JP4601877B2 - Analysis method of concrete cooling effect by pipe cooling - Google Patents

Description

ここで、ｋ_ｙ，ｋ_ｚ；コンクリートの異方性熱伝導率、
Ｔ_ｃ ；コンクリートの温度
Ｑ_ｃ（ｔ）；コンクリートの内部発熱率
Ｃ_ｃ，ρ_ｃ；コンクリートの比熱及び密度
なお、パイプクーリングにおける熱収支は、クーリングパイプ２周辺の境界において一般の対流熱伝導境界と同様であると考え、クーリングパイプ２と接する境界、すなわち、パイプクーリング節点境界ｐ_ξ（ξ＝１〜ｎ）において、以下の式（２）のように表わせる。
【数２】

ここで、ｌ_ｙ，ｌ_ｚ；境界上の垂線の方向余弦
α_ｗ ；コンクリートとクーリング水間の平均熱伝達率
Ｔ_ｗ ；クーリング水の温度
一方、クーリング水の温度Ｔ_ｗに関する一次元定常熱輸送方程式は以下の式（３）のように表わせる。
【数３】

したがって、パイプ位置間の通水距離と、上記式（３）により求められた温度勾配（∂Ｔ_ｗ／∂ｓ）とを用いて各パイプクーリング節点境界でのクーリング水の温度Ｔ_ξ（ξ＝１〜ｎ）を算出し、このクーリング水の温度Ｔ_ξを上記式（２）に代入した境界条件下において、上記非定常熱伝導方程式（１）を解くことにより、クーリング水の温度上昇を考慮したマスコンクリート１の温度分布を算出することができる。
【０００８】
次に、本発明のパイプクーリングによるコンクリート冷却効果の解析方法の詳細について図３及び図４に示すフローチャートを参照して説明する。ここで、図３は本発明の解析方法によるフローチャートの一例であり、図４は従来方法によるフローチャートの一例である。
まず、マスコンクリート１の二次元断面Ｒを多数の要素に分割し（ステップＳ１０）、その後、コンクリートの打込み温度や発熱特性などの初期条件と、対流熱伝達境界やパイプクーリング境界、及びクーリング水の温度分布などの境界条件を解析条件として設定する（ステップＳ１２）。
このクーリング水の温度分布の初期設定は、従来の解析条件設定（図４のステップＳ５２）におけるパイプクーリング境界と同様に、各パイプ位置でのクーリング水の温度は常に入口水温と同じか、あるいは各パイプ位置でのクーリング水の温度が所定の温度勾配に従い、パイプ延長に沿って徐々に上昇するように設定するが、本例では、後述するように、繰り返し計算時において、マスコンクリート１内の温度分布に応じて再設定される。
【０００９】
解析条件の設定が終了すると、第１回目の計算（Ｎ＝１）に入り（ステップＳ１４）、上記解析条件の下で非定常熱伝導方程式（１）からマスコンクリート１内の幅方向及び長さ方向の温度勾配（∂Ｔ_ｃ／∂ｙ），（∂Ｔ_ｃ／∂ｚ）を計算して（ステップＳ１６）、マスコンクリート１内の温度分布を求める（ステップＳ１８）。なお、この第１回目の計算においては、各パイプ位置でのクーリング水の温度Ｔ_ξは初期条件で与えられた温度勾配（∂Ｔ_ｗ／∂ｓ）_ｔ＝０に従った水温分布から求められるので、このクーリング水の温度Ｔ_ξを境界条件の式（２）に適用して、非定常熱伝導方程式（１）を解く。
また、上記計算の各回は、通常、コンクリートの養生時間により１回目，２回目，‥‥，Ｎ回目，‥‥と設定される。すなわち、最初の計算はパイプクーリングの開始時におけるマスコンクリート１内の温度分布を求め、その後所定の経過時間毎に同様の解析を行い、経過時間ごとのマスコンクリート１内の温度分布を順次計算する。なお、各回の時間間隔は一定でもよいし、予め設定してもよいが、例えば、マスコンクリート１の温度変化が経験的に緩やかになる時間までは予め設定された所定時間ごとに解析し、その後は、解析の時間間隔を伸ばして行い、養生の終了予測時の時間を最後の回の計算（Ｎ＝Ｎ_ｍａｘ）とすると効率的である。
【００１０】
従来の方法では、図４に示すように、Ｎ回目のマスコンクリート１の温度分布の計算が終了すると、直ちに次の回の計算（Ｎ＝Ｎ＋１）に進み、上記経過時間に対応した発熱特性や境界条件を再設定した後、所定の最終回（Ｎ＝Ｎ_ｍａｘ）まで同様の計算を順次行うことにより、マスコンクリート１の温度分布の時間変化を求めてマスコンクリート１の冷却状態を解析する。このとき、従来の方法におけるクーリング水の温度分布の再設定の仕方としては、初期条件のままか、新たに温度分布を仮定して再設定するが、本発明においては、下記に詳述するように、次の回の計算（Ｎ＝Ｎ＋１）に進まず、マスコンクリート１内の温度分布とクーリング水の温度分布とを比較してクーリング水の温度分布を再設定し、この再設定されたクーリング水の温度分布を用いてマスコンクリート１の温度分布を再計算する。この再計算は、クーリング水の温度分布とマスコンクリート１の温度分布との差が予め設定された許容値内に入るまで繰り返し行い、クーリング水の温度分布とマスコンクリート１の温度分布とがほぼ一致した段階で次の回の計算（Ｎ＝Ｎ＋１）に進む。
