CN101655012A - Method for ventilating double-hole tunnel network - Google Patents

Abstract

The present invention discloses a method for ventilating double-hole tunnel network, which comprises the following steps : A. installing two transverse ventilation channels for exchanging air at the appropriate positions of two channels for forming a bidirectional air exchange system; B. designing the most economic air quantity of the double line to one half of the total required air quantity of the channel; C. confirming the positions of the transverse ventilation channels according to a principle that the energy consumption of the ventilation is minimal; D. obtaining the quantity of the airexchanged by the bidirectional air exchange system according to the principle that the air exchange quantities of two transverse channels are equal and the concentrations of the pollutant at the channel outlets are equal for obtaining the air quantity exchanged by the bidirectional exchange system; E. dividing a ventilation network map according to the position of the transverse ventilation channels; F. calculating the ventilation network according to an air quantity balancing law, an air pressure balancing law and a resistance law; G. calculating the pressure of the ventilation network with amesh iteration correction air quantity method; and H. confirming the number of sets and standards of the fans according to the pressure increase and air quantity required by each ventilation segmentof the network. The method for ventilating double-hole tunnel network cancels the vertical ventilation well, greatly reduces the ventilation equipment and can greatly reduce the building cost and operation management cost.

Description

A kind of method of ventilating double-hole tunnel network

Technical field

The present invention relates to the tunnel ventilation technical field, more specifically relate to a kind of method of ventilating double-hole tunnel network, can be applicable in speedway or the urban road length super long tunnel ventilating engineering between 3～8km.

Background technology

Current, method of ventilation is a vital factor in construction of tunnel construction and the operation process, is related to construction of tunnel operational effect, level of security and running cost etc.

Traditional highway tunnel ventilation method comprises natural ventilation, full transverse type ventilation, semi-transverse ventilation, vertically formula ventilation and combined type ventilation etc.

Natural ventilation utilizes air and the exchange of face of land atmosphere in the natural airflow realization tunnel in the tunnel, exactly to reach a kind of draft type of tunnel ventilation purpose.This method is suitable for length of tunnel in 1km.

Full transverse type ventilates and is respectively equipped with the supply and exhaust road, the distinguished and admirable lateral flow of in the tunnel, doing, and this draft type is applicable to the tunnel of all lengths.This mode need be provided with furred ceiling and ventilating shaft in the tunnel, investment is big, and technical difficulty and ventilation energy consumption are bigger.Present this draft type is crossed in the very important tunnel of growing up such as sea and is used crossing the river.

Semi-transverse ventilation is by tunnel ventilation road air-supply or air draft, by the hole along the tunnel vertical air draft or exhausting, its suitable length of tunnel is in 5km.

Vertically formula is ventilated, and it is distinguished and admirable vertically mobile along the tunnel, can make full use of Piston Wind, is most widely used in highway tunnel.Longitudinal ventilation mode commonly used has the jet blower longitudinal ventilation, concentrates air intake longitudinal ventilation, integrated air exhaust longitudinal ventilation, air zoning, segmentation air draft, segmentation to send modes such as row's longitudinal ventilation.But the speciality highway tunnel often needs to be provided with perpendicular (tiltedly) well that ventilates, and therefore can increase a large amount of civil engineering costs and operation management expense.

The combined type ventilation is the merits and demerits according to the comprehensive various draft types of engineering actual conditions, seek the optimal ventilation mode of safety and economy, as vertically+half laterally+complete horizontal draft type, send the Design of ventilation of row's formula longitudinal ventilation, the row's of sending formula longitudinal ventilation+row's formula smoke evacuation system etc. in conjunction with the vertical shaft of electrostatic precipitator.

The present invention proposes a kind of new tunnel ventilation method---complementary Network Ventilation method.This ventilation method has utilized the otherness of the double-hole tunnel required airflow tissue that ventilates.Specific practice is to set up the transversal ventilation road between tunnel, the left and right sides, two tunnels are connected, form complete relatively ventilation network, utilize the principle of network complementation, with air quality preferably in the tunnel fresh air remove foul atmosphere in the second-rate tunnel of diluent air, and make two air qualities in the tunnel all satisfy air-conditioning requirement, thereby in guaranteeing the tunnel, reduce the construction and the running cost of ventilation system under the prerequisite of air quality significantly.

Summary of the invention

The objective of the invention is at present speciality highway tunnel left and right sides line ventilation loads unbalanced, traditional method of ventilation need be set up perpendicular (tiltedly) well that ventilates on the bigger tunnel of required airflow, and the problem that the less tunnel of required airflow exists bigger air quantity affluence to be not fully utilized.A kind of ventilating double-hole tunnel network method has been proposed, correct position is set up the transversal ventilation road between tunnel, the left and right sides, two tunnels are connected, with air quality preferably in the tunnel fresh air remove foul atmosphere in the second-rate tunnel of diluent air, and make two air qualities in the tunnel all satisfy air-conditioning requirement.Compare with traditional sectionalized ventilation mode, having cancelled perpendicular (tiltedly) well that ventilates, ventilation equipment also significantly reduce, and can speed up the work and significantly reduce civil engineering costs and operation management expense, have remarkable economical and social benefit.

A kind of method of ventilating double-hole tunnel network, its step is as follows:

1, open two ventilation transverse passage-ways that are used for exchange of air:

Open two ventilation transverse passage-ways that are used for exchange of air at the correct position in two tunnels, two tunnels are connected, constitute two-way air exchange system.The blower fan that can install certain surplus (20～50%) in than clean tunnel produces rich resh air requirement, its air-flow enters another tunnel from transverse passage-way, be used for diluting the contaminated air in this tunnel, meanwhile, polluting tunnel internal divides contaminated air to enter clean tunnel and discharge from another transverse passage-way, realize the complementation of two holes ventilation system thus, reduced the ventilation scale, reduced investment and operation cost greatly.Ventilation transverse passage-way specific embodiments as shown in Figure 1.

2, the computing method of complementary Network Ventilation left and right sides line design air flow:

The present invention is based on the most economical design air flow of left and right sides line, for the total required airflow in tunnel half, promptly line design air flow in the left and right sides equates to determine the computational methods of left and right sides line design air flow.The steps include:

1) ventilation calculation assumption fluid tool Incoercibility, continuity and stability.

