Apparatus and method for determining formation of ice slurry plunger

Abstract

The application discloses a device and method for judging formation of ice slurry plunger, which comprises a first pressure sensor for detecting pressure condition at a first position in a pipeline, a second pressure sensor for detecting pressure condition at a second position in the pipeline, and a controller for receiving pressure values detected by the first pressure sensor and the second pressure sensor to obtain a pressure difference between the first position and the second position, and combining flow resistance characteristics of a medium in the pipeline to perform ice slurry flow state recognition by using a pre-stored judgment model. The application can automatically perform ice slurry flow state recognition by using a pre-stored judgment model through the pressure difference between two positions in the pipeline and combining the flow resistance characteristics of the medium in the pipeline, accurately judges the condition of the ice slurry in the pipeline, realizes efficient use of the ice slurry, effectively reduces the use amount of the ice slurry, and helps to accurately judge the cleaning effect of the pipeline.

Description

Technical Field

[0001] This invention relates to the field of ice slurry pipeline cleaning, and specifically to a device and method for determining the formation of ice slurry plungers. Background Technology

[0002] Urban water supply pipelines have a long design lifespan, and their service life is generally quite long. Due to pipeline construction and maintenance, corrosion and scaling can occur, leaving scale, sediment, microorganisms, and biofilms on the inner walls of the pipes, affecting the quality of tap water. Cleaning the water supply network is an effective way to ensure the safety of tap water. Currently, common methods for cleaning water supply pipelines include chemical cleaning, high-pressure water jet flushing, and mechanical PIG cleaning. Chemical cleaning uses chemical agents to clean the pipelines. This technology has the advantage of not being limited by the shape of the pipeline, but it also has disadvantages such as the chemical reagents easily corroding the pipelines, leaving chemical cleaning agent residues that can cause pipeline damage and water pollution. High-pressure water cleaning can use high-pressure water jets to peel off dirt from the inner surface of the pipeline, but it has the disadvantage of not being able to clean it thoroughly.

[0003] Ice slurry cleaning technology is an advanced pipe cleaning technology. The literature (patent application number: 201810531621.0) describes a method for cleaning tap water pipes using ice slurry. However, the literature only briefly describes that ice slurry cleaning of tap water pipes includes four processes: producing ice slurry, transporting ice slurry, pumping ice slurry in, and cleaning tap water pipes. In particular, for the process of cleaning tap water pipes, the literature only describes injecting ice slurry into the tap water pipes.

[0004] Existing literature does not address core technical issues such as the transport of ice slurry within pipelines. Accurately assessing the state of the ice slurry within the pipeline during the cleaning process allows for efficient utilization of the slurry, effectively reducing its usage and facilitating accurate evaluation of the cleaning effect. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a device and method for determining the formation of ice slurry plungers.

[0006] To achieve the above objectives, the technical solution of the present invention is as follows:

[0007] In a first aspect, the present invention provides an apparatus for determining the formation of an ice slurry plunger, comprising:

[0008] The first pressure sensor is used to detect the pressure at a first location inside the pipe;

[0009] The second pressure sensor is used to detect the pressure at a second location inside the pipe.

[0010] The controller receives the pressure values ​​detected by the first pressure sensor and the second pressure sensor to obtain the pressure difference between the first position and the second position, and combines the flow resistance characteristics of the medium in the injection pipe to identify the ice slurry flow state using a pre-stored judgment model.

[0011] Furthermore, the judgment model is as follows:

[0012] ΔP / L = f(IPF, Pr, Re);

[0013] Where ΔP / L is the pressure drop per unit length, IPF is the solid content of the ice slurry, Pr is the Prandtl number, and Re is the Reynolds number.

[0014] Furthermore, the formation process of the ice slurry plunger flow is determined by the change in pressure difference between the first and second locations:

[0015] Injecting ice slurry to drain water creates a plunger flow stage, increasing the pressure differential to ΔP1.

