influence to user's usefulness gas, make troubles to the user, be the repacking of water heater the most significantly, a conversion sub-district, 2000 families at least, family more than 20000 at most, no matter how many manpowers you drop into, how superb technical merit is, and having transformed more than 20000 water heater 3～5 day time of cost is very usual thing, can be for the user, the user of southern area such as Guangzhou particularly, it will be that 5 days autumn and winter seasons were not used water heater, user for which kind of impression, and what repercussion is arranged.

As seen, development, exploitation a kind of fully uninterrupted to all user's air feed of entire city, be to be badly in need of the difficult problem that solves to customer impact degree minimum, the significant gas replacement mode of minimum, the economic environmental benefit of fund input amount, far-reaching economy, politics, social effect are arranged!

Summary of the invention

The object of the present invention is to provide that a kind of conversion speed is fast, efficient is high, fund input amount is few, no potential safety hazard, economy and environmental benefit significantly, to the customer impact degree the low and continual combustion gas method of replacing of entire city gas supply.

Gas step-by-step replacement method of the present invention is replaced old source of the gas X with new source of the gas Z, may further comprise the steps:

(A), use the operating point of original burner of allotment gas Y to fall within the allotment gas Y stable combustion region (6) with the old source of the gas X of allotment gas Y direct replacement; Use the operating point of the Z source of the gas burner of allotment gas Y also to fall within the allotment gas Y stable combustion region (6).Described stable combustion region surrounds by taking off fiery limit curve (1), tempering limit curve (2), yellow flame limit curve (3) and CO limit curve (4); Described allotment gas Y is the gaseous mixture of old source of the gas X and new source of the gas Z, the white index W of China of allotment gas Y _YWith combustion potential CP _Y, be in the white index W of China of old source of the gas X respectively _X, combustion potential CP _XWith the white index W of the China of new source of the gas Z _Z, combustion potential CP _ZBetween the two;

(B) burner transformation, the best operating point in the smooth combustion district (8) when improved operation point of gas appliance being in use new source of the gas Z, and use that the operating point of burner is positioned at burner smooth combustion district (7) after the transformation of allotment gas Y;

(C) with new source of the gas Z direct replacement allotment gas Y.

Described old source of the gas X is the manufactured gas, manufactured fuel gas, comprises at least a in the following source of the gas: coke-stove gas, self-support retort gas, moving bed pressurized gasification producer gas, water-gas, producer gas, oil gas, refinery gas, speed venting, natural gas reforming gas, LPG upgrading gas, naphtha upgrading gas, lighter hydrocarbons upgrading gas etc.Typical component (percent by volume) is respectively: 40.35%H ₂, 20.90%CH ₄, 18.3%C ₂H ₄, 1.7%C ₂H ₆, 2.5%C ₃H ₆, 8.5%CO, 4.8%CO ₂, its higher calorific value 29.68MJ/Nm ³, Lower heat value is 27.09MJ/Nm ³, the white index of China is 39.58MJ/Nm ³, the combustion heat is 87.15.

Described old source of the gas X can also be the empty gas that mixes, i.e. liquefied petroleum gas and Air mixing gas, and X=LPG+AIR, typical component (percent by volume) is respectively: 0.29%C ₂H ₆, 18.79%C ₃H ₈, 7.03%iC ₄H ₁₀, 16.07%nC ₄H ₁₀, 0.11%C ₅H ₁₂, 12.12%O ₂, 45.22%N ₂, its higher calorific value 50.24MJ/Nm ³, Lower heat value is 46.34MJ/Nm ³, the white index of China is 43.12MJ/Nm ³, the combustion heat is 39.05.

Described new source of the gas Z is a natural gas, and typical component (percent by volume) comprises 88.77%CH ₄, 7.54%C ₂H ₆, 2.59%C ₃H ₈, 0.45%iC ₄H ₁₀, 0.56%nC ₄H ₁₀, 0.07%N ₂, its higher calorific value 44.61MJ/Nm ³, Lower heat value is 40.39MJ/Nm ³, the white index of China is 56.05MJ/Nm ³, the combustion heat is 41.85.

When old source of the gas is the manufactured gas, manufactured fuel gas, the allotment gas Y=aX+bZ of employing, source of the gas proportioning n=b/a=2.2～2.8, i.e. manufactured gas, manufactured fuel gas: natural gas=1.0: (2.2～2.8), and by liquefied petroleum gas and air regulation calorific value and allotment combustion characteristics.

Old source of the gas is empty when mixing gas, the allotment gas Y=aX+bZ of employing, a=[0,1], b=1-a=[1,0], source of the gas proportioning value n=b/a, preferred 2.5～9.3, the promptly empty gas that mixes: natural gas=1.0: (2.5～9.3), and by liquefied petroleum gas and air regulation calorific value and allotment combustion characteristics.When old source of the gas is empty when mixing gas, new source of the gas (natural gas) can directly be replaced old source of the gas, but operation point of gas appliance is not in the optimum position, burner still need be changed or be reequiped, and in such cases, allotment gas can be new source of the gas, also can be old source of the gas, also can be new, old source of the gas gaseous mixture.

Enforcement of the present invention will bring very significantly economy, society and environmental benefit to country, enterprise, user, to promoting national science and technology progress, the development of promotion social productive forces positive role be arranged, and help to quicken the development process of China's natural gas cause.

(1) economic benefit

1. save the conversion engineering cost

Empirical data by domestic and international Natural Gas Conversion engineering cost, the gas ductwork (the above scale in 500,000 families) of a large-scale or megapolis, substitute mode is routinely finished the Natural Gas Conversion engineering, the 520 yuan/family of need injecting capital into approximately (comprising user's burner improvement expenses).After adopting the present invention, because of having reduced the link that gas distribution system, gas network is transformed, saved great amount of manpower and material resources, the burner modification scheme of science has been accelerated the transformation progress of user's burner especially, thereby fund input amount greatly reduces.After the invention process, conversion charges is about 280 yuan/family.The pipeline network of fuel gas in city of one 800,000 family scale, only this item just can be saved ten thousand yuan of fund 220 * 80=17600.

