CN104110008A - Method for fast regulating and controlling water passing in middle and later stage of concrete dam - Google Patents

Abstract

The invention provides a method for fast regulating and controlling water passing in the middle and later stage of a concrete dam. The method comprises the following steps that at first, a fast prediction model for water passing in the middle and later stage of the concrete dam is set up, then based on the actual measured temperature of a concrete pouring bin, important items of the fast prediction model for water passing in the middle and later stage of the concrete dam are dynamically upgraded so that errors caused by non-determinacy factors can be eliminated, then the response of the temperature in the several coming days under water passing measures to be optimized is dynamically predicted so as to set up an objective function according to the dynamic predicted temperature response and the designed temperature monitoring index, an optimization algorithm is introduced, in the feasible region space of the water passing measures, preferably, the current optimal water passing measures are obtained, water passing and cooling in the several coming days are regulated and controlled in real time, after the several days, the current temperature, actually measured, of the pouring bin can be obtained again, and dynamic upgrading, predicting and regulation and control optimizing are carried out again. According to the method, the dynamic temperature prediction model which is fast and accurate to use and small in calculation workload is set up, and feasibility is provided for fast optimizing the temperature control measures due to setting up of the dynamic temperature prediction model.

Description

A kind of method regulating and controlling fast for the water flowing of concrete dam middle and later periods

Technical field

The present invention relates to a kind of method regulating and controlling fast for the water flowing of concrete dam middle and later periods, belong to dam association area.

Background technology

Cooling problem of concrete dam water pipe middle and later periods is an important and complicated problem.It because water pipe is cooling, is a double-edged sword, although water flowing is cooling can effectively reduce concrete construction maximum temperature and be reduced to target temperature dam body temperature within a short period of time, but near water pipe, can cause larger tensile stress when starting water flowing, if rate of temperature fall is too fast, still may cause crack.Past, this problem was not paid attention to, and allowed the difference T of concrete initial temperature and water temperature in practice of construction ₀-T _w=20～25 ℃.Research is pointed out, when cooling in the second phase, if adopt 1 dash temperature, 30 ℃ of concrete initial temperature, 9 ℃ of coolant water temperatures, the difference of concrete initial temperature and water temperature is 21 ℃, in the age of concrete, begins to cool down during 90d, limit, hole maximum tension stress is about 5MPa, and the tensile stress degree of depth is that 0.33m (water pipe spacing 1.5m * 1.5m) is to 0.70m (water pipe spacing 3.0m * 3.0m).This tensile stress is enough to cause crack.In addition, in the past fairly simple to the cooling arrangement of concrete water pipe, control device is single; Too high for fear of Temperature of Concrete Dam, often take to strengthen the strategy of water flowing flow, unavoidably like this cause the water flowing wasting of resources; In addition, because the cooling arrangement of existing concrete water pipe is fairly simple, control device is single, causes actual Temperature of Concrete Dam to be controlled with design temperature and controls and differ greatly, and is still difficult to avoid the generation of Concrete Dam Crack.

In order effectively to control Concrete Dam Crack, be necessary should plan later stage water pipe is cooling, consider cooling zone height, water pipe spacing, by stages cooling and water temperature control, carry out careful analysis and multi-scheme comparison, therefrom choose the best alternatives.Strictly speaking, for the cooling planning problem of middle and later periods water flowing, should carry out thermal parameters inverting in conjunction with observed temperature, then carry out multivariant Temperature of Concrete Dam field containing cooling water pipe problem and the contrast of creep stress field simulation analysis, therefrom choose the best alternatives.

Concrete dam temperature controlled anticracking is a complicated multi-factor problem relevant to temperature control measures and concrete thermal parameters, should adopt optimum theory to determine optimal case.When adopting optimum theory to carry out the optimal design of the concrete dam engineering temperature control measures that scale is great, if carry out more accurate thermal field and creep stress field simulation analysis, owing to relating to the preferred of a plurality of factors such as different temperature control measures and concrete thermal parameters, its amount of calculation is very big.Even when carrying out that the concrete dam middle and later periods, water flowing was cooling, water pipe spacing, water pipe material (metallic water pipe or plastic water pipe), concrete heat mechanical properties etc. are completely definite, for the great concrete dam engineering of scale, if still based on more accurate thermal field and creep stress field simulation analysis, adopt the preferred water flowing measure of optimum theory, amount of calculation is still very large.Obviously, if can not be easily for the water flowing regulation and control of concrete dam middle and later periods provide timely guidance, this will cause the on-the-spot temperature control personnel of dam construction when concrete enforcement water flowing measure, have larger blindness.

Although have successively some reports about concrete water flowing cooling automatic control system, for example, Zhou Hougui, temperature, flow signal and opening information that Tan Kaiyan etc. gather according to measure and control device, then implement the aperture of motor-operated control valve to control, regulate water flowing flow and water flowing water temperature.Lin Peng, Li Qingbin etc. bury digital temperature sensor underground newly building in storehouse, one stream temperature control device is installed on water inlet pipe and water outlet pipe, according to the conservation of energy and heat transfer principle, determine real-time water flowing flow, adopt the temperature control principle of maximum temperature, rate of temperature change and abnormal temperature, set up the cooling intelligent temperature control method of concrete in mass water flowing and system.Zhao Enguo, Guo Chen etc. have researched and developed the plant and instrument of the Real-time Collections of information such as a set of dam concrete internal temperature, coolant water temperature, cooling water flow and the automatic control of cooling water flow, and have carried out Practical Research in Di La power station, Shandong.But in these concrete water flowing cooling automatic control systems, not yet introduce optimized algorithm, be still difficult to avoid causing the water flowing wasting of resources.