[0016] During the plunger flow scouring stage, the pressure difference drops to ΔP2;

[0017] After the flushing and cleaning stage is completed, the pressure difference is reduced to ΔP3.

[0018] Furthermore, ΔP1 > ΔP2 > ΔP3.

[0019] Furthermore, an upstream valve is provided in the pipeline in front of the first pressure sensor; and a downstream valve is provided in the pipeline behind the second pressure sensor.

[0020] Furthermore, the situation of impurities accumulating inside the pipe can be judged by whether the pressure difference change during the plunger flow process is within the range of ΔP1 to ΔP2.

[0021] Secondly, the present invention provides a method for determining the formation of an ice slurry plunger, comprising:

[0022] Ice slurry is produced by subcooling water. The raw water becomes subcooled water after heat exchange in a subcooled plate heat exchanger. After crystallization by an ultrasonic crystallizer, it enters an ice storage tank through a pipeline to form ice slurry. The ice slurry is stored in the ice storage tank. The concentration of the prepared ice slurry is 30-60%. The ice slurry is then transported to the pipe to be cleaned.

[0023] Pressure sensors are installed at two locations in the cleaning pipeline. By measuring the pressure difference between the inlet and outlet in real time and combining it with the flow resistance characteristics of the medium injected into the pipeline, a pre-built judgment model is used to identify the flow pattern.

[0024] Furthermore, the judgment model is as follows:

[0025] ΔP / L = f(IPF, Pr, Re);

[0026] Where ΔP / L is the pressure drop per unit length, IPF is the solid content of the ice slurry, Pr is the Prandtl number, and Re is the Reynolds number.

[0027] Furthermore, the formation process of the plunger flow can be determined by observing changes in pressure differential:

[0028] Injecting ice slurry to drain water creates a plunger flow stage, increasing the pressure differential to ΔP1.

[0029] During the plunger flow scouring stage, the pressure differential gradually decreases to ΔP2;

[0030] After the flushing and cleaning stage is completed, the pressure difference is reduced to ΔP3.

[0031] Furthermore, the method for determining the formation of ice slurry plunger also includes: after stopping the injection of ice slurry, judging the situation of impurities accumulating in the pipe by whether the pressure difference change during the plunger flow process is within the range of ΔP1 to ΔP2; ΔP1 > ΔP2 > ΔP3.

[0032] Compared with the prior art, the advantages of this invention are as follows:

[0033] This invention utilizes the pressure difference between two locations in the pipeline and the flow resistance characteristics of the medium injected into the pipeline. By employing a pre-stored judgment model, it can automatically identify the flow state of the ice slurry, accurately determine the condition of the ice slurry in the pipeline, achieve efficient utilization of the ice slurry, effectively reduce the amount of ice slurry used, and help accurately judge the pipeline cleaning effect. Attached Figure Description

[0034] Figure 1 This is a schematic diagram of plunger flow.

[0035] Figure 2 This is a schematic diagram of the pipeline layout to be cleaned;

[0036] Figure 3 This is a schematic diagram of the pressure difference changes during the ice slurry cleaning process. Detailed Implementation

[0037] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0038] See Figure 1 This is a schematic diagram of a plunger flow. After the ice slurry enters the pipe, it pushes the existing water forward. Once the ice slurry pumping stops, water is introduced from upstream, propelling the ice slurry forward. This movement of the ice slurry creates a plunger flow, generating friction that strips away dirt from the pipe.

[0039] Example 1:

[0040] See Figure 2As shown, the device for determining the formation of ice slurry plunger provided in this embodiment mainly includes a first pressure sensor 1, a second pressure sensor 2, and a controller.

[0041] The first pressure sensor 1 is used to detect the pressure at a first position in the pipeline; the second pressure sensor 2 is used to detect the pressure at a second position in the pipeline; the controller is used to receive the pressure values ​​detected by the first and second pressure sensors to obtain the pressure difference between the first and second positions, and to identify the ice slurry flow state by combining the flow resistance characteristics of the medium injected into the pipeline with a pre-stored judgment model.

