Sludge drying device for two-phase waste heat recovery through biogas power generation
By using a two-phase waste heat recovery device for biogas power generation, and combining gas-water and gas-gas heat exchangers with dehumidification and purification technology, the problems of low energy utilization and high carbon emissions in sludge drying have been solved, achieving a highly efficient, low-carbon, and energy-saving sludge drying effect.
Patent Information
- Application Number
- CN202423107100.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-17
- Publication Date
- 2025-11-25
- Estimated Expiration
- 2034-12-17
AI Technical Summary
In existing technologies, the sludge drying process suffers from low energy utilization, severe pipeline corrosion, and high carbon emissions, resulting in significant heat loss.
A two-phase waste heat recovery device for biogas power generation is adopted, including a gas-water heat exchanger and a gas-gas heat exchanger. The air is preheated by circulating coolant and waste heat from biogas combustion flue gas, and the dry waste heat air is treated by dehumidifier and purifier, so as to achieve efficient recycling of waste heat.
It achieves high efficiency, low carbon emissions, and energy saving in the sludge drying process, avoids pipeline corrosion, and significantly reduces carbon emissions and heat loss.
Smart Images
Figure CN223592580U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model belongs to the technical field of heat utilization, specifically relates to a sludge drying device utilizing biogas power generation two-phase waste heat recovery. BACKGROUND
[0002] Biogas power generation using sewage plant sludge fermentation is an ideal way for sewage plants to achieve energy saving, efficiency increase and carbon reduction, and has become a specific measure for China's large cities to fully implement the national double-carbon development strategy. Sludge drying using biogas power generation waste heat is a relatively ideal technology, which perfectly realizes the cascade utilization of biomass energy and reduces urban waste heat emissions. The biogas power generation system produces high-temperature waste heat while obtaining electric energy, and recycles part of the waste heat for sludge drying, which not only improves the overall energy utilization rate of the system, but also reduces environmental impact.
[0003] At present, China has carried out research in this regard, such as the Huaneng Linyi Power Plant, which has built the largest sludge drying and incineration project in Shandong Province, using the tail flue gas waste heat of the power plant boiler to directly contact the sludge for drying. Although the tail flue gas waste heat of the power plant boiler is used to dry the sludge, in actual operation, complete recovery and utilization of waste heat may not be achieved. Part of the flue gas heat may be lost to the surrounding environment during transmission, or due to the limited heat exchange efficiency of the drying equipment, part of the heat may not be fully transferred to the sludge, thereby reducing the energy utilization efficiency of the entire system. Directly using the tail flue gas to dry the sludge can cause the generation of toxic gases, which can corrode metal pipelines and reduce heat exchange efficiency. The utility model recovers part of the cylinder sleeve water and flue gas waste heat to achieve the effect of energy saving and carbon reduction. CONTENT OF THE UTILITY MODEL
[0004] The utility model aims at providing a sludge drying device utilizing biogas power generation two-phase waste heat recovery, solving the problems of low energy utilization rate, pipeline corrosion, large carbon emissions and large heat loss in the prior art.
[0005] To achieve the above-mentioned purpose, the utility model discloses a sludge drying device utilizing biogas power generation two-phase waste heat recovery, which comprises a combined waste heat recovery system and a sludge drying device.
[0006] The combined waste heat recovery system comprises a biogas power generation waste heat recovery device and a dried sludge waste heat recycling device.
[0007] The biogas power generation waste heat recovery device comprises a gas-water heat exchanger and a gas-gas heat exchanger. The gas-water heat exchanger preheats the dry waste heat air recovered by the dried sludge waste heat recycling device through the circulating cooling liquid for cooling the internal combustion engine to obtain preheated air. The gas-gas heat exchanger heats the preheated air through the biogas combustion flue gas waste heat of the internal combustion engine to obtain hot air, which enters the drying sludge through the air supply port of the sludge drying device.
[0008] The biogas power generation waste heat recovery device further comprises a cooling water pump and a cooling water tower.
[0009] The outlet of the circulating cooling liquid of the internal combustion engine is connected with the water inlet of the gas-water heat exchanger, the water outlet of the gas-water heat exchanger is connected with the water inlet of the cooling water tower, the water outlet of the cooling water tower is connected with the liquid inlet of the circulating cooling liquid of the internal combustion engine, and the cooling water pump is arranged between the water outlet of the gas-water heat exchanger and the water inlet of the cooling water tower.
