A reheat ejector nozzle drill bit and drilling method for ice layer hot water drilling

Abstract

The present application belongs to the technical field of ice layer hot water drilling, and particularly relates to a reheated ejection type nozzle drill bit for ice layer hot water drilling and a drilling method. The structure of the reheated ejection type nozzle drill bit comprises a main flow interface, an absorption chamber, an ejection pipe and a mixing chamber, wherein the absorption chamber is provided with a plurality of tapered nozzles. High-temperature hot water of the main flow forms a high-speed low-pressure area after passing through the tapered nozzles under the action of external pump work, and low-temperature hot water of the secondary flow is sucked into the absorption chamber through the ejection pipe, and the two are mixed in the mixing chamber and ejected to impact the ice surface to melt the ice. The present application utilizes the ejection effect of the reheated ejection type nozzle to reheat and utilize the waste heat of the low-temperature hot water at the bottom of the drill hole, and at the same time, the convection heat exchange at the hole bottom is strengthened, so that the heat utilization rate of the hot water drilling system can be significantly improved. Meanwhile, the nozzle drill bit is free of mechanical transmission devices inside, and has the advantages of simple structure and reliable work.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of ice layer hot water drilling, and particularly relates to a reheating ejection type nozzle drill bit for ice layer hot water drilling and a drilling method. BACKGROUND

[0002] Scientific exploration of glacial regions is an important means of studying regional ecology and earth changes, and is of great significance for predicting earth climate change and protecting the ecological environment of glacial regions. Therefore, how to efficiently drill ice cores and subglacial samples in glacial regions is crucial. At present, the main methods for ice layer drilling are hot water drilling, hot melting drilling and mechanical drilling. Among them, hot water drilling, as the fastest ice layer drilling method, has become an important technical means for the exploration of ice layer and subglacial environment. The hot water drilling method is to split and melt the ice layer through the hot water jet sprayed from the drill bit nozzle, so as to realize the rapid drilling of the ice layer. However, the heat utilization rate of the existing hot water drilling system is low, and only about 70% of the heat generated by the heating device of the whole system is used to melt the ice layer to form a drill hole. This is mainly because the hot water jet sprayed from the hot water drill nozzle still has a certain temperature after completing the impact melting of the ice layer, and this part of low-temperature hot water will transfer heat to the ice layer around the drill hole during the drilling and the process of returning to the ground, resulting in a large amount of heat waste. Therefore, how to improve the heat utilization rate of the hot water drilling process is of great significance to the development of hot water drilling. SUMMARY

[0003] Based on the above background, the purpose of the present application is to reduce the heat loss of hot water at the bottom of the hot water drill hole when it is pumped back to the ground, and to provide a reheating ejection type nozzle drill bit for ice layer hot water drilling and a drilling method. Compared with the ordinary drilling method currently used, the method has the advantages of reducing heat loss and improving heat utilization rate.

[0004] To achieve the above purpose, the technical solution adopted by the present application is:

[0005] A reheating ejection type nozzle drill bit for ice layer hot water drilling, which is connected to the outlet end of the main flow high-temperature hot water pipe, comprises a main flow interface, an absorption chamber, an ejection pipe and a mixing chamber, wherein a plurality of tapered nozzles are arranged in the absorption chamber, the inlet end of the tapered nozzle is connected to the upstream main flow high-temperature hot water pipe through the main flow interface, the outlet end of the tapered nozzle faces the mixing chamber, and the mixing chamber is in communication with the absorption chamber.

[0006] Further, the main flow interface, the absorption chamber and the mixing chamber are coaxial along the water flow direction, the main flow interface is provided with threads to be connected to the pipe conveying the main flow high-temperature hot water upstream, and a sealing rubber ring is arranged at the main flow interface.

[0007] Further, the flow passage cross-sectional area of the converging nozzle gradually decreases along the flow direction, and the distance between the outlet of the converging nozzle and the inlet of the mixing chamber is 0.1-10 times the inner diameter of the inlet end of the mixing chamber.

[0008] Further, the outlet end of the ejector pipe is connected to the side wall of the absorption chamber and the connection position is not lower than the outlet end of the converging nozzle, the inlet end of the ejector pipe extends to the outlet end of the mixing chamber, the inlet end of the ejector pipe is higher than the outlet of the mixing chamber, and a filter screen for preventing blockage is arranged at the inlet end of the ejector pipe.

[0009] Further, the number of the ejector pipes is at least one, and when the number of the ejector pipes is more than one, the ejector pipes are evenly distributed in an array around the circumference of the side wall of the absorption chamber.

[0010] Further, the inner diameter of the outlet end of the mixing chamber is not more than the inner diameter of the inlet end of the mixing chamber connected to the absorption chamber.

