CN202673418U - Pump assisted system for storing and supplying ammonia by one-stage waste heat mode - Google Patents

Abstract

The utility model relates to a system for ammonia storage and supply of ammonia in a single-stage waste heat mode assisted by a pump. The temperature sensor of the sensor and the pressure tank is connected to the signal input terminal of the electronic control unit through the signal line, the antifreeze liquid delivery pipe passes through the inside of the pressure tank, the sensing end of the pressure sensor is located in the pressure tank but does not touch the solid ammonia storage material, and the air is filtered The reducer is connected to the reducing agent conduit through the reducing gas delivery pipe, the nozzle of the reducing agent conduit is inserted into the exhaust gas inlet pipe, the outlet end of the SCR post-processor is connected to the exhaust gas discharge pipe, and the exhaust gas inlet temperature sensor and NOX sensor are connected to the exhaust gas inlet pipe. The induction end is located in the exhaust gas inlet pipe; the system has the characteristics of flexibility, not only can meet the emission control target when the vehicle is cold-started at low temperature, it is cheap, reliable, and easy to use; it can be used in SCR national 4 or above systems, and can also be applied In the FCEV system, it meets the application requirements of the future automotive industry. Has practical value.

Description

A system for pump-assisted single-stage waste heat storage and supply of ammonia

technical field

The utility model relates to a system for ammonia storage and supply of ammonia in a single-stage waste heat mode assisted by a pump, which is applied to the SCR after-treatment industry of automobile tail gas, and is also applicable to the FCEV energy storage system of a fuel cell.

Background technique

At present, the world is facing comprehensive challenges of energy and environment. In terms of the selection of technical means to meet the emission standards of traditional vehicles, people still face many difficulties, for example, how to choose the technical means of after-treatment and so on.

SCR (Selective Catalytic Reduction) catalytic conversion reduction technology is a traditional post-treatment technology. The essence of this traditional SCR technology using liquid urea is to use urea to decompose ammonia at high temperature, ammonia as a reducing agent and NOX in engine exhaust react under the combined action of catalyst and temperature, and generate Non-toxic N ₂ and H ₂ O, so as to achieve the purpose of purification.

Traditional SCR has many advantages, for example, it can have 50~85% NOX removal efficiency in the range of exhaust temperature 250~550oC, and can effectively reduce PM emission level; traditional SCR can easily meet Euro 4 and Euro 5 It also has the potential to reach the level of Euro 6; the traditional SCR technology currently used in Euro 4 can reduce the fuel consumption of the engine by 3~6%; the traditional SCR catalyst does not contain precious metals, and the specific cost is relatively low; the traditional SCR It is not sensitive to the quality of motor fuel, especially the sulfur content. Based on the above analysis, the traditional SCR post-processing technology is also more suitable for China's vehicle conditions and vehicle fuel conditions.

If the traditional vehicle-mounted SCR post-treatment technology is to be promoted and applied in China, it is necessary to properly address the carrier, catalyst, urea reductant supply network, dosage of urea reductant, atomized injection of urea reductant, SCR catalyst conversion efficiency, and ammonia leakage. And crucial technical difficulties such as system matching.

Every upgrade of the emission standards of motor vehicles has an impact effect on the automobile industry in one way or another. The delayed implementation of China's national 4 standards is not only the only reason for the asynchronous fuel standards, but also the complex social support system and the construction of socialized service facilities for liquid urea reducing agents. For example, national 4 After the implementation of the standard, there will be a demand for the ECU (control unit) and DCU (metering unit) required for the operation of the traditional SCR system immediately. Considering that the current vehicle ECU and other electronic control systems are imported products, the DCU independently developed by domestic enterprises It is difficult to communicate with it. On the contrary, if 100% of the ECU and DCU systems are imported, not only the price is high, which is difficult for users to accept, but also there is a problem of very tight supply, and it also faces complex after-sales service technology and cost constraints. Problems have restricted the development and progress of the entire automotive industry. In addition, the liquid urea reductant used in the traditional SCR system faces the problems of freezing in winter and thawing with heat preservation, which also causes the complexity and poor stability of the traditional SCR system.

