Dual fuel forklift: the difference between electric forklift and liquefied gas forklift

Why use a dual fuel forklift?

　 The development of liquefied gas forklifts for the development of liquefied gas forklifts In the late 1960s and early 1970s, due to the shortage of international crude oil supply, major Western industrial countries had to find new energy alternatives to crude oil. Cleaner and more economical liquefied gas has been researched and developed at this time, becoming a new generation of vehicle fuels that replace gasoline and diesel. At the same time, forklifts using liquefied gas as fuel have also been developed accordingly. Developed countries and regions such as Europe and the United States have vigorously promoted the use of liquefied gas forklifts to meet the needs of carbon emissions, occupational health and efficient operation of enterprises. In recent years, liquefied gas forklifts have continued to expand their market share in developed countries such as Europe and the United States, and sales have surpassed the trend of diesel forklifts and electric forklifts.
Since the reform and opening up, with the vigorous development of China's processing industry in the Pearl River Delta and the Yangtze River Delta, forklifts have fully utilized their functions of moving goods in all walks of life. Foreign-funded and Sino-foreign joint ventures set up in mainland China still retain the habit of using liquefied gas forklifts abroad, thus driving sales of domestic LPG forklifts. The Chinese government has also begun to pay attention to the energy conservation and emission reduction of motor vehicles. The China Industrial Vehicle Association regards energy conservation and environmental protection as the development goals of the “Twelfth Five-Year Plan”. Economic, environmentally friendly and efficient liquefied gas forklifts are favored by more and more companies.
Why is the liquefied gas forklift a trend in the future development of the forklift industry? What are its advantages?

Compared with diesel forklifts ● Liquefied gas beats diesel with absolute advantage in fuel cost.
● Liquefied gas forklifts are suitable for indoor and outdoor use, and even work environments with particularly high environmental requirements.
● Unlike diesel fuel, there is no spillage of liquefied gas during vaporization, which effectively extends engine life.
● There is almost no harmful particle discharge during the operation of the liquefied gas forklift, thus ensuring the health of the workshop workers. The discharge of a large number of harmful particles in the exhaust of diesel forklifts seriously affects the health of workers' respiratory system.
● The engine of the liquefied gas forklift has a small vibration amplitude and low noise, which guarantees the workers' hearing.

Compared with electric forklifts ● Due to the high price of industrial electricity and battery purchase, the maintenance cost of electric forklifts is high, and liquefied gas forklifts can save the cost of use more than electric forklifts.
● Even in the case of insufficient fuel, the liquefied gas forklift can maintain power. The power of the electric forklift will decrease as the power is reduced.
● Liquefied gas forklifts can travel on uneven ground or steep slopes.
● The carbon emissions of liquefied gas forklifts throughout the product life cycle, that is, the “carbon footprint” is much smaller than that of electric forklifts.
● Liquefied gas forklifts are quick and easy to replace fuel, while electric forklifts require 8 hours of charging time and 8 hours of battery cooling time.
● The battery manufacturers of electric forklifts have seriously affected the local ecological environment and human health. There have been many “blood lead” incidents caused by illegal discharge of battery companies in China.
● Liquefied gas forklifts can work at temperatures as low as minus 20 degrees.

Gas forklift

In the process of making a liquefied gas forklift, in order to achieve reasonable use, the following points should be achieved. First of all, familiar with the relevant manuals for liquefied gas forklifts, and have a comprehensive understanding and understanding of the liquefied gas conversion system. During the use of the forklift, the forklift should not be parked near heat or fire sources, such as open flames, burning cigarette butts, and Mars. , welding, high-temperature machines and electrical equipment; can not automatically adjust or modify the liquefied gas conversion device; regular maintenance and inspection should be carried out on schedule; be vigilant, any leaks or abnormalities should be dealt with immediately.
2. To achieve a reasonable start: dual fuel, such as the use of liquefied gas, before work, should confirm whether the manual valve on the cylinder has been fully opened, the forklift should be closed when it is not in use, the manual valve should be closed; do not have to step on the throttle, dual fuel The system must rotate the switch to the position of the liquefied gas. After starting, especially in the cold zone, it is best to warm the car two or three minutes to let the cooling water system of the internal combustion engine warm up before driving to ensure that warm water can flow into the vaporizer to accelerate vaporization. .
3. Pay attention to the fuel switching method (single-fuel forklift does not need to be considered): For dual-fuel forklifts, when the forklift stops, it should not be switched during driving; when the gasoline is switched to liquefied gas, let the internal combustion engine continue to idle. At this time, the switch can be turned to the neutral position, so that the gasoline in the carburetor is burned out until the flame is extinguished, and then the fuel switch is turned to the position of the liquefied gas to restart; when the liquefied gas is converted to gasoline, it can be directly Rotate the diverter switch to the gasoline position without stopping at the neutral position. At this time, pay attention to pull out the cable. When the dual fuel system is mainly based on combustion gas, it is necessary to keep at least 1/4 of the fuel in the fuel tank for occasional time. Need. Occasionally, it is necessary to burn gasoline to ensure that the gasoline system does not malfunction due to idle time and prevent the oil pipeline from becoming brittle. It is recommended to burn 10 kg of gasoline per month.
4. Do the correct refueling: there are two ways to refill, one is to change the bottle; the other is to directly inflate on the forklift. When refilling or changing bottles, it must be outdoors, to ensure good ventilation, and safety should meet the requirements of local fire protection standards. The forklift must be stopped, turned off, and the driver leaves the driver's seat. Fireworks, heat sources and fire sources are strictly prohibited. Handle the cylinder carefully and do not hit, throw, or roll on the ground. The refueling personnel must be monitored throughout the process of refueling and must not leave the site. When inflating, put the air gun on the filling valve on the bottle and tighten it. At the same time, unscrew the 80% liquid level hole on the bottle and start to inflate. When there is white mist in the 80% liquid level hole, stop the filling immediately, tighten the 80% liquid level hole and check if the liquid level meter indicates the correct amount.

