Non-clogging coal water slurry stokehole preheating device

Abstract

The utility model provides a non-clogging coal water slurry stokehole preheating device. The non-clogging coal water slurry stokehole preheating device comprises a pipeline shell, a heating assembly, a steam inlet header, a steam outlet header and an ultrasonic anti-clogging assembly. The heating assembly is arranged in a horizontal matrix mode and suitable for a pipeline shell and comprises a heating unit and heating pipe headers, and the heating pipe headers are arranged at the two ends of the heating unit. The steam inlet header and the steam outlet header are arranged on the pipeline shell, a steam inlet and a steam outlet are correspondingly formed in the steam inlet header and the steam outlet header, and the steam inlet and the steam outlet correspond to the heating pipe headers at the two ends of the heating unit respectively; the ultrasonic anti-blocking assembly comprises ultrasonic transducers which are arranged on the steam inlet header and the steam outlet header respectively. According to the utility model, the blockage problem caused by scaling and deposition in the coal water slurry heating process can be solved, and meanwhile, the heat transfer efficiency and the combustion stability are improved.

Description

Technical Field

[0001] This utility model belongs to the technical field of coal-water slurry combustion, specifically relating to an anti-clogging, high-efficiency heating device for preheating coal-water slurry in front of the furnace. Background Technology

[0002] Coal-water slurry is a novel, efficient, and clean coal-based fuel. Its combustion process includes stages such as heating, moisture evaporation, volatile matter release and combustion, and carbon particle ignition and burnout. However, the heating and moisture evaporation stages of coal-water slurry can lead to delayed ignition and decreased combustion stability. Studies have found that preheating coal-water slurry before the furnace can shorten the ignition induction cycle and stabilize ignition and combustion. At higher preheating temperatures, the moisture evaporation rate is high, which may cause some water vapor to remain in the slurry droplets, forming a steam explosion effect, generating secondary atomization, shortening the carbon particle burnout time, increasing the combustion center temperature, and reducing the incomplete combustion rate. Therefore, preheating coal-water slurry before the furnace is crucial for the reliable operation and efficient, stable combustion of the combustion system.

[0003] However, scaling and clogging of heaters during coal-water slurry heating is currently a bottleneck restricting the widespread application of coal-water slurry preheating technology. The main reasons are: calcium and magnesium ions in the coal-water slurry precipitate and crystallize during heating, forming a scale layer; organic matter polymerizes during heating, forming viscous substances that adhere to the pipe walls and form complex scale layers; at low flow velocities, dead zones and eddies easily occur, leading to the deposition of solid particles and viscous substances; high-speed flow of solid particles also erodes and wears the inner wall of the pipe, accelerating scaling and affecting structural integrity. While existing shell-and-tube heaters are less prone to scaling and clogging, their heating efficiency is low; while tubular heaters have high heating efficiency, they suffer from severe clogging; and although spiral baffle heat exchangers extend the clogging time, the low shell flow velocity still cannot completely prevent scaling and clogging. After scaling, maintenance workload is high, affecting the long-term stable operation of the system, which is a key issue hindering the promotion of coal-water slurry preheating technology. The scaling and clogging problem during coal-water slurry heating affects and limits the promotion and implementation of coal-water slurry preheating technology. Utility Model Content

[0004] The purpose of this invention is to provide a heat exchanger for heating coal-water slurry. By combining structural optimization with ultrasonic technology, it solves the problems of scaling, low heat transfer efficiency, and high maintenance costs associated with traditional heaters. It achieves the goals of long-term stable operation, no scaling, no clogging, high heating efficiency, and maintenance-free operation, which is of great significance for the promotion and application of coal-water slurry combustion technology.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A non-clogging preheating device for coal-water slurry furnace includes a pipe shell, heating components, a steam inlet header, a steam outlet header, and an ultrasonic anti-clogging component;

[0007] The heating assembly is arranged in a horizontal matrix to fit the pipe shell, and includes heating units and heating pipe manifolds, with the heating pipe manifolds located at both ends of the heating units;

[0008] The steam inlet header and steam outlet header are installed on the pipe shell. The steam inlet header and steam outlet header are respectively provided with steam inlet and steam outlet. The steam inlet and steam outlet are respectively provided with heating pipe headers at both ends of the heating unit.

[0009] The ultrasonic anti-clogging component includes an ultrasonic transducer, which is respectively installed on the steam inlet header and the steam outlet header.

[0010] Preferably, the heating unit includes multiple sets of horizontally matrix-arranged heating tubes disposed within the pipe housing; the heating tube headers are multiple and respectively disposed at both ends of each set of heating tubes.

[0011] Preferably, there is a gap between the heating tube headers at both ends of the multiple sets of heating tubes, and there is a gap between the heating tube headers and the inner wall of the pipe shell.

[0012] Preferably, a guide cone is provided on the outside of the heating pipe manifold to reduce the eddy current resistance of the coal-water slurry during the flow process.

[0013] Preferably, an ultrasonic transducer is provided in the middle section of the pipe shell.