2. stop the source of the gas waste

Adopt conventional gas replacement mode to finish conversion work, in the process of implementing to switch, need diffuse or burn a large amount of manufactured gas, manufactured fuel gases and natural gas.Statistics shows that middle pressure B level gas ductwork diffuses the combustion gas that slatterns and is about 2.8～3.5 times of effective storage volumes of pipe network.The pipeline network of fuel gas in city of one 800,000 family scale, the effective storage volumes of pipe network that is positioned at replacement areas is about 15000m ³, the combustion gas of waste is about 4.2～5.2 ten thousand m ³, amount to about 8.0 ten thousand yuans of RMB.

3. save peak regulation and emergency duty source of the gas factory construction fund

Air feed characteristics according to pipeline network of fuel gas in city, in general, the natural gas gas enterprise need be built corresponding peak regulation and emergency duty source of the gas factory, with the non-uniformity problem of solution pipe network user usefulness gas and the emergent air feed problem under the natural gas long-distance transport pipes accident condition, this need drop into bigger construction fund.After adopting the present invention, then do not need to build again again emergency duty source of the gas factory, fully can be original manufactured gas, manufactured fuel gas or empty mixing on the gas source of the gas factory basis, dropping into a spot of fund is transformed or is extended, with the emergent air feed under allotment gas instead of natural gas peak regulation or the long-distance transport pipes accident condition, save a large amount of construction funds with this.

(2) social benefit

1. shorten the Natural Gas Conversion time

The pipeline network of fuel gas in city of one 800,000 family scale, substitute mode is routinely finished the Natural Gas Conversion engineering, at least needed for 5 years, after that is to say that natural gas arrives at a city, later on whole residents just can use natural gas in 5 years, and behind employing the present invention, can finish conversion work in 8～10 months, shift to an earlier date more than 4 years than conventional conversion regime.As seen, this measure is very favourable to the image that improves government and gas enterprise.Fulfil the Natural Gas Conversion engineering ahead of schedule, shortening this project all is a significant thing to the interference time in a city in state in the people.

2. reduce influence to greatest extent to the user

The Natural Gas Conversion process is the process of a complexity, can impact the combustion gas user unavoidably therebetween, carries out the repacking family that burner is transformed for needs, and this influence is particularly outstanding.Conventional substitute mode, the professional of gas company enters the indoor number of times in repacking family and is generally 3～4 times, and the water heater down time was generally 3～7 days, and adopt the inventive method to finish conversion, enter repacking and the indoor time of family be generally once, maximum twice, water heater uses unaffected.As seen, compare, user's influence has been dropped to bottom line with conventional method.

3. quicken natural gas enterprise and reach the paces of scale management

Natural gas enterprise has typical scale management feature.After adopting the present invention, the natural gas large-scale or megapolis is managed enterprise, the time that can shift to an earlier date more than 4 years is comprehensively to city supply natural gas, make whole gas distributing system reach certain scale of operation at short notice, eliminate " cumulative phase " in the traditional gas utilization process, remove and help combustion gas sale enterprise reduction operating cost, improve outside the business economic benefit, to being responsible for natural gas extraction, purified treatment, the upstream enterprise that long-distance transport pipes are carried, tangible economic benefit is all arranged, accelerated the paces that each enterprise in the natural gas industrial chain reaches scale management greatly.

4. promote the national science and technology progress, promote the social productive forces development

After adopting the present invention, can quicken China's natural gas significantly and utilize paces, advance the China's natural gas cause to advance, advance, novelty, practicality, economy because of its technology, it has crucial politics, economic implications to promoting the national science and technology progress, promoting the social productive forces development.

(3) environmental benefit

1. avoid combustion gas directly to diffuse, reduce pollution atmosphere

Adopt conventional substitute mode, the pipeline network of fuel gas in city of one 800,000 family scale is finished in the Natural Gas Conversion process, need diffuse and the combustion gas that slatterns reaches 5.2 ten thousand m ³, this atmosphere environment impact to the bigger city of whole atmospheric environment, the particularly density of population is immeasurable.After adopting the present invention, can stop this type of fully and diffuse, hence one can see that, and its environmental benefit is significant.

2. eliminate safe hidden trouble

Giving out of gas in the conventional substitute mode, except that bringing environmental issue such as atmosphere pollution, bigger problem is to have potential safety hazards such as blast, fire, therefore, can thoroughly eliminate this class hidden danger, be a tangible technological progress of the present invention, and social influence is far-reaching.

3. close with serious pollution manufactured gas, manufactured fuel gas's source of the gas factory in advance

The present invention is used for the conversion of natural gas and manufactured gas, manufactured fuel gas's pipe network, because of before time of city full use natural gas pushes away, like this, just can close in advance exist large amount of sewage and toxic emission, with serious pollution manufactured gas, manufactured fuel gas's source of the gas factory, in addition, because of natural gas is a clear energy sources, good during burning than manufactured gas, manufactured fuel gas or empty mixed gas sanitary index, from this respect, can improve the entire city air quality, we can say that it is huge adopting the overall environmental benefit that produces behind the present invention!

Description of drawings

Fig. 1 is operating point and the combustion pattern figures of different sources of the gas at same burner.

Fig. 2 is the establishment schematic diagram of allotment gas formation and proportioning.

Fig. 3 is the operation point of gas appliance and the combustion pattern figure of source of the gas step-by-step replacement of the present invention.