[0010] The sludge drying device comprises:
[0011] A drying chamber surrounded by the heat preservation layer, one side of the drying chamber is provided with an air supply port at a lower portion, and the other side opposite to the air supply port is provided with an air return port at an upper portion;
[0012] A drying device arranged in the drying chamber, the drying device is a belt transmission structure, and the transmission direction of the belt transmission structure is from the side where the air return port is located to the side where the air supply port is located.
[0013] The sludge drying device further comprises an air induction fan, the air return port of the sludge drying device is connected with the air inlet of the gas-water heat exchanger, and the drying waste heat air of the air return port of the sludge drying device is sent into the air inlet of the gas-water heat exchanger through the air induction fan.
[0014] The sludge drying device further comprises a dehumidifier and a purifier arranged between the air return port of the sludge drying device and the air inlet of the gas-water heat exchanger in sequence.
[0015] The sludge drying device utilizes the recycled biogas power generation waste heat and the sludge drying hot air waste heat to dry the sludge, can realize efficient and low-carbon sludge drying, and can adopt other heat energy supplementing modes when the recycled waste heat amount cannot meet the sludge drying heat demand.
[0016] The sludge drying device utilizes the recycled biogas power generation waste heat and the sludge drying hot air waste heat to dry the sludge, can realize efficient and low-carbon sludge drying, and can adopt other heat energy supplementing modes when the recycled waste heat amount cannot meet the sludge drying heat demand. BRIEF DESCRIPTION OF DRAWINGS
[0017] Fig. 1 It is a whole structure schematic view of the sludge drying device of the utility model for recycling two-phase waste heat of biogas power generation;
[0018] Fig. 2 It is a structure schematic view of the biogas power generation waste heat recycling device in the sludge drying device of the utility model for recycling two-phase waste heat of biogas power generation;
[0019] Fig. 3 It is a structure schematic view of the sludge drying device in the sludge drying device of the utility model for recycling two-phase waste heat of biogas power generation;
[0020] Wherein: 1, gas-water heat exchanger, 2, gas-gas heat exchanger, 3, cooling water pump, 4, cooling water tower, 5, induced draft fan, 6, dehumidifier, 7, purifier, 8, drying equipment, 9, insulation layer, 901, air supply port, 902, return air port, 10, drying chamber, 11, internal combustion engine, 12, generator. DETAILED DESCRIPTION
[0021] The embodiment of the utility model is further explained below in combination with the drawings.
[0022] Reference Figs. 1-3 The utility model relates to the municipal environmental protection field's city sewage plant sludge treatment and disposal, especially relates to a kind of waste heat sludge drying device of recycling biogas power generation waste heat+sludge drying exhaust heat energy, for the problem of high energy consumption, carbon emission of city sewage treatment plant sludge drying process, research and development a kind of sludge drying device using biogas power generation waste heat+recycling sludge drying exhaust heat energy.The device recovers the cooling water waste heat and flue gas waste heat of biogas power generation by multiple heat exchange, and recovers the heat energy of sludge drying exhaust, realizes the recycling use water gas two-phase waste heat low-carbon efficient sludge drying.
[0023] The utility model discloses a kind of sludge drying devices for recycling two-phase waste heat of biogas power generation, including combined waste heat recovery system and sludge drying device;
[0024] The combined waste heat recovery system includes biogas power generation waste heat recovery device and drying sludge waste heat recycling device;
[0025] The biogas power generation waste heat recovery device includes gas-water heat exchanger 1 and gas-gas heat exchanger 2;Gas-water heat exchanger 1 is preheated to obtain preheated air by the dry sludge waste heat air of drying sludge waste heat recycling device recovery through the circulating cooling liquid of internal combustion engine 11 cooling;Gas-gas heat exchanger 2 is heated to obtain hot air by the preheated air through the biogas combustion flue gas waste heat of internal combustion engine 11, and hot air enters drying sludge through sludge drying device air supply port 901.
[0026] The biogas power generation waste heat recovery device further comprises a cooling water pump 3 and a cooling water tower 4;
[0027] The outlet of the circulating cooling liquid of the internal combustion engine 11 is connected with the water inlet of the gas-water heat exchanger 1, the water outlet of the gas-water heat exchanger 1 is connected with the water inlet of the cooling water tower 4, and the water outlet of the cooling water tower 4 is connected with the liquid inlet of the circulating cooling liquid of the internal combustion engine 11; the cooling water pump 3 is arranged between the water outlet of the gas-water heat exchanger 1 and the water inlet of the cooling water tower 4.