Summary of the invention

In order to overcome the deficiencies in the prior art, a kind of method regulating and controlling fast for the water flowing of concrete dam middle and later periods is provided, introduce optimized algorithm, from water flowing measure feasible zone space, preferably obtain the water flowing measure of current optimum, the on-the-spot water flowing of real-time instruction is cooling.

The technical solution used in the present invention:

A kind of method regulating and controlling fast for the water flowing of concrete dam middle and later periods, it is characterized in that: it comprises the steps, model concrete dam middle and later periods water flowing fast prediction model, then based on concrete pouring bin observed temperature, dynamically update the significant terms of concrete dam middle and later periods water flowing fast prediction model, the error causing with the factor of removing uncertainty, then dynamic prediction is treated the temperature-responsive in some days future under preferred water flowing measure, with dynamic prediction temperature-responsive and design temperature monitor control index, set up object function, introduce optimized algorithm, from water flowing measure feasible zone space, preferably obtain the water flowing measure of current optimum, the real-time monitoring water flowing of following 7-10 days is cooling, after 7-10 days, again obtain and build the current observed temperature in storehouse, again dynamically update-prediction-Optimum Regulation,

Specifically comprise: 1) middle and later periods water flowing cooling period Temperature of Concrete Dam fast prediction model

For concrete block middle and later periods water flowing cooling period is carried out fast, temperature prediction exactly, must adopt the little apriority model of a kind of amount of calculation, due to when carrying out that the concrete block middle and later periods, water flowing was cooling, most hydration heat of cement has discharged, and insulation benzene plate has generally been pasted on upstream and downstream surface, now, water pipe level interval and vertical interval, water pipe material, concrete heat mechanical property is also known, can think middle and later periods of dam concrete cooling be only one with water flowing water temperature, the complicated multi-factor problem that water flowing flow is relevant with the water flowing time,

In concrete pouring bin, burying cooling water pipe underground, to carry out water flowing cooling, and establishing equivalent cooling diameter is D, and length is L, and without thermal source, concrete initial temperature is T ₀, inlet water temperature is T _w, concrete average temperature can be expressed as

T＝T _w+(T ₀-T _w)φ (1)

Function phi has following two kinds of calculating formulas

(1) function phi calculating formula 1

φ＝exp(-p ₁τ ^s) (2)

Wherein, p ₁=k ₁(a/D ²) ^s, k ₁=2.08-1.174 ξ+0.256 ξ ², s=0.971+0.1485 ξ-0.0445 ξ ², ξ=λ L/ (c _wρ _wq _w), in formula: a is concrete thermal diffusivity, D is for building storehouse water pipe equivalence cooling diameter, and λ is concrete coefficient of thermal conductivity, and L is cooling water pipe length, c _wfor cooling water specific heat, ρ _wfor cooling water density, q _wfor water flowing flow;

(2) function phi calculating formula 2

φ＝exp(-p ₂τ) (3)

Wherein, p ₂=k ₂a/D ², k ₂=2.09-1.35 ξ+0.320 ξ ², in formula: a, D and ξ implication are the same,

When b/c ≠ 100, the thermal diffusivity a in the calculating formula of function phi should adopt equivalent thermal diffusivity a ', for metallic water pipe, has

a′＝1.947(α ₁b) ²a (4)

Wherein, ${\mathrm{\α}}_{1}b=0.926\exp [-0.0314{(\frac{b}{c}-20)}^{0.48}],20\≤\frac{b}{c}\≤130,$ In formula: b is equivalent cooling radius, and c is metallic water pipe outer radius,

For plastic water pipe, have

$a^{\′}=\frac{\ln 100}{\ln (b/c)+(\mathrm{\λ}/{\mathrm{\λ}}_1)\ln (c/r_0)}a---\left(5\right)$

In formula: λ ₁for the coefficient of thermal conductivity of plastic water pipe, c is plastic water pipe outer radius, r ₀for the inside radius of plastic water pipe, all the other symbol implications are the same,

When cool time is larger, adopt the calculating formula 1 of function phi, when be no more than 15 days cool time, adopt the calculating formula 2 of function phi,

When water flowing flow is constant, adopt many dash temperature to carry out when cooling, concrete average temperature adopts following formula to calculate

T＝T _wi+(T _i-T _wi)φ _i (6)

In formula: T _wibe i gear water flowing temperature, T _ibe the concrete temperature when water flowing of i-1 dash temperature finishes and i dash temperature starts water flowing, φ _iwater-cooled function while being the water flowing of i dash temperature, the time τ in function need to be since 0,

Constant when water flowing water temperature, adopt many baffles amount to carry out when cooling, roughly the same, similarly, the time τ in water-cooled function need to be since 0 for concrete average temperature calculating formula and formula (6);

2) cooling period concrete dam middle and later periods is built storehouse temperature dynamic forecast model