The specific embodiment

(1) according to the interchangeability of gas theory, source of the gas-manufactured gas, manufactured fuel gas's source of the gas of existing gas ductwork supply is elected to be the reference gas into manufactured gas, manufactured fuel gas's burner, find its source of the gas and form, calculate higher calorific value, Lower heat value, magnificent index, gas density, relative density, the combustion potential etc. in vain of source of the gas by the correlation computations formula.The correlation computations formula is:

The white index of China $W=\frac{\mathrm{Qg}}{\sqrt{d}}$

In the formula: W---Wobbe index, MJ/m ³(kcal/m ³)

Qg---combustion gas high heating value, MJ/m ³(kcal/m ³)

D---combustion gas relative density.(the air relative density is 1)

Combustion potential $\mathrm{Cp}=K\&times;\frac{1.0{\mathrm{<figure-callout\; id="2"\; label="H"\; filenames="C20041001546900251.png"\; state="\{\{state\}\}">H</figure-callout>}}_2+0.6(\mathrm{CmHn}+\mathrm{CO})+0.3C{H}_4}{\sqrt{d}}$

K＝1+0.0054O ₂ ²

In the formula: the Cp---combustion potential;

H ₂--hydrogen content in the-combustion gas, % (volume);

C _mH _n--the hydrocarbons content the in-combustion gas except that methane, % (volume);

In the CO---combustion gas-and content of carbon oxide, % (volume);

CH ₄--methane content in the-combustion gas, % (volume);

D---combustion gas relative density (the air relative density is 1);

Oxygen content correction factor in the K---combustion gas;

O ₂--oxygen content in the-combustion gas, % (volume).

(2) with natural gas to be converted reference gas as selected natural gas burner, find its source of the gas and form, calculate the higher calorific value of natural gas, Lower heat value, the white index of China, gas density, relative density, combustion potential etc. by the correlation computations formula;

(3) use the manufactured gas, manufactured fuel gas according to the pipe network that has calculated--the relevant physical parameter of-reference gas, according to " national standard " " gas classification " classificating requirement (GB/T13611-92), determine this manufactured gas, manufactured fuel gas's classification, and find the white index W of China of this classification combustion gas and standard value and the fluctuation range of combustion potential Cp;

(4) according to the relevant physical parameter of the natural gas to be converted that calculated, according to " national standard " " gas classification " classificating requirement (GB/T13611-92), determine in the future gas ductwork with the natural gas classification of using, and find the white index W of China of this class natural gas and standard value and the fluctuation range of combustion potential Cp;

(5) according to the existing source of the gas kind of source of the gas factory, source of the gas actual production facility situation, comprise each source of the gas composition and physical parameter, the production capacity of device, the raw material sources situation, influence degree to environmental protection, the present situation of source of the gas production cost and prediction, consider the source of the gas kind transitivity parameter that does not increase big investment and may increase again, adopt computer technology to each source of the gas kind allotment gas physical parameter and the allotment pneumatolytic under various different allotment ratios (might realize) situation originally carry out trend analysis, emphasis is a physical parameter, promptly allocate the gas calorific value, the white index of China, relative density, the theoretical air requirement, combustion potential etc., (the judgement of smooth combustion under the prerequisite that satisfies existing pipe network manufactured gas, manufactured fuel gas burner smooth combustion, foundation: the permission fluctuation range with regulation in " national standard " " gas classification " (GB/T13611-92) combines with corresponding combustion pattern test result), by microcomputer data processing, optimize the allotment gas physical parameter scope that might be able to satisfy the smooth combustion on the natural gas burner of this allotment gas and allocate each source of the gas formation in the gas, the mixed ratio scope;

(6) white index W of allotment gas China and combustion potential CP's determines

(1), " manufactured gas, manufactured fuel gas+natural gas " gaseous mixture: 1. allocate the white index W of gas China greater than 21%～25% of manufactured gas, manufactured fuel gas's burner reference gas, and less than 11%～15% of natural gas burner reference gas; 2. combustion potential CP is less than 28.0%～35.8% of manufactured gas, manufactured fuel gas's burner reference gas, and greater than 33.0%～48.5% of natural gas burner reference gas;

(2), " empty mix gas+natural gas " gaseous mixture: 1. allocate the white index W of gas China for " be lower than 5.0% of empty gas burner reference gas W of mixing and natural gas burner reference gas W median, and be higher than its 4.0% "; 2. combustion potential index CP is unrestricted, recommend to get both medians ± 10.0% scope in;

What (7) allotment gas source of the gas constituted determines

(1), mix gassiness, 1. allotment gas source of the gas constitutes " natural gas+natural gas reforming gas " gaseous mixture for " manufactured gas, manufactured fuel gas+natural gas "; Or 2. " natural gas+natural gas reforming gas+oil gas (coke-stove gas) " gaseous mixture; Or 3. " natural gas+refinery gas " gaseous mixture.The source of the gas proportioning is: the manufactured gas, manufactured fuel gas: natural gas=1.0: (2.2～2.8), and by liquefied petroleum gas LPG or air regulation calorific value and allotment combustion characteristics;

(2), for " empty mix gas+natural gas " gaseous mixture, allotment gas source of the gas constitutes " natural gas+sky mixes gas " gaseous mixture; Recommend the source of the gas proportioning to be: the empty gas that mixes: natural gas=1.0: (2.5～9.3), by liquefied petroleum gas LPG or air regulation calorific value and allotment combustion characteristics;

(8) natural gas determination of ratio in the allotment gas source of the gas proportioning

(transfer process with manufactured gas, manufactured fuel gas and natural gas is an example)

The formation of allotment gas is mixed by certain proportioning by natural gas and manufactured gas, manufactured fuel gas, and the manufactured gas, manufactured fuel gas then includes at least a in the multiple sources of the gas such as upgrading gas, oil gas, coke-stove gas, refinery gas.

As shown in Figure 2, in the manufactured gas, manufactured fuel gas, sneak into natural gas, form " natural gas+manufactured gas, manufactured fuel gas " gaseous mixture, this gas is supplied with manufactured gas, manufactured fuel gas's burner and the burning of natural gas burner simultaneously, we can find: along with the progressively increase of natural gas mixed volume (natural gas proportion B), (1) for the natural gas burner, the natural gas proportion is less than B ₁The time, burner can not normal combustion, and reaches B ₁The time, operation point of gas appliance begins to enter stable combustion region.It is pure natural gas that B reaches at 100% o'clock, and its operating point is positioned at this regional centre, promptly enters the best combustion operating mode; (2) for manufactured gas, manufactured fuel gas's burner, the natural gas proportion is 0 o'clock, and operation point of gas appliance is in the center position of stable combustion region, and promptly be the best combustion operating mode this moment, and along with the increasing of B, operation point of gas appliance is offset gradually, and combustion conditions aggravates, and reaches B ₂The time, operation point of gas appliance begins to break away from stable combustion region, and burner can not normal combustion.

