CN115809543A - A Method of Predicting the ROP of a Rock Drill in Rotary-Percussion Drilling - Google Patents

Abstract

The invention discloses a method for predicting the drilling speed of a rotary-percussion drilling rock drill, which comprises the steps of: determining the hardness of the ore rock to be crushed; and obtaining the relationship between the specific power of rotary rock-breaking drilling, rock hardness, and borehole diameter through a rotary drilling test ;Based on the balance relationship of rotary cutting power, the relationship between the specific work of rotary rock-breaking drilling and rock hardness, and the diameter of the drill hole, the rotary drilling crushing speed is calculated; the rock drilling coefficient and rock hardness and the drill rate of the rock drill are obtained through the impact drilling test. Based on the percussion drilling wave theory and the rigid piston model, according to the relationship between the rock penetration coefficient and rock hardness and the drill bit diameter of the rock drill, the percussion drilling crushing speed is calculated; the rotary rock breaking and impact rock breaking are analyzed. Interaction, based on the ROP of rotary drilling and ROP of percussion drilling, the ROP of rock drill rotary-percussion drilling is predicted. The method can be used to predict the rate of penetration of rock drills with rotary-percussion drilling methods, so as to optimize the rock drilling process.

Description

A Method of Predicting the ROP of Rock Drills in Rotary-Percussion Drilling

technical field

The invention relates to the technical field of drilling speed prediction of a rock drill, in particular to a method for predicting the drilling speed of a rock drill for rotary-percussion drilling.

Background technique

Rock drilling is a very important operation process in mining, railway construction, geological exploration and national defense engineering construction, and occupies an important position in the national economy. At present, mechanical drilling methods mainly include three types: rotary, impact-rotary and rotary-impact. The rock-breaking method of rotary-impact drilling, in addition to impact crushing, also applies a strong force for cutting and breaking rocks, making full use of the rock characteristics that the shear strength of rock is much smaller than the compressive strength of rock. Compared with the independent rotary rock breaking method, it has the characteristics of adapting to hard rock drilling. In addition, its drilling speed and energy utilization rate are much higher than those of traditional percussion-rotary drilling machines. Therefore, in terms of rock drilling, it is more inclined to adopt the rotary-percussion drilling method. And with the increasing development of engineering construction, higher requirements are put forward for the drilling speed equipment, and the crushing efficiency is guaranteed with a more ideal drilling speed, so that the engineering construction can get twice the result with half the effort. The rate of penetration prediction needs to be based on the given rock drill performance parameters and rock properties. However, due to the complexity and uncertainty of rock properties and the lack of experimental work, and the research on the rotary-percussion drilling method is not yet mature. Percussion rock drills also have weaker ROP predictions. However, the drilling speed of the rock drill affects the rock drilling efficiency and drilling cost. Therefore, it is necessary to predict the drilling speed of the rock drill with the rotary-percussion drilling method to optimize the rock drilling process.

Contents of the invention

In order to solve the above technical problems, the present invention provides a method for predicting the drilling speed of a rotary-percussion drilling rock drill, which predicts the drilling speed of a rotary-percussion drilling rock drill to optimize the rock drilling process.

The present invention adopts following technical scheme:

The invention provides a method for predicting the rate of penetration of a rock drill for rotary-percussion drilling, comprising the steps of:

(1) Take the ore rock sample to be crushed for detection to determine the rock hardness of the ore rock to be crushed, and obtain relevant parameters of the rock drill and drilling tools;

(2) Take the ore rock sample and carry out the rotary drilling test to obtain the relationship between the specific power of rotary rock-breaking drilling and rock hardness and borehole diameter;

(3) Based on the power balance relationship during rotary drilling and the relationship between the specific work of rotary rock-breaking drilling, rock hardness, and borehole diameter, the rate of penetration of rotary drilling is calculated;

(4) Get the ore rock sample and carry out the impact drilling test, obtain the relationship between the rock drilling coefficient and the rock hardness and the drill bit diameter of the rock drill;

(5) Based on the percussion drilling wave theory and rigid piston model, calculate the piston impact velocity, maximum groove depth, crushing depth and crushed volume of the rock drill, and according to the relationship between the rock drilling coefficient and rock hardness and the drill bit diameter of the rock drill, Calculation of percussion drilling breaking rate of penetration;

(6) Take ore rock samples for rotary-percussion drilling test, analyze the interaction between rotary rock breaking and impact rock breaking, and predict the rotary-percussion drilling of rock drills based on the crushing speed of rotary drilling and the crushing speed of percussion drilling Broken drilling speed.

