Cold supply system for replacing waste heat utilization device of cooling tower of biomass power plant

Abstract

The utility model discloses a cold supply system for replacing a waste heat utilization device of a cooling tower of a biomass power plant, which comprises a waste heat extraction mechanism used for collecting waste heat in flue gas, and a flue gas temperature sensor is arranged on an exhaust passage of the waste heat extraction mechanism; the lithium bromide unit is connected to an outlet of the waste heat extraction mechanism and converts the heat energy collected by the waste heat extraction mechanism into cold energy to be used by target equipment; the magnetic suspension high-speed centrifugal dust removal mechanism is connected to an inlet of the waste heat extraction mechanism and used for removing dust in the flue gas; the variable-frequency hot water circulating pump is connected between the lithium bromide unit and the waste heat extraction mechanism; and the controller is in electric signal connection with the flue gas temperature sensor and the variable-frequency hot water circulating pump. The utility model solves the problems in the background art that the conventional heat exchanger is easy to block when treating flue gas containing a large amount of dust, the normal operation is influenced, and the temperature of the flue gas is unstable when the conventional heat exchanger extracts waste heat.

Description

Technical Field

[0001] The utility model relates to a cooling system for a waste heat utilization device that replaces a cooling tower of a biomass power plant, and belongs to the technical field of waste heat utilization equipment. Background Art

[0002] Biomass power generation is a power generation method that uses biomass as fuel. It can effectively utilize waste biomass resources, reduce environmental pollution, and provide clean energy. However, a large amount of flue gas will be generated during biomass power generation. Most of the flue gas has been used for power generation, and a small part has not been used after the end flue gas treatment process. If these waste heat can be effectively utilized, the efficiency of biomass power generation will be greatly improved. In addition, air conditioning, ventilation and air conditioning equipment are also an indispensable part of modern life. They consume a lot of energy. If waste heat can be used to provide cold energy, it will greatly reduce the consumption of electricity and achieve the goal of energy conservation and emission reduction. The current existing solutions are mainly to extract the waste heat from the flue gas through various heat exchangers, and then use it to heat water or other media. These heated media can be used for heating or driving other equipment. For example, one solution is to use a spiral heat exchanger. The advantage of this heat exchanger is its simple structure, but its heat exchange efficiency is relatively low and it is easy to clog. Another solution is to use a plate heat exchanger. The advantage of this heat exchanger is its high heat exchange efficiency, but its structure is complex and the maintenance cost is high. There are some problems with the existing technology in practical applications. First, most existing heat exchangers need to be driven by mechanical equipment, which will increase additional energy consumption and reduce the efficiency of waste heat utilization. Secondly, when dealing with flue gas containing a lot of dust, existing heat exchangers are prone to clogging, affecting normal operation. Finally, when extracting waste heat, existing heat exchangers often cause the temperature of flue gas to be unstable, which may have an adverse effect on subsequent treatment processes. Therefore, how to design an efficient, stable and reliable waste heat utilization device is an urgent problem to be solved in the current fields of biomass power generation and air conditioning, ventilation and air conditioning equipment. Summary of the invention

[0003] The utility model provides a cooling system that replaces the waste heat utilization device of the cooling tower of the biomass power plant, so as to solve the problem mentioned in the background technology that most of the existing heat exchangers need to be driven by mechanical equipment, which will increase the extra energy consumption and reduce the efficiency of waste heat utilization; secondly, the existing heat exchanger is easy to be blocked when processing flue gas containing a large amount of dust, affecting normal operation; finally, the existing heat exchanger often causes the temperature of the flue gas to be unstable while extracting waste heat, which may have an adverse impact on the subsequent treatment process.

[0004] The technical problem to be solved by the utility model is achieved by adopting the following technical solutions:

[0005] A cooling system for a waste heat utilization device replacing a cooling tower in a biomass power plant, comprising:

[0006] A waste heat extraction mechanism, the waste heat extraction mechanism is used to collect waste heat in the flue gas, and a flue gas temperature sensor is provided on the exhaust passage of the waste heat extraction mechanism;

[0007] A lithium bromide unit is connected to the outlet of the waste heat extraction mechanism and converts the heat energy collected by the waste heat extraction mechanism into cold energy for use by the target device;

[0008] A magnetically suspended high-speed centrifugal dust removal mechanism is connected to the inlet of the waste heat extraction mechanism and is used to remove dust from the flue gas;

[0009] A variable frequency hot water circulation pump connected between the lithium bromide unit and the waste heat extraction mechanism;

[0010] The controller is electrically connected to the flue gas temperature sensor and the variable frequency hot water circulation pump. The flue gas temperature sensor is used to output a temperature detection signal to the controller, and the controller is used to output a corresponding working signal to the variable frequency hot water circulation pump according to the temperature detection signal.

[0011] As a preferred example, the magnetic suspension high-speed centrifugal dust removal mechanism includes:

[0012] A cylinder body, wherein a cavity is formed inside the cylinder body, and the cavity runs through the cylinder body;

[0013] The bearing support frame is fixedly connected to one end of the cylinder.