And at B ₁～B ₂This section zone, two class burners can smooth combustions, and we are with natural gas proportion B ₁＜B＜B ₂The mist in this section interval is referred to as to allocate gas, and this gas can satisfy manufactured gas, manufactured fuel gas's burner and the smooth combustion of natural gas burner simultaneously.

Scope (the B of allotment gas source of the gas proportioning B ₁～B ₂) size constitutes with manufactured gas, manufactured fuel gas's source of the gas and manufactured gas, manufactured fuel gas's burner reference gas, natural gas burner reference gas have direct relation.After two class burner reference gases were determined, then the source of the gas by the best constituted the B that can optimize widest in area, science ₁～B ₂Irrational source of the gas constitutes, and then B might occur ₂＜B ₁Situation, promptly do not have the allotment gas that can meet the demands to exist.

Indivedual and the excessive manufactured gas, manufactured fuel gas of combustion of natural gas property difference also is to satisfy B ₂＞B ₁Condition, promptly do not have preferably to allocate the switch transition source of the gas that gas is used for natural gas and manufactured gas, manufactured fuel gas.

Be illustrated in figure 3 as the operation point of gas appliance and the combustion pattern variation diagram of gas displacement process.Source of the gas X is as the reference gas of artificial burner, and operation point of gas appliance ax is in the center position of stable combustion region 5, and promptly be the best combustion operating mode this moment.If X directly burns on the natural gas burner with this source of the gas, then its operating point is in ax ', has broken away from stable combustion region, and this moment, burner can not normal combustion.And with source of the gas Y displacement source of the gas X.As Y during in artificial burner burning, operating point ay is in the stable combustion region 6, but has departed from the center, promptly non-best combustion operating mode.At this moment, manufactured gas, manufactured fuel gas's burner is transformed into the natural gas burner, source of the gas Y burns on the natural gas burner, and operating point ay ' is although near the edge of stable combustion region 7, but still is in the stable combustion region 7.That is, source of the gas Y can go up burning at manufactured gas, manufactured fuel gas's burner and improved natural gas burner (or natural gas burner of newly purchasing) simultaneously, but all is not in best operating point.At this moment, if again with source of the gas Z displacement source of the gas Y, because natural air-air source Z is the reference gas of natural gas burner, so its operating point is on the best operating point az ' of stable combustion region 8, promptly is in the best combustion operating mode.If without the displacement of source of the gas Y, with source of the gas Z direct replacement source of the gas X, then operating point will fall within on the az, outside stable combustion region.

The present invention is according to different manufactured gas, manufactured fuel gas's kinds, the allotment gas physical parameter that computerized optimization is come out, can satisfy manufactured gas, manufactured fuel gas's burner and the smooth combustion of natural gas burner is simultaneously in theory analyzed reckoning, determine each the source of the gas proportioning that constitutes this allotment gas, and make corresponding test gas by " distribution " method, simultaneously carry out the combustion characteristics test can representing on actual manufactured gas, manufactured fuel gas's burners that use, a plurality of brands of gas ductwork and the natural gas burner, promptly carry out actual verification with allocating gas Y.

Content of the test and requirement

(1), according to " international standard " " household gas utensils " (GB16410-1996) and " the general test method of domestic gas apparatus " (GB/T16411-1996) requirement, with natural gas content is the gas of B1, and the natural gas kitchen range are carried out following content of the test:

1. burner heat flow test

2. burner thermal efficiency test

3. burner combustion conditions test

I, flame transmission: after lighting main burner one place's fire hole, test flame is delivered to the time of whole fire holes and has or not detonation, and ignition method is undertaken by the regulation of each burner standard.

II, flame-out: whether after main burner is lighted 15s, estimating each fire hole all has flame.

III, from flame: after cold conditions was lighted main burner 15s, range estimation had 1/3rd fire holes to be from flame from flame.

IV, flame status: after main burner was lighted, whether range estimation flame clear, even, have or not Lian Yan.

V, tempering: after main burner is lighted 20min, the whether tempering of range estimation flame.

VI, combustion noise: after all burner was lighted 15min, content of the test comprised that the maximum noise of combustion noise should meet the regulation of each burner standard.

VII, flame-out noise: the operation of stopping working after main burner is lighted 15min presses related request and measure flame-out noise, and test has or not the detonation noise.

Carbon monoxide content in VIII, the dry flue gas: after main burner is lighted 15min, should be as far as possible equably adopt the flue gas sample and analyze, and calculate the carbon monoxide in the flue gas and the content of oxygen by the correlation computations formula in the smoke evacuation position.

IX, Huang Yan with contact yellow flame: light in main burner begins during the 15min from cold conditions, whether the visual Huang Yanhou that has or not puts Huang Yanshang with bright cold metal plate, be yellow flame state to have or not carbon black to judge; In any 1min, the yellow flame of electrode or heat exchanger Continuous Contact is when 30s is above, for electrode or heat exchanger contact yellow flame.

X, black smoke: light in main burner begins during the 30min from cold conditions, put on the kitchen range or erasing heat exchanger gap has judged whether that black smoke generates with clean pot.

XI, start-up burner test: after start-up burner was lighted 15min, the range estimation start-up burner had or not tempering, flame-out when burning separately.After lighting main burner with start-up burner, test when main burner is flame-out, whether tempering, flame-out of start-up burner.

If all contents of the test all meet " GB " requirement, then allocate gas source of the gas proportioning---natural gas ratio B ₁Then be allotment gas starting point ratio.The part test content is undesirable, then according to above-mentioned content of the test, at the different problems that exist in the test, effectively adjusts the test gas source of the gas and constitutes, or suitably increase B ₁, repeat test, qualified until result of the test, determine allotment gas ratio lower limit with this.