Further, the rock hardness of the rock to be crushed in the step (1) is obtained by performing a uniaxial compressive strength test on the ore rock sample to be crushed.

Further, in the step (2), the relationship between the specific power of rotary rock-breaking drilling, rock hardness and borehole diameter is:

α _r =165f/D _h

Among them, α _r is the specific work of rotary rock-breaking drilling, that is, the work required to rotate and break a unit volume of rock, J/cm ³ ; f is the hardness of the rock; D _h is the diameter of the drilling hole, cm.

Further, the power balance relationship during rotary drilling in the step (3) is obtained according to the principle of energy conservation in the rotary drilling process:

Among them, P _R is the rotational power of the rock drill, _VR is the rotational speed of the rock drill, cm/min; and P _R = T n/9.55, T is the rated torque of the rock drill, N m, n is the working speed of the rock drill, r/min.

Further, in the step (3), the formula for calculating the crushing penetration rate of rotary drilling is:

Further, in the step (4), the relationship between the rock penetration coefficient and the rock hardness and the drill bit diameter of the rock drill is:

Among them, K is the rock drilling coefficient; _Db is the drill bit diameter of the rock drill.

Further, the piston impact velocity of the rock drill in the step (5) is:

Among them, E ₀ is the impact energy, J; M is the mass of the impact piston of the rock drill, kg;

The maximum groove depth is:

且m＝AE/C＝AρC，m为波动惯量，A为钎杆的截面积，E为弹性模量，C为波速，ρ为密度；Among them, θ is the calculation coefficient,

And m=AE/C=AρC, m is the wave inertia, A is the cross-sectional area of the drill rod, E is the modulus of elasticity, C is the wave velocity, and ρ is the density;

The crushing depth is:

U' _M = 1.5U _M

The crushed volume is:

为岩石的破碎角。Wherein, B is the crushed volume, cm ³ ;

is the breaking angle of the rock.

Further, in the step (5), the calculation formula of percussion drilling and crushing rate of penetration is:

Among them, V _p is the crushing speed of percussion drilling, cm/min; B _s is the crushing volume per second, cm ³ /s; and B _s = _Bfr , where f _r is the impact frequency of the rock drill.

Further, in the step (6), the formula for calculating the drilling speed of the rock drill for rotating-impact drilling and breaking is:

V _RP ＝C _Z (V _R +V _P )

Among them, C _Z is the comprehensive effect coefficient.

The beneficial effects that the present invention has are:

The invention provides a method for predicting the drilling speed of a rotary-percussion drilling rock drill. Based on theoretical analysis and related test results, a rotary-percussion drilling drilling speed prediction model is established, which can predict the rock drilling machine according to the performance parameters of the rock drilling machine and the relevant characteristics of ore and rock. Prediction of drilling speed can provide drilling speed guidance for mine mining, railway construction, geological exploration and national defense engineering construction, etc., to improve rock drilling efficiency and reduce drilling costs.

Description of drawings

Fig. 1 is the drilling rate prediction flow chart of rotary-percussion drilling of the present invention;

Fig. 2 is a curve diagram of rock drilling force-cutting depth;

Fig. 3 is a rock chiseled volumetric model diagram;

Figure 4 is a comparison chart of the predicted drilling speed and the measured results of the MZQT-90/20, MZQT-65/35 pneumatic rock bolter and QYYG100 gas-hydraulic rock drill.

