Adjustable drilling fluid cooling system

Abstract

The invention provides an adjustable drilling fluid cooling system. The adjustable drilling fluid cooling system comprises a control structure, a sand pump, a water pump, a plate heat exchanger and a plurality of transmission pipelines, the sand pump, the water pump and the plate heat exchanger are connected through transmission pipelines; the control structure comprises a control module, a sand pump module, a water pump module, an electromagnetic valve, a plate heat exchanger module and a pipeline sensor. The control module adopts a flow-temperature cascade PID double-closed-loop control scheme, an inner loop is a flow loop, and an outer loop is a temperature loop; for an inner ring, a control module adopts an anti-integral saturation digital PID (Proportion Integration Differentiation) controller with feedforward, and algorithm discretization is carried out aiming at electromagnetic valve control; for the outer ring, the control module takes the expected temperature of the cooling liquid in the actual working environment as input, and the expected temperature and the current temperature are calculated through a temperature-flow solving algorithm. The heat exchange flow and the heat exchange area can be adjusted according to drilling work requirements, the heat exchange efficiency is improved, and the automation degree is high.

Description

Technical Field

[0001] The invention belongs to the technical field of intelligent control, and in particular relates to an adjustable drilling fluid cooling system. Background Art

[0002] The drilling fluid cooling system is also called a drilling fluid cooling device, which is generally used to reduce the temperature of the drilling fluid, reduce mud loss, improve the performance of the drilling fluid, and reduce the risk of stuck drill. At the same time, it improves the drilling efficiency and prevents potential risks such as casualties caused by high-temperature drilling fluid.

[0003] The current research and development of drilling fluid cooling systems mainly solves the structural design under complex and extreme working conditions. For example, ZL201911399889.4 provides a drilling fluid cooling system that can be used in high temperature environments. However, there are few effective improvements to the intelligent improvement of drilling fluid cooling systems, resulting in low heat exchange efficiency of drilling fluid cooling systems. Summary of the invention

[0004] In view of the shortcomings of the prior art, the purpose of the present invention is to provide an adjustable drilling fluid cooling system, which can adjust the heat exchange flow rate and heat exchange area according to the requirements of drilling work to improve the heat exchange efficiency.

[0005] In order to achieve the above object, the present invention provides the following technical solutions:

[0006] An adjustable drilling fluid cooling system, the adjustable drilling fluid cooling system comprises a control structure, a sand pump, a water pump, a plate heat exchanger and a plurality of transmission pipelines; the sand pump, the water pump and the plate heat exchanger are connected through the transmission pipeline, the control structure comprises: a control module, a sand pump module, a water pump module, a solenoid valve, a plate heat exchanger module and a pipeline sensor, wherein the pipeline sensor comprises a flow sensor and a temperature sensor;

[0007] The control module processes the drilling data including the drilling fluid demand, obtains the optimal power change data of the working process of the sand pump and the water pump, and controls the power of the sand pump and the water pump according to the obtained data results; the control module receives the real-time detection data of the pipe heat exchanger of the middle end plate in the plate heat exchanger, and controls the opening and closing of the solenoid valve of the middle end plate in the plate heat exchanger;

[0008] When performing the above control, the control module adopts a flow-temperature cascade PID double closed-loop control scheme, in which the inner loop is the flow loop and the outer loop is the temperature loop;

[0009] For the inner loop, the control module uses an anti-integral saturation digital PID controller with feedforward, and discretizes the algorithm for solenoid valve control. The specific algorithm formula is as follows:

[0010]

[0011] In the formula, K p is the proportionality coefficient; K f is the feedforward coefficient; K i is the integral coefficient; K d is the differential coefficient; K c is the compensation coefficient; u p is the proportional term; u f is the feedforward term; u i is the integral term; u d is the differential term; u prsat is the compensation term; e is the deviation value; R ef is the reference value; F db is the feedback value; (t) represents the value of the current beat; (t-1) represents the value of the previous beat;

