Background technology
" planning of multi-modal Transport Network Long-and Medium-term Development " and the enforcement China railways of " medium-term and long-term railway network development plan " have realized spanning development, except passenger train, China has 650,000 goods trains at present, to increase to 750,000 by 2015, yet, some backward links of process at high speed development highlight developing bottleneck, the critical component of train, braking technology has become the key restriction of the great marshalling lorry more than ten thousand tons, and existing braking technology can't be promoted ton marshalling operation and speed-raising in the system-wide system normally.
The existing goods train braking technology of more external developed countries is to adopt Electronically Controlled Pneumatic Brake Systems, control single-unit train air brake by the signal of telecommunication, make to grow, organize into groups greatly each the single-unit vehicle synchronous braking of heavy haul train group, this technology can effectively solve vertical inertial collision of Heavy-haul Freight train, is one of cutting edge technology of the heavily loaded large conveying quantity freight traffic technique of development.This technology in North America, Australia etc. very generally adopts and is referred to as ECP (Electronically Controlled Pneumatic).
ECP mainly comprises two types: a kind of is to have cable to connect mode to be called for short ECP-L, by the cable (being referred to as train bus-line) that connects the train total length, transmits brake signal and regenerative braking information.Such technology is applicable railway line for freight traffic transportation only, must use this technology under fixedly marshalling condition of train, because cable is fixedly connected with train, can't tear at random the zero group of rearranging open.
Another kind is wireless synchronization control mode abbreviation ECP-C, utilizes the special-purpose assorted in-vehicle wireless communication device of adjacent of marshalling vehicle, by the wireless interface interface, receives and transmitting system transmission braking information and regenerative braking execution information.This technology also is only suitable for for the railway line for freight traffic transportation, also needs the fixing marshalling of train, because the adjacent wave point one to one that it adopts.
The third ECP technology is referred to as ECP-R, is by a kind of special wireless network, brake signal is sent to the implementation status of organizing into groups each vehicle and can monitor in real time brake signal in network.
The first technology is due to wired transmission signal, the power supply of its actuator also can be by wire transmission, the second, the third technology belong to wireless communication technology, because goods stock does not have electric device, so the power supply of the signalling of vehicle just needs special power supply circuits, obviously, once supply line on cloth, the meaning of random marshalling has not just existed, and therefore needs a kind of these signallings of vehicle self-supporting power system to work.The self-supporting power of vehicle is two kinds of approach nothing but, the one, each joint goods train configuration storage battery, another kind is each joint goods train configuration generator, be adopt that mode all must choose lightweight, volume is little, good reliability, fail safe are good, energy savings and environmental protection.
Realize that the train self-supporting power has following several approach;
Relative wind while 1, utilizing the train high-speed cruising drives wind power generation;
While 2, utilizing the train high-speed cruising and the generating of the relative movement drives of rail friction rotating excitation technology;
3, utilize train high-speed cruising hour wheel to form tread high temperature thermo-electric generation to tread and wheel-rail friction;
Research shows, any on wheel surface be subject to a thermal shock in the process of rotation of wheel one circle, and car speed is higher, and the frequency of thermal shock is higher, and defeated people's frictional heat is just more in turn by different contact points for wheel tread.
Relative wind while 4, utilizing the train high-speed cruising acts on cooling energy conversion technique.
Although frictional heat thermal shock trailing wheel exists " cooling " effect of speed away track and surrounding air, but the speed of heat radiation is obviously than heating is slow again, and car speed is higher, the heat that is subject to a front frictional heat is accumulated just larger, and " cooling " be difficulty all the more.After continuing the stack of temperature rise, the temperature of wheel tread is increased to certain temperature value, finally need to meet wheel tread and the surrounding air heat loss through convection is reached to balance, continuing the synergistic effect of temperature rise and convection current " cooling " effect of surrounding air and can maintain a stable state.
Two-Dimensional Steady State Analysis shows, at the car speed of 350km/h and 10% cunning, rolls than in situation, and the wheel surface maximum temperature can reach 800 ℃, result of study shows, train is in traction/braking, and in the very large situation of such slip component, Wheel Rail Contact temperature rise meeting reaches a considerable numerical value; When running well, along with the raising of car speed, the also raising greatly of its absolute sliding speed [Pei Youfu, etc. the finite element analysis of Wheel Rail Contact temperature rise [J]. Chinese railway science, 1996,17(4): 48-58].