Detailed ways

The present invention is specifically described below in conjunction with accompanying drawing:

Referring to Fig. 1, the present invention provides a method for predicting the rate of penetration of a rock drill for rotary-percussion drilling, comprising steps:

(1) Take the ore rock sample to be crushed for detection to determine the rock hardness of the ore rock to be crushed, and obtain relevant parameters of the rock drill and drilling tools;

Specifically, the rock hardness of the above-mentioned ore rock to be crushed is obtained by performing a uniaxial compressive strength test on the ore rock sample to be crushed, or can also be obtained by referring to the rock classification table in the relevant literature; the relevant parameters of the above-mentioned rock drill mainly include impact energy, Impact frequency, piston mass, rated torque and operating speed; the relevant parameters of the above-mentioned drilling tools mainly include the cross-sectional area and wave inertia of the drill rod, and the diameter of the drill bit.

(2) Take some rock samples and carry out the rotary drilling test to obtain the relationship between the specific power of rotary rock-breaking drilling and rock hardness and borehole diameter;

Specifically, in this step, it is necessary to calculate the specific work of rotary rock-breaking drilling based on the obtained rotary drilling test data, and consider the influence of the reduction of hole wall clamping effect and the formation of coarser rock grains due to the increase of rock pore diameter. The specific work of rock breaking tends to decrease with the increase of the hole diameter, and the relationship between the specific work of rotary rock breaking drilling, rock hardness and drilling diameter is as follows:

α _r =165f/D _h (1)

Among them, α _r is the specific power of rotary rock-breaking drilling, that is, the work required to rotate and break a unit volume of rock, J/cm ³ ; f is the hardness of the rock; D _h is the diameter of the drilling hole, cm, which is generally 0.2- 0.4cm.

(3) Based on the power balance relationship during rotary drilling and the relationship between the specific work of rotary rock-breaking drilling, rock hardness, and borehole diameter, the rate of penetration of rotary drilling is calculated;

Specifically, in this step, according to the principle of energy conservation during rotary drilling, the power balance relationship during rotary drilling is obtained, which has the following formula:

Among them, P _R is the rotational power of the rock drill, W, and V _R is the rotational speed of the rock drill, cm/min;

In addition, the rotational power of the rock drill can also be given by the torque and speed of the rock drill, namely:

P _R = T·n/9.55 (3)

Among them, T is the rated torque of the rock drill, N m, n is the working speed of the rock drill, r/min; and when calculating the rotational power, n is the actual speed of the rock drill when drilling, not the maximum speed when idling;

Through the above formulas (1), (2) and (3), the formula for calculating the crushing penetration rate of rotary drilling is as follows:

(4) Get some ore rock samples and carry out the impact drilling test, obtain the relationship between the rock drilling coefficient and the rock hardness and the drill bit diameter of the rock drill;

Specifically, the above-mentioned impact chisel test is a stress wave method chisel characteristic experiment, through which the rock chisel coefficient K (KN/mm) can be obtained, that is, the force required for the unit depth of the impact chiseled into the rock, which is to control the impact The most important mechanical parameter in the drilling process, which is closely related to the firmness (hardness) of the rock. And K increases with the increase of the length of the drill bit when chiseling in. According to the test results, it can be expressed as:

Among them, F is the drilling force, kN; U is the drilling depth, mm; K is the rock drilling coefficient, kN/mm; D _b is the drill bit diameter of the rock drill, cm.

(5) Based on the percussion drilling wave theory and rigid piston model, calculate the piston impact velocity, maximum groove depth, crushing depth and crushed volume of the rock drill, and according to the relationship between the rock drilling coefficient and rock hardness and the drill bit diameter of the rock drill, Calculation of percussion drilling breaking rate of penetration;

Specifically, in this step, when the rock drill is used to percussively drill the ore rock, each time the impact piston of the rock drill hits the drill shank, a stress wave will be formed in the drill tool and propagate to the rock bottom, thereby realizing the process of crushing the rock. Effect. Therefore, we perform the following calculation step by step according to the percussion drilling wave theory and the rigid piston model:

The impact speed of the piston of the rock drill is:

Among them, E ₀ is the impact energy, J; M is the mass of the impact piston of the rock drill, kg;