[0042] Thus, by using the pressure difference between two locations in the pipeline and the flow resistance characteristics of the medium injected into the pipeline, the present invention can automatically identify the flow state of the ice slurry using a pre-stored judgment model, accurately determine the condition of the ice slurry in the pipeline, achieve efficient utilization of the ice slurry, effectively reduce the amount of ice slurry used, and help to accurately judge the pipeline cleaning effect.

[0043] Specifically, according to the flow dynamics model of slurry fluid in a pipe, the pressure drop per unit length (ΔP / L) is a function of the ice slurry solid content (IPF), solution concentration (wt%), flow velocity (v), and pipe diameter (D). After dimensionless transformation, we can obtain:

[0044] ΔP / L = f(IPF,Pr,Re).

[0045] Where ΔP / L is the pressure drop per unit length, IPF is the solid content of the ice slurry, Pr is the Prandtl number, and Re is the Reynolds number.

[0046] Thus, the above model can accurately determine the condition of the ice slurry inside the pipe.

[0047] Specifically, the formation process of the plunger flow is judged by the change in pressure difference. The pressure difference change and pipeline status of the ice slurry cleaning pipeline are judged as follows: (1) During the stage of injecting ice slurry and draining water to form a plunger flow, the pressure difference increases linearly and rapidly to ΔP1; (2) During the plunger flow flushing stage, the pressure difference is stable or decreases slightly to ΔP2; (3) After the flushing and cleaning stage is completed, the pressure difference gradually decreases to ΔP3, or even lower than the initial pressure drop, such as Figure 3 As shown, ΔP1>ΔP2>ΔP3.

[0048] Furthermore, the length of the plunger can be calculated using parameters such as the volume of injected ice slurry and the internal volume of the pipe. After the injection of ice slurry stops, the pressure difference change (ΔP1~ΔP2) during the plunger flow process can be used to determine the amount of impurities accumulated in the pipe.

[0049] As a preferred embodiment of the device for determining the formation of ice slurry plunger provided in this embodiment, an upstream valve 3 is provided in the pipeline in front of the first pressure sensor 1; and a downstream valve 4 is provided in the pipeline behind the second pressure sensor 2.

[0050] Example 2:

[0051] This embodiment provides a method for determining the formation of ice slurry plungers, including:

[0052] Ice slurry is produced by subcooling water. The raw water becomes subcooled water after heat exchange in a subcooled plate heat exchanger. After crystallization by an ultrasonic crystallizer, it enters an ice storage tank through a pipeline to form ice slurry. The ice slurry is stored in the ice storage tank. The concentration of the prepared ice slurry is 30-60%. The ice slurry is then transported to the pipe to be cleaned.

[0053] Pressure sensors are installed at two locations in the cleaning pipeline. By measuring the pressure difference between the inlet and outlet in real time and combining it with the flow resistance characteristics of the medium injected into the pipeline, a pre-built judgment model is used to identify the flow pattern.

[0054] According to the flow dynamics model of slurry fluid in pipe, the pressure drop per unit length (ΔP / L) is a function of the ice slurry solid content (IPF), solution concentration (wt%), flow velocity (v), and pipe diameter (D). After dimensionless transformation, we can obtain: ΔP / L=f(IPF,Pr,Re).

[0055] Where ΔP / L is the pressure drop per unit length, IPF is the solid content of the ice slurry, Pr is the Prandtl number, and Re is the Reynolds number.

[0056] The formation process of plunger flow is determined by the change in pressure difference. Pressure difference changes and pipeline status judgment in ice slurry cleaning pipelines: (1) During the stage of injecting ice slurry and draining water to form plunger flow, the pressure difference increases linearly and rapidly to ΔP1; (2) During the plunger flow scouring stage, the pressure difference stabilizes or decreases slightly to ΔP2; (3) After the scouring and cleaning stage is completed, the pressure difference gradually decreases to ΔP3, or even lower than the initial pressure drop. For example... Figure 3 As shown, ΔP1>ΔP2>ΔP3.