(2), based on same consideration, be B with natural gas content ₂Gas manufactured gas, manufactured fuel gas's kitchen range are carried out identical test.If the part test content is undesirable, then with B ₂Suitably reduce or source of the gas constituted and carry out necessary adjustment, all meet the requirements, determine the allotment gas ratio upper limit with this until content of the test.

Through natural gas proportion B in verification experimental verification, each source of the gas formation of allotment gas that can satisfy this two classes burner smooth combustion requirement and the allotment gas ₁～B ₂, be formation and the ratio range of the allotment gas Y that will develop;

(9) in order to make allotment gas perfectly safe in the actual use of gas ductwork, with each source of the gas ratio range B of the above-mentioned allotment gas of developing ₁～B ₂Suitably narrow, improve its safety factor, and with its as manufactured gas, manufactured fuel gas and natural gas the allotment gas control system index in the transitional period, formulate source of the gas factory production run scheme and production schedules, operational procedure etc. in the transitional period with this, with this allotment gas supply pipeline network of fuel gas in city, as transitional gas source;

(10) in establishment source of the gas factory allotment gas production run scheme, the overall operation scheme that the establishment pipeline network of fuel gas in city is used allotment gas instead, the modification scheme that comprises regulator, measuring instrument system, the conversion plan at industry, public merchant, public good fortune family, the adjustment scheme of combustion gas price, the medium bulletin, the propaganda scheme that adapt with it, all kinds of plans for emergency handling etc.;

(11) the overall replacement scenario of establishment entire city gas ductwork, emphasis comprise that pipe network uses the concrete technical scheme of natural gas instead at all kinds of burners of usefulness;

(12) by existing plan, source of the gas factory changes allotment gas supply pipeline network of fuel gas in city into, paying close attention to source of the gas factory produces dynamically and pipe network combustion gas user's result of use, for a small amount of not burner of adaptive new source of the gas, gas company sends the professional person to handle to the doorstep rapidly, adjust air door, change burner and repacking burner etc., the problem that the burner that can not normally use individually in the whole pipe network of the whole solutions of planted agent in 1～2 day exists;

(13) according to the arrangement of the overall replacement scenario of natural gas, to the entire city gas ductwork using burner, comprise industrial burner, the burner at public merchant, public good fortune family etc. is reequiped or is changed, and makes it to become the natural gas burner.The principle that repacking is changed is: preferentially solve for the allotment less-than-ideal burner of gas firing operating mode and the burner of the certain customers of considerable influence power is arranged;

(14) scheduling of repacking burner: formulate work quota for a group with per two people, adopt the incentive mechanism that exceeds the quata with lottery.Every group of every day transform quota and be about 12 families (gas kitchen ranges of each household, a water heater), register one's residence number of times once, promptly entered the same day, finished the repacking task same day.If the repacking troop scale by 500 people is calculated, reequip 3000 families every day, the pipeline network of fuel gas in city of one 800,000 family scale is changed 60% transformation family meter by 40%, need 160～180 days approximately, be six months, consider beyond thought difficulty such as indivedual repackings family and unmanned family, the gas ductwork of one 800,000 family scale, 8～10 months transition periods are enough, can avoid air feed peak and during the Spring Festival in winter;

(15) treat that all burners in the entire city gas ductwork are all reequiped or are replaced by satisfactory natural gas burner and confirm after, by " GB " requirement, whole pipe mesh pressure adjust device is adjusted, promptly improved oven former pressure to satisfy natural gas kitchen range burning demand;

(16) after the whole gas ductwork of affirmation possessed the Natural Gas Conversion condition, source of the gas factory stopped to produce allotment gas, and pipe network directly is converted to the natural air-air source supply.After this, user's burner combustion conditions reaches best point;

(17) after natural air-air source conversion finishes, once reequip again or adjust, make it to reach satisfactory state, pipe network user burner, combustion case are confirmed once by medium etc. more again for indivedual less-than-ideal user's burners of combustion conditions in the pipe network;

(18) all users in gas transmission and distribution pipe network and the pipe network carried out once comprehensively safety inspection and confirm after, promptly indicate the ad unguem of entire city gas ductwork Natural Gas Conversion engineering.

Embodiment 1

The source of the gas that area, Guangzhou gas ductwork uses at present is heavy oil pyrolysis gas (oil gas), by " GB " sorting technique, this manufactured gas, manufactured fuel gas is near first family manufactured gas, manufactured fuel gas 7R classification, and the liquefied natural gas from Australian import that the Guangzhou will be used after 2006 belongs to second family natural gas 12T classification (near the 13T classification) in " GB ".

1, allotment gas determines

(1) white index of allotment gas China and combustion potential determines

According to the physical parameter of area, the Guangzhou in the table 2 gas ductwork reference gas-oil gas, this manufactured gas, manufactured fuel gas's higher calorific value is 29.68MJ/m ³(7088kcal/m ³), the white index W of China is 39.58MJ/m ³(9453kcal/m ³), combustion potential Cp is 87.15, relative density 0.56; Area, Guangzhou liquefied natural gas higher calorific value to be converted is 43.47MJ/m ³(10382kcal/m ³), the white index W of China is 55.15MJ/m ³(13172kcal/m ³), combustion potential Cp is 41.85, relative density is 0.63.