[0014] A main shaft is rotatably connected to the bearing support frame, and one end of the main shaft is fixedly connected to an electromagnet, and the electromagnet is used to induce a magnetic field;

[0015] An impeller is fixedly connected to the main shaft, and micro grooves are formed on the impeller, and the micro grooves are used to capture dust in the flue gas;

[0016] There are multiple electromagnets, each of which is fixedly connected to the bearing support frame, and the multiple electromagnets are evenly spaced along the circumference of the bearing support frame.

[0017] As a preferred example, it also includes:

[0018] A cooling dust removal sleeve is sleeved on the electromagnet, and a plurality of air holes are evenly arranged on the cooling dust removal sleeve to prevent dust from adhering to the electromagnet and to cool the electromagnet;

[0019] A compressed air pipe runs through the cylinder and is connected to the cooling dust removal sleeve for conveying compressed air.

[0020] As a preferred example, the cavity includes a first dust removal chamber and a second dust removal chamber, the impeller includes a first impeller and a second impeller, the first impeller is accommodated in the first dust removal chamber, and the second impeller is accommodated in the second dust removal chamber.

[0021] As a preferred example, the first dust removal chamber and the second dust removal chamber are both provided with ash collecting layers, and ash discharge ports are formed on the ash collecting layers, and the ash discharge ports are both connected to ash discharge pipes.

[0022] As a preferred example, a dust sweeper is provided in the first dust removal chamber and the second dust removal chamber. The dust sweeper is rotatably connected to the main shaft through high-viscosity lubricating oil to reduce the rotation speed of the dust sweeper. The dust sweeper is used to sweep the dust falling into the dust collecting layer to the ash discharge port.

[0023] As a preferred example, the waste heat extraction mechanism includes:

[0024] A shell having a water cavity formed therein, the shell being connected to the magnetic suspension high-speed centrifugal dust removal mechanism;

[0025] A tube bundle structure is connected to the water cavity and penetrates the water cavity along the axial direction of the shell, the tube bundle structure is composed of a plurality of fluoroplastic tubes arranged at intervals, and the tube bundle structure is connected to the magnetic suspension high-speed centrifugal dust removal mechanism;

[0026] The shell is provided with a water inlet and a water outlet, and the water cavity is communicated with the water inlet and the water outlet.

[0027] As a preferred example, four waste heat extraction mechanisms are provided, the four waste heat extraction mechanisms are staggered and divided into a main path and a bypass path, two of them are symmetrical as one path, and the four waste heat extraction mechanisms are connected through a four-way device.

[0028] As a preferred example, a smoke damper is provided at each inlet and outlet of the four-way device for switching the smoke channels of the main and bypass of the waste heat extraction mechanism.

[0029] As a preferred example, a cooling method for replacing the cooling system of the waste heat utilization device of the cooling tower of a biomass power plant includes a flue gas dust removal stage S1, a waste heat extraction stage S2, a chilled water stage S3 and a cooling water stage S4;

[0030] The flue gas dust removal stage S1 comprises the following steps:

[0031] S1-1. The flue gas from the economizer outlet of the waste heat boiler enters the waste heat utilization device in two ways, namely the main flue gas inlet and the bypass flue gas inlet. The flue gas is controlled by the four-way device and the inlet flue gas damper. During normal operation, the flue gas only enters the main flue or the bypass. The flue gas from the economizer enters the inlet of the waste heat utilization device and enters the magnetic suspension high-speed centrifugal dust removal mechanism to separate the dust from the flue gas. The dust enters the ash discharge pipe, and the clean flue gas enters the next stage.

[0032] S1-2, the clean flue gas enters the first stage of the flue gas waste heat extraction mechanism, and after heat exchange with water, it enters the second stage through the four-way device, and the flue gas temperature is reduced again by heat exchange with water;

[0033] S1-3, the flue gas after heat exchange enters the exhaust pipe, and the flue gas temperature sensor measures its temperature and then the flue gas is discharged into the subsequent processing process. The flue gas temperature sensor measures the exhaust flue gas temperature value and transmits it to the controller, and the controller controls the water flow according to the flue gas temperature;

[0034] The waste heat extraction stage S2 comprises the following steps:

[0035] S2-1. After being pressurized by the variable frequency hot water circulation pump, the hot water is divided into two paths, one path entering the main path of the flue gas waste heat extraction mechanism, and the other path entering the bypass of the flue gas waste heat extraction mechanism. The flue gas damper is used to control the hot water so that it only enters the main path or the bypass during normal operation, and the hot water can be switched. First, the hot water is pressurized and enters the second stage of the flue gas waste heat extraction mechanism to absorb the heat energy of the flue gas and initially increase the temperature of the hot water;

[0036] S2-2, after the temperature of the hot water is initially increased, it enters the first stage of the flue gas waste heat extraction mechanism. After absorbing the flue gas temperature, the temperature of the hot water is further increased, and then it enters the next stage through the pipeline;

[0037] S2-3, after absorbing the waste heat from the flue gas, the high-temperature hot water enters the lithium bromide unit through the pipeline, providing a heat source for the lithium bromide unit to generate cold energy, and the cycle continues.