2), calculate the required airflow under the tunnel least favorable situation according to tunnel pollution concentration limit value.

3) and the design air flow of supposing left threaded list road equal its maximum ventilation that allows, according to the complementary ventilation principle in two holes, for guaranteeing that the air pollution concentration in the left threaded list road is no more than limits value, need utilize the blower fan in the right threaded list road to provide not enough air quantity for it, therefore, the design air flow in right threaded list road is greater than its required airflow.And the pollutant Cmax of supposing two tunnels all equals limits value, and the design air flow in then right threaded list road is formula as follows:

$Q_A=\frac{q_A+q_B}{\mathrm{\δ}}-Q_B$

In the formula:

Q _A: air feed Tunnel Design air quantity;

Q _B: mend wind Tunnel Design air quantity

q _A: air feed tunnel pollutant discharge amount

q _B: mend wind tunnel pollutant discharge amount

δ: tunnel internal contamination substrate concentration limit value

4) total required airflow is certain, Q _A, Q _BThe value of design air flow between the required airflow and left line Maximum Ventilatory Volume of right line, carry out tentative calculation, total according to two tunnels again ventilating power minimum is tried to achieve the most economical design air flow of left and right sides line, and is most economical when line design air flow in the left and right sides equates generally speaking.

3, complementary Network Ventilation air channel method for determining position:

The present invention provides ventilation air channel method for determining position thinking: the position in ventilation air channel is chosen scope and is determined according to the left and right sides, tunnel line design air flow, must guarantee that the high air that stains the tunnel does not exceed standard, position farthest is that low concentration of staining the tunnel equals the concentration that height stains the tunnel.Propose to utilize the computational methods of two of fronts to carry out repeatedly tentative calculation before this, last principle according to " the ventilation energy consumption is got minimum " is determined the position in network ventilation ventilation air channel.

It is quite crucial that the determining of complementary air exchange system position, two holes is, in order to bring into play best effect, needs to determine rational fitting limit.The complementary air exchange system in two holes need be installed in Lm in the Ln scope, as shown in Figure 2.

Determining and can draw for Lm, Ln according to the highway tunnel ventilation basic theories:

$L_m=L_B-\frac{3.6\&times;\mathrm{\&delta;}{Q}_B}{C_x\&CenterDot;{\mathrm{<figure-callout\; id="1"\; label="k"\; filenames="A2009100629670024H2.png"\; state="\{\{state\}\}">k</figure-callout>}}_1\&CenterDot;\underset{m=1}{\overset{n}{\mathrm{\&Sigma;}}}(N_m\&CenterDot;f_m)}$

$L_n=\frac{q_B\&CenterDot;Q_A\&CenterDot;L_A\&CenterDot;L_B}{q_A\&CenterDot;Q_B\&CenterDot;L_B+q_B\&CenterDot;Q_A\&CenterDot;L_A}$

After the permission fitting limit of determining two-way air exchange system, also need to determine the spacing (R2, L2) of two transverse passage-ways, if spacing is too small, backflow phenomenon will take place, influence the normal operation of system; If spacing is excessive, the pollutant levels phenomenon that can between transverse passage-way, exceed standard.The transverse passage-way spacing of two-way air exchange system is between 50～100m, and the situation that has pollutant levels to exceed standard as discovery after over-richness is checked calculating can suitably be adjusted its distance, till satisfying air-conditioning requirement.

4, determining of air channel exchange air quantity:

The basic ideas of this method are: according to the principle that two transverse passage-way ventilation volumes equate and tunnel exit place pollutant levels equate, draw the air mass flow of two-way air exchange system exchange.In order to prevent that two air mass flows in the tunnel from producing bigger fluctuation after passing through air exchange system, air-flow is constant through flow behind the two-way air exchange system, and promptly two interior air mass flows of transverse passage-way equate.Under the prerequisite of the design air flow of having determined two tunnels and two-way air exchange system particular location,, draw the air mass flow Qh of two-way air exchange system exchange according to the principle that two transverse passage-way ventilation volumes equate and tunnel exit place pollutant levels equate.As shown in Figure 3.

$Q_h=\frac{q_L\&CenterDot;Q_R-q_R\&CenterDot;{\mathrm{<figure-callout\; id="2"\; label="Q\; L"\; filenames="A2009100629670023H2.png,A2009100629670024H2.png"\; state="\{\{state\}\}">Q</figure-callout>}}_L}{2\&CenterDot;Q\&times;(\frac{q_L\&CenterDot;L_3}{L\&CenterDot;Q_L}-\frac{q_R\&CenterDot;R_1}{L\&CenterDot;Q_R})}$

L in the formula _i, R _iBe respectively the length of left and right sides line.

5, provide the computing method of the splitting scheme and the ventilation network of ventilation network

Concrete scheme is: the position with the ventilation transverse passage-way is basic foundation, and the ventilation system in tunnel is converted into network as shown in Figure 4, utilizes network to determine the formation of ventilation network.

The computational methods of the Network Ventilation that the present invention proposes are mesh iteration correction air quantity method, can try to achieve the blast and the air quantity of Network Ventilation system according to this.

According to blast and the air quantity that Network Ventilation is calculated, determine the blower fan scale in the wind net.

6, the calculating of ventilation network:

Under normal circumstances, distinguished and admirable in the tunnel the approximate steady and continuous that is flow, law of conservation of energy is observed in flowing of fluid,, distinguished and admirablely all follow 3 basic laws; Air balance law, pressure balance law and resistance law.Because in the tunnel traffic draft power of automobile and the existence of blower fan are arranged, the pressure balance law in the tunnel wind net will be modified to;

∑ΔP _R-(∑P _f+∑ΔP _J+∑P _m+∑P _T)＝0

In the formula: P _fAnd P _mBe respectively fan pressure and natural ventilation pressure in the mesh, just getting clockwise, get negative counterclockwise; Δ P _TWith Δ p _JBe respectively traffic draft power and blower pressure, get just identical with wind direction, opposite with wind direction get negative.Δ p _RBeing flowing resistance, is local ventilation resistance and frictional resistance sum.

According to the pressure balance law, mesh 1. in

P _f1-2+P _T1-2+P _f2-7+P _T7-8+P _v7-8+P _m1-8＝P _R1-2+P _R2-7+P _R7-8..............................1

Mesh 2. in

P _f2-7+P _f6-3+P _J6-7+P _j2-3＝P _R2-3+P _R6-7+P _R2-7+P _R6-3....................................2

Mesh 3. in

P _f5-6+P _f6-3+P _v3-4+P _T5-6+P _T3-4+P _m5-4＝P _R5-6+P _R6-3+P _R3-4.......................3

Mesh 4. in

P _f1-2+P _H2+P _H3+P _m1-4+P _T1-4＝P _R1-2+P _R2-3+P _R3-4...............................4

Mesh 5. in

P _f5-6+P _H7+P _H6+P _m5-8+P _T5-8＝P _R5-6+P _R6-7+P _R7-8..................................5

In the formula: P _Fi-jThe i node is to the fan pressure of j node in the-mesh

P _Vi-j-transverse passage-way two side pressure i nodes and j node place pressure differential

P _Hi-ventilation stack blower fan causes the power of boosting that i is ordered

P _Ti-j-i node is to the traffic blast of j node

P _Mi-j-i node is to the natural ventilation pressure of j node

P _Ri-j-i node comprises on-way resistance and local resistance to the flowing resistance of j node.Distinguished and admirable resistance is divided into on-way resistance and local resistance sum.

7, the pressure of ventilation network is found the solution:

For resolving that complex network ventilates, mesh iteration correction air quantity method is proposed.Its crucial way is:

1) determines initial air quantity

2) proofread and correct air quantity

3) iterative computation is up to satisfying precision

$\mathrm{\&Delta;Q}=-\frac{\underset{i=1}{\overset{n}{\mathrm{\&Sigma;}}}{R}_i{Q}_i^2-\underset{i=1}{\overset{F}{\mathrm{\&Sigma;}}}{H}_i-{\mathrm{<figure-callout\; id="2"\; label="NH\; M"\; filenames="A2009100629670023H2.png,A2009100629670024H2.png"\; state="\{\{state\}\}">NH</figure-callout>}}_M}{2\underset{i=1}{\overset{n}{\mathrm{\&Sigma;}}}{R}_i\left|Q_i\right|-\underset{i=1}{\overset{F}{\mathrm{\&Sigma;}}}{\mathrm{\&alpha;}}_i}$

In the formula:

The air quantity corrected value of Δ Q---M (mesh number) mesh, | Δ Q| value increases according to iterations and reduces, when mesh | when Δ Q| went to zero, the air quantity at networking, blast had promptly tended to balance, m3/s;

Qi---the nearly air quantity in the Zhejiang of i branch in the mesh, Qi by initial value to true value, when occur in iterative process reversion (by ' and just " changes " bear " or become " just " by " bearing ") time, illustrate that wind direction supposes wrongly, must correct m3/s immediately;

R _iQ _i ²---the asymptotic blast of each branch in the mesh, when the wind direction of i branch with iris wipe mesh direction R when identical _iQ _i ²Get " just " value; Otherwise, get " bearing " value, Pa;

---the pressure balance of M mesh is poor.Pa；

2 times of absolute values that windage is measured with fair wind of-mesh each branch;

Hi---the blast of the ventilation fan of i branch in the M mesh, when the wind direction of ventilation fan with to iris wipe the mesh direction identical constantly, Hi gets " just " value, otherwise, get " bearing " value, Pa;

α---ventilation fan blast curve m (Qi, slope Hi) in the i branch;

NHM---the natural ventilation pressure of M mesh, when the direction of NHM with to iris wipe the mesh direction identical constantly, Hi gets " just " value, otherwise, get " bearing " value, Pa;

After obtaining mesh fan delivery Qi, obtain immediately Qu Fengji instant operating point m (Qi, blast Hi Hi) and slope α thereof,

That is:

$H_i=A{\mathrm{<figure-callout\; id="2"\; label="Q\; i"\; filenames="A2009100629670023H2.png,A2009100629670024H2.png"\; state="\{\{state\}\}">Q</figure-callout>}}_i^{}+{\mathrm{BQ}}_i+C$

α＝2AQ _i+B

A, B, C in the formula---the third-order equation of obtaining through The Fitting Calculation according to the fan pressure curve is the coefficient of 2 equation of n th order n.

When obtain mesh air quantity correction value delta Q according to formula after, immediately each branch's air quantity of mesh is proofreaied and correct, promptly

Q′ _i＝Q _i+ΔQ _i

In the formula:

Q _i---the initial air quantity of mesh i branch or last time proofreaied and correct after air quantity, m3/s;

Q ' _i---the air quantity behind the i branch correction, m3/s,

Δ Q _i---mesh air quantity corrected value, when i branch wind direction with iris wipe the mesh direction and get " just " when identical, otherwise, get " bearing " number, m3/s;

In mesh air quantity correction calculation below carrying out, palpus attention 2 points: all branch that front mesh correction calculation is crossed, same air quantity of using after proofreading and correct (i.e. the skill of utilization " Saden that iterative computation ") of running into; The branch of wind direction was corrected in all fronts, used the wind direction after correcting during subsequent calculations without exception.

8, determining of ventilation network blower fan scale:

Can try to achieve resistance, natural ventilation pressure and the traffic blast of each Network Ventilation section according to the ventilation basic principle, and in conjunction with equation group 1～5, draw the power of boosting that the required blower fan of each Network Ventilation section provides, finally platform number and the specification of determining blower fan according to the pressure and the air quantity of calculating.

The present invention compared with prior art has the following advantages and effect:

The object of the present invention is to provide a kind of new speciality Highway Tunnel Ventilation System solution route.When hole, super long tunnel left and right sides required airflow differs greatly, traditional method of ventilation need increase airshaft on the bigger tunnel of required airflow, cause engineering quantity and investment significantly to increase, and the less tunnel of ventilation exist bigger air quantity affluence to be not fully utilized.At the unbalanced situation of speciality highway tunnel left and right sides line ventilation loads, between tunnel, the left and right sides, set up the transversal ventilation road, two tunnels are connected, with air quality preferably in the tunnel fresh air remove foul atmosphere in the second-rate tunnel of diluent air, and make two air qualities in the tunnel all satisfy air-conditioning requirement, thereby perpendicular (tiltedly) well of the ventilation that cancellation is set up can reduce civil engineering costs and operation management expense greatly.

Description of drawings

Fig. 1: complementary Network Ventilation transverse passage-way plan

Fig. 2: complementary Network Ventilation transverse passage-way is provided with schematic diagram

Fig. 3: complementary Network Ventilation sketch

Fig. 4: complementary Network Ventilation network

Wherein: 1-steel mesh door, the movable closing door of 2-, the 3-axial flow blower, the electronic purlin of 4-car, 5-steel airduct, the 6-air channel, 7-overhauls steel ladder, 8-blower fan controller switching equipment, 9-fire resistance rolling shutter door.

The specific embodiment

1, ventilating double-hole tunnel network:

This thinking should consider can be suitable for this invention under which kind of situation when implementing.Different highway tunnels is suitable for different draft types.Before the present invention proposes, also there is additive method can solve the tunnel ventilation problem.Only for some specific tunnel, the ventilation thinking among employing the present invention has the huge advantage on the economic benefit.Such as:

Many length were at the sloping highway tunnel of the list of 4～6km in the middle of China's development of the West Regions was built, because the relation of longitudinal gradient, the descending tunnel ventilation is easier to, and smog is bigger in the upward slope tunnel, the difficulty of ventilating.Traditional thinking is to increase vertical shaft to adopt sectionalized ventilation in the upward slope tunnel.Adopt this thinking, on hole, the left and right sides, increase the ventilation transverse passage-way, then can solve ventilating problem dexterously, reach the effect of getting twice the result with half the effort.The military speedway of fiber crops Dabie Mountain, Hubei Province speciality highway tunnel, total length 5km, preliminary design adopts segmentation longitudinal ventilation scheme.Working drawing adopts this invention when optimizing, investment is saved 2,300 ten thousand yuan, and a year operating charges is saved 1,640,000 yuan, and being open to traffic produced 4,750 ten thousand yuan of economic benefits in 15 years.

Generally speaking, following tunnel is applicable to the present invention when design:

Length is more than 3km, and left and right sides line required airflow difference surpasses 50% two way highway tunnel;

Length is at 2.8～5km, and the time is staggered relatively than long urban road double-hole tunnel in line peak, the left and right sides.

2, the computing method of complementary Network Ventilation left and right sides line design air flow

1) ventilation calculation assumption fluid tool Incoercibility, continuity and stability.

2), calculate the required airflow under the tunnel least favorable situation according to tunnel pollution concentration limit value.

3) and the design air flow of supposing left threaded list road equal its maximum ventilation that allows, according to the complementary ventilation principle in two holes, for guaranteeing that the air pollution concentration in the left threaded list road is no more than limits value, need utilize the blower fan in the right threaded list road to provide not enough air quantity for it, therefore, the design air flow in right threaded list road is greater than its required airflow.And the pollutant Cmax of supposing two tunnels all equals limits value, and the design air flow in then right threaded list road is formula as follows:

$Q_A=\frac{q_A+q_B}{\mathrm{\&delta;}}-Q_B$

In the formula:

Q _A: air feed Tunnel Design air quantity;

Q _B: mend wind Tunnel Design air quantity

q _A: air feed tunnel pollutant discharge amount

q _B: mend wind tunnel pollutant discharge amount

δ: tunnel internal contamination substrate concentration limit value

4) total required airflow is certain, Q _A, Q _BThe value of design air flow between the required airflow and left line Maximum Ventilatory Volume of right line, carry out tentative calculation, total according to two tunnels again ventilating power minimum is tried to achieve the most economical design air flow of left and right sides line, and is most economical when line design air flow in the left and right sides equates generally speaking.

3, complementary Network Ventilation air channel method for determining position

It is quite crucial that the determining of complementary air exchange system position, two holes is, in order to bring into play best effect, needs to determine rational fitting limit.The complementary air exchange system in two holes need be installed in Lm in the Ln scope, as shown in Figure 2.

Determining and can draw for Lm, Ln according to the highway tunnel ventilation basic theories:

$L_m=L_B-\frac{3.6\&times;\mathrm{\&delta;}{Q}_B}{C_x\&CenterDot;k_1\&CenterDot;\underset{m=1}{\overset{n}{\mathrm{\&Sigma;}}}(N_m\&CenterDot;f_m)}$

$L_n=\frac{q_B\&CenterDot;Q_A\&CenterDot;L_A\&CenterDot;L_B}{q_A\&CenterDot;Q_B\&CenterDot;L_B+q_B\&CenterDot;Q_A\&CenterDot;L_A}$

After the permission fitting limit of determining two-way air exchange system, also need to determine the spacing (R2, L2) of two transverse passage-ways, if spacing is too small, backflow phenomenon will take place, influence the normal operation of system; If spacing is excessive, the pollutant levels phenomenon that can between transverse passage-way, exceed standard.The transverse passage-way spacing of two-way air exchange system is between 50～100m, and the situation that has pollutant levels to exceed standard as discovery after over-richness is checked calculating can suitably be adjusted its distance, till satisfying air-conditioning requirement.

4, air channel exchange air quantity determines

In order to prevent that two air mass flows in the tunnel from producing bigger fluctuation after passing through air exchange system, air-flow is constant through flow behind the two-way air exchange system, and promptly two interior air mass flows of transverse passage-way equate.Under the prerequisite of the design air flow of having determined two tunnels and two-way air exchange system particular location,, draw the air mass flow Qh of two-way air exchange system exchange according to the principle that two transverse passage-way ventilation volumes equate and tunnel exit place pollutant levels equate.As shown in Figure 3.

$Q_h=\frac{q_L\&CenterDot;Q_R-q_R\&CenterDot;{\mathrm{<figure-callout\; id="2"\; label="Q\; L"\; filenames="A2009100629670023H2.png,A2009100629670024H2.png"\; state="\{\{state\}\}">Q</figure-callout>}}_L}{2\&CenterDot;Q\&times;(\frac{q_L\&CenterDot;L_3}{L\&CenterDot;Q_L}-\frac{q_R\&CenterDot;R_1}{L\&CenterDot;Q_R})}$

L in the formula _i, R _iBe respectively the length of left and right sides line.

5, the division of ventilation network

The ventilation system in tunnel is converted into network.It can clearly express each section of tunnel, the distinguished and admirable correlation in each air channel, and the spatial relation that avoid actual each ventilation section, connects the air channel as shown in Figure 4.Wherein 1,2,3 ... the expression node serial number, 1., 2., 3. ... expression loop numbering, this ventilation system always has 5 loops as can be seen.Wherein dotted line is the natural wind flanging.

6, the calculating of ventilation network

Under normal circumstances, distinguished and admirable in the tunnel the approximate steady and continuous that is flow, law of conservation of energy is observed in flowing of fluid,, distinguished and admirablely all follow 3 basic laws; Air balance law, pressure balance law and resistance law.Because in the tunnel traffic draft power of automobile and the existence of blower fan are arranged, the pressure balance law in the tunnel wind net will be modified to;

∑ΔP _R-(∑P _f+∑ΔP _J+∑P _m+∑P _T)＝0

In the formula: P _fAnd P _mBe respectively fan pressure and natural ventilation pressure in the mesh, just getting clockwise, get negative counterclockwise; Δ P _TWith Δ p _JBe respectively traffic draft power and blower pressure, get just identical with wind direction, opposite with wind direction get negative.Δ p _RBeing flowing resistance, is local ventilation resistance and frictional resistance sum.

According to the pressure balance law, mesh 1. in

P _f1-2+P _T1-2+P _f2-7+P _T7-8+P _v7-8+P _m1-8＝P _R1-2+P _R2-7+P _R7-8..........................1

Mesh 2. in

P _f2-7+P _f6-3+P _J6-7+P _j2-3＝P _R2-3+P _R6-7+P _R2-7+P _R6-3...........................2

Mesh 3. in

P _f5-6+P _f6-3+P _v3-4+P _T5-6+P _T3-4+P _m5-4＝P _R5-6+P _R6-3+P _R3-4.......................3

Mesh 4. in

P _f1-2+P _H2+P _H3+P _m1-4+P _T1-4＝P _R1-2+P _R2-3+P _R3-4...........................4

Mesh 5. in

P _f5-6+P _H7+P _H6+P _m5-8+P _T5-8＝P _R5-6+P _R6-7+P _R7-8................................5

In the formula: P _Fi-jThe i node is to the fan pressure of j node in the-mesh

P _Vi-j-transverse passage-way two side pressure i nodes and j node place pressure differential

P _Hi-ventilation stack blower fan causes the power of boosting that i is ordered

P _Ti-j-i node is to the traffic blast of j node

P _Mi-j-i node is to the natural ventilation pressure of j node

P _Ri-j-i node comprises on-way resistance and local resistance to the flowing resistance of j node.Distinguished and admirable resistance is divided into on-way resistance and local resistance sum.

7, the pressure of ventilation network is found the solution

For resolving that complex network ventilates, mesh iteration correction air quantity method is proposed.Its crucial way is:

A) determine initial air quantity

B) proofread and correct air quantity

C) iterative computation is up to satisfying precision

$\mathrm{\&Delta;Q}=-\frac{\underset{i=1}{\overset{n}{\mathrm{\&Sigma;}}}{R}_i{Q}_i^2-\underset{i=1}{\overset{F}{\mathrm{\&Sigma;}}}{H}_i-{\mathrm{<figure-callout\; id="2"\; label="NH\; M"\; filenames="A2009100629670023H2.png,A2009100629670024H2.png"\; state="\{\{state\}\}">NH</figure-callout>}}_M}{2\underset{i=1}{\overset{n}{\mathrm{\&Sigma;}}}{R}_i\left|Q_i\right|-\underset{i=1}{\overset{F}{\mathrm{\&Sigma;}}}{\mathrm{\&alpha;}}_i}$

In the formula:

The air quantity corrected value of Δ Q---M (mesh number) mesh, | Δ Q| value increases according to iterations and reduces, when mesh | when Δ Q| went to zero, the air quantity at networking, blast had promptly tended to balance, m3/s;

Qi---the nearly air quantity in the Zhejiang of i branch in the mesh, Qi by initial value to true value, when occur in iterative process reversion (by ' and just " changes " bear " or become " just " by " bearing ") time, illustrate that wind direction supposes wrongly, must correct m3/s immediately;

R _iQ _i ²---the asymptotic blast of each branch in the mesh, when the wind direction of i branch with iris wipe mesh direction R when identical _iQ _i ²Get " just " value; Otherwise, get " bearing " value, Pa;

---the pressure balance of M mesh is poor.Pa；

2 times of absolute values that windage is measured with fair wind of-mesh each branch;

Hi---the blast of the ventilation fan of i branch in the M mesh, when the wind direction of ventilation fan with to iris wipe the mesh direction identical constantly, Hi gets " just " value, otherwise, get " bearing " value, Pa;

α---ventilation fan blast curve m (Qi, slope Hi) in the i branch;

NHM---the natural ventilation pressure of M mesh, when the direction of NHM with to iris wipe the mesh direction identical constantly, Hi gets " just " value, otherwise, get " bearing " value, Pa;

After obtaining mesh fan delivery Qi, obtain immediately Qu Fengji instant operating point m (Qi, blast Hi Hi) and slope α thereof,

That is:

$H_i={\mathrm{<figure-callout\; id="2"\; label="AQ\; i"\; filenames="A2009100629670023H2.png,A2009100629670024H2.png"\; state="\{\{state\}\}">AQ</figure-callout>}}_i^{}+{\mathrm{BQ}}_i+C$

α＝2AQ _i+B

A, B, C in the formula---the third-order equation of obtaining through The Fitting Calculation according to the fan pressure curve is the coefficient of 2 equation of n th order n.

When obtain mesh air quantity correction value delta Q according to formula after, immediately each branch's air quantity of mesh is proofreaied and correct, promptly

Q′ _i＝Q _i+ΔQ _i

In the formula:

Q _i---the initial air quantity of mesh i branch or last time proofreaied and correct after air quantity, m3/s;

Q ' _i---the air quantity behind the i branch correction, m3/s,

Δ Q _i---mesh air quantity corrected value, when i branch wind direction with iris wipe the mesh direction and get " just " when identical, otherwise, get " bearing " number, m3/s;

In mesh air quantity correction calculation below carrying out, palpus attention 2 points: all branch that front mesh correction calculation is crossed, same air quantity of using after proofreading and correct (i.e. the skill of utilization " Saden that iterative computation ") of running into; The branch of wind direction was corrected in all fronts, used the wind direction after correcting during subsequent calculations without exception.

8, ventilation network blower fan scale determines

The resistance that can try to achieve each Network Ventilation section according to the ventilation basic principle is as shown in table 1, natural ventilation pressure and traffic blast are as shown in table 2, in conjunction with equation group 1～5, it is as shown in table 3 to draw the power of boosting that the required blower fan of each Network Ventilation section provides, finally platform number and the specification of determining blower fan according to the pressure that calculates and air quantity.

Table 1 Network Ventilation section calculation of resistance table

Initial point	Terminal point	Total windage R	Air quantity	Resistance P R
					??1	??2
??2	??3
					??3	??4
??5	??6

??6	??7
					??7	??8
??2	??7
					??6	??3

Table 2 natural ventilation pressure and traffic blast computational chart

Initial point	Terminal point	Natural ventilation pressure	The traffic blast
				??1	??2
??2	??3
				??3	??4
??5	??6
				??6	??7
??7	??8

Table 3 Network Ventilation section blower fan specification computational chart

Initial point	Terminal point	The required power of boosting	The separate unit blower pressure	Blower fan platform number
					??1	??2
??3	??4
					??5	??6
??7	??8
					??2	??7
??6	??3

Case history

1, project overview

The Dabie Mountain highway tunnel is fastened the super long tunnel of sea on to Macheng, Chengdu speedway Hubei Province to the Wuhan section, is the controlled engineering on the numb military speedway.The about 482m of the maximum buried depth in tunnel, sea level on the average 291m, the design road speed is 100km/h.The tunnel is the up-downgoing separate type, and two hole axises are at a distance of 40m, left tunnel line length 4901m, and the tunnel gradient is respectively+and 1.47%/2665 ,+1.97%/2243, right threaded list road length 4908m, the tunnel gradient is respectively-1.47%/2720 ,-1.97%/2181.Predict 2015 annual traffic 13100Pcu/d, the year two thousand thirty 35105Pcu/d.

2, the calculating of complementary Network Ventilation left and right sides line design air flow

The left and right line in tunnel, Dabie Mountain is as shown in table 4 by required airflow as calculated.

Tunnel, table 4 Dabie Mountain required airflow result of calculation table

As seen from the above table, compare with the pure vertical formula ventilation scheme of not segmentation with the vertical formula ventilation of a traditional segmentation, the complementary Network Ventilation scheme in two holes has effectively utilized the rich draught capacity in tunnel internal space and descending tunnel.By scheme optimization, the total required airflow in hole, the left and right sides is reduced to 780m3/s by 875m3/s, and required airflow has reduced by 17% under the operation operating mode.Even understand the discharge value to the top thoroughly on a left side, right line also occurs under this extreme unfavorable conditions of traffic jam simultaneously, and required airflow also only has 805m3/s.Required airflow reduces makes that under the prerequisite of tunnel, Dabie Mountain air quality in guaranteeing the tunnel, the ventilation system total size significantly reduces, and running cost descends, remarkable in economical benefits.

$Q_L=\frac{q_L+q_R}{\mathrm{\&delta;}}-Q_R,$ By last Biao Kede: $\frac{q_L+q_R}{\mathrm{\&delta;}}=805.47\mathrm{<figure-callout\; id="3"\; label="m"\; filenames="A2009100629670024H2.png"\; state="\{\{state\}\}">m</figure-callout>}3/s$

Then: Q _L=Q _R=420m3/s V _L=V _R=6.15m/s

3, position, complementary Network Ventilation air channel determines

$L_{L\max }=\frac{3.6\&times;\mathrm{\&delta;}{Q}_L^{\&prime;}}{C_x\&CenterDot;k_1\&CenterDot;\underset{m=1}{\overset{n}{\mathrm{\&Sigma;}}}(N_m\&CenterDot;f_m)}=3430m$

L _m＝L _L-L _Lmax＝1470m

$L_n=\frac{q_L\&CenterDot;Q_R^{\&prime;}\&CenterDot;L_R\&CenterDot;L_L}{q_R\&CenterDot;Q_L^{\&prime;}\&CenterDot;L_L+q_L\&CenterDot;Q_R^{\&prime;}\&CenterDot;L_R}=3585m$

4, air channel exchange air quantity determines

$Q_h=\frac{q_L\&CenterDot;Q_R-q_R\&CenterDot;{\mathrm{<figure-callout\; id="2"\; label="Q\; L"\; filenames="A2009100629670023H2.png,A2009100629670024H2.png"\; state="\{\{state\}\}">Q</figure-callout>}}_L}{2\&CenterDot;Q\&times;(\frac{q_L\&CenterDot;L_3}{L\&CenterDot;Q_L}-\frac{q_R\&CenterDot;R_1}{L\&CenterDot;Q_R})}$

Wherein, q _L=600m ³/ s; q _R=220m ³/ s; L=4900m; Q=840m ³/ s.

Table 5 result of calculation table

As shown in Table 5, along with ventilation transverse passage-way system moves right in allowing fitting limit, ventilation transverse passage-way design air flow is the trend of continuous increase, considers to reduce to ventilate the transverse passage-way design air flow, the ventilation transverse passage-way can be installed in the high order end that allows fitting limit.Therefore, our suggestion is arranged on the ventilation transverse passage-way from left tunnel exit 1500m place in this case, and its ventilation transverse passage-way design air flow is 120m3/s.

5, the division of ventilation network

The ventilation system in tunnel is converted into network.It can clearly express each section of tunnel, the distinguished and admirable correlation in each air channel, and the spatial relation that avoid actual each ventilation section, connects the air channel as shown in Figure 5.Wherein 1,2,3 ... the expression node serial number, 1., 2., 3. ... expression loop numbering, this ventilation system always has 5 loops as can be seen.Wherein dotted line is the natural wind flanging.

6, the calculating of ventilation network and blower fan scale

The resistance that can try to achieve each Network Ventilation section according to the ventilation basic principle is as shown in table 6, natural ventilation pressure and traffic blast are as shown in table 7, in conjunction with equation group 1～5, it is as shown in table 8 to draw the power of boosting that the required blower fan of each Network Ventilation section provides, finally platform number and the specification of determining blower fan according to the pressure that calculates and air quantity.

Table 6 Network Ventilation section calculation of resistance table

Initial point	Terminal point	Total windage R	Air quantity	Resistance P R
					??1	??2	??0.0005751	??420	??116.46
??2	??3	??0.0000233	??260	??1.57
					??3	??4	??0.0016419	??420	??289.64
??5	??6	??0.0015455	??420	??272.62

??6	??7	??0.0000233	??260	??1.57
					??7	??8	??0.0006716	??420	??118.46
??2	??7	??0.0012747	??120	??146.02
					??6	??3	??0.0009644	??120	??134.81

Table 7 natural ventilation pressure and traffic blast computational chart

Initial point	Terminal point	Natural ventilation pressure	The traffic blast
				??1	??2	??16.77	??37.36
??2	??3	??0.68	??1.87
				??3	??4	??47.87	??84.05
??5	??6	??45.06	??84.05
				??6	??7	??0.68	??1.87
??7	??8	??19.58	??37.36

Table 8 Network Ventilation section blower fan specification computational chart

Initial point	Terminal point	The required power of boosting	The separate unit blower pressure	Blower fan platform number
					??1	??2	??95.87	??12	??8
??3	??4	??243.45	??12	??20
					??5	??6	??233.63	??12	??20
??7	??8	??100.69	??12	??8
					??2	??7	??346.02		1 (axial flow blower)
??6	??3	??334.81		1 (axial flow blower)

7, complementary Network Ventilation transverse passage-way design scheme as shown in Figure 1

8, economy relatively

By implementing this project, can be with less cost, cancellation ventilation inclined shaft, contact air channel, Ventilator Room and ancillary facility reduce running cost significantly under the prerequisite of guaranteeing the tunnel ventilation effect.Send row's formula ventilation scheme to compare with the inclined shaft segmentation, can save 2,290 ten thousand yuan of initial investments; Reduce 1,640,000 yuan of running costs every year on average, the 15 years living economic benefits of common property that are open to traffic are 4,750 ten thousand yuan.Comparing with full ventilation by force draft scheme only increases by 1,100,000 yuan of initial investments; Reduce 2,430,000 yuan of running costs every year on average, the 15 years living economic benefits of common property that are open to traffic are 3,535 ten thousand yuan.Concrete measuring and calculating is as follows:

Claims (1)

1, a kind of method of ventilating double-hole tunnel network the steps include:

A, open two ventilation transverse passage-ways that are used for exchange of air:

Open two ventilation transverse passage-ways that are used for exchange of air in the position in two tunnels, two tunnels are connected, constitute two-way air exchange system, windward is installed in than clean tunnel, its air-flow enters another tunnel from transverse passage-way, be used for diluting the contaminated air in this tunnel, pollute tunnel internal and divide contaminated air to enter clean tunnel and discharge from another transverse passage-way;

The computing method of B, complementary Network Ventilation left and right sides line design air flow:

Determine the computational methods of left and right sides line design air flow, the steps include:

1) ventilation is calculated;

2), calculate the tunnel air quantity according to tunnel pollution concentration limit value;

3) and the design air flow of setting left threaded list road equal ventilation, according to the complementary ventilation in two holes, utilize the blower fan in the right threaded list road to provide air quantity for it, the design air flow in right threaded list road is greater than air quantity, the pollutant Cmax of setting two tunnels all equals limits value, and the design air flow in then right threaded list road is formula as follows:

$Q_A=\frac{q_A+q_B}{\mathrm{\&delta;}}-Q_B$

In the formula:

Q _A: air feed Tunnel Design air quantity;

Q _B: mend wind Tunnel Design air quantity

q _A: air feed tunnel pollutant discharge amount

q _B: mend wind tunnel pollutant discharge amount

δ: tunnel internal contamination substrate concentration limit value

4) total air quantity, Q _A, Q _BThe value of design air flow between the air quantity and left line ventilation of right line, carry out tentative calculation, total according to two tunnels again ventilating power minimum is tried to achieve the most economical design air flow of left and right sides line, left and right sides line design air flow equates;

C, complementary Network Ventilation air channel method for determining position:

The position in ventilation air channel is chosen scope and is determined that according to the left and right sides, tunnel line design air flow the air in dirty tunnel does not exceed standard, and position farthest is that low concentration of staining the tunnel equals the concentration that height stains the tunnel, carries out tentative calculation, determines the position in network ventilation ventilation air channel;

Determining of complementary air exchange system position, two holes, the complementary air exchange system in two holes is installed in Lm in the Ln scope, draws according to highway tunnel ventilation for the definite of Lm, Ln:

$L_m=L_B-\frac{3.6\&times;\mathrm{\&delta;}{Q}_B}{C_x\&CenterDot;k_1\&CenterDot;\underset{m=1}{\overset{n}{\mathrm{\&Sigma;}}}(N_m\&CenterDot;f_m)}$

$L_n=\frac{q_B\&CenterDot;Q_A\&CenterDot;L_A\&CenterDot;L_B}{q_A\&CenterDot;Q_B\&CenterDot;L_B+q_B\&CenterDot;Q_A\&CenterDot;L_A}$

After the fitting limit of determining two-way air exchange system, determine spacing R2, the L2 of two transverse passage-ways, the transverse passage-way spacing of two-way air exchange system is between 50～100m;

Determining of D, air channel exchange air quantity:

Equating to reach tunnel exit place pollutant levels according to two transverse passage-way ventilation volumes equates, draw the air mass flow of two-way air exchange system exchange, at the design air flow of having determined two tunnels and two-way air exchange system particular location, equate to reach tunnel exit place pollutant levels according to two transverse passage-way ventilation volumes and equate, draw the air mass flow Qh of two-way air exchange system exchange;

$Q_h=\frac{q_L\&CenterDot;Q_R-q_R\&CenterDot;Q_L}{2\&CenterDot;Q\&times;(\frac{q_L\&CenterDot;L_3}{L\&CenterDot;Q_L}-\frac{q_R\&CenterDot;R_1}{L\&CenterDot;Q_R})}$

L in the formula _i, R _iBe respectively the length of left and right sides line;

E, provide the computing method of the splitting scheme and the ventilation network of ventilation network:

Position with the ventilation transverse passage-way is a foundation, the ventilation system in tunnel is converted into network, utilize network to determine the formation of ventilation network, the computational methods of Network Ventilation are mesh iteration correction air quantity method, try to achieve the blast and the air quantity of Network Ventilation system according to this, according to blast and the air quantity that Network Ventilation is calculated, determine the blower fan scale in the wind net;

The calculating of F, ventilation network:

Distinguished and admirable in the tunnel the approximate steady and continuous that is flow, law of conservation of energy is observed in flowing of fluid, distinguished and admirablely follow three rules: air balance law, pressure balance law and resistance law, the traffic draft power of automobile and the existence of blower fan are arranged in the tunnel, and the pressure balance law in the tunnel wind net will be modified to;

∑ΔP _R-(∑P _f+∑ΔP _J+∑P _m+∑P _T)＝0

In the formula: P _fAnd P _mBe respectively fan pressure and natural ventilation pressure in the mesh, just getting clockwise, get negative counterclockwise; Δ P _TWith Δ p _JBe respectively traffic draft power and blower pressure, get just identical with wind direction, opposite with wind direction get negative, Δ p _RBeing flowing resistance, is local ventilation resistance and frictional resistance sum;

According to the pressure balance law, mesh 1. in

P _f1-2+P _T1-2+P _f2-7+P _T7-8+P _v7-8+P _m1-8＝P _R1-2+P _R2-7+P _R7-8...........................1

Mesh 2. in

P _f2-7+P _f6-3+P _J6-7+P _j2-3＝P _R2-3+P _R6-7+P _R2-7+P _R6-3..................................2

Mesh 3. in

P _f5-6+P _f6-3+P _v3-4+P _T5-6+P _T3-4+P _m5-4＝P _R5-6+P _R6-3+P _R3-4............................3

Mesh 4. in

P _f1-2+P _H2+P _H3+P _m1-4+P _T1-4＝P _R1-2+P _R2-3+P _R3-4......................................4

Mesh 5. in

P _f5-6+P _H7+P _H6+P _m5-8+P _T5-8＝P _R5-6+P _R6-7+P _R7-8......................................5

In the formula: P _Fi-jThe i node is to the fan pressure of j node in the-mesh

P _Vi-j-transverse passage-way two side pressure i nodes and j node place pressure differential

P _Hi-ventilation stack blower fan causes the power of boosting that i is ordered

P _Ti-j-i node is to the traffic blast of j node

P _Mi-j-i node is to the natural ventilation pressure of j node

P _Ri-j-i node comprises on-way resistance and local resistance to the flowing resistance of j node, and distinguished and admirable resistance is divided into on-way resistance and local resistance sum;

The pressure of G, ventilation network is found the solution:

Its way is:

D) determine initial air quantity;

E) proofread and correct air quantity;

F) iterative computation is up to satisfying precision

$\mathrm{\&Delta;Q}=-\frac{\underset{i=1}{\overset{n}{\mathrm{\&Sigma;}}}{R}_i{Q}_i^2-\underset{i=1}{\overset{F}{\mathrm{\&Sigma;}}}{H}_i-N{H}_M}{2\underset{i=1}{\overset{n}{\mathrm{\&Sigma;}}}{R}_i\left|Q_i\right|-\underset{i=1}{\overset{F}{\mathrm{\&Sigma;}}}{\mathrm{\&alpha;}}_i}$

In the formula:

The air quantity corrected value of Δ Q---M mesh, | Δ Q| value increases according to iterations and reduces, when mesh | when Δ Q| went to zero, the air quantity at networking, blast had promptly tended to balance, m3/s;

To true value, when when iterative process reversion occurs, come, m3/s by correction by initial value for Qi---the nearly air quantity in the Zhejiang of i branch in the mesh, Qi;

R _iQ _i ²---the asymptotic blast of each branch in the mesh, when the wind direction of i branch with iris wipe mesh direction R when identical _iQ _i ²Get on the occasion of; Otherwise, get negative value, Pa;

---the pressure balance of M mesh is poor, Pa;

Two times of absolute values that windage is measured with fair wind of-mesh each branch;

Hi---the blast of the ventilation fan of i branch in the M mesh, when the wind direction of ventilation fan with to iris wipe the mesh direction identical constantly, Hi get on the occasion of, otherwise, get negative value, Pa;

α---the slope that ventilation fan blast curve m is ordered in the i branch;

NHM---the natural ventilation pressure of M mesh, the direction of NHM be with to iris wipe the mesh direction identical constantly, Hi get on the occasion of, otherwise, get negative value, Pa;

After obtaining mesh fan delivery Qi, obtain blast Hi and the slope α thereof of the instant operating point m of Qu Fengji,

That is:

$H_i=A{Q}_i^2+B{Q}_i+C$

α＝2AQ _i+B

A, B, C in the formula---the third-order equation of obtaining through The Fitting Calculation according to the fan pressure curve is the coefficient of quadratic equation, obtain mesh air quantity correction value delta Q according to formula after, each branch's air quantity of mesh is proofreaied and correct, promptly

Q′ _i＝Q _i+ΔQ _i

In the formula:

Q _i---the initial air quantity of mesh i branch or last time proofreaied and correct after air quantity, m3/s;

Q ' _i---the air quantity behind the i branch correction, m3/s,

Δ Q _i---mesh air quantity corrected value, when i branch wind direction with iris wipe the mesh direction and just get when identical, otherwise, get negative sign, m3/s;

In mesh air quantity correction calculation below carrying out, run into the branch that front mesh correction calculation is crossed, with the wind after proofreading and correct; The branch of wind direction was corrected in the front, used the wind direction after correcting during subsequent calculations;

Determining of H, ventilation network blower fan scale:

Try to achieve resistance, natural ventilation pressure and the traffic blast of each Network Ventilation section according to draught principle, and, draw the power of boosting that the required blower fan of each Network Ventilation section provides, finally platform number and the specification of determining blower fan according to the pressure and the air quantity of calculating in conjunction with equation group 1～5.

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