[0028] The circulating cooling liquid of the internal combustion engine 11 is cooled in the cooling water tower 4 after passing through the gas-water heat exchanger 1 and passing through the cooling water pump 3, and then enters the internal combustion engine 11.
[0029] The process of biogas power generation is that the biogas generated by sludge anaerobic fermentation is mixed with air and inhaled into the internal combustion engine 11, combustion is generated to release energy to drive the generator 12 to work, and high-temperature flue gas is discharged at the same time. Therefore, the biogas power generation waste heat recovery can utilize two parts of waste heat, i.e. the waste heat of the internal combustion engine 11 and the waste heat of the flue gas.
[0030] Firstly, the waste heat of the internal combustion engine 11 is recovered. In order to maintain the normal circulation of the internal combustion engine 11, the cylinder sleeve of the internal combustion engine 11 needs to be cooled by the cylinder sleeve water circulation cooling, and the general circulating water temperature should be lower than 70℃. If the temperature is higher than 70℃, the cooling tower needs to be used for cooling again. This part of the waste heat recovery is more beneficial to the power generation work, and the liquid phase part of the waste heat recovery of the internal combustion engine 11 is the heat of the cooling water. The high-temperature hot water obtained by using this part of the heat enters the gas-water heat exchanger 1, the recovered heat is indirectly exchanged by the gas-water heat exchanger to preheat the dry waste heat air which is dehumidified and purified after drying the sludge, and the preheated air is obtained.
[0031] Secondly, the flue gas waste heat of the biogas generator 12 is recovered. Since the biogas contains trace impurities and corrosive substances, if the combustion temperature is too low, odor and harmful gases will be generated. Therefore, the exhaust gas emission temperature of the biogas engine needs to be several tens of degrees higher than that of other gas engines, generally about 550℃. The heat energy of this part of gas can be recovered by the gas-gas heat exchanger 2 to heat the preheated air, and the hot air is introduced into the sludge drying device to dry the sludge, and the used engine exhaust gas is discharged outdoors.
[0032] The sludge drying device comprises:
[0033] The drying chamber 10 surrounded by the heat preservation layer 9, one side of the drying chamber 10 is provided with an air supply port 901 at the lower part, and the other side opposite to the air supply port 901 is provided with an air return port 902 at the upper part;
[0034] And the drying equipment 8 arranged in the drying chamber 10, the drying equipment 8 is a belt drive structure, and the transmission direction of the belt drive structure is from the side where the air return port 902 is located to the side where the air supply port 901 is located.
[0035] The waste heat recycling device of the dried sludge comprises an air inducing fan 5; the air return port 902 of the sludge drying device is connected with the air inlet of the gas-water heat exchanger 1, and the dry waste heat air of the air return port 902 of the sludge drying device is sent into the air inlet of the gas-water heat exchanger 1 through the air inducing fan 5.
[0036] The waste heat recycling device of the dried sludge further comprises a dehumidifier 6 and a purifier 7 arranged between the air return port 902 of the sludge drying device and the air inlet of the gas-water heat exchanger 1 in sequence.
[0037] The exhaust air of the drying chamber 10 contains a large amount of recoverable heat energy, which is directly discharged, causing energy waste and environmental heat pollution. The temperature of the air supply of the drying chamber 10 is 100 DEG C, and the constant temperature of the drying chamber 10 is maintained at 80 DEG C ± 2 DEG C. The dry waste heat air is discharged after passing through the dehumidifier 6 and the purifier 7 and then recycled. The water vapor in the exhaust air is liquefied by condensation and dehumidification, and then the harmful gases are oxidized and decomposed and filtered and purified by the exhaust air purifier 7 containing a catalyst. Both processes will lower the temperature of the exhaust air. Therefore, the temperature of the exhaust air discharged from the drying chamber 10 is about 50 DEG C. Recycling this part of the heat still has significant energy-saving nature. The exhaust air after purification and dehumidification is directly introduced into the air preheater and enters the next drying sludge cycle.
