Fluidized bed thermal power plant permanent magnet heating waste heat utilization system

Abstract

This utility model provides a permanent magnet heating waste heat utilization system for fluidized bed thermal power plants. The system uses the heat from the permanent magnet speed controller of the blower to heat the demineralized water, which then undergoes secondary heating in the boiler slag cooler before entering the deaerator. This fully utilizes various types of waste heat for comprehensive waste heat utilization. A regulating valve and flow meter are installed at the inlet of the primary blower permanent magnet speed controller; a regulating valve and flow meter are also installed at the inlet of the secondary blower permanent magnet speed controller; a regulating valve and flow meter are installed at the inlet of the induced draft fan permanent magnet speed controller; the outlets of the primary, secondary, and induced draft fan permanent magnet speed controllers are all connected to the demineralized water tank; thermometers are installed at the outlets of the primary, secondary, and induced draft fan permanent magnet speed controllers; the demineralized water tank is connected to the inlet of the boiler slag cooler, and the outlet of the boiler slag cooler is connected to the deaerator.

Description

Technical Field

[0001] This utility model relates to a permanent magnet heating waste heat utilization system for fluidized bed thermal power plants. Background Technology

[0002] In thermal power plants, due to frequent changes in boiler load, the boiler fan needs to adjust the air volume according to the load. The most widely used methods for adjusting the fan air volume are the adjustment of the inlet damper of the industrial frequency fan, the speed regulation of the variable frequency motor, and the speed regulation of the hydraulic coupling.

[0003] Permanent magnet speed controllers are a novel speed control technology. By adjusting the relative position of a cylindrical permanent magnet rotor and a cylindrical conductor rotor along their axial direction, the effective coupling between the permanent magnet rotor and the conductor rotor is changed, thereby altering the torque transmitted between them. This enables repeatable, adjustable, and controllable output torque and speed, achieving the goal of speed regulation and energy saving. Permanent magnet speed controllers offer a range of advantages, including smooth stepless speed regulation, a speed range of 0-98%, simplicity and reliability, flexible start-up, vibration isolation, easy installation, and long service life, making them promising for future applications.

[0004] There are already technologies that apply permanent magnet speed controllers to boiler fans, such as the Chinese patent application number 202021685013.4, entitled "A Boiler Fan Equipped with a Permanent Magnet Speed ​​Controller." Compared to the inlet damper adjustment of industrial frequency fans, permanent magnet speed controllers have significant energy-saving advantages; compared to the motor speed regulation of high-voltage frequency converters, the mechanical transmission of permanent magnet speed controllers has good stability and requires virtually no maintenance, saving the substantial maintenance costs associated with replacing electrical components in high-voltage frequency converters; compared to hydraulic coupling speed regulation, permanent magnet speed controllers have the advantages of high transmission efficiency and system simplicity.

[0005] Permanent magnet speed controllers generate heat due to the speed difference between the motor and fan ends. If this heat cannot be dissipated in time, it will cause the permanent magnet rotor to overheat and demagnetize, leading to permanent magnet failure. Currently, common heat dissipation methods include air cooling, oil cooling, and water cooling. Air cooling is generally used in permanent magnet speed controllers below 200KW. Oil cooling systems are more complex and have a higher failure rate. Water cooling systems are simpler, but existing water cooling systems lack designs for waste heat recovery and utilization. Utility Model Content

[0006] The purpose of this utility model is to overcome the above-mentioned deficiencies in the existing technology and provide a fluidized bed thermal power plant permanent magnet heating waste heat utilization system with reasonable structural design. The heat generated by the permanent magnet speed regulator of the fan is used to heat the cold demineralized water, which is then heated again in the boiler slag cooler before entering the deaerator, thereby making full use of various types of waste heat to achieve comprehensive utilization of waste heat.