[0038] The cooling water stage S3 comprises the following steps:

[0039] S3-1, cooling water is pressurized by the cooling water pump and enters the lithium bromide unit to cool the lithium bromide unit, and the cooling water temperature rises;

[0040] S3-2, after the cooling water temperature rises, it enters the cooling tower, dissipates the heat carried by the cooling water into the air, and the cooling water temperature decreases;

[0041] S3-3. After the cooling water temperature drops, it is pressurized by the cooling water pump and enters the lithium bromide unit, and the cycle continues.

[0042] The chilled water stage S4 comprises the following steps:

[0043] S4-1, chilled water is pressurized and transported to the terminal cooling equipment by the chilled water circulation pump to provide cooling energy for the terminal;

[0044] S4-2, the temperature of the chilled water increases after the heat exchange at the end, and enters the lithium bromide unit through the pipeline;

[0045] S4-3. After the temperature of the chilled water is raised, it passes through the lithium bromide unit, where its temperature is lowered. The chilled water is then pressurized by the chilled water pump and supplied to the end, and the cycle continues.

[0046] The beneficial effects of the utility model are:

[0047] 1. The utility model solves the current industry situation of heat energy loss and low heat energy utilization in the process of cooling flue gas in biomass power plants using cooling towers. It cools the flue gas while extracting the waste heat of the flue gas, which can reduce the flue gas temperature to a controllable range and effectively utilize the waste heat of the flue gas. It is an important part of improving resource utilization, seeks a new way for flue gas cooling, reduces heat energy loss, and promotes resource conservation.

[0048] 2. The utility model solves the current problems of high electricity load for refrigeration and high consumption of fossil energy. It utilizes waste heat from flue gas to produce cold energy without increasing energy consumption. It only utilizes unused waste heat from flue gas as driving energy for refrigeration, which is in line with the development trend of energy conservation and environmental protection, and at the same time reduces the peak electricity consumption for refrigeration in the high temperature season in summer.

[0049] 3. The flue gas waste heat extraction device of the utility model adopts a magnetic levitation high-speed centrifugal dust removal mechanism, which can capture dust in the flue gas when the flue gas passes through a high-speed rotating impeller, and transfer the dust to the side wall under the action of centrifugal force. The dust falls to the ash collecting layer due to gravity and is swept to the ash discharge pipe by a slowly rotating ash sweeper for discharge. This can effectively prevent dust from clogging the heat exchanger and improve the operating stability and reliability of the equipment.

[0050] 4. The flue gas waste heat extraction device of the utility model is provided with a four-way device, and each inlet and outlet are provided with a flue gas damper. By controlling the flue gas inlet and outlet dampers, the waste heat extraction device can switch between the main bypass at will, which increases the flexibility and practicality of the device. At the same time, in order to monitor the outlet flue gas temperature of this device to meet the requirements, an outlet flue gas temperature sensor is provided, and the outlet flue gas temperature is maintained within a certain range by controlling the water flow, which improves the intelligence level of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 It is a schematic diagram of the principle structure of the utility model;

[0052] Figure 2 It is a cross-sectional structural schematic diagram of the waste heat utilization device of the utility model;

[0053] Figure 3 It is a schematic diagram of the structure of the waste heat utilization device of the utility model from a top view;

[0054] Figure 4 It is a schematic cross-sectional structure diagram of the magnetic suspension high-speed centrifugal dust removal mechanism of the utility model;

[0055] Figure 5 It is a schematic diagram of the top view of the magnetic suspension high-speed centrifugal dust removal mechanism of the utility model;

[0056] Figure 6 This is a schematic diagram of the top view of the bearing support frame of the utility model;

[0057] Figure 7 It is a schematic diagram of the structure of the cooling dust removal sleeve of the utility model;

[0058] Figure 8 It is a schematic diagram of the top view of the waste heat extraction mechanism of the utility model;

[0059] Fig. 9 This is a diagram showing the connection relationship between the dust sweeper and the main shaft of the utility model.

[0060] In the figure: waste heat utilization device 1, device integrated block housing 2, magnetic suspension high-speed centrifugal dust removal mechanism 3, cylinder 301, bearing support frame 302, main shaft 303, electromagnet 304, first impeller 305, second impeller 306, micro groove 307, first dust removal chamber 308, second dust removal chamber 309, electromagnet 310, cooling dust removal sleeve 311, air hole 312, compressed air pipe 313, ash collection layer 314, ash discharge port 315, ash discharge pipe 316, ash sweeper 317, high viscosity lubricating oil 318, 18. Waste heat extraction mechanism 4. Shell 401. Tube bundle structure 402. Water cavity 403. Main water inlet 404. Main water outlet 405. Bypass water inlet 406. Bypass water outlet 407. Cross-connector 5. Smoke damper 6. Smoke temperature sensor 7. Frequency conversion hot water circulation pump 8. Generator 9. Circulation pump 10. Absorber 11. Vacuum pump 12. Evaporator 13. Chilled water pump 14. Terminal cooling equipment 15. Throttle valve 16. Condenser 17. Cooling water pump 18. Cooling tower 19. DETAILED DESCRIPTION

[0061] In order to make the technical means, creative features, objectives and effects of the present invention easier to understand, the present invention is further described below in conjunction with specific illustrations.