Calculate with the correlation technique index in the research conclusion of the present invention, the white index W of China and the combustion potential Cp that are used for the transitional supply source of the gas of Natural Gas Conversion-allotment gas should satisfy following condition

W ₁＝9453〔(1+21％)～(1+25％)〕＝11438～11816

W ₂＝13172〔(1-15％)～(1-11％)〕＝11149～11723

Get: W=11460～11720

CP＝41.85〔(1+33.0％)～(1+48.5％)〕＝55.66～62.15

Cp＝87.15[(1-35.8％)～(1-28.0％)]＝55.95～62.75

Get: CP=56～62

What (2) allotment gas source of the gas constituted determines

According to white index W of developing of allotment gas China and combustion potential Cp control indication range, adopt microcomputer data processing, to Guangzhou gas ductwork source of the gas factory--the parameter of each source of the gas process units of-Guangzhou oil gas factory is carried out analyzing and processing, consider and utilize natural gas and the preferential lower factors such as source of the gas process units source of the gas of use cost to greatest extent, consider allotment gas production capacity and the air feed scale problem that adapts again, determine that Guangzhou allocates the source of the gas of gas and constitute " natural gas+natural gas reforming gas+oil gas+LPG+AIR " gaseous mixture in the natural gas transitional period of area.Wherein LPG and AIR are used for regulation and control allotment gas calorific value and adjust combustion characteristics.Generally speaking, the LPG proportion is 0; When oil gas is used for upgrading gas process units fault, be complementary by its regulation and control total productive capacity and air feed demand, generally speaking, the oil gas proportion is 0.

(3) the determining of each source of the gas proportioning in the allotment gas

Following table 4 is established the principle form of area, Guangzhou allotment gas source of the gas proportioning for computer system.

Table 4: several sources of the gas in area, Guangzhou are formed and burning performance parameter

2	CH 4		16.35	88.77	4.70	0		66.63
									3	CO	15.28	0	18.51	0		4.87
4	CO 2		7.72	0	7.82	0		2.06
									5	N 2	4.18	0.07	3.11	0	79.00	0.89
6	C 2H 4		7.83	0	0.24	0		0.04
									7	C 2H 6	0.73	7.54	0.07	0.69		5.57
8	C 3H 6		0.45	0	0.19	0		0.05
									9	C 3H 8	0.31	2.59	0.47	44.43		2.03
10	iC 4H 10		1.19	0.45	0.14	16.77		0.33
									11	nC 4H 10	1.13	0.56	2.00	37.85		0.98
12	C 5		0.09	0	0.03	0.26		0.01
									13	O 2	0.45	0	0.08	0	21.00	0.03
14	Higher calorific value H h(MJ/Nm 3)		23.44	44.62	15.91	118.81		37.05
									15	Lower heat value H l(MJ/Nm 3)		21.31	40.39	14.22	109.59		33.49
16	White index W (the MJ/Nm of China 3)		30.84	56.00	23.54	87.17		48.35
									17	Combustion potential C p		86.13	41.85	113.99	44.17		58.48
18	Gas density (kg/Nm 3)		0.7472	0.8192	0.5911	2.3856	1.2927	0.7593
									Output (ten thousand m 3/ day)			A	B	C	D	E	M

Allotment gas component, combustion characteristics etc. depend on the formation of five kinds of sources of the gas, i.e. each source of the gas component, output etc., and computing formula is:

Allotment gas f _i=(a _i* A+b _i* B+c _i* C+d _i* D+e _i* E)/M

In the formula: a _i, b _i, c _i, d _i, e _jBe the parameter value of each source of the gas in the i sequence number;

A, B, C, D, E are each source of the gas output, wherein total output M=A+B+C+D+E

Computer is according to the control index request of allotment gas, and each source of the gas parameter and corresponding calculated formula according in the table 4 utilize dedicated program, can optimize each the source of the gas proportioning that satisfies allotment gas index request.

Specific to the Guangzhou gas ductwork, in above-mentioned five kinds of sources of the gas, the component of every kind of source of the gas or proportion change, and all can directly have influence on gaseous mixture---allocate the burning performance parameter of gas, have influence on the operating point of burner.Scope according to magnificent white index W of the definite allotment gas of aforementioned part and combustion potential CP: W=11450～11800; Cp=56～62.By computerized optimization technique, optimize each source of the gas proportioning of allotment gas that can satisfy burner smooth combustion and be:

(oil gas+upgrading gas): natural gas=1.0: (2.2～2.8)

That is: B1=2.2 B2=2.8

With natural gas content is B ₁～B ₂Allotment gas according to " GB " requirement, on manufactured gas, manufactured fuel gas's kitchen range and natural gas kitchen range, carry out simultaneously the combustibility test, verified.

Generally speaking, oil gas output=0, promptly the oil gas process units need not start.By LPG or AIR regulation and control allotment gas Lower heat value is 33.49～34.54MJ/Nm ³(8000～8250kcal/Nm ³), higher calorific value is 37.10～38.18MJ/Nm ³(8860～9120kcal/Nm ³).The gaseous mixture that source of the gas factory produces by above-mentioned source of the gas proportioning is the transitional supply source of the gas of Guangzhou area Natural Gas Conversion---allotment gas Y, existing burner of adaptive Guangzhou gas ductwork and the smooth combustion of 12T classification natural gas burner simultaneously.

2, the production of allotment gas

Natural Gas Conversion is in the transitional period, and source of the gas factory formulates corresponding production control index, establishment production scheduling scheme, opens the associated production device by operational procedure by the technical parameter of above-mentioned allotment gas, to the qualified allotment gas of pipe network supply.It should be noted that the oil gas process units does not start generally speaking, unless: 1. oil gas source of the gas cost is lower than the natural gas reforming pneumatolytic originally; 2. source of the gas factory allotment gas inefficiency of production is to satisfy pipe network gas demand.

3, the transformation of gas ductwork burner and replacing

After the pipe network source of the gas changes allotment gas supply into by the manufactured gas, manufactured fuel gas, to the transformation of user's burner or more change jobs and just can carry out in full preparation.According to the service life regulation of country to burner, manufactured gas, manufactured fuel gas's burner is scrapped the time limit, water heater 8 years, gas-cooker 6 years.User's burner in the gas ductwork of Guangzhou handled in the following way: 1. reach and scrap the time limit, involuntary conversion; 2. do not reach or be about to reach and scrap the time limit, encourage the user to upgrade at a reduced price; 3. upgrade being unwilling really and do not reach user's burner of scrapping the time limit and transform.

Burner transformation and the basic principle and the target that more change jobs are: the means that adopt all to employ, with the time be exactly the idea and the consciousness of benefit, accelerate burner transformation and replacing progress to greatest extent.The scheduling of Guangzhou gas ductwork is 6～8 months.