Without thermal source water pipe Cooling calculation formula, having implied equivalent cooling diameter is that the external surface of the concrete prism of D is adiabatic border, and has supposed that the heat of hydration of concrete prism completes completely, in without thermal source state.Because the Massive Concrete Blocks of middle and later periods cooling stage is not without thermal source state; In addition, the Massive Concrete Blocks of middle and later periods cooling stage neither adiabatci condition, on the temperature of concrete block inside, still there is certain impact in ambient temperature, directly adopt the concrete pouring bin temperature prediction that carries out cooling period middle and later periods without thermal source water pipe Cooling calculation formula (6), effect is undesirable, dynamically updates without the T in thermal source water pipe Cooling calculation formula _ithereby, overcome without the undesirable problem of thermal source water pipe Cooling calculation formula temperature prediction effect, can carry out exactly the prediction of following 7-10 days concrete pouring bin temperature informations;

3) the concrete analysis step of the cooling quick regulate and control method of concrete dam middle and later periods water flowing

(1) Current Temperatures state and current water flowing feasible zone obtain, and first obtain mid-term during cooling beginning or typical section each the concrete pouring bin temperature T i of second phase during cooling beginning; Then according to engineering experience, determine water flowing water temperature T _w, water flowing flow T _qwith water flowing time T _tinitial value Deng water flowing measure;

(2) the dynamic prediction temperature-responsive of following some days, adopts without thermal source water pipe Cooling calculation formula, carries out the calculating of concrete cooling curve, obtains the cooling final temperature T of each concrete pouring bin under the combination of water flowing measure value _iendwith maximum day rate of temperature fall

(3) by cold in calculating or two cold lower final temperatures and maximum day rate of temperature fall, with in cold or two cold design object temperature T _i ^objwith suitable rate of temperature fall residual sum of squares (RSS) as object function, the water flowing stimulation optimization model of setting up is thus

$\min f(T_i,T_w,T_Q,T_t)={({T_i}^{\mathrm{obj}}-T_{\mathrm{iend}})}^2+{({{\stackrel{\·}{T}}_i}^{\mathrm{opt}}-{\stackrel{\·}{T}}_{i\max })}^2---\left(7\right)$

$s.t.\left\{\begin{array}{c}\underset{\‾}{T_w}\≤T_w\≤\stackrel{\‾}{T_w}\\ \underset{\‾}{T_Q}\≤T_Q\≤\stackrel{\‾}{T_Q}\\ \underset{\‾}{T_t}\≤T_t\≤\stackrel{\‾}{T_t}\end{array}\right.$

In formula: t _w , be respectively water flowing water temperature T _wupper lower limit value, t _q , be respectively water flowing flow T _qupper lower limit value, t _t , be respectively water flowing time T _tupper lower limit value;

(4) adopt the optimized algorithm of belt restraining preferably to obtain the water flowing scheme that each storehouse concrete is optimized;

(5) to typical section in the middle and later periods logical water-cooled each build storehouse and analyze one by one, according to engineering actual conditions and engineering experience, the water flowing measure optimizing is slightly adjusted, then instruct middle and later periods water flowing cooling.

Above-mentioned owing to adopting while calculating concrete cooling curve without thermal source water pipe Cooling calculation formula, need known mid-term during cooling beginning or the concrete pouring bin temperature T of second phase during cooling beginning _i, this temperature can obtain in the following way: mode one, in concrete pouring bin, buried thermometer underground, and using observed temperature as mid-term during cooling start or the concrete pouring bin temperature of second phase during cooling beginning; Mode two, the underway phase cooling or the second stage of cooling before, by vexed water thermometric, as mid-term during cooling start or the concrete pouring bin temperature of second phase during cooling beginning; In order to guarantee to obtain the accuracy of concrete pouring bin temperature, the temperature of mode one and mode two acquisitions can be weighted to average computation.

The above-mentioned underway phase is cooling or the second stage of when cooling, sometimes need repeatedly to regulate water temperature or flow to carry out cooling, now, based on optimized algorithm, carry out the key step of the cooling quick regulation and control of water flowing of middle and later periods, being analogous to cooling period in mid-term and second phase adopts a kind of water temperature and flow to carry out cooling step the cooling period, but need to be when each adjusting water temperature or flow, the water flowing scheme of the concrete pouring bin temperature while regulating water temperature or flow preferably, due to based on without thermal source water pipe Cooling calculation formula to build storehouse temperature dynamic forecast model amount of calculation little, this can guarantee each preferred water flowing scheme feasible while regulating water temperature or flow.

Above-mentionedly when calculating water-cooled function phi, relate to concrete thermal diffusivity, coefficient of thermal conductivity and plastic water pipe coefficient of thermal conductivity, these parameters adopt design load and producer's quality inspection values, or carry out parametric inversion acquisition based on observed temperature.

The technique effect that the present invention obtains:

(1) for the water flowing of concrete dam middle and later periods, be a complicated multi-factor problem relevant to water flowing water temperature, water flowing flow and water flowing time etc., observed temperature is organically fused to without in thermal source water pipe Cooling calculation formula, based on observed temperature, dynamically update without the significant terms in thermal source water pipe Cooling calculation formula, eliminate the temperature prediction error that the uncertainties such as fringe conditions, material parameter and computation model are brought, thereby set up a kind of quick, accurate and little temperature dynamic forecast model of amount of calculation.The preferred realization fast that is established as temperature control measures of temperature dynamic forecast model provides feasibility.