[0062] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0063] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0064] In the present utility model, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0065] The disclosure below provides many different embodiments or examples for realizing different structures of the embodiments of the utility model. In order to simplify the disclosure of the embodiments of the utility model, the components and settings of specific examples are described below. Of course, they are merely examples, and the purpose is not to limit the utility model. In addition, the embodiments of the utility model may repeat reference numbers and / or reference letters in different examples, and such repetition is for the purpose of simplification and clarity, and does not itself indicate the relationship between the various embodiments and / or settings discussed. In addition, the embodiments of the utility model provide examples of various specific processes and materials, but those of ordinary skill in the art may be aware of the application of other processes and / or the use of other materials.

[0066] like Figure 1-Figure 9 As shown, a cooling system for a waste heat utilization device replacing a cooling tower of a biomass power plant comprises:

[0067] The waste heat utilization device 1 comprises a device integrated block housing 2, a waste heat extraction mechanism 4 and a magnetic suspension high-speed centrifugal dust removal mechanism 3, both of which are installed in the device integrated block housing 2. The waste heat extraction mechanism 4 is used to collect waste heat in the flue gas; the magnetic suspension high-speed centrifugal dust removal mechanism 3 is connected to the inlet of the waste heat extraction mechanism 4, and is used to remove dust in the flue gas, and the inlet of the magnetic suspension high-speed centrifugal dust removal mechanism 3 is connected to the outlet of the boiler economizer.

[0068] Specifically, the magnetic levitation high-speed centrifugal dust removal mechanism 3 includes: a cylinder 301 fixedly connected to the air inlet of the waste heat extraction mechanism 4 and a cavity is formed inside the cylinder 301, and the cavity penetrates the cylinder 301 along the axial direction of the cylinder 301; the bearing support frame 302 is made of copper, and the bearing support frame 302 is fixedly connected to one end of the cylinder 301 away from the waste heat extraction mechanism 4, and the other end of the bearing support frame 302 away from the cylinder 301 is connected to the boiler economizer outlet. The main shaft 303 is rotatably connected to the bearing support frame 302 through a bearing, and one end of the main shaft 303 is fixedly connected to an electromagnet 304, and the electromagnet 304 is used to induce a magnetic field; the impeller is fixedly connected to the main shaft 303, and a microgroove 307 is formed on the impeller, and the microgroove 307 is used to capture dust in the flue gas; there are multiple electromagnets 310, and all of them are made of high-temperature resistant materials, and the multiple electromagnets 310 are fixedly connected to the bearing support frame 302, and the multiple electromagnets 310 are evenly spaced along the circumference of the bearing support frame 302, and the multiple electromagnets 310 generate a low-frequency magnetic field (such as 200HZ). The cooling dust removal sleeve 311 is made of copper and is sleeved on the electromagnet 304. A plurality of air holes 312 are evenly arranged on the cooling dust removal sleeve 311 to prevent dust from adhering to the electromagnet 304 and to cool the electromagnet 304. A compressed air pipe 313 runs through the cylinder 301 and is connected to the cooling dust removal sleeve 311 to transport compressed air. When in use, compressed air with a pressure of 0.8 MPa and a temperature of 20-30 degrees Celsius is connected to the compressed air pipe 313 to cool the electromagnet 304 on the one hand and prevent dust in the flue gas from adhering to the cooling dust removal sleeve 311 on the other hand.

[0069] Compared with the prior art, the main shaft 303 is fixed on the bearing support frame 302, and an external electromagnet 310 is used to provide rotational force for the main shaft 303, so that the impeller can rotate at high speed without gear transmission, providing a power source for centrifugal force, saving space, and allowing the flue gas to flow along the axial direction; when the flue gas passes through the high-speed rotating impeller with microgrooves 307, the microgrooves 307 can capture dust in the flue gas, transfer the dust to the side wall of the cylinder 301 under the action of centrifugal force, and fall along the side wall of the cylinder 301 under the action of gravity.

[0070] In order to further improve the dust removal effect and the flow speed of the flue gas, the cavity of the cylinder 301 includes a first dust removal chamber 308 and a second dust removal chamber 309, and the impeller includes a first impeller 305 and a second impeller 306. The first impeller 305 is accommodated in the first dust removal chamber 308, and the second impeller 306 is accommodated in the second dust removal chamber 309. The first dust removal chamber 308 and the second dust removal chamber 309 are both provided with an ash collection layer 314, and the ash collection layer 314 is formed with an ash discharge port 315, and the ash discharge port 315 is connected to an ash discharge pipe 316. A dust sweeper 317 is provided in the first dust removal chamber 308 and the second dust removal chamber 309. The dust sweeper 317 is equipped with a brush, which is in contact with the dust collecting layer 314. The dust sweeper 317 is rotatably connected to the main shaft 303 through a high-viscosity lubricating oil 318 (in this embodiment, No. 680 gear oil is used as an example) to reduce the rotation speed of the dust sweeper 317. It should be noted that the connection between the dust sweeper 317 and the main shaft 303 is connected by a dynamic seal. The dust sweeper 317 is used to sweep the dust falling into the dust collecting layer 314 to the ash discharge port 315, and transport it to the ash conveying system through the ash discharge pipe 316.