[0057] Preferably, the length of the plunger can be calculated using parameters such as the volume of the injected ice slurry and the internal volume of the pipe. After the injection of ice slurry stops, the pressure difference change (ΔP1~ΔP2) during the plunger flow process is used to determine the amount of impurities accumulated in the pipe.

[0058] Preferably, by judging the condition of the ice slurry in the pipeline, calculating the ice slurry plunger flow length, and combining the pipeline volume parameters, ice crystal particle size and concentration parameters, as well as relevant data from the outlet water quality test, the relationship between the ice slurry plunger flow parameters and the cleaning effect is determined, and the optimal amount of ice slurry is obtained.

[0059] The above embodiments are merely illustrative of the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be construed as limiting the scope of protection of the present invention. All equivalent changes or modifications made based on the essence of the content of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A device for determining the formation of ice slurry plungers, characterized in that, include: The first pressure sensor is used to detect the pressure at a first location inside the pipe; The second pressure sensor is used to detect the pressure at a second location inside the pipe. The controller is used to receive the pressure values ​​detected by the first pressure sensor and the second pressure sensor to obtain the pressure difference at the first position and the second position, and to identify the ice slurry flow state by combining the flow resistance characteristics of the medium in the injection pipe and using a pre-stored judgment model. The judgment model is as follows: ΔP / L=f(IPF,Pr,Re); Where ΔP / L is the pressure drop per unit length, IPF is the solid content of the ice slurry, Pr is the Prandtl number, and Re is the Reynolds number; The formation process of the ice slurry plunger flow can be determined by the change in pressure difference between the first and second locations: Injecting ice slurry to drain water creates a plunger flow stage, increasing the pressure differential to ΔP1. During the plunger flow scouring stage, the pressure difference drops to ΔP2; After the flushing and cleaning stage is completed, the pressure difference is reduced to ΔP3; ΔP1>ΔP2>ΔP3.

2. The device for determining the formation of ice slurry plungers as described in claim 1, characterized in that, An upstream valve is installed in the pipeline in front of the first pressure sensor; a downstream valve is installed in the pipeline behind the second pressure sensor.

3. The device for determining the formation of ice slurry plungers as described in claim 1, characterized in that, The extent of impurities accumulating inside the pipe can be determined by whether the pressure difference during the plunger flow process is within the range of ΔP1~ΔP2.

4. A method for determining the formation of an ice slurry plunger, characterized in that, include: Ice slurry is produced by subcooling water. The raw water becomes subcooled water after heat exchange in a subcooled plate heat exchanger. After crystallization by an ultrasonic crystallizer, it enters an ice storage tank through a pipeline to form ice slurry. The ice slurry is stored in the ice storage tank. The concentration of the prepared ice slurry is 30-60%. The ice slurry is then transported to the pipe to be cleaned. Pressure sensors are installed at two locations in the cleaning pipeline. By measuring the pressure difference between the inlet and outlet in real time and combining it with the flow resistance characteristics of the medium injected into the pipeline, the flow pattern is identified using a pre-built judgment model. The judgment model is as follows: ΔP / L=f(IPF,Pr,Re); Where ΔP / L is the pressure drop per unit length, IPF is the solid content of the ice slurry, Pr is the Prandtl number, and Re is the Reynolds number; Determining the formation process of plunger flow by analyzing changes in pressure differential: Injecting ice slurry to drain water creates a plunger flow stage, increasing the pressure differential to ΔP1. During the plunger flow scouring stage, the pressure difference drops to ΔP2; After the flushing and cleaning stage is completed, the pressure difference is reduced to ΔP3; It also includes: after stopping the injection of ice slurry, judging the situation of impurities in the pipe by whether the pressure difference change during the plunger flow process is within the range of ΔP1~ΔP2; ΔP1>ΔP2>ΔP3.

Images