Therefore, how to obtain a low-cost and high-performance post-processing system is the core content of promoting technological progress in this field. The adsorption and desorption characteristics of inorganic salts to ammonia can be used as a good technical choice for future SCR systems.

Some salts of industrial grade, for example, chlorides such as strontium chloride, magnesium chloride or calcium chloride and their mixtures, the system used in conjunction with ammonia, that is, the endothermic and exothermic process of the above-mentioned chloride and ammonia adsorption and desorption process Phenomenon, it has been maturely applied to the refrigeration system of large-scale cold storage in industry.

The chemical adsorption of the above-mentioned anhydrous chloride and ammonia is a common chemical principle. In theory, one molecule of chloride can adsorb 6-8 molecules of ammonia to form a stable complex. In-depth, it was found that the adsorption and desorption models and chemical principles of these chlorides and ammonia can be fully applied to the SCR system for the purification of motor vehicle exhaust.

In the national patent information network, search with ammonia storage as the subject word, the patent number is CN201120099229.7 'A device for recovering ammonia from urotropine tail gas by gas phase method', and the patent number is CN201020677361.7 'Used for cold storage room distribution The ammonia connecting mechanism' and the 'composite functional ammonia storage device' with patent number CN201020269811.9 are not related to the characteristic components of the present invention. Patent No. CN200520057558.X's patent of 'an ammonia distillation device' is a kind of environmental protection treatment device for ammonia nitrogen discharge treatment of ammonia nitrogen industrial wastewater, and does not involve the characteristic components in the present invention. Not relevant to the present invention.

The patent No. CN201010244091.5 'method and system for checking the operation of SCR catalyst' and the patent No. CN200880104697.X 'operation method and diagnosis method of SCR exhaust aftertreatment system' provide An ammonia dosing module and control system for selective catalytic reduction (SCR) catalytic converters and conventional liquid urea splitting, not involving the characteristic components of the present invention.

Patent No. CN200910197860.8, the invention of 'a preparation method of high-efficiency low-temperature ammonia storage material' is applied to the SCR post-treatment system, which is characterized by the use of aminoborane ammonia complex ammonia BH3(NH3)n (n=1~3 ); the maximum ammonia storage capacity at room temperature can reach 62.4wt%, but, considering that aminoborane is expensive, it has higher explosion and combustion grades, and is not suitable for mass application in general industrial fields.

The patent No. CN200580026626.9 'solid material for storing and transporting ammonia' relates to a solid material for storing and transporting ammonia. The ammonia-storing solid material includes M _a (NH3) _n X _z ionic salt, and the salt solid material is directly molded by high pressure through a mold, for example, made into a cylinder, and then many such cylinders are arranged together. The biggest disadvantage of this patent is that the cylindrical body is too dense, and it takes a long time to perform saturated adsorption of ammonia after each ammonia desorption is completed, such as 4~6 hours, and the efficiency is very low, which is very low for the SCR ammonia storage system used in automobiles. It is very inconvenient, which is the reason for limiting its application.

The patent number is CN200580009219.7 'Application of ammonia storage device in energy production', the invention relates to a power generation unit, including ammonia absorption and release salt with the general formula _Ma (NH3) _nXz , the patent is mainly applicable to fuel battery system. In claim 4 of the patent, it is mentioned that the characteristic substance is the type of salt or located on a porous carrier material, but it does not declare what kind of porous material it is, and those skilled in the art cannot implement it.

The patent No. CN200710156866.1 'an amino complex and its preparation method and use' discloses an amino complex and its preparation method and use. The composition of the amino complex is MX _m (NH3) _n , and the invention is used for the separation of ammonia in the circulating gas used in the ammonia synthesis process. The claims only relate to the preparation process of the amino metal complex.