【００１１】
すなわち、本発明においては、上記ステップＳ１８においてマスコンクリート１内の各点の温度Ｔ_ｃを求めた後に、上記式（３）を用いて、クーリング水の温度を計算し（ステップＳ２０）、この計算されたクーリング水の温度（水温の計算値Ｔ_ｗＡξ）と、初期条件で与えられた温度勾配（∂Ｔ_ｗ／∂ｓ）_ｔ＝０から求めたクーリング水の温度Ｔ_ｗＢξ（水温分布の設定値）とを比較する（ステップＳ２２）。そして、水温の計算値Ｔ_ｗＡξと水温分布の設定値Ｔ_ｗＢξとの差が所定誤差範囲を越えた場合には、上記差に基づいて、初期条件である温度勾配（∂Ｔ_ｗ／∂ｓ）_ｔ＝０を修正して、水温分布を再設定する（ステップＳ２４）。その後、上記ステップＳ１６に戻り、マスコンクリート１内の温度勾配を再度計算する。そして、上記ステップＳ１６〜ステップＳ２２により、マスコンクリート１内の温度勾配を再度計算して、新たな水温の計算値Ｔ_ｗＡξを算出し、この水温の計算値Ｔ_ｗＡξと上記再設定された水温分布の設定値Ｔ_ｗＢξとを再度比較する。
このような、再計算を繰り返すことにより、水温の計算値Ｔ_ｗＡξと水温分布の設定値Ｔ_ｗＢξとの差が次第に解消される。そして、マスコンクリート１内の温度分布とクーリング水の温度分布とが上記所定誤差範囲に入った時点で、最初の回の計算を終了し、次の回（Ｎ＝Ｎ＋１）の計算、すなわち、所定時間後におけるマスコンクリート１内の温度分布の計算に進む（ステップＳ２６）。
【００１２】
次の回（Ｎ＝Ｎ＋１）の計算では、上記解析結果及び時間経過によるコンクリート状態の変化等に基づいて、発熱特性や境界条件を再設定し（ステップＳ２８）、上記第１回目の計算（ステップＳ１６〜ステップＳ２２，Ｓ２４）と同様にして、所定時間後におけるマスコンクリート１内の温度分布の計算を行う（ステップＳ２８〜ステップＳ３４，Ｓ３６）。
そして、所定の最終回（Ｎ＝Ｎ_ｍａｘ）まで同様の計算を順次行うことにより、それぞれの時間でのマスコンクリート１の温度分布を求め、マスコンクリート１の冷却状態を解析する。
【００１３】
なお、上記実施の形態では、折り曲げあるいは接続により構成された１本のクーリングパイプ２をＸ方向に往復させた配管の例について説明したが、クーリングパイプの配管方法はこれに限るものではなく、例えば、図５（ａ）に示すように、クーリングパイプ２Ａを一旦マスコンクリート１内のクーリングパイプの導入口側とは反対側に延長してから上記導入口側に戻したり、図５（ｂ）に示すように、クーリングパイプ２Ｂをマスコンクリート１のクーリングパイプの導入口側とは反対側近傍で一旦往復させるなどしてクーリング水の温度がマスコンクリート１内で増減するような配管としてもよい。
あるいは、図５（ｃ）に示すように、複数本のクーリングパイプ２１，２２，２３を用いてもよい。なお、クーリングパイプが複数本であっても、上記二次元断面Ｒにいて、各パイプの通水距離に基づいてパイプクーリング節点境界におけるパイプクーリング水の温度を算出することにより、パイプクーリングの水温上昇を考慮に入れたコンクリートの温度分布を求めることができることはいうまでもない。
【００１４】
【発明の効果】
以上説明してきたように、本発明によれば、クーリングパイプに流れるクーリング水により冷却されるコンクリートの非定常熱伝導解析を二次元解析モデルを用いて行う際に、各パイプ位置におけるクーリング水の温度を算出した後、これをパイプクーリング境界として境界条件に付加して再度コンクリートの温度分布を求めるようにしたので、大規模な三次元解析を行うことなく、従来の二次元解析では不可能であったクーリング水の流れ方向における水温上昇を考慮に入れたコンクリートの温度分布を求めることができる。したがって、パイプクーリングによるコンクリート冷却効果を的確にかつ短時間で評価することができるので、より適切なパイプクーリングの設計・施工計画を行うことができる。
【図面の簡単な説明】
【図１】 三次元熱伝導場におけるマスコンクリートとクーリングパイプの座標系を示す図である。
【図２】 図１のＸＹ平面図である。
【図３】 本発明の実施の形態に係るパイプクーリングによるコンクリート冷却効果の解析方法を示すフローチャートである。
【図４】 従来のパイプクーリングによるコンクリート冷却効果の解析方法を示すフローチャートである。
【図５】 クーリングパイプの他の配管方法を示す図である。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for analyzing a concrete cooling effect by pipe cooling, and more particularly, to a method for calculating a temperature distribution in concrete by accurately evaluating a cooling effect by pipe cooling water in two-dimensional analysis.
