NAME HUSSNAIN AHMAD
SAP ID 70135185
ASSIGNMENT #01
THERMODYNAMICS-2
TITLE:IN THE PAST PAKISTAIN HAS UTILIZED LPG AND CNG VIGOROUSLY FOR
ENGINES THAT WERE DESIGNED FOR GASOLINE WAS THAT DECISION BEING
RIGHT OR WRONG EXPLAIN AND JUSTIFY YOUR ANSWER WEATHER YOU
CHOOSE IN FAVOUR OF DESCION OR AGINAST. IN CASE YOU CHOOSE THAT THIS
DESCION WAS WRONG THAN GIVE THE BASICS DESIGN AND PARAMETER FOR
NEW ENGINES DESIGN THAT CAN USE LPG AND CNG. IN MARKET YOU HAVE
BUSSES WITH ENGINES THAT ARE SPECIFED FOR CNG. WHAT IS THE
DIFFERENCE BETWEEN.
Introduction
1. Background of Fuel Use in Pakistan
2. Advantages of Utilizing LPG and CNG
3. Environmental Benefits
4. Economic Factors
5. Energy Security
6. Infrastructure Development
7. Disadvantages of Utilizing LPG and CNG
8. Engine Compatibility Issues
9. Performance Limitations
10. Safety Concerns
11. Maintenance and Operational Challenges
12. Evaluation of the Decision: Right or Wrong?
13. Proposed Design Parameters for New LPG and CNG Engines
14. Compression Ratio
15. Fuel Delivery System
16. Ignition System
17. Cooling System
18. Material Selection
19. Safety Systems
20. Exhaust Management
21. Control Systems
22. Tuning and Calibration
23. Regulatory Compliance
24. Differences in Buses with CNG-Specific Engines
25. Fuel System Differences
26. Engine Calibration
27. Power Output Variations
28. Maintenance Requirements
29. Performance Characteristics
30. Conclusion
31. References
1. Introduction
In the last few decades, Pakistan has made considerable efforts to overcome energy shortfalls
and environmental issues through the use of bio-fuels, particularly liquefied petroleum gas
(LPG) and compressed natural gas (CNG). Two key factors drove this shift; the need to cut
the imported fuel dependency and contribute to the reduction of air pollution in cities. But the
adoption of these gaseous fuels in engines built primarily for gasoline usage begs the question
of whether such an approach.
This study turns to factors which contributed to the making of this decision in order to be able
to decide whether it was a good decision or not. At the same time, the paper will give guides
setting new tenders for engines which will be constructed for LPG and CNG use, which will
cover the loopholes of current vehicles. Lastly, it will specify whether the buses were CNG
based designs or if they were modified from gasoline engine buses.
2. Use of Fuel in Pakistan
Pakistan’s energy sector can be said to have relied on oil and gas since time immemorial.
Rising oil prices as well as the implications of such oil prices for the environment saw the
government in the early 2000s trying to encourage the use of other fuels such as LPG and
CNG. There was quite an aggressive off-take for CNG which was well supported with
investment into CNG filling stations and other related infrastructure. As a result, millions of
vehicles were converted to run on CNG, significantly altering the transportation sector.
However, questions arose on the effectiveness and efficiency of these vehicles and their
safety especially for CNG vehicles that had not been specially designed to use gas. This
analysis sets out to handle these matters in the respective sections.
3. LPG and CNG Benefits
Environmental Considerations
Transition to LPG and CNG technologies was fuelled with expected reduction in pollution.
Emissions from CNG and LPG are much more environmentally friendly than those from
gasoline.
Less CO2 Emission: Emission of carbon gases from both CNG, and LPG is less thus
assisting in the overall reduction of gasses that lead to climatic changes.
Reduced NOx and Particulate Matter: The combustion of these gaseous fuels results in fewer
nitrous oxides and particulate matter which are important role players in city smog.
The negative effects of these factors should be more apparent in those highly populated areas
of the city where the quality of air is a public health issue.
Economic Factors
Benefits in the adoption of CNG and LPG will include:
Low Operational Fuel Cost: For many consumers, the price of CNG has been cheaper than
gasoline making the option of using it for daily commuting and mass transport very viable.
Subsidies: Government interventions provided for the building of the CNG infrastructure as
well as conversion to CNG further move to encourage the adoption.
These factors have explained the increasing levels of the use of vehicles powered by CNG
especially public and taxi cabs.
Energy Security Policy The strategic utilization of the available local natural gas reserves
for CNG adds an additional layer of energy security. Decreasing Vulnerability to Imports:
Through the use of indigenous feedstock, as in the case of Pakistan, there is no requirement
for imported crude oil that is subject to world inflation.