The difference between electric forklift and liquefied gas forklift

The liquefied gas engine belongs to the internal combustion engine. After burning the fuel, it converts the chemical energy in the fuel into the mechanical energy that drives the vehicle forward by pushing the piston in the cylinder to reciprocate. The battery forklift is in the form of chemical energy converted into mechanical energy. The most important difference between liquefied gas and battery is the difference in the ignition mode caused by the physical properties of the fuel, thus showing different thermal efficiencies and economics. The comparison is as follows:
1. Characteristics of battery forklift: The battery pack itself has a large weight; the acceleration and startability of the motor are poor, and the whole vehicle is subject to the design of the battery pack, which is not suitable for occasions with poor road conditions.
Standard 8-hour single-day fuel quantity: Assume that 80V520AH battery pack is used. The three-phase charger power input power is 8.9kVA, and the charging time is about 10 hours. It is estimated that each full power needs to consume 100 degrees, according to March 10, 2009. The price of 1.25 yuan / kW calculation, 125 yuan.
Sustainable working hours: According to the battery hours, it usually takes 10 hours to work for 8 hours, which means you can only work one day.
Post-purchasing cost: The battery group needs to be replaced every 3 years. The cost is about 28,000. It is calculated by international standard 1000 charge and discharge. The general extra cost is 35 yuan per day. In addition, the depreciation expense of the smart charger needs to be increased. 12 yuan a day.
Comparison of the cost of one-year work 250 days: 3 ton battery forklift, 80V520AH battery pack, charging time of about 10 hours, work 250 days calculation: 250 days * 125 yuan / day = 31250 yuan 2, liquefied gas forklift features: small size, weight Light, good startability, low price, high speed at maximum power; low vibration and noise.
The standard 8-hour single-day fuel quantity is equivalent to 5.15 liters per hour according to the calorific value, and is calculated as the price of 2.61 yuan/liter = 4.93 yuan/kg on March 10, 2009, which is 41 liters per day for 8 hours, about 107 yuan.
Sustainable working hours: Replacing liquefied gas cylinders for sustainable operation.
Later purchase cost: The gas system is generally attached to the engine. The user only needs to purchase a certain number of cylinders for liquefied gas vehicles according to the production conditions. The price of each market ranges from 150 to 200 yuan.
Comparison of the cost of 250 days a year: K25 engine works on a 3 ton forklift for 250 days: 250 days * 107 yuan / day = 26750 yuan.
Comparison of advantages and disadvantages:
1. Electric forklifts have short working hours and long charging time. Generally, they are not qualified for multi-shift work (of course, 2 to 4 battery groups can be considered to solve the problem); battery forklifts can only be used on roads with good working conditions. Acceleration and start-up are significantly worse than internal combustion engines; the most important thing is that the customer's site needs a good environment for charging and discharging in order to avoid battery explosion, and it needs to be replenished regularly, otherwise the battery life will be greatly reduced. In this way, the limitations of its use are compared, and the overall cost performance is not higher than that of a liquefied petroleum gas (LPG) forklift in some cases. However, if the user does not consider the time efficiency of charging and the user's site conditions are very good, the electric forklift is the first choice.
2. Liquefied gas forklift:
(1), emissions are good. Even the simplest open-loop system, the forklift has greatly reduced exhaust emissions. Compared with gasoline, the liquefied gas is reduced by 80%, HC is reduced by 75%, and NOx is also significantly reduced. positive effect.
(2) It is beneficial to improve the lubrication condition of the engine. Using liquefied gas as fuel, since the mixture entering the engine is a dry mixture, there is no such problem that the gasoline is not atomized when using gasoline, and the carbon is rarely burned, and the lubrication state is good to extend the use of the engine. More than double the life expectancy, but also extend the use of oil, reducing engine maintenance costs.
(3) Improve the working condition of the engine. Since the main component of the liquefied gas is propane, its antiknock performance is excellent, the octane number is above 120, the knocking phenomenon is not easy to occur, the noise of the engine can be significantly reduced, and the engine overhaul is greatly extended due to sufficient combustion without carbonization. Time can save 50-80% of maintenance funds.
(4), reduce fuel costs, calculate today's oil prices, about 1/2 of the daily savings in diesel costs, and with the country's fuel tax policy year after year, the economic benefits are very obvious.
(5), has a reliable security. Since the ignition point of the liquefied gas is higher than that of the gasoline, the latent heat of vaporization is large and has a self-cooling effect, thereby greatly increasing its safety. The cylinder has undergone physical test, hydraulic test, blast test, impact test, drop test, fire test, gun test, penetration test, operation test, and is equipped with an explosion-proof device to ensure safety.
(6) For the dual-fuel forklift, the working time of the forklift is doubled due to the backup of the two fuels. Conducive to the multi-shift work system of customers.