[0002]
[Prior art]
The pipe cooling method is used in concrete dams, etc., to suppress the temperature rise of the concrete due to the heat of hydration of cement and the subsequent temperature change, thereby reducing the temperature stress generated in the block and opening the shrink joints sufficiently. In recent years, it has been adopted for the purpose of lowering the concrete to a set temperature, and recently, it has also been adopted for temperature control of mass concrete in large concrete structures other than dams.
These structures are rich blended concrete, and the scale, shape, construction environment, etc. are fundamentally different from those of dams. Therefore, in order to properly control the temperature cracking of concrete according to the above structures, etc. The selection of the diameter of the cooling pipe, the layout of the piping network, the temperature and the flow velocity of the cooling water, etc. is required. Therefore, it is desired to develop a cooling pipe design method capable of effectively reducing the temperature stress generated in the block by analyzing the temperature distribution in the mass concrete provided with the cooling pipe.
As a conventional method for analyzing the temperature distribution in mass concrete, there is a three-dimensional unsteady heat conduction analysis method that takes into account the heat balance due to pipe cooling using the finite element method (for example, Sato and Satani; (Study on pipe cooling effect; Proceedings of Japan Society of Civil Engineers, No. 372, 1986. 8).
This divides the three-dimensional shape of mass concrete into a finite number of elements and creates a finite element model that approximates each element by giving physical properties such as density, specific heat, or thermal conductivity. The model gives boundary conditions such as pipe cooling conditions and ambient temperature, and performs numerical analysis by a computer to simulate the temperature distribution of the mass concrete.