[0007] The technical solution adopted by this utility model to solve the above problems is: a fluidized bed thermal power plant permanent magnet heating waste heat utilization system, including a demineralized water pipe, a primary air fan permanent magnet speed regulator, a secondary air fan permanent magnet speed regulator, an induced draft fan permanent magnet speed regulator, a boiler slag cooler, and a deaerator; the demineralized water pipe is connected to the inlet of the primary air fan permanent magnet speed regulator, the inlet of the secondary air fan permanent magnet speed regulator, and the inlet of the induced draft fan permanent magnet speed regulator, respectively; characterized in that: it also includes a demineralized water tank; a primary air fan permanent magnet cooling water regulating valve and a primary air fan permanent magnet cooling water flow meter are installed on the inlet of the primary air fan permanent magnet speed regulator; a secondary air fan permanent magnet cooling water regulating valve and a secondary air fan permanent magnet speed regulator are installed on the inlet of the secondary air fan permanent magnet speed regulator. A permanent magnet cooling water flow meter for the secondary air fan is installed; a permanent magnet cooling water regulating valve and a permanent magnet cooling water flow meter for the induced draft fan are installed at the inlet of the permanent magnet speed controller for the induced draft fan; the outlets of the permanent magnet speed controllers for the primary, secondary, and induced draft fans are all connected to the demineralized water tank; a permanent magnet cooling water thermometer for the primary, secondary, and induced draft fans is installed at the outlets of the permanent magnet speed controllers for the primary, secondary, and induced draft fans; the demineralized water tank is connected to the inlet of the boiler slag cooler, and the outlet of the boiler slag cooler is connected to the deaerator.

[0008] This utility model also includes a demineralized water tank pump, and the demineralized water tank is connected to the inlet of the boiler slag cooler through the demineralized water tank pump.

[0009] The demineralized water tank of this utility model includes a main demineralized water tank and a secondary demineralized water tank. The outlets of the primary fan permanent magnet speed regulator, the secondary fan permanent magnet speed regulator, and the water sampling and cooling device are all connected to the main demineralized water tank; the outlet of the induced draft fan permanent magnet speed regulator is connected to the secondary demineralized water tank; the secondary demineralized water tank is connected to the main demineralized water tank; and the main demineralized water tank is connected to the inlet of the boiler slag cooler.

[0010] This utility model also includes a secondary demineralized water tank pump, which connects the secondary demineralized water tank to the main demineralized water tank.

[0011] This invention features a main demineralized water tank level gauge on the main demineralized water tank and a secondary demineralized water tank level gauge on the secondary demineralized water tank.

[0012] This utility model also includes a bypass water supply regulating valve, through which the demineralized water pipe is connected to the main demineralized water tank.

[0013] This utility model also includes a water sampling cooler, with the demineralized water pipe connected to the inlet of the water sampling cooler and the outlet of the water sampling cooler connected to the demineralized water tank.

[0014] Compared with the prior art, this utility model has the following advantages and effects: This utility model can reuse the heat generated by the permanent magnet speed controller, which can save coal consumption of the whole plant while ensuring the safe operation of the permanent magnet speed controller; the adoption of this system can recover about 30% of the heat of the installed power of the fan, which has good economic benefits. Attached Figure Description

[0015] Figure 1 is a structural schematic diagram of an embodiment of the present invention. Detailed Implementation

[0016] The present invention will be further described in detail below with reference to the accompanying drawings and through embodiments. The following embodiments are explanations of the present invention, but the present invention is not limited to the following embodiments.

[0017] This utility model embodiment includes a primary fan permanent magnet cooling water regulating valve 1, a primary fan permanent magnet cooling water flow meter 2, a primary fan permanent magnet speed regulator 3, a demineralized water tank, a secondary fan permanent magnet cooling water regulating valve 5, a secondary fan permanent magnet cooling water flow meter 6, a secondary fan permanent magnet speed regulator 7, a demineralized water tank pump 9, an induced draft fan permanent magnet cooling water regulating valve 10, an induced draft fan permanent magnet cooling water flow meter 11, an induced draft fan permanent magnet speed regulator 12, a boiler slag cooler 16, a primary fan permanent magnet cooling water thermometer 17, a secondary fan permanent magnet cooling water thermometer 18, an induced draft fan permanent magnet cooling water thermometer 19, a bypass water supply regulating valve 20, a water sampling cooler 21, a deaerator 22, and a demineralized water pipe 23.

[0018] The demineralized water pipes are connected to the inlet of the primary fan permanent magnet speed controller 3, the inlet of the secondary fan permanent magnet speed controller 7, the inlet of the induced draft fan permanent magnet speed controller 12, and the inlet of the water sampling cooler 21, respectively. A primary fan permanent magnet cooling water regulating valve 1 and a primary fan permanent magnet cooling water flow meter 2 are installed at the inlet of the primary fan permanent magnet speed controller 3; a secondary fan permanent magnet cooling water regulating valve 5 and a secondary fan permanent magnet cooling water flow meter 6 are installed at the inlet of the secondary fan permanent magnet speed controller 7; and an induced draft fan permanent magnet cooling water regulating valve 10 and an induced draft fan permanent magnet cooling water flow meter 11 are installed at the inlet of the induced draft fan permanent magnet speed controller 12. The primary fan permanent magnet cooling water regulating valve 1, the secondary fan permanent magnet cooling water regulating valve 5, and the induced draft fan permanent magnet cooling water regulating valve 10 are used to regulate the cooling water volume; the primary fan permanent magnet cooling water flow meter 2, the secondary fan permanent magnet cooling water flow meter 6, and the induced draft fan permanent magnet cooling water flow meter 11 are used to measure the cooling water volume.