[0071] Specifically, the waste heat extraction mechanism 4 includes: a shell 401, a water cavity 403 is formed inside the shell 401, and the shell 401 is connected to the cylinder 301 in the magnetic suspension high-speed centrifugal dust removal mechanism 3; a tube bundle structure 402, which is connected to the water cavity 403 and penetrates the water cavity 403 along the axial direction of the shell 401, and the tube bundle structure 402 is composed of a plurality of fluoroplastic tubes arranged at intervals, and the tube bundle structure 402 is connected to the cavity of the cylinder 301 in the magnetic suspension high-speed centrifugal dust removal mechanism 3; the shell 401 is provided with a water inlet and a water outlet, and the water cavity 403 is connected to the water inlet and the water outlet. The tube bundle structure 402 is arranged in layers and symmetrically, and each layer reserves a spacing of 50-100mm to increase the hot water flow space and increase the heat transfer effect. It should be particularly noted that the utility model adopts a countercurrent arrangement of flue gas and water. The water is first preheated in the flue gas with a lower temperature section and then enters the flue gas with a higher temperature section for heating, which can effectively extract the heat energy of the flue gas. In order to further effectively extract the thermal energy of the flue gas, two waste heat extraction mechanisms 4 are provided, the flue gas channels of the two waste heat extraction mechanisms 4 are connected by a communicating vessel, and the water chambers 403 in the two waste heat extraction mechanisms 4 are connected by a pipe. It should be noted that a magnetic levitation high-speed centrifugal dust removal mechanism 3 is connected to the waste heat extraction mechanism 4 at the flue gas inlet, and the flue gas outlet of the other waste heat extraction mechanism 4 is connected to the smoke exhaust pipe.

[0072] Considering the maintenance, failure and other situations, a bypass is added in this embodiment. There are 4 waste heat extraction mechanisms 4 in the bypass and the main road. The 4 waste heat extraction mechanisms 4 are arranged alternately, and two are symmetrically arranged as one road. The water chambers 403 in the two waste heat extraction mechanisms 4 between the bypass or the main road are connected by a pipeline. The smoke channels of the 4 waste heat extraction mechanisms 4 are connected by a four-way device 5. The smoke inlets of the bypass and the main road are connected with a magnetic suspension high-speed centrifugal dust removal mechanism 3, and the smoke outlets of the bypass and the main road are connected to the smoke exhaust pipe. Each inlet and outlet of the four-way device 5 is provided with a smoke damper 6 for switching the smoke channels of the main road and the bypass of the waste heat extraction mechanism 4.

[0073] A controller having a preset temperature value inside; a flue gas temperature sensor 7 installed on the exhaust passage of the waste heat extraction mechanism 4 and electrically connected to the controller, for detecting the temperature in the exhaust passage of the waste heat extraction mechanism 4, and converting the temperature in the exhaust passage of the waste heat extraction mechanism 4 into a temperature electrical signal corresponding thereto, and transmitting the temperature electrical signal to the controller; a variable frequency hot water circulation pump 8 installed between the lithium bromide unit and the waste heat extraction mechanism 4, and electrically connected to the controller.

[0074] The controller is used to receive the temperature electrical signal, and when the temperature in the exhaust channel of the residual heat extraction mechanism 4 is less than 165 degrees Celsius, the controller sends a first control signal for controlling the start of the variable frequency hot water circulation pump 8, and the variable frequency hot water circulation pump 8 is used to receive the first control signal and change the frequency to less than 30HZ according to the first control signal. When the temperature in the exhaust channel of the residual heat extraction mechanism 4 is greater than or equal to 165 degrees Celsius and less than or equal to 170 degrees Celsius, the controller sends a second control signal for controlling the start of the variable frequency hot water circulation pump 8, and the variable frequency hot water circulation pump 8 is used to receive the second control signal and change the frequency to 30-40HZ according to the second control signal. When the temperature in the exhaust channel of the residual heat extraction mechanism 4 is greater than 170 degrees Celsius, the controller sends a third control signal for controlling the start of the variable frequency hot water circulation pump 8, and the variable frequency hot water circulation pump 8 is used to receive the third control signal and change the frequency to 40-50HZ according to the third control signal.

[0075] The lithium bromide unit is connected to the outlet of the waste heat extraction mechanism 4, and converts the heat energy collected by the waste heat extraction mechanism 4 into cold energy for use by the target equipment.