Based on the wave theory, according to the ideal rock drilling force-depth curve in Figure 2, that is, after reaching the maximum drilling depth, immediately unload according to the inelastic (full plastic) method, keep the maximum drilling depth unchanged, and obtain the maximum groove depth as follows:

且m＝AE/C＝AρC，m为波动惯量，即波阻，是进行波动力学计算重要的特征参量，其物理意义为钎杆中单位质点速度所产生的力；A为钎杆的截面积，E为弹性模量，C为波速，ρ为密度；Among them, θ is the calculation coefficient,

And m=AE/C=AρC, m is the wave inertia, that is, the wave resistance, which is an important characteristic parameter for wave mechanics calculation, and its physical meaning is the force generated by the unit particle velocity in the drill rod; A is the cross-sectional area of the drill rod , E is the elastic modulus, C is the wave velocity, and ρ is the density;

However, in the actual rock impact crushing, due to the cracking of the rock, there is a negative slope unloading process, and the cutting depth will continue to increase. Therefore, in this embodiment, according to the actual unloading curve obtained by the rock impact crushing test, the crushing depth is taken as:

U' _M = 1.5 U _M (8)

According to Fig. 3, the rock chipping section model is established, and the volume B of the chipping rock is calculated, namely:

为岩石的破碎角，一般取

Wherein, B is the crushed volume, cm ³ ;

is the breaking angle of the rock, generally taken as

According to the above formulas (6), (7), (8) and (9), the formula for calculating the crushing ROP of percussion drilling is as follows:

Among them, V _p is the crushing speed of percussion drilling, cm/min; B _s is the crushing volume per second, cm ³ /s; and B _s = _Bfr , where f _r is the impact frequency of the rock drill.

(6) Take a number of rock samples for rotary-impact drilling tests, analyze the interaction between rotary rock breaking and impact rock breaking, and predict the rock drill's rotary-impact drilling based on the crushing speed of rotary drilling and the crushing speed of impact drilling. Drilling into broken drilling speed;

Specifically, according to the results of the rotary-percussion drilling test, the performance of the comprehensive interaction of the rotary-percussion rock breaking can be divided into two parts: the effect of impact on rotary drilling and the effect of rotation on percussion drilling: among them, the effect of impact on rotary drilling The role of the rock bottom is to form a groove, which increases the free surface of the rotary shearing and breaking; the effect of the rotation on the percussion drilling is that the strong rotary torque provides additional lateral stress for the percussion drilling process, making percussion drilling easier.

The above two effects respectively reduce the crushing specific work of rotation and impact, which is finally attributed to the fact that the comprehensive chisel speed is higher than the sum of the penetration speed of the single action of rotation and impact. Based on the comprehensive test results, the penetration speed of rotation-impact crushing is obtained as:

V _RP ＝C _Z (V _R +V _P ) (11)

Among them, C _Z is the comprehensive effect coefficient, and according to the test results, it is desirable that C _Z =1.1.

Taking the MZQT-90/20, MZQT-65/35 pneumatic rock bolter and QYYG100 gas-hydraulic linkage rock drill produced by Qingdao Dabang Drilling Rig Co., Ltd. It is shown in Table 1 below, and the comparison between the predicted data of drilling speed and the measured data is shown in Fig. 4.

Table 1

As can be seen from Fig. 4: the penetration rate prediction result calculated according to the calculation formula of the present invention is basically consistent with the actual measurement penetration rate result, and the error is less than 10%, which shows that the penetration rate prediction method of rotation-percussion drilling of the present invention can be more accurate Predicting the drilling speed of the rock drill for rotary-percussion drilling means that the drilling speed of the rock drilling machine can be predicted according to the performance parameters of the rock drilling machine and the related characteristics of ore and rock.

Of course, the above descriptions are not intended to limit the present invention, and the present invention is not limited to the above examples. Changes, modifications, additions or replacements made by those skilled in the art within the scope of the present invention shall also belong to the present invention. protection scope of the invention.