Patent No. CN200680005886.2 for 'High Density Storage of Ammonia' contains solid ammonia storage and delivery materials for ammonia absorbing/desorbing solid materials that have been compacted to a density greater than 50% of the theoretical skeletal density The material provides a solid ammonia storage material. The metal salt solid material described in this patent is also directly molded. It is stated that a binder is used. It only states that a silica fiber binder may be used, and there is no dosage ratio. Without clearly stating the details of other ingredients used, it is almost impossible for those skilled in the art to implement.

The retrieval and analysis of the above-mentioned patents show that the use of active ammonia storage compounds to adsorb and decompose ammonia to form an aftertreatment system applied to vehicles has not been reported yet.

Contents of the invention

The purpose of this utility model is to provide a pump-assisted single-stage waste heat system for ammonia storage and ammonia supply, which uses a composition composed of active materials, porous materials and binders as the carrier for ammonia storage and release; engine cooling The residual heat of the liquid is heated, relying on the control unit and a set of solenoid valves or proportional valves to realize the dose delivery of ammonia and conveniently introduce it into the SCR post-treatment system to achieve the removal of NOX; simplify the system, improve reliability, and greatly reduce cost, and eliminate obstacles to large-scale industrial promotion and application.

The technical scheme of the utility model is realized in the following way: a pump-assisted single-stage waste heat ammonia storage and supply system, which consists of an engine, an antifreeze delivery pipe, a solenoid valve, a pressure tank, a solid ammonia storage material, and an air filter , feeding port, pressure sensor, spare pipe valve, pressure tank temperature sensor, reducing gas delivery pipe, electronic control unit, proportional valve, exhaust gas inlet temperature sensor, NOX sensor, reducing agent conduit, exhaust gas inlet pipe, exhaust gas discharge pipe, SCR Composed of post-processor and gas delivery pump, it is characterized in that the electronic control unit is connected to the solenoid valve, gas delivery pump and proportional valve through the signal harness, and the exhaust gas inlet temperature sensor, NOX sensor, pressure sensor and pressure tank temperature sensor are connected through the signal line The signal input end of the electronic control unit, the antifreeze delivery pipe and the engine antifreeze system are connected in series or in parallel, the antifreeze delivery pipe passes through the inside of the pressure tank, and the antifreeze delivery pipe inside the pressure tank is distributed in a coiled form, and the electromagnetic The valve is located on the antifreeze delivery pipe, and the pressure tank is filled with solid ammonia storage material, the filling amount is 40% of the volume capacity of the tank, and the pressure tank is equipped with an air filter, a feeding port, a pressure sensor, a spare pipe valve, a pressure Tank temperature sensor, wherein the air filter is located at the gas outlet end of the pressure tank, the sensing end of the pressure tank temperature sensor is inserted into the solid ammonia storage material, the sensing end of the pressure sensor is located in the pressure tank but does not contact the solid ammonia storage material, and the air The filter is connected to the reducing agent conduit through the reducing gas delivery pipe, and the nozzle of the reducing agent conduit is inserted into the exhaust gas inlet pipe. There are proportional valves and gas delivery pumps on the reducing gas delivery pipeline, and the exhaust gas inlet pipe is connected to the inlet port of the SCR post-processor. , the outlet end of the SCR post-processor is connected to the exhaust pipe, the exhaust gas inlet temperature sensor and the NOX sensor are connected to the exhaust gas inlet pipe, and the sensing end is located in the exhaust gas inlet pipe.

The thickness of the pressure tank body is 4-5 mm, cylindrical, and a layer of nylon is thermally sprayed inside the tank body. the

The positive effect of the utility model is that the system can be used for a long time after one-time ammonia charging, and has sufficient practicability, economy and advancement; the application of the technology on the vehicle-mounted SCR has practical significance.

Description of drawings

Fig. 1 is the accompanying drawing of the present utility model.