[0076] Specific lithium bromide units include:

[0077] Generator 9: There are 5 reserved interfaces on the surface, namely, hot water inlet and outlet interfaces, lithium bromide solution inlet and outlet, and water vapor outlet. The water vapor outlet is connected to the condenser 17 through a pipeline. The variable frequency hot water circulation pump 8 is connected between the water outlet of the generator 9 and the water inlet of the waste heat utilization device 1 (the water inlet of the waste heat utilization device 1 includes the main water inlet 404 and the bypass water inlet 406). The water inlet of the generator 9 is connected to the water outlet of the waste heat utilization device 1 through a pipeline (the main water outlet 405 and the bypass water outlet 407 of the waste heat utilization device 1). ) is connected; the inlet and outlet of lithium bromide solution are connected to the shell of generator 9, the top of generator 9 is the inlet of lithium bromide solution, and multiple pipes are arranged inside the shell of generator 9 to connect with the inlet of lithium bromide solution, multiple nozzles are installed on the pipes to atomize the lithium bromide solution, increase the heating area, and exchange heat with the hot water of the shell to evaporate. The evaporated lithium bromide concentrated solution gathers at the bottom of the shell of generator 9, and the steam enters the condenser 17 through the top outlet. The bottom is the outlet of lithium bromide concentrated solution, which is connected to the absorber 11 through a pipe. The concentrated solution flows to the absorber 11 due to gravity and internal pressure. Working process of generator 9: dilute lithium bromide solution from absorber 11 enters generator 9, exchanges heat with hot water from flue gas, so that the water content of dilute lithium bromide solution evaporates into steam, and becomes lithium bromide concentrated solution, which flows into the absorber 11 through the pipe, and the evaporated water vapor enters the condenser 17.

[0078] Absorber 11: 3 interfaces are arranged on the surface, the top interface is connected to the generator 9 through a pipeline, and multiple pipelines are arranged on the inner top to communicate with the top interface, and multiple nozzles are arranged on the pipeline to atomize the lithium bromide concentrated solution to increase the adsorption effect; a water vapor receiving port is arranged in the middle and upper part, which is connected to the generator 9 through a pipeline to receive water vapor from the generator 9. After the water vapor enters the absorber 11, it contacts with the atomized lithium bromide concentrated solution, absorbs the water vapor, and becomes a dilute solution and gathers at the bottom of the absorber 11; a lithium bromide dilute solution outlet is arranged at the bottom of the absorber 11, which is connected to the circulation pump 10 through a pipeline, and the dilute solution enters the generator 9 after being pressurized by the circulation pump 10. Working process of absorber 11: water vapor from the evaporator 13 reacts with the lithium bromide concentrated solution from the generator 9. The lithium bromide concentrated solution has great absorptivity and can absorb the water vapor from the generator 9 to become a dilute solution of lithium bromide. The dilute solution of lithium bromide is pumped to the generator 9 through the circulation pump 10.

[0079] Condenser 17: 4 reserved interfaces are set on the surface, one on each side of the condenser 17, and two in the middle. The middle interface is the cooling water inlet and outlet, connected to the tube layer of the condenser 17, and the left and right interfaces are the water vapor inlet and outlet, connected to the shell layer of the condenser 17. The left interface of the condenser 17 is connected to the generator 9 through a pipeline, and the water vapor received from the generator 9 enters the shell layer of the condenser 17, and condenses into liquid water after heat exchange with the cooling water in the tube layer; the right interface of the condenser 17 is connected to the throttle valve 16 through a pipeline, and the condensed liquid water enters the throttle valve 16 through the pipeline; the two middle interfaces are connected to the cooling tower 19 and the cooling water pump 18 through pipelines respectively, and the cooling water in the shell absorbs the heat of the water vapor and enters the cooling tower 19 for cooling. The cooled water gathers at the bottom of the cooling tower 19, and is transported to the cooling water pump 18 through a pipeline for pressurization and then enters the tube layer of the condenser 17. Working process of condenser 17: high-temperature water vapor from generator 9 exchanges heat with cooling water to condense into low-temperature liquid water, enters throttle valve 16 to throttle into low-pressure liquid water, and enters evaporator 13.

[0080] The throttle valve 16 is connected to the condenser 17 and the evaporator 13 through pipelines. The condensed water from the condenser 17 is throttled by the throttle valve 16 to reduce the pressure and then transported to the evaporator 13 through the pipeline.