(2) fairly simple for the cooling arrangement of existing concrete water pipe, control device is single, causing actual Temperature of Concrete Dam to be controlled with design temperature controls and differs greatly, and not yet introduce optimized algorithm in existing concrete water flowing cooling automatic control system, still be difficult to avoid causing the water flowing wasting of resources, patent of the present invention is introduced the cooling regulation and control of water flowing by optimized algorithm, set up temperature dynamic prediction-Optimum Regulation integrated monitoring model, from water flowing measure feasible zone space, preferably obtain the water flowing measure of current optimum, the real-time monitoring water flowing of following some days is cooling.Thereby avoid the waste of water flowing resource, and the middle and later periods water flowing of real-time instruction concrete dam is cooling effectively.

Accompanying drawing explanation

Fig. 1 is middle and later periods concreting warehouse receipt measuring point temperature dynamic prediction block diagram when cooling;

Fig. 2 is the cooling Optimum Regulation block diagram of typical section middle and later periods water flowing, and wherein, NI is for building storehouse number in water flowing stage middle and later periods;

Fig. 3 be cooling period middle and later periods typical section vertically to temperature.

The specific embodiment

Below in conjunction with accompanying drawing, embodiments of the present invention are described further.

Patent of the present invention is mainly applicable to the water flowing measure of concrete dam middle and later periods and regulates and controls fast.Model concrete dam middle and later periods water flowing fast prediction model, then based on concrete pouring bin observed temperature, dynamically update the significant terms of concrete dam middle and later periods water flowing fast prediction model, the error causing with the factor of removing uncertainty, then dynamic prediction is treated the temperature-responsive in some days future under preferred water flowing measure, with dynamic prediction temperature-responsive and design temperature monitor control index, set up object function, introduce optimized algorithm, from water flowing measure feasible zone space, preferably obtain the water flowing measure of current optimum, the real-time monitoring water flowing of following some days is cooling.After some days, again obtain and build the current observed temperature in storehouse, again dynamically update-prediction-Optimum Regulation.

Patent detailed technology scheme of the present invention is as follows:

1) middle and later periods water flowing cooling period Temperature of Concrete Dam fast prediction model

For concrete block middle and later periods water flowing cooling period is carried out to temperature prediction quickly and accurately, must adopt the little apriority model of a kind of amount of calculation.Due to when carrying out that the concrete block middle and later periods, water flowing was cooling, most hydration heat of cement has discharged, and insulation benzene plate has generally been pasted on upstream and downstream surface, now, water pipe level interval and vertical interval, water pipe material (metallic water pipe or plastic water pipe), concrete heat mechanical property etc. is also known, can think middle and later periods of dam concrete cooling be only a complicated multi-factor problem relevant with water flowing water temperature, water flowing flow and water flowing time etc.For this reason, patent of the present invention adopts and carries out middle and later periods water flowing cooling period Temperature of Concrete Dam fast prediction without thermal source water pipe Cooling calculation formula.

Below provide in detail without thermal source water pipe Cooling calculation formula design formulas.In concrete pouring bin, burying cooling water pipe underground, to carry out water flowing cooling, and establishing equivalent cooling diameter is D, and length is L, and without thermal source, concrete initial temperature is T ₀, inlet water temperature is T _w, concrete average temperature can be expressed as

T＝T _w+(T ₀-T _w)φ (1)

Function phi has following two kinds of calculating formulas

(1) function phi calculating formula 1

φ＝exp(-p ₁τ ^s) (2)

Wherein, p ₁=k ₁(a/D ²) ^s, k ₁=2.08-1.174 ξ+0.256 ξ ², s=0.971+0.1485 ξ-0.0445 ξ ², ξ=λ L/ (c _wρ _wq _w).

In formula: a is concrete thermal diffusivity, D is for building storehouse water pipe equivalence cooling diameter, and λ is concrete coefficient of thermal conductivity, and L is cooling water pipe length, c _wfor cooling water specific heat, ρ _wfor cooling water density, q _wfor water flowing flow.

(2) function phi calculating formula 2

φ＝exp(-p ₂τ) (3)

Wherein, p ₂=k ₂a/D ², k ₂=2.09-1.35 ξ+0.320 ξ ²

In formula: a, D and ξ implication are the same.

When b/c ≠ 100, the thermal diffusivity a in the calculating formula of function phi should adopt equivalent thermal diffusivity a ', for metallic water pipe, has

a′＝1.947(α ₁b) ²a (4)

Wherein, ${\mathrm{\α}}_{1}b=0.926\exp [-0.0314{(\frac{b}{c}-20)}^{0.48}],20\≤\frac{b}{c}\≤130$

In formula: b is equivalent cooling radius, and c is metallic water pipe outer radius,

For plastic water pipe, have

$a^{\′}=\frac{\ln 100}{\ln (b/c)+(\mathrm{\λ}/{\mathrm{\λ}}_1)\ln (c/r_0)}a---\left(5\right)$

In formula: λ ₁for the coefficient of thermal conductivity of plastic water pipe, c is plastic water pipe outer radius, r ₀for the inside radius of plastic water pipe, all the other symbol implications are the same.