In addition, the unsteady heat conduction analysis method by the finite element method in the general-purpose two-dimensional problem related to the above, as well as the three-dimensional analysis, (1) analysis method with the pipe position as a special heat conduction boundary is known. However, (2) an analysis method using the pipe position as an endothermic node has also been announced. Of these, the analysis method (1), which analyzes by giving the heat transfer coefficient at the pipe location and the water flow characteristics of the cooling water, has been validated both theoretically and analytically. It is often used as a simple analysis method.
[0003]
[Problems to be solved by the invention]
However, in both methods (1) and (2), there is a problem of how much the water temperature in the pipe (hereinafter referred to as the pipe water temperature) is evaluated. For simplicity, the temperature of the cooling water at the pipe position is a problem. Are often handled in the same way as the inlet water temperature. In this case, the situation where the pipe water temperature is gradually rising along the pipe extension is not taken into consideration, so that the pipe cooling effect is overestimated.
In addition, Tanabe et al. Have devised an analysis method called quasi-three-dimensional analysis (eg, Tanabe, Yamakawa, Watanabe; Determination of heat transfer coefficient of pipe wall surface in pipe cooling and analysis of cooling effect; 343, 1984.3 etc.). In this method, several two-dimensional slice sections directly connected to the cooling pipe are cut out from a three-dimensional mass concrete block, and each slice section is subjected to two-dimensional unsteady heat conduction analysis using the analysis method (1). For the change in the water temperature at the pipe position after a short time, another equation of the temperature distribution in the pipe length direction is obtained, and this is treated as the pipe water temperature of each section again to calculate the next time step. ing.
Although this method can reduce the scale of calculation compared to three-dimensional analysis, in order to increase the analysis accuracy, it is necessary to increase the slice section to be cut out, resulting in a very complicated analysis. was there.
[0004]
The present invention has been made to solve the above problems, and by taking into account the rise in the water temperature in the flow direction of the cooling water, the concrete cooling effect by pipe cooling is accurately obtained without performing a large-scale three-dimensional analysis. The purpose is to provide a method of evaluation.
[0005]
[Means for Solving the Problems]
The invention according to claim 1 of the present invention is to create a two-dimensional analytical model the two-dimensional cross-section of the concrete to be cooled is divided into a finite number of multiple elements by cooling water flowing in the cooling pipe, to the two-dimensional analysis model On the other hand, unsteady heat conduction is established by setting boundary conditions including concrete injection temperature, concrete heat generation conditions, and temperature distribution of cooling water at the pipe cooling node boundary, which is a cut in the two-dimensional section of the cooling pipe. in the analysis method of the concrete cooling effect by pipe cooling for obtaining the temperature distribution of the concrete it has line analysis, to calculate the temperature distribution of the cooling water in each pipe position from the temperature distribution of the concrete obtained by the transient thermal analysis after the calculated value of the calculated temperature distribution and the boundary conditions odor The set value of the set temperature distribution is compared, and if the difference between the calculated value and the set value exceeds a predetermined error range, the set value is corrected and the temperature distribution of the corrected cooling water is corrected. and the set value is added to the boundary conditions is characterized in that so as to obtain again the temperature distribution of the concrete. Thus, without performing large-scale three-dimensional analysis, the temperature distribution of the conventional two-dimensional non-a which was click-ring water flow direction in the analysis concrete taking into account the temperature rise in the (border nodes continuous) Can be sought. Therefore, the concrete cooling effect by pipe cooling can be evaluated accurately and in a short time without overestimation as seen in the conventional analysis method where the inlet water temperature is the inlet water temperature. Appropriate pipe cooling design and construction planning can be performed .
The invention according to claim 2 is the method for analyzing concrete cooling effect by the pipe cooling according to claim 1, and to calculate the temperature of the click-ring water each pipe position based on the water flow distance between the pipe position It is characterized by that.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail.
In the present invention, the three-dimensional unsteady heat conduction analysis method considering the heat balance by pipe cooling using the finite element method is applied to a two-dimensional problem, and the concrete between the pipe boundary nodes in the two-dimensional analysis model is applied. Coupled analysis considering heat balance between cooling pipes.