[0081] Evaporator 13: 5 and interfaces are set on the surface, the upper interface on the middle left is the condensate inlet, which receives the low-pressure condensate from the throttle valve 16 and enters the shell of the evaporator 13, the upper interface is the outlet for the condensate to evaporate into steam in the evaporator 13, the two interfaces on the middle right are the inlet and outlet of chilled water, and the lower interface on the middle left is the suction port of the vacuum pump 12; the upper interface on the middle left, the upper interface and the lower interface on the middle left are connected to the shell of the evaporator 13, the upper interface on the middle left is connected to the throttle valve 16 through a pipeline, so that the low-pressure condensate enters the shell of the evaporator 13, and evaporates after heat exchange with the chilled water in the tube layer, and the upper interface is connected to the absorber 11 through a pipeline, so that the shell of the evaporator 13 condenses The vapor from the evaporated water enters the absorber 11; the lower interface on the left side of the middle is connected to the vacuum pump 12 through a pipeline, and the outlet of the vacuum pump 12 is connected to the atmosphere through a pipeline, and the non-condensable gas in the shell of the evaporator 13 is pumped into the atmosphere through the vacuum pump 12 to maintain the negative pressure of the evaporator 13; the two interfaces on the right side of the middle are respectively connected to the chilled water pump 14 and the terminal cold equipment 15 through pipelines, so that the chilled water is pressurized by the chilled water pump 14 and enters the tube layer of the evaporator 13, and the temperature is reduced by heat exchange with the condensed water in the shell and then transported to the terminal cold equipment 15 through a pipeline. After heat exchange with the cold equipment, the temperature rises and enters the inlet of the chilled water pump 14 and is pressurized again to enter the tube layer of the evaporator 13, and the cycle is repeated. Working process of evaporator 13: the evaporator 13 is in a vacuum state, and low-temperature and low-pressure water enters the evaporator 13 through the throttle valve 16 (because the evaporator 13 is in a vacuum state, water can evaporate at 5°C), the low-temperature and low-pressure water exchanges heat with the chilled water, the low-temperature and low-pressure water in the evaporator 13 evaporates, and absorbs the heat brought by the chilled water at the end, so that the chilled water outlet temperature is maintained at about 7°C, and the low-temperature and low-pressure water in the evaporator 13 becomes steam and enters the absorber 11, reacts with the lithium bromide concentrated solution to absorb the water vapor and turn it into a dilute solution, and the cycle is repeated.

[0082] A cooling method for replacing the cooling system of the waste heat utilization device 1 of the cooling tower of a biomass power plant, comprising a flue gas dust removal stage S1, a waste heat extraction stage S2, a chilled water stage S3 and a cooling water stage S4;

[0083] The flue gas dust removal stage S1 comprises the following steps:

[0084] S1-1, the flue gas from the waste heat boiler economizer outlet enters the waste heat utilization device 1 in two ways, namely the main flue gas inlet and the bypass flue gas inlet, which are controlled by the four-way device 5 and the inlet flue gas baffle 6. During normal operation, the flue gas only enters the main flue or the bypass. The flue gas from the economizer enters the inlet of the waste heat utilization device 1 and enters the magnetic suspension high-speed centrifugal dust removal mechanism 3 to separate the dust in the flue gas. The dust enters the ash discharge pipe 316, and the clean flue gas enters the next stage.

[0085] S1-2, the clean flue gas enters the first stage of the flue gas waste heat extraction mechanism 4, and after heat exchange with water, enters the second stage through the cross-connector 5, and the flue gas temperature is reduced again after heat exchange with water;

[0086] S1-3, the flue gas after heat exchange enters the exhaust pipe, and the flue gas temperature sensor 7 measures its temperature and then the flue gas is discharged into the subsequent processing steps. The exhaust flue gas temperature value measured by the flue gas temperature sensor 7 is transmitted to the controller, and the controller controls the water flow according to the flue gas temperature;

[0087] The waste heat extraction stage S2 comprises the following steps:

[0088] S2-1, after being pressurized by the variable frequency hot water circulation pump 8, the hot water is divided into two paths, one path entering the main path of the flue gas waste heat extraction mechanism 4, and the other path entering the bypass of the flue gas waste heat extraction mechanism 4. The flue gas damper 6 is used to control the hot water so that it only enters the main path or the bypass during normal operation, and the hot water can be switched. First, the hot water is pressurized and enters the second stage of the flue gas waste heat extraction mechanism 4 to absorb the heat energy of the flue gas and initially increase the temperature of the hot water;

[0089] S2-2, after the temperature of the hot water is initially increased, it enters the first stage of the flue gas waste heat extraction mechanism 4. After absorbing the flue gas temperature, the temperature of the hot water is further increased, and then it enters the next stage through the pipeline;

[0090] S2-3, after absorbing the waste heat from the flue gas, the high-temperature hot water enters the lithium bromide unit through the pipeline, providing a heat source for the lithium bromide unit to generate cold energy, and the cycle continues.

[0091] The cooling water stage S3 comprises the following steps:

[0092] S3-1, cooling water is pressurized by the cooling water pump 18 and enters the lithium bromide unit to cool the lithium bromide unit, and the cooling water temperature increases;

[0093] S3-2, after the cooling water temperature rises, it enters the cooling tower 19, dissipates the heat carried by the cooling water into the air, and the cooling water temperature decreases;

[0094] S3-3, after the cooling water temperature is lowered, it is pressurized by the cooling water pump 18 and enters the lithium bromide unit, and the cycle continues.

[0095] The chilled water stage S4 comprises the following steps:

[0096] S4-1, chilled water is pressurized and transported by the chilled water circulation pump 10 to the terminal cooling equipment 15 to provide cooling energy for the terminal;

[0097] S4-2, the temperature of the chilled water increases after the heat exchange at the end, and enters the lithium bromide unit through the pipeline;

[0098] S4-3, the temperature of the heated chilled water drops after passing through the lithium bromide unit, and is then pressurized by the chilled water pump 14 and supplied to the end, and the cycle continues.