[0019] The outlets of the primary fan permanent magnet speed controller 3, the secondary fan permanent magnet speed controller 7, the induced draft fan permanent magnet speed controller 12, and the water sampling cooler 21 are all connected to the demineralized water tank. A primary fan permanent magnet cooling water thermometer 17 is installed at the outlet of the primary fan permanent magnet speed controller 3, a secondary fan permanent magnet cooling water thermometer 18 is installed at the outlet of the secondary fan permanent magnet speed controller 7, and an induced draft fan permanent magnet cooling water thermometer 19 is installed at the outlet of the induced draft fan permanent magnet speed controller 12. These thermometers are used to monitor the cooling water outlet temperature. The demineralized water tank is connected to the inlet of the boiler slag cooler 16 via the demineralized water tank pump 9; the outlet of the boiler slag cooler 16 is connected to the deaerator 22.

[0020] Furthermore, the demineralized water tank includes a main demineralized water tank 4 and a secondary demineralized water tank 13. The outlets of the primary fan permanent magnet speed regulator 3, the secondary fan permanent magnet speed regulator 7, and the water sampling cooler 21 are all connected to the main demineralized water tank 4, while the outlet of the induced draft fan permanent magnet speed regulator 12 is connected to the secondary demineralized water tank 13. The secondary demineralized water tank 13 is connected to the main demineralized water tank 4 via the secondary demineralized water tank pump 15, and the main demineralized water tank 4 is connected to the inlet of the boiler slag cooler 16 via the demineralized water tank pump 9. The permanent magnet cooled demineralized water needs to flow to the tank by gravity. Since the induced draft fan is located far from the primary and secondary fans at the rear of the furnace, it is necessary to set up a main demineralized water tank 4 and a secondary demineralized water tank 13.

[0021] A main demineralized water tank 4 is equipped with a main demineralized water tank level gauge 8, and a secondary demineralized water tank 13 is equipped with a secondary demineralized water tank level gauge 14. The demineralized water pipe 23 is connected to the main demineralized water tank 4 via a bypass water supply regulating valve 20. The secondary demineralized water tank pump 15 adjusts its operating frequency according to the secondary demineralized water tank level gauge 14 to maintain a stable level in the secondary demineralized water tank 13. The bypass water supply regulating valve 20 adjusts its opening degree according to the main demineralized water tank level gauge 8 to maintain a stable level in the main demineralized water tank 4.

[0022] The operation process of this utility model is as follows:

[0023] The demineralized water from the water treatment plant enters each permanent magnet speed controller through the demineralized water pipe 23, and then heats up after absorbing the heat generated by the operation of the permanent magnet speed controller.

[0024] The hot demineralized water from the primary fan permanent magnet speed regulator 3 and the secondary fan permanent magnet speed regulator 7, and the cooling demineralized water from the water sampling cooler 21 are directly fed into the main demineralized water tank 4; the hot demineralized water from the induced draft fan permanent magnet speed regulator 12 is first stored in the auxiliary demineralized water tank 13, and then pumped into the main demineralized water tank 4 by the auxiliary demineralized water tank pump 15; the mixed water in the main demineralized water tank 4 is sent to the boiler slag cooler 16 by the demineralized water tank pump 9 to absorb the waste heat from the boiler slag discharge for secondary heating; the demineralized water after secondary heating is finally fed into the deaerator 22 to complete the comprehensive utilization of waste heat and reduce the steam consumption required for deaerator heating.

[0025] The primary fan permanent magnet cooling water regulating valve 1, the secondary fan permanent magnet cooling water regulating valve 5, and the induced draft fan permanent magnet cooling water regulating valve 10 adjust their openings according to the water temperature signals fed back from the primary fan permanent magnet cooling water thermometer 17, the secondary fan permanent magnet cooling water thermometer 18, and the induced draft fan permanent magnet cooling water thermometer 19, respectively, to ensure that the outlet water temperature of the primary fan permanent magnet speed controller 3, the secondary fan permanent magnet speed controller 7, and the induced draft fan permanent magnet speed controller 12 is ≤50℃. The demineralized water tank pump 9 is set to operate at a frequency based on the number of boiler slag coolers 16 in operation and the required cooling water volume.

