What is Bulk Email: Definition, Examples, Tips

A bulk email could be a selling message sent by a whole to multiple recipients right away. It aims to market a business, sell goods, and develop relationships. when registering with SendPulse, you'll be able to send bulk emails for completely free.

Contents

Types of Bulk Emails

What is a bulk email service?

How to Send Bulk Emails for complimentary

How to Send Bulk Emails while not Spamming and obtaining Blacklisted

Bulk Email Examples

Bulk Email Best Practices

References

Today, marketers choose to use bulk email services to deliver necessary messages with marginal effort. in contrast to junk emails sent while not the recipients’ permission, bulk emails square measure legal selling campaigns since the recipients take receive them. However, if bulk email selling isn't properly managed, users could think about it spam, and consequently, it should hurt sender name. once making and causation bulk email campaigns, keep in mind to stick to the CAN-SPAM Act to avoid penalties and losses to your business.

Types of Bulk Emails

Newsletters

Promotional emails

Acquisition emails

Retention emails

Newsletters. A news report is a wonderful approach of keeping subscribers within the loop regarding what’s occurring with a business. In most cases, newsletters offer insights, notifications, or guides to customers during a bid to assist them higher perceive a specific service or product.

Promotional emails. Bulk emails square measure effective at promoting sales, attracting customers with offers and deals, and building whole awareness. These emails can even be wont to recommend acceptable merchandise to existing and prospective customers.

Acquisition emails. These square measure messages sent to amass new customers, directed at prospects on an inventory UN agency have nevertheless to convert. they'll be wont to share special offers to convert potential customers to create a procurement.

Retention emails. These mass emails square measure typically sent to existing shoppers to encourage them to stay getting from your company. They aim to spice up a brand’s client loyalty.

LUBRICATION 

Frictional forces causes wear and tear of rubbing parts of the engine and thereby the life of the engine is reduced. This requires that some substance should be introduced between the rubbing surfaces in order to decrease the frictional force between them. Such substance is called lubricant. The lubricant forms a thin film between the rubbing surfaces and prevents metal to metal contact. The various parts of an I.C. engine requiring lubrication are cylinder walls and pistons, big end bearing and crank pins small end bearing and gudgeon pins, main bearing cams and bearing valve tappet and guides and timing gears etc. The functions of a lubricant are as follows

• It reduces wear and tear of various moving parts by minimizing the force of friction and ensures smooth running of parts. 

• It helps the piston ring to seal the gases in the cylinder. 

• It removes the heat generated due to friction and keeps the parts cool. 

The various lubricants used in engines are of three types: 

1. Liquid Lubricants. 

2. Solid Lubricants. 

3. Semi-solid Lubricants. 

Liquid oils lubricants are most commonly used. Liquid lubricants are of two types: 

(a) Mineral Oils 

(b) Fatty oils. 

Graphite, while lead and mica are the solid lubricants. Semi solid lubricants or greases as they are often called are made from mineral oils and fatty oils. 

A Rood lubricant should possess the following properties: 

• It should not change its state with change in temperature. 

• It should maintain continuous films between the rubbing surfaces. 

• It should have high specific heat so that it can remove maximum amount of heat. 

• It should be free from corrosive acids. 

The lubricant should be purified before it enters the engine. It should be free from dust, moisture, metallic chips, etc. The lubricating oil consumed is nearly 1% of fuel consumption. The lubricating oil gets heated because of friction of moving parts and should be cooled before recirculation. The cooling water used in the engine may be used for cooling the lubricant. Nearly 2.5% of heat of fuel is dissipated as heat which is removed by the Lubrication oil. 

Lubricating oil is purified by following four methods: 

1. Settling, 

2. Centrifuging, 

3. Filtering,

4. Chemical reclaiming. 

The centrifuging widely used gives excellent purification when properly done. 

The figure shows the lubricating oil external circuit. 

ENGINE STARTING METHODS 

Spark ignition engines are used mainly in smaller size where compression ratio to be our come in cranking is only 5 to 7. Hand and electric motor (6 - 12 V, DC) cranking are practical. Diesel engines are difficult to be started by hand cranking because of high compression required and therefore mechanical cranking system is used. 

The various methods used for the starting of diesel engine are as follows: 

Compressed Air System: Compressed air system is used to start large diesel engines. In this system compressed air at a pressure of about 20 kg per sq. cm is supplied from an air bottle the engine an inlet valve through the distributor or through inlet manifold. 

Electric Starting: Electric starting arrangement consists of an electric motor which a drives pinion which engages a toothed 11 on engine flywheel. Electric power supply for the motor is made available by a small electric generator driven from the engine in case of small plants a storage battery of 12 to 36 volts is used to supply power to the electric motor. 