Larger when cool time, while surpassing 15 days, preferably adopt the calculating formula 1 of function phi, but in actual concrete work, it is more some more that the calculating formula 2 of function phi is used.

When water flowing flow is constant, adopt many dash temperature to carry out when cooling, concrete average temperature adopts following formula to calculate

T＝T _wi+(T _i-T _wi)φ _i (6)

In formula: T _wibe i gear water flowing temperature, T _ibe the concrete temperature when water flowing of i-1 dash temperature finishes and i dash temperature starts water flowing, φ _iwater-cooled function while being the water flowing of i dash temperature, the time τ in function need to be since 0.

Constant when water flowing water temperature, adopt many baffles amount to carry out when cooling, roughly the same, similarly, the time τ in water-cooled function need to be since 0 for concrete average temperature calculating formula and formula (6).

2) cooling period concrete dam middle and later periods is built storehouse temperature dynamic forecast model

As Fig. 1, owing to having implied equivalent cooling diameter without thermal source water pipe Cooling calculation formula, be that the external surface of the concrete prism of D is adiabatic border, and supposed that the heat of hydration of concrete prism completes completely, in without thermal source state.Because the Massive Concrete Blocks of middle and later periods cooling stage is not without thermal source state,, there is slow heat release of later stage etc. in general concrete height of dam fly ash for example; In addition, the Massive Concrete Blocks of middle and later periods cooling stage neither adiabatci condition, and for example external surface has been pasted insulation benzene plate, and ambient temperature still exists certain impact to the temperature of concrete block inside.Directly adopt the concrete pouring bin temperature prediction that carries out cooling period middle and later periods without thermal source water pipe Cooling calculation formula (6), effect is undesirable.

Patent of the present invention, based on the current observed temperature of concrete pouring bin, dynamically updates without the T in thermal source water pipe Cooling calculation formula _i, can be by the slow heat release of high fly ash, and upstream and downstream surface is not the error that adiabatic border etc. causes, by dynamically updating T _icome dynamically to revise in real time, thereby overcome without the undesirable problem of thermal source water pipe Cooling calculation formula temperature prediction effect, can carry out exactly the prediction of following 7-10 days concrete pouring bin temperature informations.

3) the cooling quick regulate and control method of concrete dam middle and later periods water flowing

Patent of the present invention adopts that the amount of calculation of setting up is little, concrete pouring bin dynamic prediction model fast and accurately, dynamic prediction is treated the temperature-responsive in some days future under preferred water flowing measure, with dynamic prediction temperature-responsive and design temperature monitor control index, set up object function, introduce the optimized algorithm (for example compound algorithm) of belt restraining, from water flowing measure feasible zone space, preferably obtain the water flowing measure of current optimum, the real-time monitoring water flowing of following some days is cooling.After some days, again obtain and build the current observed temperature in storehouse, again dynamically update-prediction-Optimum Regulation.Set up thus the cooling quick regulation-control model of concrete dam middle and later periods water flowing.

As Fig. 2, below provide in detail the analytical procedure of the cooling quick regulate and control method of concrete dam middle and later periods water flowing.

(1) Current Temperatures state and current water flowing feasible zone obtain.First obtain mid-term during cooling start or each concrete pouring bin temperature T of typical section i of second phase during cooling beginning; Then according to engineering experience, determine water flowing water temperature T _w, water flowing flow T _qwith water flowing time T _tinitial value Deng water flowing measure.

(2) the dynamic prediction temperature-responsive of following some days.Employing, without thermal source water pipe Cooling calculation formula, is carried out the calculating of concrete cooling curve, obtains the cooling final temperature T of each concrete pouring bin under the combination of water flowing measure value _iendwith maximum day rate of temperature fall

(3) by cold in calculating or two cold lower final temperatures and maximum day rate of temperature fall, with in cold or two cold design object temperature T _i ^objwith suitable rate of temperature fall residual sum of squares (RSS) as object function, the water flowing stimulation optimization model of setting up is thus

$\min f(T_i,T_w,T_Q,T_t)={({T_i}^{\mathrm{obj}}-T_{\mathrm{iend}})}^2+{({{\stackrel{\·}{T}}_i}^{\mathrm{opt}}-{\stackrel{\·}{T}}_{i\max })}^2---\left(7\right)$

$s.t.\left\{\begin{array}{c}\underset{\‾}{T_w}\≤T_w\≤\stackrel{\‾}{T_w}\\ \underset{\‾}{T_Q}\≤T_Q\≤\stackrel{\‾}{T_Q}\\ \underset{\‾}{T_t}\≤T_t\≤\stackrel{\‾}{T_t}\end{array}\right.$

In formula: t _w , be respectively water flowing water temperature T _wupper lower limit value, t _q , be respectively water flowing flow T _qupper lower limit value, t _t , be respectively water flowing time T _tupper lower limit value.

(4) adopt the optimized algorithm (for example compound algorithm) of belt restraining preferably to obtain the water flowing scheme that each storehouse concrete is optimized.

(5) to typical section in the middle and later periods logical water-cooled each build storehouse and analyze one by one.According to engineering actual conditions and engineering experience etc., the water flowing measure optimizing is slightly adjusted, then instruct middle and later periods water flowing cooling.