FIG. 1 is a diagram showing a coordinate system of mass concrete 1 and a coordinate system (S; one-dimensional) of cooling pipe 2 in a three-dimensional heat conduction field, and FIG. 2 is an XY plan view thereof. Here, a plane parallel to the YZ plane indicated by the hatched portion in FIG. 1 is a two-dimensional section R used in the two-dimensional analysis model of this example.
As shown in FIGS. 1 and 2, the cooling pipe 2 is composed of a single pipe formed by bending or connection, and is introduced into the mass concrete 1 from the side surface end portion of the mass concrete 1, in the width direction (X (Direction) so as to reciprocate many times. In the two-dimensional analysis, the cuts p ₁ , p ₂ ,..., P _ξ ,... (Ξ = 1 to n) in the two-dimensional section R of the cooling pipe 2 are converted into heat transfer nodes in the two-dimensional analysis model. Treated as a boundary (hereinafter referred to as pipe cooling node boundary).
Then, the two-dimensional section R is divided into a finite number of elements, and a finite element model is created by approximating each element with physical properties such as density, specific heat, or thermal conductivity. On the other hand, the initial conditions such as the temperature and heat generation characteristics of mass concrete 1 and the boundary conditions such as the convection heat conduction boundary such as the ambient temperature and the pipe cooling boundary that regulates the temperature of the cooling water at the pipe cooling node boundary are set. Then, the temperature distribution in the mass concrete 1 is calculated by solving the following unsteady heat conduction equation under the above conditions, and the temperature state of the mass concrete 1 is analyzed.
In this example, as described in detail below, the pipe cooling boundary is set in consideration of the temperature rise of the cooling water.
[0007]
In general, an unsteady heat conduction equation (here, YZ plane) in a two-dimensional problem can be expressed by the following equation (1).
[Expression 1]

Where k _y , k _z ; anisotropic thermal conductivity of concrete,
T _c ; concrete temperature Q _c (t); concrete internal heating rate C _c , ρ _c ; concrete specific heat and density Note that the heat balance in pipe cooling is a general convection heat conduction boundary at the boundary around the cooling pipe 2. Therefore, at the boundary that contacts the cooling pipe 2, that is, the pipe cooling node boundary p _ξ (ξ = 1 to n), it can be expressed as the following equation (2).
[Expression 2]

Here, l _y , l _z ; direction cosine α _w on the boundary α _w ; average heat transfer coefficient T _w between concrete and cooling water, one-dimensional steady-state heat transfer with respect to cooling water temperature T _w The equation can be expressed as the following equation (3).
[Equation 3]

Therefore, using the water flow distance between the pipe positions and the temperature gradient (∂T _w / ∂s) obtained by the above equation (3), the temperature T _ξ (ξ = 1 to n) is calculated, and the temperature rise of the cooling water is taken into account by solving the unsteady heat conduction equation (1) under the boundary condition where the temperature T _{ξ of the} cooling water is substituted into the above equation (2). The temperature distribution of the mass concrete 1 can be calculated.
[0008]
Next, details of the method for analyzing the concrete cooling effect by pipe cooling according to the present invention will be described with reference to the flowcharts shown in FIGS. Here, FIG. 3 is an example of a flowchart according to the analysis method of the present invention, and FIG. 4 is an example of a flowchart according to the conventional method.
First, the two-dimensional cross section R of the mass concrete 1 is divided into a number of elements (step S10), and then initial conditions such as concrete placing temperature and heat generation characteristics, convective heat transfer boundary, pipe cooling boundary, and cooling water are obtained. A boundary condition such as a temperature distribution is set as an analysis condition (step S12).
The initial setting of the temperature distribution of the cooling water is the same as the pipe cooling boundary in the conventional analysis condition setting (step S52 in FIG. 4). Although the temperature of the cooling water at the pipe position is set to gradually increase along the pipe extension according to a predetermined temperature gradient, in this example, as will be described later, the temperature in the mass concrete 1 during the repeated calculation Reset according to the distribution.