Detailed ways

Below in conjunction with accompanying drawing and embodiment, the utility model is further described: as shown in Figure 1, a kind of pump-assisted single-stage waste heat mode stores ammonia and supplies ammonia system, consists of engine 1, antifreeze delivery pipe 2, solenoid valve 3, Pressure tank 4, solid ammonia storage material 5, air filter 6, feeding port 7, pressure sensor 8, spare pipe valve 9, pressure tank temperature sensor 10, reducing gas delivery pipe 11, electronic control unit 12, proportional valve 13 , an exhaust gas inlet temperature sensor 14, a NOX sensor 15, a reducing agent conduit 16, an exhaust gas inlet pipe 17, an exhaust gas discharge pipe 18, an SCR post-processor 19, and a gas delivery pump 20, and is characterized in that the electronic control unit 12 is connected through a signal harness Solenoid valve 3, gas delivery pump 20, proportional valve 13, exhaust gas inlet temperature sensor 14, NOX sensor 15, pressure sensor 8, pressure tank temperature sensor 10 are connected to the signal input end of electronic control unit 12 through signal lines, antifreeze fluid delivery pipe 2. It is connected in series or in parallel with the antifreeze system of the engine 1. The antifreeze delivery pipe 2 passes through the inside of the pressure tank 4. The antifreeze delivery pipe 2 is located inside the pressure tank 4. On the pipe 2, the pressure tank 4 is filled with solid ammonia storage material 5, the filling amount is 40% of the volume capacity of the tank body, and the pressure tank 4 has an air filter 6, a feeding port 7, a pressure sensor 8, and a spare pipe valve 9 , pressure tank temperature sensor 10, wherein the air filter 6 is located at the gas outlet of the pressure tank 4, the sensing end of the pressure tank temperature sensor 10 is inserted in the solid ammonia storage material 5, and the sensing end of the pressure sensor 8 is located at the pressure tank 4 Inside but not in contact with the solid ammonia storage material 5, the air filter 6 is connected to the reducing agent conduit 16 through the reducing gas conveying pipe 11, the nozzle of the reducing agent conduit 16 is inserted into the exhaust gas entering pipe 17, and the reducing gas conveying pipe 11 has a proportional Valve 13, gas delivery pump 20, exhaust gas inlet pipe 17 is connected to the inlet end of SCR post-processor 19, the outlet end of SCR post-processor 19 is connected to exhaust gas discharge pipe 18, exhaust gas inlet temperature sensor 14, and NOX sensor 15 are connected to exhaust gas inlet pipe 17 On, its sensing end is located in the tail gas inlet pipe 17 pipeline.

The thickness of the pressure tank 4 is 4-5 mm, cylindrical, and a layer of nylon is thermally sprayed inside the tank.

Example 1

Select a SUS304 plate with a thickness of 4mm and first weld it into a stainless steel barrel with an inner diameter of 300mm and a height of 330mm, complete the welding of the cooling liquid circulation pipeline and the coil, and complete the welding of the bottom. The inner wall of the barrel is thermally sprayed with nylon powder once, pay attention to heating The coil is not sprayed with nylon; the welding of the upper cover is completed, and the feeding port 7, pressure sensor 8, spare pipe valve 9, temperature sensor 10, reducing gas delivery pipe 11 and filter 6 are completed on the upper cover to complete the durable The connection of the relevant parts of the pressure tank 4; pressure leak test to ensure that the sealing and welding quality meet the requirements;

Use 58 parts of industrial anhydrous magnesium chloride, 2 parts of expanded graphite, 15 parts of deionized water, 10 parts of industrial ethanol and 15 parts of industrial ball clay. The above materials are mixed evenly into wet powder by mechanical dough mixer. 5min, the mixture is filled into the pressure tank 4 through the feeding port 7 on the pressure tank 4, and the pressure tank body is shaken by a mechanical vibration method for 5-10min, and the air gap is removed. 40%; the whole tank is placed in a vacuum oven, heated from room temperature 25°C under normal pressure, with an average of 5°C/10min, and the temperature rises to 70°C, the feeding port 7 is opened to discharge water vapor and alcohol vapor, and the temperature is maintained at 70°C for 30 minutes, then Start the vacuum pump at this temperature, gradually evacuate, and make the vacuum degree reach 550mabr three times, and keep the temperature and pressure for 30min;