When carrying out the cooling quick regulation and control of middle and later periods water flowing based on optimized algorithm, there is following several problem should be noted that

(1), owing to adopting while calculating concrete cooling curve without thermal source water pipe Cooling calculation formula, need known mid-term during cooling beginning or the concrete pouring bin temperature T of second phase during cooling beginning _i, this temperature can obtain in the following way: mode one, in concrete pouring bin, buried thermometer underground, and using observed temperature as mid-term during cooling start or the concrete pouring bin temperature of second phase during cooling beginning; Mode two, the underway phase cooling or the second stage of cooling before, by vexed water thermometric, as mid-term during cooling start or the concrete pouring bin temperature of second phase during cooling beginning; In order to guarantee to obtain the accuracy of concrete pouring bin temperature, the temperature of mode one and mode two acquisitions can be weighted to average computation.

(2) when calculating water-cooled function phi, relate to concrete thermal diffusivity, coefficient of thermal conductivity and plastic water pipe coefficient of thermal conductivity etc., these parameters adopt design load and producer's quality inspection value, or carry out parametric inversion acquisition based on observed temperature.

(3) the underway phase is cooling or the second stage of when cooling, sometimes need repeatedly to regulate water temperature or flow to carry out cooling, now, based on optimized algorithm, carry out the key step of the cooling quick regulation and control of water flowing of middle and later periods, being analogous to cooling period in mid-term and second phase adopts a kind of water temperature and flow to carry out cooling step the cooling period, but need to be each while regulating water temperature or flow, the water flowing scheme of the concrete pouring bin temperature while regulating water temperature or flow preferably.Due to based on without thermal source water pipe Cooling calculation formula to build storehouse temperature dynamic forecast model amount of calculation little, this can guarantee each preferred water flowing scheme feasible while regulating water temperature or flow.

Case history

High arch dam in certain construction of southwest divides 31 monoliths, crest elevation 610m, maximum height of dam 285.5m.For construction period concrete temperature being reduced to envelope arch temperature, according to Arch Dam Concrete temperature controlled anticracking feature, divide carry out concrete cooling cooling three periods such as the first period cooling, mid-term is cooling, the second phase is cooling, to reach the little temperature difference, slow cooling effect but.Meanwhile, at monolith, vertically to being provided with irrigated area, grout compartment, same cold-zone, transition region, Gai Chongqu and pouring area, reduce vertical to temperature gradient and control cooling zone height etc.For the state of temperature that carries out preferably the cooling control of water flowing and obtain dam concrete, in concrete pouring bin, bury thermometer underground and carry out temperature monitoring.Now choose 12 concrete pouring bin of typical section and carry out the cooling Optimum Regulation analysis of middle and later periods water flowing, as Fig. 3.The high 9m in this each irrigated area of high arch dam, builds the thick 3m in storehouse, 20 ℃ of the first period cooling target temperatures, and mid-term, cooling target temperature was 16 ℃, 12 ℃ of the second stage of cooling target temperatures (envelope arch temperature).In figure, solid line is for respectively building storehouse Current Temperatures state, and dotted line, for respectively building the cooling target temperature in storehouse, is analyzed by above-mentioned concrete middle and later periods water flowing Optimum Regulation principle.

(1) preferred factor determines

The water flowing of concrete dam middle and later periods is cooling need to be carried out preferably water flowing water temperature, water flowing flow and water flowing time 3 factors.Owing to being saving refrigeration cost, this high arch dam only provides two dash temperature: when cooling, adopt 15～16 ℃ of water temperatures mid-term, this water temperature approaches cooling target temperature in mid-term; Second phase, when cooling, adopts 8～9 ℃ of water temperatures, and this water temperature is lower than the water temperature of envelope arch temperature.Therefore, for this actual concrete work, while specifying mid-term cooling when this is analyzed, water flowing water temperature is 15.2 ℃, and when the second stage of water flowing is cooling, water flowing water temperature is 8.5 ℃.Only water flowing flow and water flowing time 2 water flowing factors are carried out preferably.

(2) water flowing measure span

According to this concrete dam engineering experience and this project physical condition, cooling for water flowing in mid-term, selected water flowing flow span is 10～30L/min, and water flowing time span is 5～45d; Cooling for the second stage of water flowing, selected water flowing flow span is 5～25L/min, and water flowing time span is 5～25d.

(3) the quick regulation and control of water flowing measure

12 concrete pouring bin water pipe spacing choosing typical section are 1.5m * 1.5m, all adopt polyethylene plastic water pipe, because this concrete dam engineering is vertically to irrigated area, grout compartment, same cold-zone, transition region, Gai Chongqu and pouring area are set, it can avoid vertically and control cooling zone height excessive to temperature gradient of Massive Concrete Blocks preferably, meanwhile, this concrete work divides and carries out the little temperature difference, Slow cooling three periods.From this concrete dam engineering, completed the observed temperature statistical analysis of cooling and the second stage of cooling concrete pouring bin in mid-term, mid-term and a second stage of water flowing maximum day rate of temperature fall of cooling period all meet design requirement, for this reason, herein main in building storehouse temperature information during cold or two cold beginnings and in cold or two cold target temperatures, in conjunction with without thermal source water pipe Cooling calculation formula, adopt optimized algorithm to determine water flowing flow and the water flowing time of optimizing.Wherein, optimized algorithm adopts the compound algorithm of Problem with Some Constrained Conditions, and water flowing flow and the constraints of water flowing time are water flowing measure span.