[0011] A reheating ejecting type drilling method for an ice layer hot water drill adopts the reheating ejecting type nozzle drill bit, high-temperature hot water in a main flow enters the reheating ejecting type nozzle drill bit through a main flow interface under the action of external pump work, passes through the converging nozzle, and forms a high-speed low-pressure area at the outlet of the converging nozzle, under the action of pressure difference and entrainment, low-temperature hot water after completing ice melting work at the bottom of the drill hole is sucked to the absorption chamber through the ejector pipe, and after mixing of the low-temperature hot water and the high-temperature hot water in the main flow in the mixing chamber, the low-temperature hot water is ejected again to impact the ice layer to perform ice melting, and the reheating utilization of the waste heat of the low-temperature hot water at the bottom of the drill hole is realized.

[0012] In summary, the present application has the following advantages:

[0013] (1) The high-speed jet flow ejected by the converging nozzle in the absorption chamber can form a certain vacuum area in the absorption chamber, and the hot water with a certain temperature after completing ice melting work is sucked into the absorption chamber under the action of pressure difference and entrainment, and continues to perform ice melting work, thereby realizing the reheating utilization of the waste heat of the low-temperature hot water and reducing the heat loss generated in the process of pumping the low-temperature hot water at the bottom of the hole to the ground by the water pump.

[0014] (2) The entraining effect of the high-temperature hot water in the main flow on the low-temperature hot water intensifies the flow field disturbance at the bottom of the drill hole, thins the boundary layer, strengthens the convective heat exchange between the hot water and the ice layer, increases the ice layer drilling speed, and simultaneously improves the heat utilization rate of the ice layer drilling.

[0015] (3) The reheating ejecting type nozzle drill bit provided by the present application realizes the reheating utilization of the low-temperature hot water without increasing additional mechanical transmission devices, and has the advantages of simple structure and reliable work. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 It is a three-dimensional schematic view of the reheating ejecting type nozzle drill bit of the present application.

[0017] Figure 2 This is a cross-sectional view of the reheat ejector nozzle drill bit of the present invention.

[0018] Figure 3 This is a schematic diagram illustrating the drilling principle of the reheat ejector nozzle drill bit of the present invention.

[0019] Figure 4 This is a schematic diagram of the multi-converging nozzle structure of the present invention.

[0020] Figure 5 for Figure 4 Sectional view of AA.

[0021] Figure 6 This is a comparison chart of the return water temperatures tested in the experiment.

[0022] Among them: 1 is the main interface, 2 is the absorption chamber, 3 is the ejector tube, 4 is the mixing chamber, 5 is the converging nozzle, 6 is the filter screen, 7 is the sealing ring, 8 is the thread, 9 is the main high-temperature hot water, 10 is the low-temperature hot water, and 11 is the ice layer. Detailed Implementation

[0023] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments.

[0024] like Figures 1-6 As shown, this invention discloses a reheat ejector nozzle drill bit for drilling hot water in ice layers. The reheat ejector nozzle drill bit is connected to the outlet end of the main high-temperature hot water pipe for reusing waste heat from low-temperature hot water. It includes a main water interface 1, an absorption chamber 2, an ejector tube 3, and a mixing chamber 4. The absorption chamber 2 is equipped with several tapered nozzles 5. The structure of a single tapered nozzle and multiple tapered nozzles is as follows. Figure 2 and Figure 4As shown, the inlet end of the tapered nozzle 5 is connected to the upstream main flow high-temperature hot water pipeline through the main flow interface 1, the outlet end of the tapered nozzle 5 faces the mixing chamber 4, the cross-sectional area of the flow passage of the tapered nozzle 5 gradually decreases along the flow direction, the distance between the outlet of the tapered nozzle 5 and the inlet of the mixing chamber 4 is 0.1-10 times the inner diameter of the inlet end of the mixing chamber 4, and the mixing chamber 4 is in communication with the absorption chamber 2, the inner diameter of the outlet end of the mixing chamber 4 is not more than the inner diameter of the inlet end of the mixing chamber 4 connected with the absorption chamber 2, and the structure of the mixing chamber 4 can be an equal cross-section circular pipe with a constant cross-sectional area along the flow direction or a tapered circular pipe with a gradually decreasing cross-sectional area along the flow direction; the main flow interface 1, the absorption chamber 2 and the mixing chamber 4 are coaxial along the water flow direction, the main flow interface 1 is connected to the pipeline conveying the upstream main flow high-temperature hot water through the thread 8, and the sealing rubber ring 7 is arranged at the main flow interface 1; the outlet end of the injection pipe 3 is connected to the side wall of the absorption chamber 2 and the connection position is not lower than the outlet end of the tapered nozzle 5, the injection pipe 3 is at least one, and when the number of the injection pipes 3 exceeds one, the plurality of injection pipes 3 are evenly distributed in an array around the circumference of the side wall of the absorption chamber 2, the inlet end of the injection pipe 3 extends to the outlet end of the mixing chamber 4, the inlet end of the injection pipe 3 is higher than the outlet of the mixing chamber 4, and the filter screen for preventing blockage is arranged at the inlet end of the injection pipe 3 to prevent impurities in the low-temperature hot water 10 from entering the absorption chamber 2 through the injection pipe 3 and causing blockage.