[0009]
When the analysis conditions are set, the first calculation (N = 1) is entered (step S14), and the width direction and length in the mass concrete 1 are calculated from the unsteady heat conduction equation (1) under the above analysis conditions. direction of the temperature gradient (∂T _c / ∂y), by calculating the (∂T _c / ∂z) (step S16), and determine the temperature distribution in the mass concrete 1 (step S18). In this first calculation, the temperature T _ξ of the cooling water at each pipe position is obtained from the water temperature distribution according to the temperature gradient (∂T _w / ∂s) _{t = 0} given in the initial condition. Therefore, the temperature T _{ξ of the} cooling water is applied to the boundary condition equation (2) to solve the unsteady heat conduction equation (1).
In addition, each time of the above calculation is usually set as the first time, the second time,..., The Nth time,. That is, the first calculation obtains the temperature distribution in the mass concrete 1 at the start of pipe cooling, and then performs the same analysis every predetermined elapsed time, and sequentially calculates the temperature distribution in the mass concrete 1 for each elapsed time. . In addition, although the time interval of each time may be constant or may be set in advance, for example, until the time when the temperature change of the mass concrete 1 becomes empirically gentle, the analysis is performed at predetermined time intervals, and thereafter Is efficient by extending the time interval of analysis, and assuming that the time at the end of curing is the last calculation (N = N _max ).
[0010]
In the conventional method, as shown in FIG. 4, when the calculation of the temperature distribution of the Nth mass concrete 1 is completed, the calculation immediately proceeds to the next calculation (N = N + 1), and the heat generation characteristics corresponding to the elapsed time or After resetting the boundary condition, the same calculation is sequentially performed until a predetermined final time (N = N _max ), thereby obtaining a temporal change in the temperature distribution of the mass concrete 1 and analyzing the cooling state of the mass concrete 1. At this time, as a method of resetting the temperature distribution of the cooling water in the conventional method, the initial condition is maintained or a new temperature distribution is assumed and reset, but the present invention will be described in detail below. to, without proceeding to the next round of calculation (N = N + 1), and re-set the temperature distribution of the cooling water by comparing the temperature distribution of the temperature distribution and the cooling water in the mass concrete 1, it is the re-set The temperature distribution of the mass concrete 1 is recalculated using the temperature distribution of the cooling water. This recalculation and differences have returned Shi line repeatedly until fall within preset allowable value, the temperature distribution and the temperature distribution of mass concrete 1 the cooling water of the temperature distribution and the temperature distribution of mass concrete 1 of the cooling water When the values substantially coincide with each other, the process proceeds to the next calculation (N = N + 1).
[0011]
That is, in this invention, after calculating | requiring the temperature _Tc of each point in the mass concrete 1 in said step S18, the temperature of cooling water is calculated using said Formula (3) (step S20), and this calculation is carried out. Temperature of the cooling water (calculated value of the water temperature T _wAξ ) and the temperature gradient given in the initial condition (∂T _w / ∂s) The temperature T _{wBξ of the} cooling water obtained from _{t = 0} (set value of the water temperature distribution) ) Is compared (step S22). When the difference between the calculated water temperature value T _wAξ and the set value T _wBξ of the water temperature exceeds a predetermined error range, the temperature gradient (あ る T _w / ∂s), which is an initial condition, is based on the difference. _{t = 0} is corrected, and the water temperature distribution is reset (step S24). Then, it returns to said step S16 and calculates the temperature gradient in the mass concrete 1 again. Then, the temperature gradient in the mass concrete 1 is calculated again by the above steps S16 to S22, and a new calculated water temperature value _TwAξ is calculated. The calculated water temperature value _TwAξ and the reset water temperature distribution described above. The set value _TwBξ is compared again.
By repeating such _{recalculation} , the difference between the calculated water temperature value T _wAξ and the set value T _wBξ of the water temperature distribution is gradually eliminated. Then, when the temperature distribution in the mass concrete 1 and the temperature distribution of the cooling water are within the predetermined error range, the calculation of the first round is finished and the calculation of the next round (N = N + 1), that is, predetermined Proceed to the calculation of the temperature distribution in the mass concrete 1 after time (step S26).