The water flowing parameter that 12 concrete pouring bin in middle and later periods water flowing cooling stage optimize is in Table 1, then according to engineering actual conditions and engineering experience etc., the water flowing measure optimizing slightly adjusted, adjustment time and adjust flow in Table 1.From table 1, each concrete pouring bin water flowing is different cool time, now, for guaranteeing cooling uniformity, should start to carry out cooling mid-term to each concrete pouring bin simultaneously and cool with the second phase, when certain concrete pouring bin reaches the water flowing that optimizes cool time during the time, this is built storehouse and transfers the temperature control stage to.

Table 1 is respectively built the water flowing measure that storehouse optimizes

Claims (4)

1. one kind for the quick method of regulation and control of concrete dam middle and later periods water flowing, it is characterized in that: it comprises the steps, model concrete dam middle and later periods water flowing fast prediction model, then based on concrete pouring bin observed temperature, dynamically update the significant terms of concrete dam middle and later periods water flowing fast prediction model, the error causing with the factor of removing uncertainty, then dynamic prediction is treated the temperature-responsive in some days future under preferred water flowing measure, with dynamic prediction temperature-responsive and design temperature monitor control index, set up object function, introduce optimized algorithm, from water flowing measure feasible zone space, preferably obtain the water flowing measure of current optimum, the real-time monitoring water flowing of following 7-10 days is cooling, 7-10 days, again obtain and build the current observed temperature in storehouse, again dynamically update-prediction-Optimum Regulation,

Specifically comprise: 1) middle and later periods water flowing cooling period Temperature of Concrete Dam fast prediction model:

For concrete block middle and later periods water flowing cooling period is carried out fast, temperature prediction exactly, must adopt the little apriority model of a kind of amount of calculation, due to when carrying out that the concrete block middle and later periods, water flowing was cooling, most hydration heat of cement has discharged, and insulation benzene plate has generally been pasted on upstream and downstream surface, now, water pipe level interval, vertical interval, water pipe material and concrete heat mechanical property are also known, can think middle and later periods of dam concrete cooling be only one with water flowing water temperature, the complicated multi-factor problem that water flowing flow is relevant with the water flowing time,

In concrete pouring bin, burying cooling water pipe underground, to carry out water flowing cooling, and establishing equivalent cooling diameter is D, and length is L, and without thermal source, concrete initial temperature is T ₀, inlet water temperature is T _w, concrete average temperature can be expressed as:

T＝T _w+(T ₀-T _w)φ (1)

Function phi has following two kinds of calculating formulas

(1) function phi calculating formula 1

φ＝exp(-p ₁τ ^s) (2)

Wherein, p ₁=k ₁(a/D ²) ^s, k ₁=2.08-1.174 ξ+0.256 ξ ², s=0.971+0.1485 ξ-0.0445 ξ ², ξ=λ L/ (c _wρ _wq _w), in formula: a is concrete thermal diffusivity, D is for building storehouse water pipe equivalence cooling diameter, and λ is concrete coefficient of thermal conductivity, and L is cooling water pipe length, c _wfor cooling water specific heat, ρ _wfor cooling water density, q _wfor water flowing flow;

(2) function phi calculating formula 2

φ＝exp(-p ₂τ) (3)

Wherein, p ₂=k ₂a/D ², k ₂=2.09-1.35 ξ+0.320 ξ ², in formula: a, D and ξ implication are the same,

When b/c ≠ 100, the thermal diffusivity a in the calculating formula of function phi should adopt equivalent thermal diffusivity a ', for water pipe material, is metallic water pipe, has

a′＝1.947(α ₁b) ²a (4)

Wherein, ${\mathrm{\α}}_{1}b=0.926\exp [-0.0314{(\frac{b}{c}-20)}^{0.48}],20\≤\frac{b}{c}\≤130,$ In formula: b is equivalent cooling radius, and c is metallic water pipe outer radius,

For water pipe material, be plastic water pipe, have

$a^{\′}=\frac{\ln 100}{\ln (b/c)+(\mathrm{\λ}/{\mathrm{\λ}}_1)\ln (c/r_0)}a---\left(5\right)$

In formula: λ ₁for the coefficient of thermal conductivity of plastic water pipe, c is plastic water pipe outer radius, r ₀for the inside radius of plastic water pipe, all the other symbol implications are the same,

When cool time is larger, adopt the calculating formula 1 of function phi, when be no more than 15 days cool time, adopt the calculating formula 2 of function phi,

When water flowing flow is constant, adopt many dash temperature to carry out when cooling, concrete average temperature adopts following formula to calculate

T＝T _wi+(T _i-T _wi)φ _i (6)

In formula: T _wibe i gear water flowing temperature, T _ibe the concrete temperature when water flowing of i-1 dash temperature finishes and i dash temperature starts water flowing, φ _iwater-cooled function while being the water flowing of i dash temperature, the time τ in function need to be since 0,

Constant when water flowing water temperature, adopt many baffles amount to carry out when cooling, roughly the same, similarly, the time τ in water-cooled function need to be since 0 for concrete average temperature calculating formula and formula (6);

2) cooling period concrete dam middle and later periods is built storehouse temperature dynamic forecast model

Without thermal source water pipe Cooling calculation formula, having implied equivalent cooling diameter is that the external surface of the concrete prism of D is adiabatic border, and has supposed that the heat of hydration of concrete prism completes completely, in without thermal source state.Because the Massive Concrete Blocks of middle and later periods cooling stage is not without thermal source state; In addition, the Massive Concrete Blocks of middle and later periods cooling stage neither adiabatci condition, on the temperature of concrete block inside, still there is certain impact in ambient temperature, directly adopt the concrete pouring bin temperature prediction that carries out cooling period middle and later periods without thermal source water pipe Cooling calculation formula (6), effect is undesirable, dynamically updates without the T in thermal source water pipe Cooling calculation formula _ithereby, overcome without the undesirable problem of thermal source water pipe Cooling calculation formula temperature prediction effect, can carry out exactly the prediction of following 7-10 days concrete pouring bin temperature informations;

3) the concrete analysis step of the cooling quick regulate and control method of concrete dam middle and later periods water flowing

(1) Current Temperatures state and current water flowing feasible zone obtain, and first obtain mid-term during cooling beginning or second phase each concrete pouring bin temperature T of typical section during cooling beginning _i; Then according to engineering experience, determine water flowing water temperature T _w, water flowing flow T _qwith water flowing time T _tinitial value Deng water flowing measure;

(2) the dynamic prediction temperature-responsive of following some days, adopts without thermal source water pipe Cooling calculation formula, carries out the calculating of concrete cooling curve, obtains the cooling final temperature T of each concrete pouring bin under the combination of water flowing measure value _iendwith maximum day rate of temperature fall

(3) by cold in calculating or two cold lower final temperatures and maximum day rate of temperature fall, with in cold or two cold design object temperature T _i ^objwith suitable rate of temperature fall residual sum of squares (RSS) as object function, the water flowing stimulation optimization model of setting up is thus

$\min f(T_i,T_w,T_Q,T_t)={({T_i}^{\mathrm{obj}}-T_{\mathrm{iend}})}^2+{({{\stackrel{\·}{T}}_i}^{\mathrm{opt}}-{\stackrel{\·}{T}}_{i\max })}^2---\left(7\right)$

$s.t.\left\{\begin{array}{c}\underset{\‾}{T_w}\≤T_w\≤\stackrel{\‾}{T_w}\\ \underset{\‾}{T_Q}\≤T_Q\≤\stackrel{\‾}{T_Q}\\ \underset{\‾}{T_t}\≤T_t\≤\stackrel{\‾}{T_t}\end{array}\right.$

In formula: t _w , be respectively water flowing water temperature T _wupper lower limit value, t _q , be respectively water flowing flow T _qupper lower limit value, t _t , be respectively water flowing time T _tupper lower limit value;

(4) adopt the optimized algorithm of belt restraining preferably to obtain the water flowing scheme that each storehouse concrete is optimized;

(5) to typical section in the middle and later periods logical water-cooled each build storehouse and analyze one by one, according to engineering actual conditions and engineering experience, the water flowing measure optimizing is slightly adjusted, then instruct middle and later periods water flowing cooling.

2. according to claim 1 for the quick method of regulation and control of concrete dam middle and later periods water flowing, it is characterized in that: owing to adopting while calculating concrete cooling curve without thermal source water pipe Cooling calculation formula, need known mid-term during cooling beginning or the concrete pouring bin temperature T of second phase during cooling beginning _i, this temperature can obtain in the following way: mode one, in concrete pouring bin, buried thermometer underground, and using observed temperature as mid-term during cooling start or the concrete pouring bin temperature of second phase during cooling beginning; Mode two, the underway phase cooling or the second stage of cooling before, by vexed water thermometric, as mid-term during cooling start or the concrete pouring bin temperature of second phase during cooling beginning; In order to guarantee to obtain the accuracy of concrete pouring bin temperature, the temperature of mode one and mode two acquisitions can be weighted to average computation.

3. according to claim 2 for the quick method of regulation and control of concrete dam middle and later periods water flowing, it is characterized in that: the underway phase is cooling or the second stage of when cooling, sometimes need repeatedly to regulate water temperature or flow to carry out cooling, now, based on optimized algorithm, carry out the key step of the cooling quick regulation and control of water flowing of middle and later periods, being analogous to cooling period in mid-term and second phase adopts a kind of water temperature and flow to carry out cooling step the cooling period, but need to be when each adjusting water temperature or flow, the water flowing scheme of the concrete pouring bin temperature while regulating water temperature or flow preferably, due to based on without thermal source water pipe Cooling calculation formula to build storehouse temperature dynamic forecast model amount of calculation little, this can guarantee each preferred water flowing scheme feasible while regulating water temperature or flow.

4. according to claim 2 for the quick method of regulation and control of concrete dam middle and later periods water flowing, it is characterized in that: when calculating water-cooled function phi, relate to concrete thermal diffusivity, coefficient of thermal conductivity and plastic water pipe coefficient of thermal conductivity, these parameters adopt design load and producer's quality inspection value, or carry out parametric inversion acquisition based on observed temperature.