Claims (9)

1. A rock drilling rate prediction method for rotary-percussion drilling, characterized in that it comprises the steps: (1) Take the ore rock sample to be crushed for detection to determine the rock hardness of the ore rock to be crushed, and obtain relevant parameters of the rock drill and drilling tools; (2) Take the ore rock sample and carry out the rotary drilling test to obtain the relationship between the specific power of rotary rock-breaking drilling and rock hardness and borehole diameter; (3) Based on the power balance relationship during rotary drilling and the relationship between the specific work of rotary rock-breaking drilling, rock hardness, and borehole diameter, the rate of penetration of rotary drilling is calculated; (4) Get the ore rock sample and carry out the impact drilling test, obtain the relationship between the rock drilling coefficient and the rock hardness and the drill bit diameter of the rock drill; (5) Based on the percussion drilling wave theory and rigid piston model, calculate the piston impact velocity, maximum groove depth, crushing depth and crushed volume of the rock drill, and according to the relationship between the rock drilling coefficient and rock hardness and the drill bit diameter of the rock drill, Calculation of percussion drilling breaking rate of penetration; (6) Take ore rock samples for rotary-percussion drilling test, analyze the interaction between rotary rock breaking and impact rock breaking, and predict the rotary-percussion drilling of rock drills based on the crushing speed of rotary drilling and the crushing speed of percussion drilling Broken drilling speed. 2. The method for predicting the drilling speed of a rock drill according to claim 1, wherein the rock hardness of the rock to be broken in the step (1) is determined by performing a uniaxial test on the rock sample to be broken. Obtained from compressive strength experiments. 3. a kind of rock drilling speed prediction method of rotary-percussion drilling according to claim 1, is characterized in that, in described step (2), the relation of rotary rock-breaking drilling specific power and rock hardness, borehole diameter for: α _r =165f/D _h Among them, α _r is the specific work of rotary rock-breaking drilling, that is, the work required to rotate and break a unit volume of rock, J/cm ³ ; f is the hardness of the rock; D _h is the diameter of the drilling hole, cm. 4. a kind of rock drilling speed prediction method of rotary-percussion drilling according to claim 3, is characterized in that, in the described step (3) based on the power balance relation when rotary drilling, obtain:

Among them, P _R is the rotational power of the rock drill, _VR is the rotational speed of the rock drill, cm/min; and P _R = T n/9.55, T is the rated torque of the rock drill, N m, n is the working speed of the rock drill, r/min. 5. the method for predicting the rate of penetration of a rock drill according to claim 4, wherein the formula for calculating the rate of penetration of rotary drilling in the step (3) is:

6. a kind of rock drilling speed prediction method of rotary-percussion drilling according to claim 5, is characterized in that, in the described step (4), the relationship between the rock drilling coefficient and the rock hardness and the drill bit diameter of the rock drilling machine is :

Among them, K is the rock drilling coefficient; _Db is the drill bit diameter of the rock drill. 7. A method for predicting the rate of penetration of a rock drill for rotary-percussion drilling according to claim 6, wherein the impact velocity of the rock drill piston in the step (5) is:

Among them, E ₀ is the impact energy, J; M is the mass of the impact piston of the rock drill, kg; The maximum groove depth is:

Among them, θ is the calculation coefficient,

And m=AE/C=AρC, m is the wave inertia, A is the cross-sectional area of the drill rod, E is the modulus of elasticity, C is the wave velocity, and ρ is the density; The crushing depth is: U' _M = 1.5U _M The crushed volume is:

Wherein, B is the crushed volume, cm ³ ;

is the breaking angle of the rock. 8. The method for predicting the rate of penetration of a rock drill for rotary-percussion drilling according to claim 7, wherein the formula for calculating the rate of penetration of percussion drilling in the step (5) is:

Among them, V _p is the crushing speed of percussion drilling, cm/min; B _s is the crushing volume per second, cm ³ /s; and B _s = _Bfr , where f _r is the impact frequency of the rock drill. 9. A method for predicting the rate of penetration of a rock drill for rotary-percussion drilling according to claim 8, wherein the formula for calculating the rate of penetration of the rock drill for rotary-percussion drilling in the step (6) is: V _RP ＝C _Z (V _R +V _P ) Among them, C _Z is the comprehensive effect coefficient.

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