[0012]
In the next calculation (N = N + 1), heat generation characteristics and boundary conditions are reset based on the analysis results and changes in the concrete state over time (step S28), and the first calculation (step Similarly to S16 to steps S22, S24), the temperature distribution in the mass concrete 1 after a predetermined time is calculated (steps S28 to S34, S36).
Then, the same calculation is sequentially performed until a predetermined final time (N = N _max ) to obtain the temperature distribution of the mass concrete 1 at each time, and the cooling state of the mass concrete 1 is analyzed.
[0013]
In the above embodiment, an example of piping in which one cooling pipe 2 configured by bending or connection is reciprocated in the X direction has been described, but the piping method of the cooling pipe is not limited to this, for example, As shown in FIG. 5A, the cooling pipe 2A is once extended to the side opposite to the inlet side of the cooling pipe in the mass concrete 1 and then returned to the inlet side. As shown, the cooling pipe 2 </ b> B may be reciprocated once in the vicinity of the mass concrete 1 on the side opposite to the inlet side of the cooling pipe so that the temperature of the cooling water increases or decreases in the mass concrete 1.
Alternatively, as shown in FIG. 5C, a plurality of cooling pipes 21, 22, and 23 may be used. Even if there are a plurality of cooling pipes, the temperature of the pipe cooling water rises by calculating the temperature of the pipe cooling water at the pipe cooling node boundary in the two-dimensional section R based on the water flow distance of each pipe. Needless to say, it is possible to obtain the temperature distribution of concrete in consideration of the above.
[0014]
【The invention's effect】
As described above, according to the present invention, when the unsteady heat conduction analysis of the concrete cooled by the cooling water flowing through the cooling pipe is performed using the two-dimensional analysis model, the temperature of the cooling water at each pipe position. After calculating the above, it was added to the boundary condition as a pipe cooling boundary and the temperature distribution of the concrete was calculated again , so it was not possible with conventional two-dimensional analysis without conducting a large-scale three-dimensional analysis. the temperature rise in the flow direction of a phrase-ring water may determine a temperature distribution of the concrete taking into account. Therefore, since the concrete cooling effect by pipe cooling can be evaluated accurately and in a short time, a more appropriate pipe cooling design and construction plan can be performed.
[Brief description of the drawings]
FIG. 1 is a diagram showing a coordinate system of mass concrete and a cooling pipe in a three-dimensional heat conduction field.
FIG. 2 is an XY plan view of FIG. 1;
It is a flow chart illustrating a method of analyzing a concrete cooling effect by pipe cooling according to an embodiment of the present invention; FIG.
FIG. 4 is a flowchart showing a method for analyzing a concrete cooling effect by conventional pipe cooling.
FIG. 5 is a diagram showing another piping method of the cooling pipe.

Claims (2)

A two-dimensional analysis model is created by dividing a two-dimensional section of concrete cooled by the cooling water flowing in the cooling pipe into a finite number of elements, and the concrete implantation temperature and heat generation of the concrete are compared to the above two-dimensional analysis model. determined conditions, and the temperature distribution of the rows have the concrete a transient thermal analysis by setting boundary conditions including the temperature distribution of the cooling water in the pipe cooling nodal boundary is cut in the two-dimensional cross-section of the cooling pipe In the analysis method of the concrete cooling effect by pipe cooling,
After calculating the cooling water temperature distribution at each pipe position from the concrete temperature distribution obtained by the unsteady heat conduction analysis , set the calculated temperature distribution and the temperature distribution set in the boundary conditions. When the difference between the calculated value and the set value exceeds a predetermined error range, the set value is corrected, and the corrected set value of the cooling water temperature distribution is set as the boundary condition. The method for analyzing the concrete cooling effect by pipe cooling is characterized in that the temperature distribution of the concrete is obtained again in addition to the above . The method of analyzing concrete cooling effect by the pipe cooling according to claim 1, characterized in that on the basis of the water flow distance between the pipe position and to calculate the temperature of the click-ring water each pipe position.

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