4, the security affirmation of gas ductwork and regulator pressure stage system are adjusted

After the burner retrofit work was finished, can the security of spending 1～2 month satisfy the natural gas service requirement to whole pipe network check comprehensively and add their confirmation, and the pressure stage system of whole pipe mesh pressure adjust device is carried out necessary adjustment, to adapt to the Natural Gas Conversion requirement.

5, source of the gas switches

After possessing switch condition, source of the gas factory stops to allocate gas production, changes the natural gas supply gas ductwork into, and whole handoff procedure is undisturbed, can not have any impact to the user, and finishing of switch operating then means the smooth end of Natural Gas Conversion engineering.By substitute mode of the present invention, the time that the Guangzhou gas ductwork is finished Natural Gas Conversion is 10 months.

Embodiment 2

The empty gas replacement scheme of mixing the gas gas ductwork in ground such as Guangdong Zhong Shan, Fanyu

The source of the gas that ground gas ductworks such as Guangdong Zhong Shan, Fanyu use at present is the empty gas (" LPG+AIR " gaseous mixture) that mixes.By " GB " sorting technique, this combustion gas is near second family natural gas 10T classification (near the 13T classification), and after 2006, the liquefied natural gas from Australian import will be used in above-mentioned area, belongs to second family natural gas 12T classification in " GB ".As seen, two kinds of sources of the gas do not belong to same classification, can not directly change.

Ground skies such as middle mountain, Fanyu mix the gas component and burning performance parameter sees the following form 5.

Table 5: empty gas component and the burning performance parameter of mixing in ground such as middle mountain, Fanyu

Project	H 2	CH 4	C 2H 4	C 2H 6	C 3H 8	C 3H 6	O 2	N 2	iC 4H 10	nC 4H 10	Higher calorific value	Lower heat value	The white index of China	Combustion potential	Relative density
																(％)										MJ/Nm 3(kcal/Nm 3)
	The empty gas that mixes	0	0	0	0.29	18.7	0.02	12.12	45.22	7.03	16.18	50.24 (12000)	46.34 (11069)																43.12 (10300)	39.05	0.5838
Natural gas														0	88.77	0	7.54	2.59	0	0	0.07	0.45	0.56	44.61 (10656)	40.39 (9647)	56.05 (13387)	41.85	0.6335

1, allotment gas determines

(1) white index of allotment gas China and combustion potential determines

Mix the gas physical parameter according to ground gas ductwork reference gas-skies such as the middle mountain in the table 5, Fanyu, this combustion gas higher calorific value is 50.24MJ/m ³(12000kcal/m ³), the white index W of China is 43.12MJ/m ³(10300kcal/m ³), combustion potential Cp is 39.05, relative density 0.58; And liquefied natural gas higher calorific value to be converted is 43.47MJ/m ³(10382kcal/m ³), the white index W of China is 55.15MJ/m ³(13172kcal/m ³), combustion potential Cp is 41.85, relative density is 0.63.

Calculate with the correlation technique index in the research conclusion of the present invention, the white index W of China and the combustion potential Cp that are used for the transitional supply source of the gas of Natural Gas Conversion-allotment gas should satisfy following condition

W＝(10300+13172)/2×〔(1-5.0％)～(1+4.0％)〕＝11150～12205

Get: W=11200～12200

The CP index is unrestricted

Get: CP=35～38

What (2) allotment gas source of the gas constituted determines

According to white index W of developing of allotment gas China and combustion potential Cp control indication range, adopt microcomputer data processing, parameter to two places gas ductwork source of the gas factory process units is carried out analyzing and processing, consider and utilize the natural gas factor to greatest extent, determine that the source of the gas of allotment gas in the two places natural gas transitional period constitutes " natural gas+sky mixes gas (LPG+AIR) " gaseous mixture.

(3) the determining of each source of the gas proportioning in the allotment gas

Computer utilizes dedicated program according to the control index request of allotment gas, optimizes each source of the gas proportioning that can satisfy two places allotment gas index request to be: the white index W of allotment gas China=11200～12200; Combustion potential CP=35～38.By computerized optimization technique, optimize each source of the gas proportioning of allotment gas that can satisfy two class burner smooth combustions and be:

(LPG+AIR): natural gas=(1+2): (2.50～5.33)

That is: B ₁=2.50 B ₂=5.33

Allotment gas Lower heat value is 39.29～39.78MJ/Nm ³(9384～9501kcal/Nm ³), higher calorific value is 43.18～43.82MJ/Nm ³(10314～10467kcal/Nm ³).

With natural gas content is B ₁～B ₂Allotment gas according to " GB " requirement, mix simultaneously and carry out the combustibility test on gas stove and the natural gas kitchen range, verified at sky.

The gaseous mixture that source of the gas factory produces by above-mentioned source of the gas proportioning is middle mountain, the transitional supply source of the gas of two places, Fanyu Natural Gas Conversion---allotment gas, the smooth combustion of existing burner of adaptive this area gas ductwork and 12T classification natural gas burner simultaneously.

2, the transformation of gas ductwork burner and replacing

3, source of the gas switches

Embodiment 3

The empty gas replacement scheme of mixing the gas gas ductwork in ground such as Foochow, Fujian, Xiamen

The source of the gas that ground gas ductworks such as Foochow, Fujian, Xiamen use at present also is the empty gas (" LPG+AIR " gaseous mixture) that mixes, by " GB " sorting technique, this combustion gas is near second family natural gas 10T classification, and this area will use after 2007 is liquefied natural gas from Indonesia's import, belongs to second family natural gas 12T classification in " GB ".As seen, two kinds of sources of the gas do not belong to same classification, can not directly change.

Empty mixed gas component in ground such as Foochow, Xiamen and burning performance parameter see the following form 6.