[0014] Preferably, the pipe shell, heating pipe, heating pipe header, steam inlet header, and steam outlet header are all made of metal.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] This invention is applicable to solving the blockage problem caused by scaling and deposition during the heating process of coal-water slurry, while improving heat transfer efficiency and combustion stability.

[0017] Anti-clogging: Ultrasonic air pressure and shearing action effectively remove scale, prevent wall adhesion and deposition, and ensure long-term stable operation of the heater. Compared with the water-coal slurry heater, it will not be affected by scale clogging and other problems, thus ensuring normal operation.

[0018] High-efficiency heat transfer: The straight-through structure reduces flow resistance, and ultrasonic shearing and peeling destroy the stagnant layer, enhancing the heat transfer effect;

[0019] Long lifespan: Designed with no fatigue period, supporting long-term maintenance-free operation;

[0020] Flexible adaptation: The heater is modular, and multiple operating modes can be matched with different production scenarios.

[0021] Improve the combustion effect of coal-water slurry: reduce the viscosity of coal-water slurry, shorten the ignition time, improve the combustion conditions, and increase combustion efficiency; reduce the energy costs of enterprises and reduce pollution emissions. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structure of the heater of this utility model;

[0023] Figure 2 This is a schematic diagram of the heating tube bundle of this utility model;

[0024] Figure 3 This is a schematic diagram of the heating tube bundle guide cone of this utility model;

[0025] Figure 4 This is a schematic diagram of the cross-section of the heater of this utility model;

[0026] Figure 5 This is a schematic diagram of the appearance of the heater of this utility model.

[0027] The serial numbers in the diagram are as follows:

[0028] 1. Pipe shell; 2. Heating pipe; 3. Heating pipe header; 4. Steam inlet header; 5. Steam outlet header; 6. Steam inlet; 7. Steam outlet; 8. Ultrasonic transducer; 9. Coal-water slurry inlet; 10. Coal-water slurry outlet; 11. Guide cone. Detailed Implementation

[0029] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments.

[0030] like Figures 1 to 5 As shown, this embodiment provides a non-clogging coal-water slurry preheating device, applicable to the pipe shell 1, including a heating pipe 2, a heating pipe header 3, a steam inlet header 4, a steam outlet header 5, and an ultrasonic transducer 8.

[0031] The pipe shell 1 adopts a straight-through shell type. The two ends of the pipe shell 1 are connected to the coal-water slurry inlet 9 and the coal-water slurry outlet 10, respectively. After the coal-water slurry enters the pipe shell 1 from the coal-water slurry inlet 9, the heated coal-water slurry flows through the shell side in the straight-through shell type pipe shell 1. There are no baffles to guide the flow in the shell side, so as to avoid the generation of eddy current resistance and sedimentation.

[0032] In this embodiment, the pipe shell 1 adopts a straight-through shell design without baffles, forming a continuous flow shell-side space. The heated coal-water slurry flows directly through the shell side, avoiding the eddy current resistance and particle deposition caused by traditional baffle structures. The main body of the pipe shell 1 is made of high-temperature resistant alloy steel, which is suitable for the high-temperature and corrosive media environment of coal-water slurry.

[0033] Steam inlet header 4 and steam outlet header 5 are installed on the pipe shell 1 to provide the inlet and outlet of the heating source; steam inlet header 4 and steam outlet header 5 are respectively provided with steam inlet 6 and steam outlet 7. Steam outlet 7 is used to discharge steam or condensate.

[0034] The pipe shell 1 contains heating components arranged in a horizontal matrix, including heating units and heating pipe manifolds.

[0035] The heating unit consists of multiple heating tubes 2, each with a wall thickness of 1-1.5mm and a diameter of 10-16mm. High-frequency welding ensures a tight seal. Steam, thermal oil, or high-temperature flue gas can flow inside the heating tubes 2 for heating coal-water slurry. The heating assembly's structure effectively transmits ultrasonic energy, allowing for flexible installation of ultrasonic transducers to fully utilize the ultrasonic effect.

[0036] Each heating tube 2 is welded to both ends with a heating tube manifold 3, which is vertically installed inside the pipe shell 1. The heating tube manifolds 3 at both ends of the heating tube 2 correspond to and are sealed tightly against the steam inlet 6 and steam outlet 7, respectively. This heating structure can effectively transmit ultrasonic energy, allows for flexible installation of ultrasonic transducers to fully utilize the ultrasonic effect, and can adopt various operating modes such as independent operation, series operation, parallel operation, and mixed operation according to the characteristics of the site conditions and specific requirements.

[0037] like Figure 4 The diagram shown is a cross-sectional view of the device. Gaps are left between the heating pipe manifolds 3 at both ends of the multiple sets of heating pipes 2 to allow the coal-water slurry to flow through. Furthermore, gaps are left between the heating pipe manifolds 3 and the inner wall of the pipe casing 1. This ensures that the coal-water slurry flows directly without generating eddy current resistance.

[0038] Three ultrasonic transducers (8) are used, respectively installed on the steam inlet header (4), the steam outlet header (5), and the middle section of the pipe shell (1). During operation, the ultrasonic equipment generates approximately 10,000 micrometer-level ultrasonic energy fluctuations per second in all components and materials within the pipe. This provides peeling and shearing effects, along with a highly penetrating high-frequency ultrasonic air compression effect, effectively preventing blockages such as wall adhesion, scaling, and deposition during the water-coal slurry heating process. It also provides ultrasonic stirring and enhanced heat transfer. The single-unit power is 0.3-0.5kW, the frequency range is 10-13kHz, and energy superposition is achieved through phase control.

[0039] The ultrasonic transducer effectively drives the pipe shell 1, heating tube 2, steam inlet manifold 4, and steam outlet manifold 5 to generate micron-level ultrasonic energy fluctuations of approximately 10,000 times per second, thereby producing excellent peeling and shearing effects. In addition, the special frequency ultrasonic air pressure (not cavitation) has strong penetrating power and enhances heat transfer, mass transfer, and mixing. Ultimately, it effectively avoids wall adhesion, scaling, and deposition.

[0040] In this embodiment, the ultrasonic equipment adopts a novel high-power long-pulse frequency conversion phase-shifting ultrasonic technology made of magnetostrictive materials, which has the characteristics of strong load-carrying capacity, wide effective operating bandwidth, strong penetration ability, no fatigue period, long-term stable operation and maintenance-free operation.

[0041] Furthermore, in this embodiment, a guide cone 11 is provided on the outside of the heating pipe manifold 3 to reduce the eddy resistance of the coal-water slurry during the flow process.

[0042] Furthermore, in this embodiment, the pipe shell 1, heating pipe 2, heating pipe manifold 3, steam inlet manifold 4, and steam outlet manifold 5 are all made of metal materials that are corrosion-resistant, elastic, and conducive to the transmission of ultrasonic energy.

[0043] The application method of this embodiment is as follows:

[0044] Taking steam as a heating source as an example, the heater is connected to the coal-water slurry conveying system. The heat source enters the heating tube 2 through the inlet header 3, and the coal-water slurry flows through the shell side. The frequency and power of the ultrasonic transducer 8 are adjusted according to the operating conditions to ensure that the air pressure effect covers the entire heating area.

[0045] If the on-site steam temperature and pressure are relatively high, the flow rate of the coal-water slurry is relatively slow, and the temperature requirements for the coal-water slurry are not strict, then one heater can be connected in series with the circuit of one coal-water slurry combustion nozzle.

[0046] If the on-site steam temperature and pressure are relatively low, the flow rate of the coal-water slurry is relatively slow, and the temperature requirements for the coal-water slurry are not strict, then one to three heaters can be connected in series in the circuit of one coal-water slurry combustion nozzle.

[0047] If the on-site steam temperature and pressure are relatively high, the flow rate of the coal-water slurry is relatively fast, and the temperature requirements for the coal-water slurry are strict, then multiple heaters need to be connected in series in the circuit of a coal-water slurry combustion nozzle.

[0048] If heater 2 is installed on the main pipeline, it needs to be used in parallel and in series depending on the flow rate and temperature requirements of the coal-water slurry.

[0049] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. A non-clogging preheating device for coal-water slurry furnaces, characterized in that, It includes a pipe shell (1), a heating assembly, a steam inlet header (4), a steam outlet header (5), and an ultrasonic anti-clogging assembly; The heating components are arranged in a horizontal matrix within the pipe housing (1), including a heating unit and a heating pipe manifold (3), with the heating pipe manifold (3) located at both ends of the heating unit; The steam inlet manifold (4) and the steam outlet manifold (5) are installed on the pipe shell (1). The steam inlet manifold (4) and the steam outlet manifold (5) are respectively provided with a steam inlet (6) and a steam outlet (7). The steam inlet (6) and the steam outlet (7) are respectively corresponding to the heating pipe manifolds (3) at both ends of the heating unit. The ultrasonic anti-blocking component includes an ultrasonic transducer (8), which is respectively installed on the steam inlet header (4) and the steam outlet header (5).

2. The non-clogging coal-water slurry preheating device according to claim 1, characterized in that, The heating unit includes multiple sets of horizontally matrix-arranged heating tubes (2) disposed within the pipe housing (1); the heating tube manifold (3) comprises multiple units respectively disposed at both ends of each set of heating tubes (2).

3. The non-clogging coal-water slurry preheating device according to claim 1, characterized in that, There is a gap between the heating tube manifolds (3) corresponding to both ends of the multiple sets of heating tubes (2), and there is a gap between the heating tube manifolds (3) and the inner wall of the pipe shell (1).

4. The non-clogging coal-water slurry preheating device according to claim 1, characterized in that, The outer side of the heating pipe manifold (3) is provided with a flow guide cone (11) to reduce the eddy resistance of the coal-water slurry during the flow process.

5. The non-clogging coal-water slurry preheating device according to claim 1, characterized in that, An ultrasonic transducer (8) is provided in the middle section of the pipe shell (1).

6. The non-clogging preheating device for coal-water slurry furnace according to claim 1, characterized in that, The pipe shell (1), heating pipe (2), heating pipe manifold (3), steam inlet manifold (4) and steam outlet manifold (5) are all made of metal.

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