Use the high-purity industrial ammonia bottle through the spare pipe valve 9 to fill the ammonia; carry out in a naturally ventilated environment, put the pressure tank 4 into a water tank with a large enough cooling water in advance, connect the ammonia steel bottle, and decompress The valve and the drying system are filled with ammonia slowly within the outlet pressure range of 0.1Mpa, and the ammonia filling time is 3 hours; before and after the ammonia filling, weigh the 4-pressure tank with the insulation layer inside, and confirm the density of the filled ammonia. The net mass is greater than 8kg; after the ammonia filling is completed, the valves of the entire system are closed to ensure no leakage;

Connect the relevant electronic control unit 12, proportional valve 13, NOX sensor 15, reducing agent conduit 16, exhaust gas inlet 17, exhaust gas outlet 18, SCR post-processor 19 and gas delivery pump 20; and with an 8.6L country 4 The engine test bench is connected to each other, and the above system is started. According to the setting, the 20-gas delivery pump is started while the engine is running, to realize the delivery of ammonia from 'zero time', and the supply of ammonia is set to be the theoretical demand. 90%, start the test, and test the NOX conversion rate of the engine under 6 working conditions. When the ammonia leakage is less than 15ppm, the NOX conversion rate is maintained in the range of 70~92%; after the engine runs for 8 minutes, the 10-temperature sensor When the temperature is higher than 60°C, the 20-gas delivery pump stops working. At this time, rely on the waste heat of the system to realize the supply of ammonia. Also set the supply of ammonia to 90% of the theoretical demand and start the test. In 6 working conditions The NOX conversion rate of the engine is tested under the condition that the ammonia leakage rate is less than 10ppm, and the NOX conversion rate is maintained in the range of 63~80%;

When the above system is assembled on the chassis of a heavy-duty diesel truck, the gas delivery pump 20 starts to work immediately, and the gas delivery pump 20 stops working after the vehicle runs for 13 minutes. Assuming that the supply of ammonia gas is 80% of the theoretical demand, the system still has ammonia supply at 15,000km, and the NOX results measured by the real vehicle under full load conditions are in the range of 44% to 66%, which meets the design requirements;

The gas delivery pump 20 is controlled by the electronic control unit 12 to start or stop, start the vacuum pump, and the vacuum degree is 550 mabr. Under this condition, the ammonia gas adsorbed in the active material will be automatically decomposed and sent to the SCR for post-processing When the temperature of the 10-temperature sensor is less than 60°C, the pump starts, and when it is greater than 60°C, it stops working, because the residual heat of the coolant can meet the heating requirements of the active material; the antifreeze delivery pipe 2 flows through the built-in insulation The amount of antifreeze in the pressure tank 4 of the first layer is controlled by the signal fed back from the temperature sensor 10 of the pressure tank to the electronic control unit 12. When the temperature exceeds 90°C, the ammonia resolution rate reaches the maximum value and excessive ammonia is generated in the tank. Can not be consumed, at this time, the electromagnetic valve 3 is closed by the signal of the electronic control unit, the flow of the engine coolant is stopped, and the continuous input of heat is prevented; in addition, when the car is stopped, the SCR post-processor 19 stops working, and ammonia is no longer needed. At the same time, the electromagnetic valve 3 is closed by the signal of the electronic control unit 12, the flow of the engine coolant is stopped, and the continuous input of heat is prevented; Also close the solenoid valve 3 through the signal of the electronic control unit 12, stop the flow of the engine coolant, and prevent the continuous input of heat;