Under the different braking operating mode, the maximum temperature analysis and research of locomotive wheel tread show: 20 tons to 22.5 tons, speed 130~160Km/h, 332.5~480 ℃ of railway train wheel tread temperature [Yu Lijuan. the Finite-Element Study of locomotive wheel transient state temperature field [J]. railway society, 1993,15(3): 11-16].
Sun Qiong research shows, train is at a high speed in the situation of (250km/h) and high creep rate (10%), the highest Contact Temperature up to 1102 ℃ and 1030 ℃ [Sun Qiong, etc. [J] studied in Wheel Rail Contact temperature rise and numerical analysis thereof. Chinese railway science, 1997,18(4): 14-24].
Above-mentioned research shows, selects to utilize train high-speed cruising hour wheel to form tread high temperature thermo-electric generation to tread and wheel-rail friction, without increasing any load of train, belongs to pure used heat utilization.
The thermo-electric generation technology utilizes thermo-electric converting material directly heat energy to be converted into to electric energy, is a kind of all solid state power conversion mode, without chemical reaction or fluid media (medium), therefore power generation process has noiseless, without wearing and tearing, without leaking, volume is little, lightweight, conveniently moving, the characteristics such as long service life, in military affairs, space flight, some special dimensions such as microelectronics are widely used.
The thermo-electric generation principle, be based on 3 basic effects that thermoelectric material has, it is the Peltier effect, the Seebeck effect, the Thomson effect, these 3 effects have been established the basis of hot spot theory in thermodynamics, and thermo-electric generation is the Seebeck effect of utilizing material, by charge carrier (electric cave and hole), carry out power conversion.
The end combination of commodity thermoelectric power generation device N and P also is placed on the high-temperature heating state, the other end is opened a way and is given cooling or low temperature, because the thermal excitation effect of temperature end is stronger, hole and the electron concentration of this end are higher than low-temperature end, under the driving of this carrier concentration gradient, hole and electronics spread to low-temperature end, thereby form electrical potential difference at the low temperature open end.By many, P type and N-type focus transition material are coupled together to the composition module, just can obtain sufficiently high voltage and form a thermal generator.
Thermoelectric is the technology that research heat energy and electric energy are directly changed.Germany scientist Seebeck (Seebeck) has at first been found thermoelectric effect.When there is the temperature difference in two kinds of different metals formation two ends, ,Dang loop, closed-loop path, in loop, by generation current, this effect becomes the technical foundation of thermo-electric generation, is referred to as Seebeck effect.The operation principle of thermoelectric generator, based on Seebeck effect, adopts the P type N-type bi-material (as sige alloy, lead telluride) of the high figure of merit that heat energy is directly changed into as electric energy.
The device that the thermoelectric components and parts are solid state, the machinery-free moving component, noiseless during work, the life-span is long, volume is little, lightweight, do not need or only need very little maintenance.
The isotope thermoelectric generator is the accessory power supply of best up to now interstellar vehicle.The former Soviet Union and the U.S. are the maximum countries of development and application isotope thermoelectric generator, since 1961, the isotope thermoelectric generator sum that only U.S. is used in space flight just reaches 40, the power output of these isotope thermoelectric generators is 2.7~300W, the longest operating time surpassed 30 years [Cai Shanyu. the application status and prospects [J] of Spatial Co-location element generating system. Nuclear Science And Engineering, 1994, 14 (4): 373~379] [Gao Min, Deng. Thermoelectric Generators For Space Applications [J]. the China's Space science and technology, 1992, 06:27~33] [Rowe D M.Applications of Nuclear-powered Thermoelectric Generators in Space[J] .Applied Energy.1991, 40 (4): 241~271].
Voyager 2's interplanetary flight device of emission in 1977, use
238Pu isotope thermoelectric generator, successfully leapt Jupiter, Saturn, Uranus and Neptune, the solar system that now flown out, and thermoelectric generator is still in normal operation.
There is report to utilize the application of succeeding of the used heat thermo-electric generation of fuel engines, by after a plurality of thermoelectric conversion element series/parallels, be fixed on the diesel exhaust gas tube passage, device hot junction one side is discharge duct, cold junction one side is heat exchanger [Kushch A.The effects of an exhaust thermoelectric generator of a GM sierra pickup truck[C] .2004DEER Conference Coronado, California, USA, 2004].