[0038] The specific process used by the utility model is as follows:
[0039] Start the biogas generator 12 group, and the biogas and air are introduced into the internal combustion engine 11 to burn, and the generator 12 generates electric energy and high-temperature exhaust gas under the drive of the internal combustion engine 11. The high-temperature exhaust gas is discharged to the outdoor after the sludge drying air is heated by the gas-gas heat exchanger 2 using the waste heat of the high-temperature exhaust gas.
[0040] Start the biogas generator 12 group and the cooling water pump 3. The high-temperature cooling water is first heat-exchanged and recycled by the gas-water heat exchanger 1 to preheat the dry waste heat air discharged in the previous cycle, and the temperature of the dry waste heat air is preheated from 50 DEG C to 60 DEG C. Then, the dry waste heat air is pressurized by the cooling water pump 3 to reach the cooling water tower 4 for heat dissipation. The cooling system is equipped with a temperature sensor and an automatic control system. When the temperature of the cooling water is reduced to below 70 DEG C, the cooling water is recycled back to the internal combustion engine 11 to maintain the stable temperature of the internal combustion engine 11 and the normal operation of the equipment.
[0041] Start the biogas generator 12 group and the air inducing fan 5. The dry waste heat air is first preheated by the gas-water heat exchanger 1, and then the preheated air is heated to the drying temperature by the gas-gas heat exchanger 2 using the exhaust gas of the internal combustion engine 11, and then enters the drying equipment 8.
[0042] The wet sludge is transported into the drying equipment 8 for drying. The drying exhaust pipe is opened, and the dry residual heat air is dehumidified and purified by the dehumidifier 6 and the purifier 7, and then introduced into the air preheater for the next cycle.
Claims
1. A sludge drying device using biogas power generation two-phase waste heat recovery, characterized by, The application relates to a combined waste heat recovery system and a sludge drying device. The combined waste heat recovery system comprises a biogas power generation waste heat recovery device and a drying sludge waste heat circulation recovery device. The biogas power generation waste heat recovery device comprises a gas-water heat exchanger (1) and a gas-gas heat exchanger (2); the gas-water heat exchanger (1) preheats drying waste heat air recovered by the drying sludge waste heat circulation recovery device to obtain preheated air through circulating cooling liquid for cooling of an internal combustion engine (11); the gas-gas heat exchanger (2) heats the preheated air to obtain hot air through waste heat of biogas combustion flue gas of the internal combustion engine (11), and the hot air enters drying sludge through a sludge drying device air supply port (901).
2. The sludge drying device with biogas power generation and two-phase waste heat recovery according to claim 1, characterized in that, The biogas power generation waste heat recovery device further comprises a cooling water pump (3) and a cooling water tower (4). An outlet of the circulating cooling liquid of the internal combustion engine (11) is connected with an inlet of the gas-water heat exchanger (1), an outlet of the gas-water heat exchanger (1) is connected with an inlet of the cooling water tower (4), and an outlet of the cooling water tower (4) is connected with an inlet of the circulating cooling liquid of the internal combustion engine (11); the cooling water pump (3) is arranged between the outlet of the gas-water heat exchanger (1) and the inlet of the cooling water tower (4).
3. The sludge drying device with biogas power generation and two-phase waste heat recovery according to claim 1, characterized in that, The sludge drying device comprises: A drying chamber (10) surrounded by an insulation layer (9), one side of the drying chamber (10) is provided with a air supply port (901) at a lower part, and the other side of the drying chamber (10) is provided with an air return port (902) at an upper part opposite to the air supply port (901); and a drying device (8) arranged in the drying chamber (10), the drying device (8) is a belt transmission structure, and a transmission direction of the belt transmission structure is from the side where the air return port (902) is located to the side where the air supply port (901) is located.
4. The sludge drying device with biogas power generation and two-phase waste heat recovery according to claim 3, characterized in that, The drying sludge waste heat circulation recovery device comprises an air inducing fan (5); the air return port (902) of the sludge drying device is connected with an air inlet of the gas-water heat exchanger (1), and drying waste heat air of the air return port (902) of the sludge drying device is sent into the air inlet of the gas-water heat exchanger (1) through the air inducing fan (5).
5. The sludge drying device with biogas power generation and two-phase waste heat recovery according to claim 4, characterized in that, The drying sludge waste heat circulation recovery device further comprises a dehumidifier (6) and a purifier (7) arranged between the air return port (902) of the sludge drying device and the air inlet of the gas-water heat exchanger (1) in sequence.