[0012] The final output of the PID controller is limited to obtain the following final output value formula:

[0013]

[0014] In the formula, u max To set the maximum limit value; u min is the minimum limit value; u is the final output value of the PID controller;

[0015] For the outer loop, the control module uses the expected temperature of the coolant in the actual working environment as input. The expected temperature and the current temperature are calculated through the temperature-flow solution algorithm. The appropriate expected flow change curve is obtained based on the error between the two. The real-time temperature is used as the outer loop feedback to obtain the expected flow, which is the inner loop input. The temperature-flow solution algorithm formula is as follows:

[0016]

[0017] Where, T is the coolant temperature; W is the set cooling load; C p is the constant pressure specific heat capacity of the coolant; Q is the coolant flow rate; ρ is the coolant density; T ref is the expected temperature; (t) represents the value of the current beat; (t-1) represents the value of the previous beat.

[0018] Furthermore, the plate heat exchanger comprises: a front end plate, a middle end plate, a rear end plate, a bracket, a plurality of heat exchange plates and a bolt assembly.

[0019] Furthermore, the front end plate, the middle end plate and the rear end plate are arranged equidistantly; a number of heat exchange plates are evenly and tightly placed between the end plates, and each heat exchange plate is connected and fixed to the bracket by a bolt assembly; each heat exchange plate is provided with a drilling fluid inlet, a drilling fluid outlet, a coolant inlet and a coolant outlet; wherein the middle end plate and each heat exchange plate are all S-shaped bent plate structures with the same shape and size.

[0020] Furthermore, a three-channel structure is provided at the middle end plate of the plate heat exchanger to control the coolant flowing through the middle end plate to flow into the rear plate heat exchanger or directly flow out of the plate heat exchanger; the coolant inlet of the middle end plate is the first channel, the coolant outlet flowing into the rear plate heat exchanger is the second channel, and the coolant outlet flowing out of the plate heat exchanger is the third channel.

[0021] Furthermore, the first channel is provided with a pipeline sensor for detecting the flow and temperature of the coolant in the first channel in real time and transmitting the data back to the control module; solenoid valves are respectively provided at the second channel and the third channel for receiving signal instructions from the control module to open or close, thereby controlling the opening or closing of the second channel and the third channel.

[0022] Furthermore, the control module is used to process data including drilling fluid demand according to pre-input instructions, obtain the most economical and energy-saving power change data of the sand pump module and the water pump module, and control the working power of the sand pump module and the water pump module in different time periods according to the change data.

[0023] Furthermore, a pipeline sensor located in the three-channel structure of the middle end plate of the plate heat exchanger module detects the real-time flow and temperature of the coolant during the cooling process and transmits the data back to the control module; the control module processes the data and sends instructions to the solenoid valves at the three channels.

[0024] Furthermore, when the coolant flow rate and temperature have met the drilling fluid cooling standard, the control module controls the solenoid valve at the second channel to close, and the solenoid valve at the third channel to open, and the coolant leaves the plate heat exchanger module through the third channel, that is, the cooling process of the drilling fluid in the plate heat exchanger is ended in advance; when the coolant flow rate and temperature have not yet met the drilling fluid cooling standard, the control module controls the solenoid valve at the second channel to open, and the solenoid valve at the third channel to close, and the coolant continues to flow into the rear plate heat exchanger through the second channel, that is, the drilling fluid continues to complete the complete cooling process.

[0025] Beneficial effects of the present invention:

[0026] The present invention can adjust the heat exchange flow and heat exchange area according to the drilling work requirements, improve the heat exchange efficiency, and has a high degree of automation. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is an overall structural diagram of an adjustable drilling fluid cooling system of the present invention;

[0028] Figures 2-3 A heat exchanger structure diagram of an adjustable drilling fluid cooling system of the present invention;

[0029] Figure 4 A control structure diagram of an adjustable drilling fluid cooling system of the present invention;

[0030] Figure 5 A schematic diagram of the flow ring working of an adjustable drilling fluid cooling system of the present invention;

[0031] Figure 6 The figure is a schematic diagram of the temperature ring operation of an adjustable drilling fluid cooling system of the present invention. DETAILED DESCRIPTION

[0032] The present invention is described in detail below through examples. It is necessary to point out that the following examples are only used to further illustrate the present invention and cannot be understood as limiting the scope of protection of the present invention. Some non-essential improvements and adjustments made by technical personnel in the field according to the above invention content still fall within the scope of protection of the present invention.

