книги / Innovative power engineering

(NOTE t1: Ambient temperature; t2: Frozen chamber average temperature; t3: Evaporator surface temperature; t4: Compressor shell average temperature; t5: Compressor inlet average temperature; t6: Compressor outlet average temperature; t7: Box temperature after defrosting)

V.Benefit Analysis

A. Economic Benefit Analysis

According to the design and manufacture handbook of the refrigerators, the specification of each parts has been analyzed and calculated. The following Table 2. is the latest offer for the cost in the refrigeration equipment company website.

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Assuming the average power of defrosting is P0. The unit price of power is ™. The use time of refrigerator in one year is t0. Compared to the widely used heating defrosting, this device can save the power consumption. Consulting document and design handbook, the calculation process of this device is shown as follows:

The value of P0 is 0.216 kw·h. According to the current published price of the power system in China, the value of ™ is 0.58 yuan/kw·h. National Bureau of Statistics of the PRC in December 2014 statistics show that the national total number of refrigerator is 93.371 million that means n = 93371000.

As a result, the annual electricity fee can be saved by 4211.11 million yuan. (E0= n·P0·t0·™=93371000×0.216×360×0.58 • 4211.11million).

The device is based on the waste heat of compressor. Under this condition, the operating load of compressor and the temperature of the refrigerator shell are reduced, as a result, the service life of the refrigerator is extended.

B. Environmental Benefit Analysis

This device is driven by waste heat without external power source. Zero discharge for this device is realizable. The analysis and discussion of its environmental benefits are shown as follows:

1. Assuming the value of carbon dioxide emission in producing 1kw/h electric is ‘m’. Taking the average value of different kinds of power plants, the value of ‘m’ is 0.6kg/kw·h. Compared to the

traditional heating defrosting, the carbon dioxide emission reduction is about T=P0·m·t0• OJ A C š

2. The device for the recovery of compressor waste heat can reduce the temperature of the refrigerator shell and improve indoor living environment.

VI. Conclusion

On the basis analysis and discussion of the experimental results, the following conclusion can be made:

1. The defrosting refrigerator of such a structure is simple and flexible so that we can fix it on the original refrigerating system. The defrosting and energy-saving effects are impressive, and this device solves the problems that the temperature of the box might rise to such

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an extent after defrosting and the extra power consumption which caused by the process of defrosting. Compressor’s working condition has been improved after the device recovering the waste-heat of compressor.

2. The extensive household refrigerators are either without defrosting device, or with device in high energy consumption. This novel device will be in great demand on the market because of its low cost and low energy consumption. It will satisfy the consumers and be more widely accepted over counterparts. By changing the parameters of this device, it also can be applied to large frozen storages, for example, the outdoor unit of air conditioner, the automobile condenser, etc.

References

1.Qi Y., Zhang Y-J. A study for the power consumption measurement of defrosting refrigerators // Appliance Technology. – 2014. – Vol. 20. – P. 56–57.

2.A study for the large capacity air-cooled refrigerators frosting and defrosting experiment / Cheng Z-M. [et al.] // Appliance Technology. – 2009. – Vol. Z1. – P. 52–53.

3.Tang X-L. A study for the control technology of BCD-350W aircooled refrigerators // HeFei University of technology. – 2013.

4.Yu Y-Z. A study for the potential of reduction, governance efficiency, implementation way in China // China Industrial Economy. – 2011. – Vol. 5. – P. 58–68.

5.Tang X-D. A study for the air-cooled refrigerators feature and experiment of the rally of box temperature // Xi`an Jiaotong University learned journal. – 2014. – Vol. 11. – P. 81–85+108.

6.Evaluating the treatment of E-waste – a case study of discarded refrigerators // Journal of China University of Mining & Technology. – 2008. – Vol. 3. – P. 454–458.

7.Performance characteristics of an energy selective electron refrigerator with double resonances / Wang X-M [et al.] // Chinese Physics B. – 2009. – Vol. 03. – P. 984–991.

8.Mei B-J. A device for defrosting refrigerator // An`hui: CN102564014A. – 2012. – Vol. 07–11.