Development of National CNG Depot: Creation of the CNG infrastructure will boost the
CNG market and ensure proper allocation of indigenous resources that will be beneficial for
CNG resource utilization.
Infrastructure Development LPG and CNG replacement led to considerable infrastructure
expansion: Creation of CNG Filling Stations: The CNG filling stations network setting up
created jobs in and around the CNG stations as well as stimulated the CNG industry in locally
owned businesses. Maintenance Facilities: The requirement for specialized maintenance and
repair for the CNG vehicles created the momentum of skill development in the working
population.
Energy Security The enhancement of energy security comes from the strategic employment
of domestic natural gas reserves towards CNG usage: And furthermore, the useful decreased
reliance on imports would be made possible either through: Locally sourced fuels are what
Pakistan uses hence diminishing the need for imported oils which are always volatile in the
world market.
Utilization of Local Resources: When developing the CNG infrastructure, it opens up the
local economy assisting in the better use of the resources available in the country.
Infrastructure Development The trends towards LPG and CNG encouraged infrastructural
improvements: CNG Filling Stations: The establishment of a comprehensive network of
CNG stations allowed for the creation of employment opportunities and stimulated the
development of local enterprises.
Maintenance Facilities: The increased demand for specialist maintenance and repair
services for CNG vehicles was met with development activities in the skill level of the
workforce.
comparing whether or not the decision to make use of LPG and
CNG become proper or wrong includes weighing the blessings in opposition to the
drawbacks.
Arguments against the decision
Given the sizeable challenges associated with engine compatibility, overall
performance obstacles, and protection concerns, one could argue that
the selection became incorrect. The initial enthusiasm for CNG and
LPG regularly overshadowed the complexities involved in changing present motors and
the ability dangers to public safety.
Arguments in choose of the choice
Conversely, the environmental advantages, economic incentives,
and energy protection furnished by means of CNG and LPG can not be unnoticed.
The discount in city air pollution and the establishment of a strong CNG infrastructure have
had lasting nice affects on the transportation quarter.
Design parameters proposed for new LPG and CNG engines To address the shortcomings of
existing vehicles, new engine designs should be developed specifically for LPG and CNG.
The following design parameters should be preferred: Compression ratio Higher compression
ratio: Design engines with a compression ratio between 12:1 and 15:1 to optimize
performance for CNG and LPG and take advantage of their higher-octane rating. Fuel
delivery system Dedicated Fuel Injection: Implement a fuel delivery system optimized for
gaseous fuels to ensure precise air-fuel mixtures and increase combustion efficiency.
Ignition system Advanced Ignition Technology: Use high-energy ignition systems capable
of delivering more sparks to improve ignition timing and reliability, especially under varying
loads.
Cooling system Improved cooling performance: Design cooling systems to accommodate
the unique thermal characteristics of gaseous fuels, preventing overheating and ensuring
optimal engine temperatures.
Material selection Durable components: Choose materials resistant to the corrosion of
gaseous fuels and capable of withstanding higher combustion pressures, extending engine
life.
Security systems Integrated safety features: Incorporate advanced safety systems,
including leak detection, pressure regulation and emergency shut-off valves, to mitigate risks
associated with gaseous fuels.
Exhaust control Optimized Emissions Control: Equip engines with catalytic converters
and exhaust aftertreatment systems designed to effectively control emissions from CNG and
LPG combustion.
Control systems Engine Management Systems: Develop sophisticated electronic control
units (ECUs) that can dynamically adjust engine parameters based on fuel type and operating
conditions for optimal performance.
Tuning and calibration Specific calibration: Ensure engines can be easily tuned and
calibrated for CNG, LPG and petrol, providing flexibility for different fuel types.
Compliance with regulations Compliance: Design engines to meet local and international
emissions and safety regulations, enabling smoother market adoption.
Differences in buses with CNG engines Buses specially designed for CNG differ from
buses converted from gasoline engines in several ways: Differences in the fuel system
CNG storage and delivery: CNG buses use high-pressure tanks and specialized piping
systems designed for gaseous fuels, which are different from traditional gasoline fuel
systems.
Engine calibration CNG Optimized Performance: CNG engines are calibrated to
maximize natural gas performance, affecting ignition timing and air-fuel ratios for better
combustion efficiency.
Fluctuations in output power Engine performance characteristics: CNG-specific engines
can have different torque and power curves, which affects overall performance, especially
under load. Maintenance requirements Specialized maintenance protocols