Japan Nissan motor corporation has developed the exhaust thermoelectric generator in research center, can reclaim 11% heat [Ikoma K, etal.Thermoelectric module and generator for gasoline engine vehicles, Proceedings of ICT, 1998,464~467].
U.S. Hi-Z company has carried out the research of diesel engine bogie exhaust heat thermo-electric generation under Ministry of Energy subsidizes, and has carried out stand and roadway experiment.Be arranged on the thermoelectric generator of diesel locomotive, vertical muffler of outer image.On blast pipe, by 72 HZ-14 modules, by circumferential arrangement, arrange, the cold junction water cooling, 250~270 ℃ of temperature difference have been formed, power [the Masahide M of 2000~4000W can be provided, et al.Thermoelectric generator utilizing automobile engine exhaust gas[J] .Thermal Science and Engineering, 2001,9:17~18].
The examples prove of thermo-electric generation, it is lightweight, volume is little, good reliability, and fail safe is good, the energy savings environmental protection.
In existing document, no matter be to use the thermo-electric generation of isotope as thermal source, or U.S. Hi-Z company, the exhaust thermoelectric generator technology of Japan Nissan motor corporation research center development all can't directly be used the frictional heat generating at the wheel tread of train, can't utilize this used heat energy, because, U.S. Hi-Z company, Japan Nissan motor corporation adopts heat transfer type, rather than utilize thermal-radiating power conversion mode, the heat energy that the wheel tread thermal radiation of train can't be used heat transfer type to make semiconductor thermoelectric generator obtain it is realized thermo-electric generation.
Summary of the invention
The objective of the invention is to overcome existing technical disadvantages, a kind of Railway wheelset tread thermal radiation thermal generator is provided.
According to document record, 20 tons to 22.5 tons, speed 130~160Km/h, 332.5~480 ℃ of railway train wheel tread temperature, the highest Contact Temperature is up to 1100 ℃ with 1030 ℃.The present invention utilizes the thermal effect of railway train wheel tread to realize thermo-electric generation by radiant heat transfer, this waste heat source is converted to electric energy and to Heavy-haul Freight train ECP (Electronically Controlled Pneumatic), provides power supply.
Railway wheelset tread thermal radiation thermal generator of the present invention is comprised of thermal radiation heated sheet, hot junction conductive graphite sheet, semiconductor thermoelectric generator, cold junction conductive graphite sheet, convector radiator, air channel and baffler.Described thermal radiation heated sheet is the right tread layout of wheel of train in opposite directions, and the thermal radiation of Railway wheelset tread is to thermal radiation heated sheet radiation heating, and the thermal radiation heated sheet forms high temperature.For the more effective hot junction to semiconductor thermoelectric generator of the high temperature of thermal radiation heated sheet, conduct heat, the thermal radiation heated sheet is close to by the hot junction of hot junction conductive graphite sheet and semiconductor thermoelectric generator.In like manner, for the cold junction of semiconductor thermoelectric generator obtains better cooling, the cold junction of semiconductor thermoelectric generator and convector radiator contact-making surface have good heat conduction, pass through cold junction conductive graphite sheet close contact between the cold junction of conductor thermoelectric generator and convector radiator, to improve heat transfer efficiency.The convector radiator radiating surface is placed in air channel, and duct shield is on convector radiator.For the air-flow that the train speed of travel is produced enters air channel and convector radiator heat convection, at wind passage mouth, baffler is installed, the baffler guide functions, the air-flow produced when train is walked imports in air channel.
In order to obtain larger radiation efficiency, the raying face of thermal radiation heated sheet is designed to many fins rectangular configuration.According to heat transfer theory, convection efficiency is directly proportional to heat exchange area, and heat exchange area is larger, and heat exchange efficiency is higher, in order to reach the increase heat exchange area, convector radiator stream interface is designed to the rib male structure.