Table 6: empty gas component and the burning performance parameter of mixing in ground such as Foochow, Xiamen

Project	H 2	CH 4	C 2H 6	C 3H 8	C 3H 6	O 2	N 2	iC 4H 10	nC 4H 10	C 5H 12	Higher calorific value	Lower heat value	The white index of China	Combustion potential	Relative density
																(％)										MJ/Nm 3(kcal/Nm 3)
	The empty gas that mixes	0	0	0.29	18.7	0.02	12.12	45.22	7.03	16.18	0	50.24 (12000)	46.34 (11069)																43.12 (10300)	39.05	0.5838
Indonesia's natural gas														0	71.89	5.64	2.57	0	0	14.87	1.44	0	3.59	43.16 (10309)	39.21 (9365)	46.85 (11189)	32.03	0.8490

1, allotment gas determines

(1) white index of allotment gas China and combustion potential determines

Mix the gas physical parameter according to ground gas ductwork reference gas-skies such as the Foochow in the table 6, Xiamen, this combustion gas higher calorific value is 50.24MJ/m ³(12000kcal/m ³), the white index W of China is 43.12MJ/m ³(10300kcal/m ³), combustion potential Cp is 39.05, relative density 0.58; And liquefied natural gas higher calorific value to be converted is 43.16MJ/m ³(10309kcal/m ³), the white index W of China is 46.85MJ/m ³(11189kcal/m ³), combustion potential Cp is 32.03, relative density is 0.85.

Calculate with the correlation technique index in the research conclusion of the present invention, the white index W of China and the combustion potential Cp that are used for the transitional supply source of the gas of Natural Gas Conversion-allotment gas should satisfy following condition

W＝(10300+11189)/2×〔(1-5.0％)～(1+4.0％)〕＝10207～11174

Get: W=10200～11150

The CP index is unrestricted

Get: CP 〉=30

What (2) allotment gas source of the gas constituted determines

According to white index W of developing of allotment gas China and combustion potential Cp control indication range, adopt microcomputer data processing, parameter to two places gas ductwork source of the gas factory process units is carried out analyzing and processing, consider and utilize the natural gas factor to greatest extent, determine that the source of the gas of allotment gas in the two places natural gas transitional period constitutes " natural gas+sky mixes gas " gaseous mixture.

(3) the determining of each source of the gas proportioning in the allotment gas

Computer utilizes dedicated program according to the control index request of allotment gas, optimizes each source of the gas proportioning that can satisfy two places allotment gas index request and is the white index W of allotment gas China=10200～11150; Combustion potential CP 〉=30.0.By computerized optimization technique, optimize each source of the gas proportioning of allotment gas that can satisfy burner smooth combustion and be:

The empty gas that mixes: natural gas=1.0: (5.2～9.3)

That is: B ₁=5.2 B ₂=9.3

Allotment gas Lower heat value is 38.10～41.03MJ/Nm ³(9100～9800kcal/Nm ³), higher calorific value is 42.08～45.22MJ/Nm ³(10050～10800kcal/Nm ³).The gaseous mixture that source of the gas factory produces by above-mentioned source of the gas proportioning is Foochow, Fujian, the transitional supply source of the gas of two places, Xiamen Natural Gas Conversion---allotment gas, existing burner of adaptive this area gas ductwork and the smooth combustion of 12T classification natural gas burner simultaneously.

2, the transformation of gas ductwork burner and replacing

3, source of the gas switches

Claims (7)

1, a kind of gas step-by-step replacement method is replaced old source of the gas X with new source of the gas Z, may further comprise the steps:

(A) with the old source of the gas X of allotment gas Y direct replacement, use the operating point of original burner of allotment gas Y to fall within the allotment gas Y stable combustion region (6), described stable combustion region surrounds by taking off fiery limit curve (1), tempering limit curve (2), yellow flame limit curve (3) and CO limit curve (4); Described allotment gas Y is the gaseous mixture of old source of the gas X and new source of the gas Z, the white index W of China of allotment gas Y _YWith combustion potential CP _Y, be in the white index W of China of old source of the gas X respectively _X, combustion potential CP _XWith the white index W of the China of new source of the gas Z _Z, combustion potential CP _ZBetween the two;

(B) burner transformation, the best operating point in the smooth combustion district (8) when improved operation point of gas appliance being in use new source of the gas Z, and use that the operating point of burner falls within the burner smooth combustion district (7) after the transformation of allotment gas Y;

(C) with new source of the gas Z direct replacement allotment gas Y.

2, gas step-by-step replacement method according to claim 1, it is characterized in that described old source of the gas X is the manufactured gas, manufactured fuel gas, comprise at least a in coke-stove gas, water-gas, oil gas, refinery gas, natural gas reforming gas, liquefied gas upgrading gas, naphtha upgrading gas, the lighter hydrocarbons upgrading gas.

3, gas step-by-step replacement method according to claim 1 is characterized in that described old source of the gas X is the empty gas that mixes, and it is liquefied petroleum gas and Air mixing gas that described sky mixes gas.

4, gas step-by-step replacement method according to claim 1 is characterized in that described new source of the gas Z is a natural gas.

5, gas step-by-step replacement method according to claim 2, it is characterized in that described allotment gas source of the gas proportioning is: manufactured gas, manufactured fuel gas: natural gas=1.0: (2.2～2.8), and by liquefied petroleum gas and air regulation calorific value and allotment combustion characteristics, and the white exponential sum combustion potential of China of allotment gas Y satisfies following condition: W respectively _X≤ W _Y≤ W _ZCP _X≤ CP _Y≤ CP _Z

6, gas step-by-step replacement method according to claim 3, it is characterized in that described allotment gas source of the gas proportioning is 0～100% for empty percent by volume of mixing gas, natural gas volume percentage is 100%～0, and by liquefied petroleum gas and air regulation calorific value and allotment combustion characteristics, and the white exponential sum combustion potential of China of allotment gas Y satisfies following condition: W respectively _X≤ W _Y≤ W _ZCP _X≤ CP _Y≤ CP _Z

7, gas step-by-step replacement method according to claim 6 is characterized in that the empty preferred proportion that mixes gas and natural gas is 1.0: (2.5～9.3).

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