[0025] The reheat injection type nozzle drill bit can be in the form of one-piece casting or can adopt a threaded structure to realize the connection between the components. The main flow high-temperature hot water 9 enters the tapered nozzle 5 through the main flow interface 1 and forms a high-speed low-pressure area at the outlet of the tapered nozzle, the secondary flow low-temperature hot water 10 is sucked into the absorption chamber 2 through the injection pipe 3, the main flow high-temperature hot water 9 and the sucked low-temperature hot water 10 are mixed in the mixing chamber 4 and are ejected to impact the ice surface to melt the ice.

[0026] With the gradual reduction of the cross-sectional area of the flow passage of the tapered nozzle 5 along the flow direction, the fluid velocity gradually increases and reaches the maximum value at the outlet of the nozzle. Due to the viscous effect between the air and the high-speed fluid, the air in the absorption chamber 2 is taken away by the high-speed fluid, so that a certain vacuum area is formed in the absorption chamber 2. The low-temperature hot water 10 impacting the ice layer at the bottom of the borehole is sucked into the absorption chamber 2 through the injection pipe 3 under the action of the pressure difference and the entrainment, and is mixed with the main flow high-temperature hot water 9 in the mixing chamber 4 and then impacts the ice layer 11 again to melt the ice. The low-temperature hot water 10 after completing the ice melting work is sucked into the absorption chamber 2 and continues to melt the ice after being heated again by the main flow high-temperature hot water 9. Compared with the mode of directly pumping the low-temperature hot water to the ground surface, the injection type nozzle can utilize the waste heat of the part of the hot water, thereby reducing the heat loss and improving the heat utilization rate.

[0027] The tapered nozzles 5 can be arranged individually or in plurality in the absorption chamber 2, when a single tapered nozzle 5 is arranged in the absorption chamber 2, the main flow of high-temperature hot water 9 forms a high-speed jet after passing through the tapered nozzle 5; when a plurality of tapered nozzles 5 are arranged in the absorption chamber 2, the main flow of high-temperature hot water 9 is divided in the plurality of tapered nozzles 5, and a plurality of high-speed jets are formed at the outlets of the plurality of tapered nozzles 5.

[0028] The application also discloses a reheating ejection type drilling method for ice layer hot water drilling, which is realized by using the reheating ejection type nozzle drill head. Figure 3 As shown in the figure, when the reheating ejection type nozzle drill head works, the high-temperature hot water 9 enters the tapered nozzle 5 through the main flow interface 1 under the action of external pump work, the fluid velocity gradually increases with the gradual reduction of the cross-sectional area of the tapered nozzle 5, and the maximum velocity is reached at the outlet of the nozzle. Due to the viscous effect between air and high-speed fluid, the air in the absorption chamber 2 is taken away by the high-speed fluid, so that a certain vacuum area is formed in the absorption chamber 2. The low-temperature hot water 10 impacting the ice layer at the bottom of the drill hole is sucked into the absorption chamber 2 through the ejection pipe 3 under the action of pressure difference, and then impacts the ice layer 11 for ice melting after mixing with the main flow of high-temperature hot water 9 in the mixing chamber 4. The low-temperature hot water 10 after completing the ice melting work is sucked into the ejection type nozzle, and then continues to melt ice after being reheated by the main flow of high-temperature hot water 9. Compared with the method of directly pumping the low-temperature hot water to the ground, the method of the application can realize the waste heat reheat utilization of the low-temperature hot water after completing the ice melting, thereby reducing the heat loss and improving the heat utilization rate. At the same time, the ejection of the ejection pipe 3 on the low-temperature hot water 10 after melting ice intensifies the flow field disturbance at the bottom of the drill hole, so that the convective heat exchange between the hot water and the ice layer 11 is strengthened.

[0029] Embodiment:

[0030] The application verifies the principle of the ice layer drilling feasibility of the reheating ejection type nozzle drill head through experimental tests. The vertical ice layer drilling method is adopted in the experiment, the water in the ice hole is pumped out and the water temperature is measured while the drill head drills. The ice layer drilling is compared by using the common conical nozzle drill head and the reheating ejection type nozzle drill head, and the diameters of the nozzle outlets of the two are consistent.