9.Lu J-Q. Through changing the wettability to improve the anti-freezing feature of the solid surface // Zhe`Jiang University of technology. – 2012.

10.A device for defrosting refrigerator / J. T-H [et al.] // Tian`jin: CN1474143. – 2004. – Vol. 02–11.

11.Practical design hand book for refrigeration engineering / Guo Q-T [et al.] // China construction industry press. – 1994.

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POWER RESOURCE SAVING TECHNOLOGIES

CAVITATION OPTIONS FOR WASTE AUTOCLAVE

TECHNOLOGY FOR POWER GENERATION

A.S. Kudryavtsev

Currently, one of the most promising areas of recycling is the

Fig. 1. The landfill

On dumps of our planet we already have millions tons of waste.

One percent efficiency of waste treatment means billions MW additional energy capacity

Autoclave technology is the mass in garbage handling autoclave at

pressures of from 4 to 7 bar of superheated steam at a temperature of 120 to 200 ° .

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In the most basic applications as the primary treatment vessel is used the horizontal rotating autoclaves combined with some debris grinder. In the processing of plastic bottles pulverization occurs, packets, boxes, etc. and their partial softening and melting. Organic wastes decompose into cellulose, lignin and other fractions, wherein the cellulose content after autoclaving is 50 %.

The main element of autoclave technology is horizontal rotating autoclave. Our project based on autoclaves GV-2,0 of Degtyarsk Plant (DMZ).

Fig. 2. Autoclave GV-2,0

Here we have introduced an additional option of cavitation by acting on the mass of treated garbage inside autoclave electric field and ultrasound influence.

Fig. 3. Electric field and ultrasound influence

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Then autoclave begin to rotate high frequency voltage inside autoclave begin to charge cellulose particles.

Steam and high frequency voltage together begin cavitation process.

These particles is a initiator of cavitation processes.

Fig. 4. Cavitation processes

Cavitation creates micro bubbles. Then bubbles begin to collapse with high energy discharging and extremely high velocity. A lot of collapsing bubbles begin to destroy rubbish particles. As a result cellulose, plastic and metal particles became smaller and smaller.

Fig. 5. The conveyor

Air jet takes the top part of the mass that consists from organic, out of the conveyor.

High quality of secondary cellulose produced by cavitation treatment provide more than 0,5 kWh electrical energy per 1 kg of MSW.

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A NOVEL ENERGY-SAVING INTELLIGENT CONTROL SYSTEM FOR DIESEL ENGINE STARTING

Ming-Jia Li, Zheng-Tao Hu, Hui-Dong Tian

Shaanxi Province, P.R. China

With rapid economic growth and technology evolution, diesel engines, as power engines with high energy efficiency, are widely adopted in many fields such as transportation, engineering machinery, agricultural machinery etc. However, it has been agreed that the following issues are eager to be solved for diesel engines, especially high-power diesel engine systems, including the difficulty of selfstarting, the huge weight of the starting system and the high consumption of starting battery, the low reliability of the starting system, the high failure rate and the large emission.

In order to overcome these difficulties, efforts have been made from the point of view of increasing the power of starting system. Although problems could be solved in some extent via this method, it leads many other questions. First, the cost becomes higher because the starting system has higher power and the storage battery has greater capacity. Second, the heavier system leads to higher energy consumption and machinery abrasion rate, reduces the life of the engine. Furthermore, this method will lead to more assumption of heavy metals (copper, lead, etc.) and sulfuric acid, which will increase the cost. The production, utilization and recycle of the heavy metals and sulfuric acid also impose a severe nuisance to environment and public health. In addition, problem emerges in the starting oil supply. Finally, the oil at the early stage of starting cannot be fired, it leads the oil consumption and emission increase. The oil will dilute the engine oil and harm the lubrication system either.