Operation principle of the present invention and the course of work are as follows:
During train operation, take turns right tread and track friction and form high temperature, the thermal radiation heated sheet tread of Railway wheelset in opposite directions, in heating status, forms high temperature.The heat of thermal radiation heated sheet raying heat conducts heat to the hot junction of semiconductor thermoelectric generator by hot junction conductive graphite sheet, the hot-side temperature of semiconductor thermoelectric generator raises, the cold junction of semiconductor thermoelectric generator and cold junction conductive graphite sheet are close to installation, cold junction conductive graphite sheet is close to convector radiator and is installed, make it to conduct heat good, convector radiator is installed among air channel, and it is cooling that convector radiator enters the airflow convection in air channel from the baffler water conservancy diversion during by train operation.According to the document record, 332.5~480 ℃ of railway train wheel tread temperature, during with respect to train operation, the ambient temperature air-flow is 45 ℃, that is to say 45 ℃ of convection current coolant temperatures.As long as train is in running status, the air-flow produced from the speed of train walking keeps the cooling effect of convection current, and the hot junction of its semiconductor thermoelectric generator and cold-end temperature difference have reached 250 ℃~270 ℃ of the data of the diesel engine bogie exhaust heat thermo-electric generation of U.S. Hi-Z company.Document has been put down in writing U.S. Hi-Z company development temperature difference electricity generation device in 250 ℃~270 ℃ temperature ranges, can send the electrical power of 2000~4000W.
The present invention utilizes the thermal effect of railway train wheel tread to realize thermo-electric generation, this waste heat source is converted to electric energy and to Heavy-haul Freight train ECP, provides power supply, for the heavily loaded large conveying quantity freight traffic technique of the development of China provides Railway wheelset tread thermal radiation thermal generator, to promote " medium-term and long-term railway network development plan " to implement technical support, carry out the technology upgrading transformation process at existing 650,000 goods trains, the train self-supporting power has the very wide market demand, except bringing social benefit, itself also has considerable economic implications.
Embodiment
Further illustrate the present invention below in conjunction with the drawings and specific embodiments.
As shown in Figure 1 and Figure 2, Railway wheelset tread thermal radiation thermal generator of the present invention, comprise thermal radiation heated sheet 8, hot junction conductive graphite sheet 2, semiconductor thermoelectric generator 3, cold junction conductive graphite sheet 4, convector radiator 5, air channel 6, baffler 7.
Thermal radiation heated sheet 8 is taken turns in opposite directions 1 tread is installed, hot junction conductive graphite sheet 2 is close to the hot junction of semiconductor thermoelectric generator 3, semiconductor thermoelectric generator 3 cold junctions are close to cold junction conductive graphite sheet 4, convector radiator 5 is close to cold junction conductive graphite sheet 4, air channel 6 covers on convector radiator 5, and baffler 7 is arranged on the porch in air channel 6.
During train operation, wheel forms high temperature to 1 tread and track friction, and thermal radiation heated sheet 8 is taken turns the tread to 1 in opposite directions, in the thermal radiation state, forms high temperature.The heat of thermal radiation heated sheet 8 raying heat conducts heat to the hot junction of semiconductor thermoelectric generator 3 by hot junction conductive graphite sheet 2, the hot-side temperature of semiconductor thermoelectric generator 3 raises, it is cooling that the convector radiator 5 that the cold junction of semiconductor thermoelectric generator 3 and cold junction conductive graphite sheet 4 are close to enters the air-flow in air channel 6 from baffler 7 during by train operation, as long as train keeps running status, the hot junction of semiconductor thermoelectric generator 3, always in the thermal radiation state, the cold junction of semiconductor thermoelectric generator 3 is always in being subject to enter from baffler 7 the air-flow state of cooling in air channel 6, semiconductor thermoelectric generator 3 hot junctions and cold-end temperature difference are in persistent state, semiconductor thermoelectric generator 3 has also just kept lasting generating.
According to document, put down in writing, the railway train wheel tread temperature can reach 332.5~480 ℃, during with respect to train operation, the ambient temperature air-flow is 45 ℃, 45 ℃ of the cold junction convection current chilling temperatures of the hot junction radiation heating temperature of semiconductor thermoelectric generator 3 and semiconductor thermoelectric generator 3, hot junction, cold-end temperature difference reach 278.5~435.5 ℃.
As shown in Figure 3, in order to improve the thermal radiation area of thermal radiation heated sheet 8, the heating surface of thermal radiation heated sheet 8 is many fins rectangular configuration.
As shown in Figure 4, in order to improve convector radiator 5 heat convection areas, convector radiator 5 to stream interface, be the rib male structure.