[0031] In the experiment, the temperature of the main flow of high-temperature hot water is 60℃, and the flow rate adopts two working conditions of 70L / h and 50L / h. Figure 4The curve of the backwater temperature changing with time is shown, and the final time point of the curve is the drilling end time point. It can be seen from the figure that under the same flow and temperature of the main hot water, the reheat ejection nozzle drill has not only faster drilling speed, but also significantly lower backwater temperature compared with the ordinary nozzle drill. This is because in the drilling process of the reheat ejection nozzle drill, the low-temperature hot water 10 impacting the ice layer is sucked into the absorption chamber 2 by the main high-temperature hot water 9 for reheat mixing and then continues to melt ice, which makes the waste heat of the low-temperature hot water 10 be reheat utilized, so more heat of the hot water is used for ice melting, the drilling speed is faster, the backwater temperature is lower, and the energy utilization rate is improved. Under the current verification condition, compared with the ordinary nozzle drill, the reheat ejection nozzle drill can improve the drilling speed by 11.3%, and the heat utilization amount can be improved by 23.4%.

[0032] Through the above principle verification experiment, it is proved that the reheat ejection nozzle drill proposed in the application can realize ice layer drilling, and the drilling speed and drilling thermal efficiency can be obviously improved compared with the ordinary nozzle, which demonstrates the feasibility of the scheme.

[0033] The above is only the preferred embodiment of the application, and the protection scope of the application is not limited to the above-mentioned embodiments. Any technical scheme falling within the idea of the application belongs to the protection scope of the application. It should be noted that for ordinary technical personnel in the technical field, some improvements and decorations without departing from the principles of the application should also be considered as the protection scope of the application.

Claims

1. A reheat ejection drilling method for ice layer hot water drilling, implemented by a reheat ejection nozzle bit for ice layer hot water drilling, characterized in that: The reheat-ejector nozzle drill is connected at the outlet end of the main flow high-temperature hot water pipeline, comprising a main flow interface (1), an absorption chamber (2), an ejector pipe (3), and a mixing chamber (4), wherein the absorption chamber (2) is provided with a plurality of tapered nozzles (5), the inlet end of the tapered nozzles (5) is connected with the upstream main flow high-temperature hot water pipeline through the main flow interface (1), the outlet end of the tapered nozzles (5) faces the mixing chamber (4), and the mixing chamber (4) is in communication with the absorption chamber (2); The main flow high-temperature hot water (9) enters the reheat-ejector nozzle drill through the main flow interface (1) under the action of external pump work, passes through the tapered nozzles (5), and forms a high-speed low-pressure area at the outlet of the tapered nozzles (5), under the action of pressure difference and entrainment, the low-temperature hot water (10) after completing ice melting at the bottom of the drill hole is sucked into the absorption chamber (2) through the ejector pipe (3), and the low-temperature hot water (10) and the main flow high-temperature hot water (9) are mixed in the mixing chamber (4) and then ejected to impact the ice layer (11) for ice melting, thereby realizing the reheat utilization of the waste heat of the low-temperature hot water (10) at the bottom of the drill hole.

2. The reheat ejector drilling method for ice layer hot water drilling as claimed in claim 1, wherein: The main flow interface (1), the absorption chamber (2), and the mixing chamber (4) are coaxial along the water flow direction, the main flow interface (1) is provided with threads (8) to be connected with the pipeline conveying the main flow high-temperature hot water, and a sealing rubber ring (7) is arranged at the main flow interface (1).

3. The reheat ejector drilling method for ice layer hot water drilling as claimed in claim 1, wherein: The flow passage cross-sectional area of the tapered nozzles (5) gradually decreases along the flow direction, and the distance between the outlet of the tapered nozzles (5) and the inlet of the mixing chamber (4) is 0.1-10 times the inner diameter of the inlet end of the mixing chamber (4).

4. The reheat ejector drilling method for ice layer hot water drilling as claimed in claim 1, wherein: The outlet end of the ejector pipe (3) is connected to the side wall of the absorption chamber (2) and the connection position is not lower than the outlet end of the tapered nozzles (5), the inlet end of the ejector pipe (3) extends to the outlet end of the mixing chamber (4), the inlet end of the ejector pipe (3) is higher than the outlet of the mixing chamber (4), and a filter screen (6) for preventing blockage is arranged at the inlet end of the ejector pipe (3).

5. The reheat ejector drilling method for ice layer hot water drilling as claimed in claim 4, wherein: The number of the ejector pipes (3) is at least one, and when the number of the ejector pipes (3) is more than one, the ejector pipes (3) are evenly distributed in an array around the circumference of the side wall of the absorption chamber (2).

6. The reheat ejector drilling method for ice layer hot water drilling as claimed in claim 1, wherein: The inner diameter of the outlet end of the mixing chamber (4) is not more than the inner diameter of the inlet end of the mixing chamber (4) connected with the absorption chamber (2).

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