Aiming at these problems, we propose a novel approach in the other direction, which is to decrease the starting load of diesel engines. By decreasing the resistance of compressed air intelligently, the performance of starting engine is greatly improved. The energy-saving

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intelligent control system for diesel engine starting is produced, which consists of 4 parts: starting switch, intelligent controller, valve control mechanism and oil supply solenoid valve. The principles are as bellows. The intelligent controller controls the valve control mechanism and the open and off of the intake valve is controlled when the engine starts. At the early stage of starting, the intake valve is open. The resistance of compressed air decreases and rotation speed of crankshaft increases rapidly. The starting load of diesel engine is reduced and the starting performance is improved. The injection of diesel oil is off at the early stage to reduce the oil consumption and exhaust emission. After that, the intake valve will get back to normal operating condition when the rotation speed of crankshaft reaches starting speed. Then, the injection of diesel oil will accomplish starting.

Fig. Energy-saving inteligent starting control system

There are following four experiments were carried out for this novel energy-saving control system: the functional experiment, lowtemperature starting experiment, low-capacity battery experiment, tolerance evaluation of the pressure-relief push rod and abrasion test of main components. Experiments proved that the proposed system was advanced and reliable, and it had the following advantages: 1) saving energy by reduce 67.4 % energy consumption and 82.5 % oil consumption in the starting stage; 2) slowing down the abrasion and

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expanding the safe life of diesel engine by more than 1 time; 3) reducing the battery capacity from 120Ah to 60Ah, reducing lead consumption by 6.7kg and sulfuric acid consumption by 425kg; 4) achieving low-temperature starting and starting the engine in –25 ° environment without heating; 5) highly reliability, operating 35,000 times without breakdown and reaching the national standards of China.

The proposed novel energy-saving intelligent control system has promising practical applications and economic value. It does not change the structure of the diesel engines and can be installed directly. It has simple structure and low cost (100RMB per system when installed on the Dongfeng 6105 diesel engine). The manual pressurerelief is changed to be automatic one, which is more convenient for utilization. The widely focused “separate cylinder oil-saving technology” and “vehicle automatic start stop system” problems are solved by the control of the valves. Based on the 60,000,000 diesel engine ownership in China, this product can reduce lead consumption by 400,000 tons and sulfuric acid consumption by 26 tons every year. About 3,310,000 tons of oil consumptions can be reduced as well as the environment pollution caused by the emissions. It can expand the life of the engines, reduce the expenses of production and maintenance, and achieve energy-saving and emission reduction.

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THE ELECTRICITY GENERATION SYSTEM

BASED ON PIEZOELECTRIC CERAMIC APPLYING

ON ROAD DECELERATION STRIP

Shi Rui, Huang Lixiao, Yang Chenxiao

Southeast University

Nowadays, using the road deceleration strips to announce vehicles to decrease its speed are very common. Due to the decrease of the speed, we can find that the road with deceleration strips usually has more traffic. Moreover, according to our research, we found that a normal sedan owes a weight of 1 to 2 tons. By effectively using the high speed and great weight of the motor vehicle, we can convert the unwanted kinetic energy into useful electricity through out electricity generation system. In this system, we use piezoelectric ceramic as main material to produce energy. The piezoelectric ceramic has the ability to exchange deformation into electricity and the bigger the pressure and deformation, the more energy the material could produce, which perfectly match the specialties of the road deceleration strips. When the vehicle passes through the strip, the strip will deliver the pressure and deformation to the piezoelectric ceramics which are installed inside the strips. After that, the energy collecting circuits will store the electricity to the accumulator in high efficiency. Moreover, this system also can be used in different situation such as the subway rail ,which also works by using the high weight and velocity. This system successfully achieved the target of converting the wasted energy to useful electricity, so that this design perfectly match with the aim of this competition.

Keywords: piezoelectric patches, electricity generation, Road Deceleration Strip, pressure, energy collecting circuit

1. The Background and Significant of the Design

The Background of the Piezoelectric Effect

The piezoelectric effect is understood as the linear electromechanical interaction between the mechanical and the electrical state in crystalline materials with no inversion symmetry. The piezoelectric effect is a reversible process in that materials exhibiting the direct piezoelectric effect (the internal generation of electrical charge resulting from an applied mechanical force) also exhibit the reverse piezoelectric effect (the internal generation of a mechanical strain resulting from an applied electrical field). For example, lead zirconate titanate crystals will generate measurable piezoelectricity when their

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