Featured Research

from universities, journals, and other organizations

Saving Gas: Pneumatic Hybrid Engine Is Much Cheaper Than Electric Hybrids And Almost As Economical

Date:
February 4, 2009
Source:
ETH Zurich
Summary:
A pneumatic hybrid engine could be used to power vehicles in the future. The benefit of this technology: it is much cheaper than today's electric hybrids and almost just as economical.

Physics laboratory technician Till Coester works on the new hybrid engine being checked thoroughly on the test stand.
Credit: Photo: P. Rόegg / ETH Zurich

A pneumatic hybrid engine could be used to power vehicles in the future. The benefit of this technology: it is much cheaper than today’s electric hybrids and almost just as economical.

The Japanese automobile manufacturer Toyota has built a car, the “Prius”, which is seen as a concept for the future. It uses an electric hybrid engine to save fuel while still offering the usual drivability standards. However, this vehicle has a serious disadvantage. It is expensive and is unaffordable especially for consumers in up-and-coming countries such as China and India that are increasing rapidly their mobility demands. In addition, the battery needed by the electric hybrid as an energy storage device is heavy and expensive. Last but not least, the technology in the coupling between the gasoline engine and the electric drive is very complicated.

Simpler and cheaper

This is why Lino Guzzella, Professor of Thermotronics, does not think the electric hybrid is the only solution. As an experienced engineer, he therefore looked for an approach that was simpler than an electric hybrid but remained affordable even for people with less purchasing power. Guzzella explains that “The apple must be ripe but still hang just low enough to stay within reach.” The 'fruit' ripening in his group is the pneumatic hybrid drive. The concept is simpler than that of an electric hybrid: the new hybrid engine has a compressed air tank connected to the engine instead of a battery unit. When required, e.g. when starting from rest or after changing gear, compressed air flows into the engine through an electronically controlled valve. If fuel is also injected, the engine responds quickly. Although the system used to control the valve is also technologically complex, this challenge can be mastered nowadays thanks to powerful algorithms and computer systems.

The compressed air supply also allows the engine constructors led by Lino Guzzella to achieve extreme downsizing. Conventional car engines can have peak powers of 150 hp or more, but usually need no more than 30 hp for everyday driving. Downsizing the engine halves the number of cylinders from four to two. This also halves frictional losses and increases the engine’s average efficiency. To keep the maximum power and thus satisfy the consumer’s drivability demands, the engine is highly supercharged by a turbocharger – which exploits the exhaust gas enthalpy as an energy source, and which boosts the to the desired levels..

Efficiency up by a third

Initial tests on the test stand in the ETH Zurich Machinery Laboratory show that Guzzella and his group are on the right track. They were able to increase the engine’s average efficiency in the European Test Cycle from 18 to 24 percent. This corresponds to a fuel saving of one third. Energy savings of up to 50 percent are achievable in purely urban traffic, because the engine can pump air into the compressed air tank during braking, thus recovering the kinetic energy.

Although the fuel saving achieved by the pneumatic hybrid is not as large as that of an electric hybrid, it still amounts to 80 percent of the latter. In return, the price-performance ratio is distinctly better. So good, in fact, that Guzzella can imagine the pneumatic hybrid also being suitable for use in poorer countries. He estimates the additional costs compared to a conventional gasoline engine to be approximately 20 percent. On the other hand, the additional costs for an electric hybrid are calculated to be at least 200 percent.

Motor manufacturers interested

The new engine concept has aroused the interest of several major motor companies and automitive suppliers, who have obtained information on-site. Some of the ideas of the new concept have already been patented. Only the financial crisis and the global recession worry Guzzella slightly. He says that these are difficult times in which to launch a new drive concept. Nevertheless, he is convinced that he will find people interested in adopting this system, since no other technology is on the horizon that could replace the internal combustion engine, even in the next two decades. This is why the way leads via hybrid concepts, which remain affordable while retaining the advantages of a gasoline or diesel engine.


Story Source:

The above story is based on materials provided by ETH Zurich. Note: Materials may be edited for content and length.


Journal Reference:

  1. Dφnitz et al. Realizing a concept for high efficiency and excellent driveability: The downsized and supercharged hybrid pneumatic engine. Soc. of Automotive Engineers, April 2009

Cite This Page:

ETH Zurich. "Saving Gas: Pneumatic Hybrid Engine Is Much Cheaper Than Electric Hybrids And Almost As Economical." ScienceDaily. ScienceDaily, 4 February 2009. <www.sciencedaily.com/releases/2009/01/090131113216.htm>.
ETH Zurich. (2009, February 4). Saving Gas: Pneumatic Hybrid Engine Is Much Cheaper Than Electric Hybrids And Almost As Economical. ScienceDaily. Retrieved July 31, 2014 from www.sciencedaily.com/releases/2009/01/090131113216.htm
ETH Zurich. "Saving Gas: Pneumatic Hybrid Engine Is Much Cheaper Than Electric Hybrids And Almost As Economical." ScienceDaily. www.sciencedaily.com/releases/2009/01/090131113216.htm (accessed July 31, 2014).

Share This




More Matter & Energy News

Thursday, July 31, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Britain Testing Driverless Cars on Roadways

Britain Testing Driverless Cars on Roadways

AP (July 30, 2014) — British officials said on Wednesday that driverless cars will be tested on roads in as many as three cities in a trial program set to begin in January. Officials said the tests will last up to three years. (July 30) Video provided by AP
Powered by NewsLook.com
Amid Drought, UCLA Sees Only Water

Amid Drought, UCLA Sees Only Water

AP (July 30, 2014) — A ruptured 93-year-old water main left the UCLA campus awash in 8 million gallons of water in the middle of California's worst drought in decades. (July 30) Video provided by AP
Powered by NewsLook.com
Smartphone Powered Paper Plane Debuts at Airshow

Smartphone Powered Paper Plane Debuts at Airshow

AP (July 30, 2014) — Smartphone powered paper airplane that was popular on crowdfunding website KickStarter makes its debut at Wisconsin airshow (July 30) Video provided by AP
Powered by NewsLook.com
U.K. To Allow Driverless Cars On Public Roads

U.K. To Allow Driverless Cars On Public Roads

Newsy (July 30, 2014) — Driverless cars could soon become a staple on U.K. city streets, as they're set to be introduced to a few cities in 2015. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



    Save/Print:
    Share:  

    Free Subscriptions


    Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

    Get Social & Mobile


    Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

    Have Feedback?


    Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
    Mobile iPhone Android Web
    Follow Facebook Twitter Google+
    Subscribe RSS Feeds Email Newsletters
    Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins