Boiler water recycling and heating device and method for once-through boiler without forced circulation pump

Abstract

The invention belongs to the technical field of once-through boilers, and particularly relates to a boiler water recycling and heating device and method of a once-through boiler without a forced circulation pump, and the boiler water recycling and heating device of the once-through boiler without the forced circulation pump comprises a first unit and a second unit, the first unit comprises a first furnace body, a first condenser, a first drain flash tank, a first heat supply network heater, a first deaerator, a first high-pressure heater, a second condenser and a first steam turbine, the output end of one side of the first drain flash tank is communicated with the first condenser, and the output end of the other side of the first drain flash tank is communicated with the first heat supply network heater. The discharged boiler water is recovered into the boiler, and after recovery, steam of an adjacent machine is adopted for secondary heating to raise the temperature, so that fuel can be effectively reduced when the unit is started each time, the consumption of demineralized water is saved, heat loss is reduced, and the fuel cost is reduced; and the electric dust remover and desulfurization slurry are prevented from being polluted by oil, and the reliability of equipment is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of direct-current boilers, and in particular relates to a boiler water recovery and heating device and method for a direct-current boiler without a forced circulation pump. Background Art

[0002] A direct current boiler refers to a boiler that relies on the pressure of the feed water pump to sequentially pass the feed water through the economizer, evaporation heating surface (water-cooled wall), and superheater and all become superheated steam. After the feed water enters the boiler, the heating, evaporation and superheating of the water vapor are all carried out continuously on the heating surface, and there is no need to separate steam and water during the heating process. At the initial start-up of the unit, all 330t / h of feed water is discharged into the boiler drain expansion tank after passing through the boiler start-up separator. As the boiler load increases, a small part of the steam is separated by the boiler start-up separator, and discharged into the boiler drain expansion tank through the boiler superheater and reheater drain water; the remaining steam is recovered to the condenser through the turbine bypass system.

[0003] The saturated water of the startup separator is all discharged to the boiler drain expansion tank, and after the expansion of the drain expansion tank, the steam is discharged to the atmosphere, and the drain is then discharged to the cooling tower forebay through the drain pump until the boiler load reaches 30% BMCR, and the steam passing through the startup separator enters the superheater system, and no drain passes through the drain expansion tank. In this process, the water (maximum temperature exceeds 200℃) is completely discharged from the furnace through the startup separator, and part of the water (about 250℃) is discharged from the furnace after the grid connection. The external discharge of hot water not only causes waste of water and energy, but also prolongs the boiler startup time. Summary of the invention

[0004] Based on the technical problem that all water is discharged out of the furnace by starting the separator, and part of the water is discharged out of the furnace after being connected to the grid, and the discharged hot water not only causes waste of water and energy, but also the boiler startup time is long, the present invention proposes a boiler water recovery and heating device and method for a direct current boiler without a forced circulation pump.

[0005] The present invention provides a boiler water recovery and heating device for a direct current boiler without a forced circulation pump, comprising a first unit and a second unit, wherein the first unit comprises a first furnace body, a first condenser, a first drain expansion tank, a first heat network heater, a first deaerator, a first high-pressure heater, a second condenser, and a first steam turbine, wherein an output end on one side of the first drain expansion tank is connected to the first condenser, and an output end on the other side is connected to the first heat network heater;

[0006] The second unit includes a No. 2 furnace, a No. 3 condenser, a No. 2 drain expansion tank, a No. 2 heat network heater, a No. 2 deaerator, a No. 2 high-pressure heater, a No. 4 condenser, and a No. 2 steam turbine. One output end of the No. 2 drain expansion tank is connected to the No. 3 condenser, and the other output end is connected to the No. 2 heat network heater.

[0007] The No. 4 condenser is connected to the No. 1 high-pressure heater through a temporary machine delivery pipe. A control body is provided at the connection between the temporary machine delivery pipe and the No. 1 high-pressure heater. A valve for blocking the temporary machine delivery pipe is provided in the control body. A temperature control mechanism is provided inside the temporary machine delivery pipe on the side close to the No. 1 high-pressure heater. The temperature control mechanism includes a copper guide shaft and a memory metal shaft. The temperature control mechanism is arranged between the control body and the No. 1 high-pressure heater.

[0008] Preferably, the output end of the No. 1 condenser is connected to the No. 1 heat network heater through the second conveying pipe, the output end of the No. 1 heat network heater is connected to the No. 1 deaerator, the output end of the No. 1 furnace body is connected to the No. 1 drain expansion tank and the No. 1 steam turbine, the output end of the No. 1 steam turbine is connected to the No. 2 condenser, the output end of the No. 1 high-pressure heater is connected to the No. 1 deaerator, the output end of the No. 1 deaerator is connected to the No. 1 furnace body, the output end of the No. 3 condenser is connected to the No. 2 heat network heater, the output end of the No. 2 heat network heater is connected to the No. 2 deaerator, the output end of the No. 2 furnace body is connected to the No. 2 drain expansion tank and the No. 2 steam turbine, the output end of the No. 2 steam turbine is connected to the No. 4 condenser, the No. 4 condenser is provided with two output ends, which are respectively connected to the No. 2 high-pressure heater and the No. 1 high-pressure heater, the output end of the No. 2 high-pressure heater is connected to the No. 2 deaerator, and the output end of the No. 2 deaerator is connected to the No. 2 furnace body.

[0009] Preferably, the No. 1 furnace body and the No. 2 furnace body are both provided with a water collecting tank, the No. 1 furnace body is connected with the No. 1 hydrophobic expansion tank through a steam inlet pipe, the liquid in the No. 1 hydrophobic expansion tank is transported to the No. 1 heat network heater through a third delivery pipe, the steam in the No. 1 hydrophobic expansion tank is transported to the No. 1 condenser through a first delivery pipe, the liquid in the No. 2 hydrophobic expansion tank is transported to the No. 3 condenser, and the steam in the No. 2 hydrophobic expansion tank is transported to the No. 2 heat network heater.

[0010] Preferably, a heating port is provided on one side of the No. 1 heating network heater and the No. 2 heating network heater, and a heat exchange tube is provided inside the No. 2 heating network heater, and the heat exchange tube passes through the heating port.

[0011] Preferably, the output end of the No. 2 condenser is connected to the No. 1 high-pressure heater through the fourth delivery pipe, one of the output ends of the No. 4 condenser is connected to the No. 2 high-pressure heater through the fifth delivery pipe, the No. 1 steam turbine is connected to the input end of the No. 2 condenser through the secondary steam pipe, the No. 1 furnace body is connected to the input end of the No. 1 steam turbine, the No. 2 furnace body is connected to the input end of the No. 2 steam turbine, and the No. 1 high-pressure heater is also provided with an output port.

[0012] Preferably, the section between the control body on the temporary conveying pipe and the No. 1 high-pressure heater is the control section, the temperature control mechanism is arranged in the control section, one end of the copper guide shaft is fixedly installed on the inner wall of the control section, the copper guide shaft and the memory metal shaft are fixedly connected together, a moving cavity is arranged on the inner wall of the control section, a first guide block and a second guide block are respectively arranged at both ends of the inner wall of the moving cavity, and the end of the memory metal shaft away from the copper guide shaft is fixedly connected to a connecting guide block.

[0013] Preferably, the movable cavity is connected with a first conductive wire and a second conductive wire, the first conductive wire is fixedly connected to the first guide block, the second conductive wire is fixedly connected to the second guide block, and one end of the second conductive wire away from the second guide block is installed on the control body.

[0014] Preferably, an active cavity is opened in the control body, and the active cavity is divided into an upper cavity and a lower cavity. The valve is slidably inserted in the lower cavity. The upper end of the valve is fixedly connected with a linkage shaft, and the linkage shaft is arranged in the upper cavity. An electric spring is sleeved on the surface of the linkage shaft, one end of the electric spring is fixedly connected to the valve, and the other end of the electric spring is fixedly connected to the top wall of the upper cavity, one end of the electric spring is connected to the second wire, and the other end of the electric spring is connected to the fourth wire, and the fourth wire is installed on one side of the control body.

[0015] Preferably, a third wire is electrically connected to the second wire, and the third wire is connected in series with the energized spring.

[0016] A method for recovering and heating boiler water of a direct-flow boiler without a forced circulation pump comprises the following steps:

[0017] S1: The unit needs to be preheated before it is officially used. The No. 1 furnace body burns, and the water in the water collecting tank is heated by the No. 1 furnace body. The heated water generates steam. Part of the steam is transported to the No. 1 steam turbine, causing the blades in the No. 1 steam turbine to rotate and generate electricity. The other part of the steam is transported to the No. 1 drain expansion tank. The liquid in the No. 1 drain expansion tank is directly transported downward to the No. 1 heat network heater. The steam is transported to the No. 1 condenser and condensed into liquid. The formed liquid is also transported to the No. 1 heat network heater. The hot water in the No. 1 heat network heater will exchange heat with the heat exchange tube. The hot water in the heat exchange tube will eventually be transported to the user for use;

[0018] S2: The water in the No. 1 heating network heater will be transported to the No. 1 deaerator, which will deoxygenate the transported water;

[0019] S3: After passing through the No. 1 steam turbine, part of the steam generated by the No. 1 furnace body will be cooled and depressurized to form secondary steam, which will be transported to the No. 2 condenser for condensation to form liquid. The liquid will be transported to the No. 1 high-pressure heater through the fourth transport pipe. The liquid will be transported to the No. 1 high-pressure heater for treatment. At the same time, the hot water entering the No. 1 high-pressure heater will also heat other heat exchange tubes through heat transfer to transport hot water to users.

[0020] S4: During the preheating stage of the unit, in order to ensure the normal operation of the No. 1 deaerator, the hot water supplied to the No. 1 deaerator is of sufficient temperature. When the temperature control mechanism detects that the temperature in the No. 1 high-pressure heater is insufficient, the control body is opened, so that the liquid condensed from the secondary steam generated by the No. 2 steam turbine is also transported to the No. 1 high-pressure heater through the temporary machine delivery pipe. When the temperature control mechanism detects that the temperature in the No. 1 high-pressure heater is sufficient, the control body is automatically closed to cut off the flow.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] 1. The present invention recycles the discharged boiler water into the boiler, and after the recycling, uses the steam of the adjacent machine for secondary heating to raise the temperature by about 100%. This allows the unit to effectively reduce fuel each time it is started, which not only saves desalted water consumption, reduces heat loss, and reduces fuel costs, but is also very important for preventing the electrostatic precipitator and desulfurization slurry from being contaminated by oil and improving the reliability of the equipment.

[0023] 2. The present invention designs the empty hydrophobic container as a closed structure, and directly recycles the heat energy contained in the steam and hydrophobic material that need to be discharged. The heat energy can be used to heat hot water used by users and can also be used for preheating.

[0024] 3. During the pretreatment period of the present invention, when the boiler is washed with water, the secondary steam generated by the second unit is introduced to heat the deaerator to achieve rated effective stability. The adjacent unit can be used to provide preheating temperature to provide auxiliary means for the heating of this unit.

[0025] 4. The present invention is provided with a temperature control device, which can automatically identify the internal ambient temperature of the No. 1 high-pressure heater. When the internal ambient temperature is too low, the secondary steam of the adjacent machine is introduced for heating, thereby effectively heating the temperature. The device is operated in two ways: automatic control and manual remote control, which is efficient and convenient. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a schematic structural diagram of a boiler water recovery and heating device for a direct current boiler without a forced circulation pump proposed by the present invention;

[0027] Figure 2This is a schematic diagram of the top plan structure of a boiler water recovery and heating device for a direct current boiler without a forced circulation pump proposed by the present invention;

[0028] Figure 3 This is a bottom-up perspective structural diagram of a boiler water recovery and heating device for a direct-flow boiler without a forced circulation pump proposed by the present invention;

[0029] Figure 4 is a structural schematic diagram of one side of the second unit;

[0030] Figure 5 is a structural schematic diagram of one side of the first unit;

[0031] Figure 6 It is a schematic diagram of the structure of the No. 1 high-pressure heater;

[0032] Figure 7 for Figure 6 The enlarged view of point A in the middle;

[0033] Figure 8 It is a side plan view of the No. 1 high-pressure heater;

[0034] Fig. 9 It is a schematic diagram of the internal plane of the control volume.

[0035] In the figure: 1 No. 1 condenser, 2 No. 1 drain expansion tank, 3 No. 1 heating network heater, 4 No. 1 deaerator, 5 No. 1 high-pressure heater, 6 No. 2 condenser, 7 No. 1 steam turbine, 8 steam inlet pipe, 9 first delivery pipe, 10 second delivery pipe, 11 No. 3 condenser, 12 No. 2 drain expansion tank, 13 No. 2 heating network heater, 14 No. 2 deaerator, 15 No. 2 high-pressure heater, 16 No. 4 condenser, 17 No. 2 steam turbine, 18 heating port, 19 The third delivery pipe, 20 the water delivery pipe, 21 the fourth delivery pipe, 22 the secondary steam pipe, 23 the temporary delivery pipe, 24 the control body, 25 the output port, 26 the first guide block, 27 the fifth delivery pipe, 28 the copper guide shaft, 29 the second wire, 30 the movable cavity, 31 the energized spring, 32 the linkage shaft, 33 the valve, 34 the memory metal shaft, 35 the first wire, 36 the connecting guide block, 37 the fourth wire, 38 the second guide block, 39 the movable cavity, 40 the third wire. DETAILED DESCRIPTION

[0036] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0037] Reference Figure 1-Figure 9, a boiler water recovery and heating device for a direct current boiler without a forced circulation pump, comprising a first unit and a second unit, the first unit comprising a No. 1 furnace body, a No. 1 condenser 1, a No. 1 drain expansion tank 2, a No. 1 heat network heater 3, a No. 1 deaerator 4, a No. 1 high-pressure heater 5, a No. 2 condenser 6, and a No. 1 steam turbine 7, an output end of one side of the No. 1 drain expansion tank 2 is connected to the No. 1 condenser 1, and an output end of the other side is connected to the No. 1 heat network heater 3;

[0038] The second unit includes a No. 2 furnace, a No. 3 condenser 11, a No. 2 drain expansion tank 12, a No. 2 heat network heater 13, a No. 2 deaerator 14, a No. 2 high-pressure heater 15, a No. 4 condenser 16, and a No. 2 steam turbine 17. One output end of the No. 2 drain expansion tank 12 is connected to the No. 3 condenser 11, and the other output end is connected to the No. 2 heat network heater 13;

[0039] The fourth condenser 16 is connected to the No. 1 high-pressure heater 5 through the temporary machine delivery pipe 23. A control body 24 is provided at the connection between the temporary machine delivery pipe 23 and the No. 1 high-pressure heater 5. A valve 33 for sealing the temporary machine delivery pipe 23 is provided in the control body 24. A temperature control mechanism is provided inside the temporary machine delivery pipe 23 on the side close to the No. 1 high-pressure heater 5. The temperature control mechanism includes a copper guide shaft 28 and a memory metal shaft 34. The temperature control mechanism is arranged between the control body 24 and the No. 1 high-pressure heater 5.

[0040] The output end of the No. 1 condenser 1 is connected to the No. 1 heat network heater 3 through the second delivery pipe 10, the output end of the No. 1 heat network heater 3 is connected to the No. 1 deaerator 4, the output end of the No. 1 furnace body is connected to the No. 1 drain expansion tank 2 and the No. 1 steam turbine 7, the output end of the No. 1 steam turbine 7 is connected to the No. 2 condenser 6, the output end of the No. 1 high pressure heater 5 is connected to the No. 1 deaerator 4, the output end of the No. 1 deaerator 4 is connected to the No. 1 furnace body, and the output end of the No. 3 condenser 11 is connected to the No. 2 heat network heater 13 The output end of the No. 2 heat network heater 13 is connected to the No. 2 deaerator 14, the output end of the No. 2 furnace body is connected to the No. 2 drain expansion tank 12 and the No. 2 steam turbine 17, the output end of the No. 2 steam turbine 17 is connected to the No. 4 condenser 16, the No. 4 condenser 16 is provided with two output ends, and are respectively connected to the No. 2 high-pressure heater 15 and the No. 1 high-pressure heater 5, the output end of the No. 2 high-pressure heater 15 is connected to the No. 2 deaerator 14, and the output end of the No. 2 deaerator 14 is connected to the No. 2 furnace body.

[0041] The first furnace body and the second furnace body are both provided with water collecting tanks. The first furnace body is connected with the first drain expansion tank 2 through the steam inlet pipe 8. The liquid in the first drain expansion tank 2 is transported to the first heat network heater 3 through the third delivery pipe 19. The steam in the first drain expansion tank 2 is transported to the first condenser 1 through the first delivery pipe 9. The liquid in the second drain expansion tank 12 is transported to the third condenser 11. The steam in the second drain expansion tank 12 is transported to the second heat network heater 13. The water heated by the first furnace body and the second furnace body will flow to the first drain expansion tank 2 and the second drain expansion tank 12 respectively. The steam is located at the upper position and the liquid is located at the lower position. The steam enters the first condenser 1 and the third condenser 11 upward to be condensed into liquid. The condensed liquid is transported to the first heat network heater 3 for recycling, and the generated drain is directly transported to the first heat network heater 3.

[0042] A heating port 18 is provided on one side of the first heating network heater 3 and the second heating network heater 13. A heat exchange pipe is provided in the second heating network heater 13, and the heat exchange pipe passes through the heating port 18. When the high-temperature hot water enters the first heating network heater 3, it contacts the outside of the heat exchange pipe for heat energy exchange, and heats the water delivered through the heating port 18. The heated hot water can be directly delivered to the user.

[0043] The output end of the No. 2 condenser 6 is connected to the No. 1 high-pressure heater 5 through the fourth delivery pipe 21, one of the output ends of the No. 4 condenser 16 is connected to the No. 2 high-pressure heater 15 through the fifth delivery pipe 27, the No. 1 steam turbine 7 is connected to the input end of the No. 2 condenser 6 through the secondary steam pipe 22, the No. 1 furnace body is connected to the input end of the No. 1 steam turbine 7, the No. 2 furnace body is connected to the input end of the No. 2 steam turbine 17, and the No. 1 high-pressure heater 5 is also provided with an output port 25. The high-temperature and high-pressure steam generated by the No. 1 furnace body and the No. 2 furnace body enters the interior through the input ends of the No. 1 steam turbine 7 and the No. 2 steam turbine 17 respectively, and then drives the blades in the No. 1 steam turbine 7 and the No. 2 steam turbine 17 to rotate, thereby achieving the power generation effect. The steam passing through the No. 1 steam turbine 7 and the No. 2 steam turbine 17 will be reduced in pressure and then respectively passed through the secondary steam pipe 22, and transported to the No. 2 condenser 6 and the No. 4 condenser 16 for re-condensation. The output port 25 is used to transfer heat to the outside, which is used to heat other heat exchange tubes and transport hot water to users.

[0044] The section between the control body 24 on the temporary machine conveying pipe 23 and the No. 1 high-pressure heater 5 is the control section, and the temperature control mechanism is arranged in the control section. One end of the copper guide shaft 28 is fixedly installed on the inner wall of the control section, and the copper guide shaft 28 is fixedly connected to the memory metal shaft 34. A movable cavity 39 is arranged on the inner wall of the control section, and the first guide block 26 and the second guide block 38 are respectively arranged at both ends of the inner wall of the movable cavity 39, and the end of the memory metal shaft 34 away from the copper guide shaft 28 is fixedly connected to the connecting guide block 36. The temperature of the copper guide shaft 28 will be affected by the temperature inside the No. 1 high-pressure heater 5. The temperature of the copper guide shaft 28 will be directly transmitted to the memory metal shaft 34. When the temperature is below the rated temperature, the memory metal shaft 34 is in a contracted state. When the temperature is above the rated temperature, the memory metal shaft 34 is in an extended state. When the memory metal shaft 34 contracts and drives the connecting guide block to move, the two ends of the connecting guide block 36 will contact the first guide block 26 and the second guide block 38 at the same time to achieve the power-on effect, and then control the valve 33 in the control body 24 to open the control body 24. Otherwise, the memory metal shaft 34 extends and disengages from the first guide block 26 and the second guide block 38 to achieve the power-off effect.

[0045] The moving cavity 39 is connected with the first wire 35 and the second wire 29. The first wire 35 is fixedly connected to the first guide block 26, the second wire 29 is fixedly connected to the second guide block 38, and one end of the second wire 29 away from the second guide block 38 is installed on the control body 24. When the connecting guide block 36 moves to a position between the first guide block 26 and the second guide block 38, the electrical connection between the first wire 35 and the second wire 29 can be achieved.

[0046] The control body 24 is provided with an active chamber 30, which is divided into an upper chamber and a lower chamber. A valve 33 is slidably inserted in the lower chamber. The upper end of the valve 33 is fixedly connected with a linkage shaft 32, which is arranged in the upper chamber. An energized spring 31 is sleeved on the surface of the linkage shaft 32. One end of the energized spring 31 is fixedly connected with the valve 33, and the other end of the energized spring 31 is fixedly connected with the top wall of the upper chamber. One end of the energized spring 31 is connected with the second wire 29, and the other end of the energized spring 31 is connected with a fourth wire 37, which is installed on one side of the control body 24. The two ends of the energized spring 31 are connected with the second wire 29 and the fourth wire 37 respectively. When the second wire 29 is connected, a circuit path can be formed between the second wire 29 and the fourth wire 37. The energized contraction of the energized spring 31 can drive the linkage shaft 32 and the valve 33 to move upward, thereby opening the control body 24 and allowing the temporary conveying pipe 23 to flow smoothly.

[0047] The second wire 29 is electrically connected to a third wire 40, and the third wire 40 is connected in series with the energized spring 31. By adding the third wire 40 to the second wire 29, when the temporary delivery pipe 23 needs to be disconnected manually, the third wire 40 is directly connected to the circuit, and the energized spring 31 can be directly controlled to contract through the third wire 40 route of the external device.

[0048] When the temperature in the No. 1 high-pressure heater 5 is insufficient, the temperature transmitted to the memory metal shaft 34 by the copper guide shaft 28 is also insufficient. The memory metal shaft 34 is in a contracted state under low temperature. The contracted memory metal shaft 34 makes the connecting guide block 36 between the first guide block 26 and the second guide block 38, and contacts both of them at the same time, which will cause the first wire 35 and the second wire 29 to form a circuit path. The power-on spring 31 at one end of the second wire 29 is connected to the circuit breaker and energized. The power-on spring 31 is energized and contracts, driving the valve 33 to move upward, so that the valve 33 separated in the control body 24 moves upward, so that the lower cavity is opened, and the temporary machine delivery pipe 23 is opened, and the hot water in the No. 4 condenser 16 can enter the No. 1 high-pressure heater 5 through the temporary machine delivery pipe 23, and heat the No. 1 high-pressure heater 5, to ensure that the water temperature of the final No. 1 deaerator 4 in the same direction is sufficient.

[0049] A method for recovering and heating boiler water of a direct-flow boiler without a forced circulation pump comprises the following steps:

[0050] S1: The unit needs to be preheated before it is officially used. The No. 1 furnace body is heated and burned. The water in the water collecting tank is heated by the No. 1 furnace body, and the heated water generates steam. Part of the steam is transported to the No. 1 steam turbine 7, causing the blades in the No. 1 steam turbine 7 to rotate and generate electricity, and the other part of the steam is transported to the No. 1 drain expansion tank 2. The liquid in the No. 1 drain expansion tank 2 is directly transported downward to the No. 1 heat network heater 3. The gas in the No. 1 drain expansion tank 2 is transported to the No. 1 condenser 1 to condense into liquid, and the formed liquid is also transported to the No. 1 heat network heater 3. A heating port 18 is provided on one side of the No. 1 heat network heater 3. The heat exchange tube enters the No. 1 drain expansion tank 2 through the heating port 18, and the hot water in the No. 1 heat network heater 3 will exchange heat with the heat exchange tube. The hot water in the heat exchange tube will eventually be transported to the user for use. The water in the heat exchange tube is not mixed with the water in the No. 1 heat network heater 3. Through heat conduction energy conversion, the steam and drain are recycled to avoid waste and save resources.

[0051] S2: The water in the No. 1 heat network heater 3 will be transported to the No. 1 deaerator 4, which deoxygenates the transported water. The deoxygenated water returns to the water collecting tank through the water pipe 20 for the next heating operation. When the water is transported to the No. 1 deaerator 4, the temperature is reduced after multiple energy conversions.

[0052] S3: Part of the steam generated by the No. 1 furnace body will be cooled and reduced in pressure to form secondary steam after passing through the No. 1 steam turbine 7. The secondary steam will be transported to the No. 2 condenser 6 for condensation to form liquid. The formed liquid will be transported to the No. 1 high-pressure heater 5 through the fourth delivery pipe 21. After the liquid is transported to the No. 1 high-pressure heater 5, it will be processed. At the same time, the hot water entering the No. 1 high-pressure heater 5 will also heat other heat exchange tubes through heat transfer to deliver hot water to users.

[0053] After the boiler is started and the boiler water system is flushed and qualified, start the boiler drain pump and the heat network drain pump, send the 100℃ drain generated during the startup process to the deaerator, recover the high-temperature drain, increase the feed water and furnace temperature, until the unit is loaded and the steam-water separator is switched to dry operation. In order to ensure the quality of boiler drain reuse water, the mechanical seal cooling water of the two drain pumps is replaced with closed water; the valve from the drain pump outlet to the circulating water return main pipe should be kept tight, and the water quality of the water collecting tank should be sampled and tested regularly to avoid unqualified water contaminating the steam-water system. The drain pump reuse system pipeline is relatively long, and a small flow rate should be carried out to warm the pipe and exhaust the air before it is put into use. The outlet Fe of the heat network deironing device is ≤5ug / L. The qualified requirement for the hot flushing of the boiler is that the outlet water quality of the startup separator is Fe≤50ug / L, which can achieve the expected goal.

[0054] S4: During the preheating stage of the unit, the normal operation of the No. 1 deaerator 4 is ensured. The hot water transported to the No. 1 deaerator 4 through the No. 1 high-pressure heater 5 needs to be of sufficient temperature. The secondary steam of the No. 2 furnace body is also introduced into the No. 1 high-pressure heater 5. When the temperature control mechanism detects that the temperature in the No. 1 high-pressure heater 5 is insufficient, the control body 24 is opened, so that the liquid condensed from the secondary steam generated by the No. 2 steam turbine 17 is also transported to the No. 1 high-pressure heater 5 through the temporary delivery pipe 23. When the temperature control mechanism detects that the temperature in the No. 1 high-pressure heater 5 is sufficient, the control body 24 is automatically closed to cut off the flow.

[0055] Through thermal heat recovery calculation, when the outlet water temperature of the deaerator is 107℃, the steam parameters entering the #3 high-pressure heater reach 0.8Mpa, 315℃, 23.2t / h, and the steam parameters entering the #2 high-pressure heater reach 2.4Mpa, 315℃, 41t / h, the feed water with a flow rate of 330t / h can be heated to 222℃, meeting the hot flushing requirements of the boiler. In order to achieve the upper steam parameters, the existing industrial steam supply system can be used, and the adjacent machine's two-stage extraction steam source can be used to supply steam. Because the adjacent machine's steam source consumption is too large and affects the adjacent machine's steam pump output, the CV valve from the middle discharge to the low-pressure cylinder can be adjusted to meet the steam pump demand. After the adjacent machine's cold section steam is put into high-pressure heating, it is necessary to withdraw from various industrial steam supply users due to its large steam consumption, and pay attention to the increase in wall temperature and steam temperature of the adjacent machine's reheat cold section and reheat hot section. Start the unit to prevent the second and third stage extraction steam inlet electric valves from being loose, and the adjacent machine's heating steam from entering the turbine, causing a large temperature difference between the upper and lower cylinders and a turntable jump.

[0056] The discharged boiler water is recycled into the boiler at a temperature of about 95°C. After recycling, it is heated again to about 220°C using steam from an adjacent unit. It is estimated that each start-up of the unit can save 53 tons of fuel oil, which not only saves desalted water consumption, reduces heat loss and fuel costs, but is also very important for preventing the electrostatic precipitator and desulfurization slurry from being contaminated by oil and improving the reliability of the equipment.

[0057] S5: A part of the steam generated by the No. 2 furnace is transported to the No. 2 drain expansion tank 12. The No. 2 drain expansion tank 12 divides the transported steam into liquid and gas. The liquid is transported downward to the No. 2 heat network heater 13, and the gas is transported upward to the No. 3 condenser 11 to condense into liquid. The liquid conducts heat with the heat exchange tube in the No. 2 heat network heater 13 to heat the water in the heat exchange tube. The water after heat exchange is transported to the No. 2 deaerator 14, and the other part of the steam is transported to the No. 2 steam turbine 17 to realize power generation. The secondary steam output by 17 enters the fifth delivery pipe 27 and is condensed into liquid. The hot water can be delivered to the No. 1 high-pressure heater 5 through the temporary delivery pipe 23 to heat the No. 1 high-pressure heater 5. It can also be delivered to the No. 2 high-pressure heater 15 through the fifth delivery pipe 27. The water delivered to the No. 2 high-pressure heater 15 is directly pressurized and heated and delivered to the No. 2 deaerator 14. The water in the No. 2 high-pressure heater 15 does not heat other heat exchange tubes. After the hot water enters the No. 2 deaerator 14, it is deoxygenated and delivered to the water collecting tank of the No. 2 furnace body again.

[0058] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A boiler water recovery and heating device for a direct current boiler without a forced circulation pump, characterized in that: The invention comprises a first unit and a second unit, wherein the first unit comprises a first furnace body, a first condenser (1), a first drain expansion tank (2), a first heat network heater (3), a first deaerator (4), a first high-pressure heater (5), a second condenser (6), and a first steam turbine (7), wherein an output end on one side of the first drain expansion tank (2) is connected to the first condenser (1), and an output end on the other side is connected to the first heat network heater (3); The second unit comprises a No. 2 furnace body, a No. 3 condenser (11), a No. 2 drain expansion tank (12), a No. 2 heat network heater (13), a No. 2 deaerator (14), a No. 2 high-pressure heater (15), a No. 4 condenser (16), and a No. 2 steam turbine (17, wherein one output end of the No. 2 drain expansion tank (12) is connected to the No. 3 condenser (11), and the other output end is connected to the No. 2 heat network heater (13); The fourth condenser (16) is connected to the first high-pressure heater (5) through a temporary machine delivery pipe (23). A control body (24) is provided at the connection between the temporary machine delivery pipe (23) and the first high-pressure heater (5). A valve (33) for sealing the temporary machine delivery pipe (23) is provided in the control body (24). A temperature control mechanism is provided inside the temporary machine delivery pipe (23) near the first high-pressure heater (5). The temperature control mechanism includes a copper guide shaft (28) and a memory metal shaft (34). The temperature control mechanism is provided between the control body (24) and the first high-pressure heater (5).

2. The boiler water recovery and heating device of a direct-flow boiler without a forced circulation pump according to claim 1, characterized in that: The output end of the No. 1 condenser (1) is connected to the No. 1 heat network heater (3) through the second delivery pipe (10), the output end of the No. 1 heat network heater (3) is connected to the No. 1 deaerator (4), the output end of the No. 1 furnace body is connected to the No. 1 drain expansion tank (2) and the No. 1 steam turbine (7), the output end of the No. 1 steam turbine (7) is connected to the No. 2 condenser (6), the output end of the No. 1 high-pressure heater (5) is connected to the No. 1 deaerator (4), the output end of the No. 1 deaerator (4) is connected to the No. 1 furnace body, the output end of the No. 3 condenser (11) is connected to the No. 2 heat network heater (1 3), the output end of the No. 2 heat network heater (13) is connected to the No. 2 deaerator (14), the output end of the No. 2 furnace body is connected to the No. 2 drain expansion tank (12) and the No. 2 steam turbine (17), the output end of the No. 2 steam turbine (17) is connected to the No. 4 condenser (16), the No. 4 condenser (16) is provided with two output ends, which are respectively connected to the No. 2 high-pressure heater (15) and the No. 1 high-pressure heater (5), the output end of the No. 2 high-pressure heater (15) is connected to the No. 2 deaerator (14), and the output end of the No. 2 deaerator (14) is connected to the No. 2 furnace body.

3. The boiler water recovery and heating device of a direct current boiler without a forced circulation pump according to claim 2, characterized in that: The first furnace body and the second furnace body are both provided with a water collecting tank. The first furnace body is connected to the first drain expansion tank (2) through a steam inlet pipe (8). The liquid in the first drain expansion tank (2) is transported to the first heating network heater (3) through a third transport pipe (19). The steam in the first drain expansion tank (2) is transported to the first condenser (1) through a first transport pipe (9). The liquid in the second drain expansion tank (12) is transported to the third condenser (11). The steam in the second drain expansion tank (12) is transported to the second heating network heater (13).

4. The boiler water recovery and heating device of a direct-flow boiler without a forced circulation pump according to claim 3 is characterized in that: A heating port (18) is provided on one side of the first heating network heater (3) and the second heating network heater (13), and a heat exchange tube is provided inside the second heating network heater (13), and the heat exchange tube passes through the heating port (18).