[0033] Example 1

[0034] like Figures 1 to 4 As shown, an adjustable drilling fluid cooling system includes a control structure 1, a sand pump 2, a water pump 3, a plate heat exchanger 4 and a plurality of transmission pipelines. The sand pump 2, the water pump 3 and the plate heat exchanger 4 are connected through the transmission pipelines.

[0035] The plate heat exchanger 4 includes: a front end plate 41, an intermediate end plate 42, a rear end plate 44, a bracket 45, a plurality of heat exchange plates 43 and a bolt assembly 46; the front end plate, the intermediate end plate and the rear end plate are arranged equidistantly, and a plurality of heat exchange plates are evenly and tightly placed between each end plate, and each heat exchange plate is connected and fixed to the bracket by a bolt assembly, and each heat exchange plate is provided with a drilling fluid inlet, a drilling fluid outlet, a coolant inlet and a coolant outlet; wherein, the intermediate end plate and each heat exchange plate are all S-shaped bent plate structures with the same shape and size.

[0036] A three-channel structure is provided at the middle end plate of the plate heat exchanger to control the coolant flowing through the middle end plate to flow into the rear plate heat exchanger or directly flow out of the plate heat exchanger; the coolant inlet of the middle end plate is the first channel 421, the coolant outlet flowing into the rear plate heat exchanger is the second channel 422, and the coolant outlet flowing out of the plate heat exchanger is the third channel 423; wherein, the first channel is provided with a pipeline sensor 424 for real-time detection of the flow rate and temperature of the coolant in the first channel and transmitting the data back to the control module; solenoid valves 425 are respectively provided at the second channel and the third channel for receiving the signal command of the control module to open or close, thereby controlling the opening or closing of the second channel and the third channel.

[0037] The control structure includes: a control module 210, a sand pump module 220, a water pump module 230, a solenoid valve 240, a plate heat exchanger module 250 and a pipeline sensor 260. The pipeline sensor 260 includes a flow sensor and a temperature sensor.

[0038] The workflow of this system is as follows:

[0039] ① The control module 210 processes the drilling fluid demand and other data according to the pre-input instructions, obtains the most economical and energy-saving power change data of the sand pump module 220 and the water pump module 230, and controls the working power of the sand pump module 220 and the water pump module 230 in different time periods according to the change data;

[0040] ② The pipe sensor 260 located in the three-channel structure of the middle end plate of the plate heat exchanger module 250 detects the real-time flow and temperature of the coolant during the cooling process, and transmits the data back to the control module 210. The control module 210 processes the data and sends instructions to the solenoid valve 240 at the three-channel (the processing process is shown in the following control flow);

[0041] ③ Since the power change of the sand pump module 220 and the water pump module 230 causes the coolant consumption to change, the drilling fluid cooling data standard of different time periods also changes all the time. When the coolant flow and temperature flowing through here have met the drilling fluid cooling standard under this working condition, the control module 210 controls the solenoid valve 240 at the second channel to close, and the solenoid valve 240 at the third channel to open, and the coolant leaves the plate heat exchanger module 250 through the third channel, that is, the cooling process of the drilling fluid in the plate heat exchanger is terminated in advance, saving time and resources and improving cooling efficiency; when the coolant flow and temperature flowing through here have not met the drilling fluid cooling standard under this working condition, the control module 210 controls the solenoid valve 240 at the second channel to open, and the solenoid valve 240 at the third channel to close, and the coolant continues to flow into the rear plate heat exchanger through the second channel, that is, the drilling fluid continues to complete the complete cooling process.