An air filter 6 is installed in the direction of the ammonia outlet on the upper part of the pressure tank 4 to ensure that the inorganic powder in the tank will not enter the pipeline system and block the precision devices; the tank body is tightened after the active material is added to the feeding port 7; the pressure The sensor 8 is also an automatic pressure limiting valve to ensure the automatic pressure relief of the overpressure system; the spare pipe valve 9, the temperature sensor 10 and the reducing gas delivery pipe 11 connected through the air filter 6 are installed on the tank body;

The introduction of active gas and the completion of adsorption are carried out through the spare pipe valve 9; high-purity industrial ammonia cylinders can be used, and in a naturally ventilated environment, considering that the adsorption of ammonia is an exothermic process, the heat of the system can be removed in time It is the key to ensure the rapid adsorption of ammonia. Therefore, put the pressure tank 4 with stainless steel insulation layer into a water tank with a large enough water volume in advance, connect the ammonia cylinder, and pass through the pressure reducing valve and drying system. Slowly fill the ammonia within the outlet pressure range, and the ammonia filling time is 2~3h; weigh the pressure tank 4 with the insulation layer inside before and after the ammonia filling, and confirm that the net mass of the filled ammonia is within the predetermined range; complete After filling ammonia, the valves of the whole system are closed to ensure no leakage;

The installation position of the pressure tank 4 on the vehicle is on the side of the vehicle with the SCR post-processor 19, so as to reduce the length of the pipeline, reduce the system response time, and increase the system response sensitivity;

When the exhaust temperature of the engine or the NOX level reaches a certain level, the electronic control unit 12 controls the opening of the proportional valve 13 to realize the change in the delivery of ammonia to the SCR post-processor 19 to meet the needs of NOX removal under different working conditions of the vehicle .

Claims (2)

1. the auxiliary single-stage waste heat mode of pump is stored up ammonia for the system of ammonia, by motor, the antifreeze liquid delivery pipe, solenoid valve, autoclave, the solid ammonia-storing material, air filter, charging hole, pressure transducer, pipe valve for subsequent use, the autoclave temperature transducer, the reducing gas delivery pipe, electronic control unit, Proportional valve, the gas inlet temperature transducer, the NOX sensor, the reducing agent conduit, tail gas enters pipe, exhaust emission tube, the SCR preprocessor, gas transfer pump forms, it is characterized in that: electronic control unit is by signal wire harness connected electromagnetic valve, gas transfer pump, Proportional valve, the gas inlet temperature transducer, the NOX sensor, pressure transducer, the autoclave temperature transducer is by the signal input part of signaling line connecting electronic control unit, antifreeze liquid delivery pipe and engine fluid Cascade System or in parallel, the antifreeze liquid delivery pipe passes autoclave inside, the pipeline that the antifreeze liquid delivery pipe is positioned at autoclave inside is the coil pipe distribution, solenoid valve is positioned on the antifreeze liquid delivery pipe, fill the solid ammonia-storing material in the autoclave, loading is 40% of tank body volume capacity, air filter is arranged on the autoclave, charging hole, pressure transducer, pipe valve for subsequent use, the autoclave temperature transducer, wherein air filter is positioned at the outlet side of autoclave, the induction end of autoclave temperature transducer is inserted in the solid ammonia-storing material, the induction end of pressure transducer is positioned at autoclave but does not contact the solid ammonia-storing material, air filter is connected with the reducing agent conduit by the reducing gas delivery pipe, the reducing agent catheter nozzle inserts tail gas and enters in the pipe pipeline, proportional valve on the reducing gas delivery pipe pipeline, gas transfer pump, tail gas enters pipe and connects SCR preprocessor inlet end, SCR preprocessor outlet side connects exhaust emission tube, the gas inlet temperature transducer, the NOX sensor is connected to tail gas and enters on the pipe, and its induction end is positioned at tail gas and enters the pipe pipeline.

2. the auxiliary single-stage waste heat mode of a kind of pump described in is according to claim 1 stored up ammonia for the system of ammonia, it is characterized in that the thickness of described autoclave tank body is 4 ~ 5mm, and is cylindrical, tank interior thermal spraying one deck nylon.

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