5. The boiler water recovery and heating device of a direct-flow boiler without a forced circulation pump according to claim 4, characterized in that: The output end of the No. 2 condenser (6) is connected to the No. 1 high-pressure heater (5) through a fourth delivery pipe (21), one of the output ends of the No. 4 condenser (16) is connected to the No. 2 high-pressure heater (15) through a fifth delivery pipe (27), the No. 1 steam turbine (7) is connected to the input end of the No. 2 condenser (6) through a secondary steam pipe (22), the No. 1 furnace body is connected to the input end of the No. 1 steam turbine (7), the No. 2 furnace body is connected to the input end of the No. 2 steam turbine (17), and the No. 1 high-pressure heater (5) is also provided with an output port (25).

6. The boiler water recovery and heating device of a direct current boiler without a forced circulation pump according to claim 5, characterized in that: The section between the control body (24) on the temporary conveying pipe (23) and the No. 1 high-pressure heater (5) is the control section, the temperature control mechanism is arranged in the control section, one end of the copper guide shaft (28) is fixedly mounted on the inner wall of the control section, the copper guide shaft (28) is fixedly connected to the memory metal shaft (34), a movable cavity (39) is arranged on the inner wall of the control section, the first guide block (26) and the second guide block (38) are respectively arranged at the two ends of the inner wall of the movable cavity (39), and the end of the memory metal shaft (34) away from the copper guide shaft (28) is fixedly connected to the connecting guide block (36).

7. The boiler water recovery and heating device of a direct-flow boiler without a forced circulation pump according to claim 6, characterized in that: The movable cavity (39) is connected to a first conductive wire (35) and a second conductive wire (29); the first conductive wire (35) is fixedly connected to the first guide block (26); the second conductive wire (29) is fixedly connected to the second guide block (38); and one end of the second conductive wire (29) away from the second guide block (38) is mounted on the control body (24).

8. The boiler water recovery and heating device of a direct-flow boiler without a forced circulation pump according to claim 7, characterized in that: The control body (24) is provided with an active chamber (30), the active chamber (30) being divided into an upper chamber and a lower chamber, the valve (33) being slidably inserted in the lower chamber, the upper end of the valve (33) being fixedly connected with a linkage shaft (32), the linkage shaft (32) being arranged in the upper chamber, an electric spring (31) being sleeved on the surface of the linkage shaft (32), one end of the electric spring (31) being fixedly connected with the valve (33), the other end of the electric spring (31) being fixedly connected with the top wall of the upper chamber, one end of the electric spring (31) being connected with a second wire (29), the other end of the electric spring (31) being connected with a fourth wire (37), the fourth wire (37) being installed on one side of the control body (24).

9. The boiler water recovery and heating device of a direct-flow boiler without a forced circulation pump according to claim 8, characterized in that: The second wire (29) is electrically connected to a third wire (40), and the third wire (40) is connected in series with an energized spring (31).

10. The method for recovering and heating boiler water of a boiler water recovery and heating device for a direct current boiler without a forced circulation pump according to claim 9, characterized in that: The steps include: S1: The unit needs to be preheated before it is officially used. The No. 1 furnace body burns, and the water in the water collecting tank is heated by the No. 1 furnace body. The heated water generates steam. Part of the steam is transported to the No. 1 steam turbine (7), causing the blades in the No. 1 steam turbine (7) to rotate and generate electricity. The other part of the steam is transported to the No. 1 drain expansion tank (2). The liquid in the No. 1 drain expansion tank (2) is directly transported downward to the No. 1 heat network heater (3). The steam is transported to the No. 1 condenser (1) to condense into liquid. The formed liquid is also transported to the No. 1 heat network heater (3). The hot water in the No. 1 heat network heater (3) will exchange heat with the heat exchange tube. The hot water in the heat exchange tube will eventually be transported to the user for use; S2: The water in the No. 1 heating network heater (3) is transported to the No. 1 deaerator (4), and the No. 1 deaerator (4) deoxygenates the transported water; S3: After passing through the No. 1 steam turbine (7), part of the steam generated by the No. 1 furnace body is cooled and reduced in pressure to form secondary steam, which is then transported to the No. 2 condenser (6) for condensation to form liquid. The liquid is then transported to the No. 1 high-pressure heater (5) through the fourth transport pipe (21). The liquid is then transported to the No. 1 high-pressure heater (5) for treatment. At the same time, the hot water entering the No. 1 high-pressure heater (5) heats other heat exchange pipes through heat transfer, and the hot water is then transported to the user. S4: During the preheating stage of the unit, in order to ensure the normal operation of the No. 1 deaerator (4), the hot water supplied to the No. 1 deaerator (4) is of sufficient temperature. When the temperature control mechanism detects that the temperature in the No. 1 high-pressure heater (5) is insufficient, the control body (24) is opened, so that the liquid condensed from the secondary steam generated by the No. 2 steam turbine (17) is also transported to the No. 1 high-pressure heater (5) through the temporary delivery pipe (23). When the temperature control mechanism detects that the temperature in the No. 1 high-pressure heater (5) is sufficient, the control body (24) is automatically closed to cut off the flow.

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