[0042] Control Flow:

[0043] The control module 210 adopts a flow-temperature cascade PID double closed-loop control scheme, in which the inner loop is a flow loop and the outer loop is a temperature loop.

[0044] Flow loop (inner loop) part: the expected flow of the flow change curve is used as input, the expected flow and the current flow are calculated by the PID controller, the difference between the two is error controlled, and then the driving current is obtained. The driving current controls the working state (opening or closing degree) of the electromagnetic valve at the middle end plate in the plate heat exchanger 4, so that the coolant flow changes, and the changed real-time flow is used as the inner loop feedback to control the temperature of the coolant;

[0045] The PID controller in the control module 210 is an anti-integral windup digital PID controller with feedforward.

[0046] The algorithm is discretized for valve control, and the PID algorithm is converted and improved to obtain the following controller algorithm formula:

[0047]

[0048] In the formula, K p is the proportionality coefficient; K f is the feedforward coefficient; K i is the integral coefficient; K d is the differential coefficient; K c is the compensation coefficient; u p is the proportional term; u f is the feedforward term; u i is the integral term; u d is the differential term; u prsat is the compensation term; e is the deviation value; R ef is the reference value; F db is the feedback value; (t) represents the value of the current beat; (t-1) represents the value of the previous beat.

[0049] The final output of the PID controller is limited to obtain the following final output value formula:

[0050]

[0051] In the formula, u max To set the maximum limit value; u min is the set minimum limit value; u is the final output value of the PID controller.

[0052] Temperature loop (outer loop) part: The expected temperature of the coolant in the actual working environment is used as input. The expected temperature and the current temperature are calculated through the temperature-flow solution algorithm. The appropriate expected flow change curve is obtained based on the error between the two. The real-time temperature is used as the outer loop feedback to obtain the expected flow, which is the inner loop input.

[0053] Temperature-flow solution algorithm formula:

[0054]

[0055] Where, T is the coolant temperature; W is the set cooling load; C p is the constant pressure specific heat capacity of the coolant; Q is the coolant flow rate; ρ is the coolant density; T ref is the expected temperature; (t) represents the value of the current beat; (t-1) represents the value of the previous beat.

[0056] During the research and development of the present invention, the inventors have used PID in the outer loop, but the introduction of integral I control will lead to a slower response speed, and the introduction of differential D control will introduce noise and cause system oscillation, so the PID controller is only used in the inner loop. Moreover, the calculation process of the present invention is simpler, and it is simpler and more effective than the solution of using PID control in both the inner and outer loops.

Claims

1. An adjustable drilling fluid cooling system, comprising a control structure, a sand pump, a water pump, a plate heat exchanger and a plurality of transmission pipelines; the sand pump, the water pump and the plate heat exchanger are connected through the transmission pipeline, characterized in that: The control structure includes: a control module, a sand pump module, a water pump module, a solenoid valve, a plate heat exchanger module and a pipeline sensor, wherein the pipeline sensor includes a flow sensor and a temperature sensor; The control module processes the drilling data including the drilling fluid demand, obtains the optimal power change data of the working process of the sand pump and the water pump, and controls the power of the sand pump and the water pump according to the obtained data results; the control module receives the real-time detection data of the pipe heat exchanger of the middle end plate in the plate heat exchanger, and controls the opening and closing of the solenoid valve of the middle end plate in the plate heat exchanger; When performing the above control, the control module adopts a flow-temperature cascade PID double closed-loop control scheme, in which the inner loop is the flow loop and the outer loop is the temperature loop; For the inner loop, the control module uses an anti-integral saturation digital PID controller with feedforward, and discretizes the algorithm for solenoid valve control. The specific algorithm formula is as follows: In the formula, K p is the proportionality coefficient; K f is the feedforward coefficient; K i is the integral coefficient; K d is the differential coefficient; K c is the compensation coefficient; u p is the proportional term; u f is the feedforward term; u i is the integral term; u d is the differential term; u prsat is the compensation term; e is the deviation value; R ef is the reference value; F db is the feedback value; (t) represents the value of the current beat; (t-1) represents the value of the previous beat; The final output of the PID controller is limited to obtain the following final output value formula: In the formula, u max To set the maximum limit value; u min is the minimum limit value; u is the final output value of the PID controller; For the outer loop, the control module uses the expected temperature of the coolant in the actual working environment as input. The expected temperature and the current temperature are calculated through the temperature-flow solution algorithm. The appropriate expected flow change curve is obtained based on the error between the two. The real-time temperature is used as the outer loop feedback to obtain the expected flow, which is the inner loop input. The temperature-flow solution algorithm formula is as follows: Where, T is the coolant temperature; W is the set cooling load; C p is the constant pressure specific heat capacity of the coolant; Q is the coolant flow rate; ρ is the coolant density; T ref is the expected temperature; (t) represents the value of the current beat; (t-1) represents the value of the previous beat.