[0026] Furthermore, it should be noted that the specific embodiments described in this specification may differ in the shape and name of their components. The above description is merely illustrative of the structure of this utility model. All equivalent or simple variations made based on the structure, features, and principles described in this utility model patent concept are included within the protection scope of this utility model patent. Those skilled in the art to which this utility model pertains may make various modifications or additions to the described specific embodiments or use similar methods to replace them, as long as they do not deviate from the structure of this utility model or exceed the scope defined in these claims, all of which should fall within the protection scope of this utility model.

Claims

1. A fluidized bed thermal power plant permanent magnet heating waste heat utilization system, comprising a demineralized water pipe, a primary air fan permanent magnet speed regulator, a secondary air fan permanent magnet speed regulator, an induced draft fan permanent magnet speed regulator, a boiler slag cooler, and a deaerator; the demineralized water pipe is connected to the inlet of the primary air fan permanent magnet speed regulator, the inlet of the secondary air fan permanent magnet speed regulator, and the inlet of the induced draft fan permanent magnet speed regulator, respectively; characterized in that: It also includes a demineralized water tank; a primary fan permanent magnet cooling water regulating valve and a primary fan permanent magnet cooling water flow meter are installed at the inlet of the primary fan permanent magnet speed controller; a secondary fan permanent magnet cooling water regulating valve and a secondary fan permanent magnet cooling water flow meter are installed at the inlet of the secondary fan permanent magnet speed controller; an induced draft fan permanent magnet cooling water regulating valve and an induced draft fan permanent magnet cooling water flow meter are installed at the inlet of the induced draft fan permanent magnet speed controller; and the outlet of the primary fan permanent magnet speed controller, the secondary... The outlets of the permanent magnet speed controller for the blower and the permanent magnet speed controller for the induced draft fan are both connected to the demineralized water tank. A primary fan permanent magnet cooling water thermometer is installed at the outlet of the primary fan permanent magnet speed controller, a secondary fan permanent magnet cooling water thermometer is installed at the outlet of the secondary fan permanent magnet speed controller, and an induced draft fan permanent magnet cooling water thermometer is installed at the outlet of the induced draft fan permanent magnet speed controller. The demineralized water tank is connected to the inlet of the boiler slag cooler, and the outlet of the boiler slag cooler is connected to the deaerator.

2. The fluidized bed thermal power plant permanent magnet heating waste heat utilization system according to claim 1, characterized in that: It also includes a demineralized water tank pump, which connects the demineralized water tank to the inlet of the boiler slag cooler.

3. The fluidized bed thermal power plant permanent magnet heating waste heat utilization system according to claim 1, characterized in that: The demineralized water tank includes a main demineralized water tank and a secondary demineralized water tank. The outlets of the primary fan permanent magnet speed regulator, the secondary fan permanent magnet speed regulator, and the water sampling and cooling unit are all connected to the main demineralized water tank. The outlet of the induced draft fan permanent magnet speed regulator is connected to the secondary demineralized water tank. The secondary demineralized water tank is connected to the main demineralized water tank, and the main demineralized water tank is connected to the inlet of the boiler slag cooler.

4. The fluidized bed thermal power plant permanent magnet heating waste heat utilization system according to claim 3, characterized in that: It also includes a secondary demineralized water tank pump, which connects the secondary demineralized water tank to the main demineralized water tank.

5. The fluidized bed thermal power plant permanent magnet heating waste heat utilization system according to claim 3, characterized in that: A level gauge for the main demineralized water tank is installed on the main demineralized water tank, and a level gauge for the auxiliary demineralized water tank is installed on the auxiliary demineralized water tank.

6. The fluidized bed thermal power plant permanent magnet heating waste heat utilization system according to claim 3, characterized in that: It also includes a bypass water supply regulating valve, through which the demineralized water pipe is connected to the main demineralized water tank.

7. The fluidized bed thermal power plant permanent magnet heating waste heat utilization system according to claim 1, characterized in that: It also includes a water sampling cooler, with the demineralized water pipe connected to the inlet of the water sampling cooler and the outlet of the water sampling cooler connected to the demineralized water tank.

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