[0099] The above shows and describes the basic principle and main features of the utility model and the advantages of the utility model. Those skilled in the art should understand that the utility model is not limited to the above embodiments. Without departing from the spirit and scope of the utility model, the utility model may have various changes and improvements, which fall within the scope of the utility model to be protected. The scope of protection of the utility model is defined by the attached claims and their equivalents.

Claims

1. A cooling system that replaces the waste heat utilization device of the cooling tower of a biomass power plant, characterized in that: include: A waste heat extraction mechanism, the waste heat extraction mechanism is used to collect waste heat in the flue gas, and a flue gas temperature sensor is provided on the exhaust passage of the waste heat extraction mechanism; A lithium bromide unit is connected to the water outlet of the waste heat extraction mechanism and converts the heat energy collected by the waste heat extraction mechanism into cold energy for use by the target device; A magnetically suspended high-speed centrifugal dust removal mechanism is connected to the inlet of the waste heat extraction mechanism and is used to remove dust from the flue gas; A variable frequency hot water circulation pump connected between the lithium bromide unit and the waste heat extraction mechanism; The controller is electrically connected to the flue gas temperature sensor and the variable frequency hot water circulation pump. The flue gas temperature sensor is used to output a temperature detection signal to the controller, and the controller is used to output a corresponding working signal to the variable frequency hot water circulation pump according to the temperature detection signal.

2. According to claim 1, a cooling system for replacing the waste heat utilization device of the cooling tower of a biomass power plant, characterized in that: The magnetic suspension high-speed centrifugal dust removal mechanism comprises: A cylinder body, wherein a cavity is formed inside the cylinder body, and the cavity runs through the cylinder body; The bearing support frame is fixedly connected to one end of the cylinder. A main shaft is rotatably connected to the bearing support frame, and one end of the main shaft is fixedly connected to an electromagnet, and the electromagnet is used to induce a magnetic field; An impeller is fixedly connected to the main shaft, and micro grooves are formed on the impeller, and the micro grooves are used to capture dust in the flue gas; There are multiple electromagnets, each of which is fixedly connected to the bearing support frame, and the multiple electromagnets are evenly spaced along the circumference of the bearing support frame.

3. The cooling system of the waste heat utilization device replacing the cooling tower of a biomass power plant according to claim 2 is characterized in that: Also includes: A cooling dust removal sleeve is sleeved on the electromagnet, and a plurality of air holes are evenly arranged on the cooling dust removal sleeve to prevent dust from adhering to the electromagnet and to cool the electromagnet; A compressed air pipe runs through the cylinder and is connected to the cooling dust removal sleeve for conveying compressed air.

4. The cooling system of the waste heat utilization device replacing the cooling tower of a biomass power plant according to claim 3 is characterized by: The cavity includes a first dust removal cavity and a second dust removal cavity, the impeller includes a first impeller and a second impeller, the first impeller is accommodated in the first dust removal cavity, and the second impeller is accommodated in the second dust removal cavity.

5. The cooling system of the waste heat utilization device replacing the cooling tower of a biomass power plant according to claim 4 is characterized in that: The first dust removal chamber and the second dust removal chamber are both provided with ash collecting layers, and ash discharging ports are formed on the ash collecting layers, and the ash discharging ports are both connected with ash discharging pipes.

6. The cooling system of the waste heat utilization device replacing the cooling tower of a biomass power plant according to claim 5 is characterized by: A dust sweeper is provided in the first dust removal chamber and the second dust removal chamber. The dust sweeper is rotatably connected to the main shaft through high-viscosity lubricating oil to reduce the rotation speed of the dust sweeper. The dust sweeper is used to sweep the dust falling into the dust collecting layer to the ash discharge port.

7. A cooling system for replacing waste heat utilization device of cooling tower in biomass power plant according to any one of claims 1 to 6, characterized in that: The waste heat extraction mechanism comprises: A shell having a water cavity formed therein, the shell being connected to the magnetic suspension high-speed centrifugal dust removal mechanism; A tube bundle structure is connected to the water cavity and penetrates the water cavity along the axial direction of the shell, the tube bundle structure is composed of a plurality of fluoroplastic tubes arranged at intervals, and the tube bundle structure is connected to the magnetic suspension high-speed centrifugal dust removal mechanism; The shell is provided with a water inlet and a water outlet, and the water cavity is communicated with the water inlet and the water outlet.

8. The cooling system of the waste heat utilization device replacing the cooling tower of a biomass power plant according to claim 7 is characterized in that: There are four waste heat extraction mechanisms, which are arranged in a staggered manner and are divided into a main path and a bypass path, and two of them are symmetrically arranged as one path. The four waste heat extraction mechanisms are connected through a four-way device.

9. The cooling system of the waste heat utilization device replacing the cooling tower of a biomass power plant according to claim 8, characterized in that: A smoke damper is provided at each inlet and outlet of the four-way device for switching the smoke channels of the main and bypass of the waste heat extraction mechanism.

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