2. The adjustable drilling fluid cooling system according to claim 1, characterized in that: The plate heat exchanger comprises: a front end plate, a middle end plate, a rear end plate, a bracket, a plurality of heat exchange plates and a bolt assembly.

3. The adjustable drilling fluid cooling system according to claim 2, characterized in that: The front end plate, the middle end plate and the rear end plate are arranged equidistantly; a number of heat exchange plates are evenly and tightly placed between the end plates, and each heat exchange plate is connected and fixed to the bracket by a bolt assembly; each heat exchange plate is provided with a drilling fluid inlet, a drilling fluid outlet, a coolant inlet and a coolant outlet; wherein, the middle end plate and each heat exchange plate are all S-shaped bent plate structures with the same shape and size.

4. The adjustable drilling fluid cooling system according to claim 3, characterized in that: A three-channel structure is provided at the middle end plate of the plate heat exchanger to control the coolant flowing through the middle end plate to flow into the rear plate heat exchanger or directly flow out of the plate heat exchanger; the coolant inlet of the middle end plate is the first channel, the coolant outlet flowing into the rear plate heat exchanger is the second channel, and the coolant outlet flowing out of the plate heat exchanger is the third channel.

5. The adjustable drilling fluid cooling system according to claim 4, characterized in that: The first channel is provided with a pipeline sensor for detecting the flow and temperature of the coolant in the first channel in real time and transmitting the data back to the control module; solenoid valves are respectively provided at the second channel and the third channel for receiving signal instructions from the control module to open or close, thereby controlling the opening or closing of the second channel and the third channel.

6. The adjustable drilling fluid cooling system according to claim 1, characterized in that: The control module is used to process data including drilling fluid demand according to pre-input instructions, obtain the most economical and energy-saving power change data of the sand pump module and the water pump module, and control the working power of the sand pump module and the water pump module in different time periods according to the change data.

7. The adjustable drilling fluid cooling system according to claim 5, characterized in that: The pipeline sensor located in the three-channel structure of the middle end plate of the plate heat exchanger module detects the real-time flow and temperature of the coolant during the cooling process and transmits the data back to the control module; the control module processes the data and sends instructions to the solenoid valve at the three channels.

8. The adjustable drilling fluid cooling system according to claim 7, characterized in that: When the coolant flow rate and temperature have met the drilling fluid cooling standard, the control module controls the solenoid valve at the second channel to close, the solenoid valve at the third channel to open, and the coolant leaves the plate heat exchanger module through the third channel, that is, the cooling process of the drilling fluid in the plate heat exchanger is ended in advance; when the coolant flow rate and temperature have not yet met the drilling fluid cooling standard, the control module controls the solenoid valve at the second channel to open, the solenoid valve at the third channel to close, and the coolant continues to flow into the rear plate heat exchanger through the second channel, that is, the drilling fluid continues to complete the complete cooling process.

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