The electric motor disengages automatically after the engine has started. The advantages of electric starting are its simplicity and effectiveness. 

Starting by an Auxiliary Engine: In this method a small petrol engine is connected to the main engine through clutch and gear arrangements. Firstly, the clutch is disengaged and petrol engine is started by hand. Then clutch is gradually engaged and the main engine is cranked for starting. Automatic disengagement of clutch takes place after the main engine has started.

STARTING PROCEDURE 

Actual process of starting the engine differs from engine to engine. Some common steps for starting the engine are as follows:

• Before starting the engine it is desirable to check fuel system, lubricating system and cooling water supply. 

• Depending upon the method of starting a check for the same is essential. If air starting is used the pressure of air should be checked and also the air system should be checked for possible leakage. The storage battery should be checked if electric motor is used for starting. 

• There should be no load on the engine. 

• Crank the engine and run it at slow speed for a few minutes and again check the working of various systems such as fuel, lubricating oil system etc.

The speed of the engine should be gradually increased till it synchronizes with the bus bars. Then connect the generator to the bus and finally increase the engine speed so that it takes up desired load. 

STOPPING THE ENGINE 

The engine should not be stopped abruptly. Top stop the engine the speed should be decreased gradually until no power is delivered by the alternator. Then the engine is disconnected from the bus bars and is allowed to run idle for some time. 

STARTING AIDS 

Starting aids may be used during cold weather to obtain quicker starting of the engine. Ethyl ether is mostly used as such aid. Glow plugs another starting aid. Glow plug forms a local hot spot thus imitating the combustion of fuel even if the compression temperature of air in sufficient. 

FUEL SUPPLY 

The fuels used in I.C. engines are in liquid form. They HIP preferred because of their high calorific value and case of storage and handling. The storage of oil fuel is simpler than the solid I n. I the amount of fuel to be stored depends upon the service hour’s unit vary for different installations. Bulk storage and engine day I hold the engine fuel. The fuel delivered to the power plant is received in storage tanks. Pumps draw the oil from storage tanks and supply it is the smaller day tanks from where the oil is supplied to the engine as shown in figure. 

The fuel oil used should be free from impurities. Efforts should he made to prevent contamination of the fuel. An important step is to reduce the number of times the fuel is handled. Greater amount OF impurities settle down in the storage tank and remaining impurities are removed by passing the oil through filters. Storage tank may be located above the ground or underground. But underground storage tanks are preferred. It is provided with coils, heated by steam or hot water to reduce for viscosity and to lower the pumping cost. Main hole is provided FIN internal access and repair. Vent pipe is provided to allow the tank to breathe as it is filled or emptied. Level indicator measures the quantity of oil in the tank, and an overflow line is provided to control the quantity of oil. 

A generating station during which high speed diesel (HSD) is employed as fuel and diesel is employed because the first cause for the generation of electricity is understood as High Speed Diesel (HSD) power station . High speed diesel power station is suitable for little and medium outputs. it's used as central power plant for smaller power supplies and as a standby plant to hydro-electric power plants and steam power plants. The diesel power plants are commonly used where fuel prices or reliability of supply favors oil over coal, where water system is restricted , where loads are relatively small, and where electric line service is unavailable or is out there at too high rates. High speed diesel power plants in common use have capacities up to about 5 MW. This is one quite Diesel power station but there's used smaller engine than diesel power station .

APPLICATIONS OF HSD power station

1. They are quite suitable for mobile power generation and are widely utilized in transportation systems consisting of rail roads, ships, automobiles and aero planes.

2. They can be used for little electric power generation in capacities.

3. They can be used as standby power plants.

4. They can be used as peak load plants for a few other sorts of power plants.

5. Industrial concerns where power requirement are small.

6. HSD power plants become more economical thanks to their higher overall efficiency.

HSD POWER PLANTS IN BANGLADESH

There are two methods of cooling the I.C. Engines. 

1. Air cooling 

2. Water cooling. 

Air Cooling: It is a direct method of cooling. In air cooled engine fins are cast on the cylinder head and cylinder barrel to increase its exposed surface of contact with air. Air passes over fins and carried away heat, with it. Air for cooling the fins may be lined from a blower or fan driven by the engine. Air moment relative to engine may be used to cool the engine as in case of motor cycle’s engine. About 13 to 15% of heat is lost by this method. It own air cooling system. Simplicity and lightness are the ad shows not as effective as water cooling. The rate of cooling depends upon the velocity, quantity and temperature of cooling air and size of surface being cooled. 

The position of valves, Fins and head in air cooling system. This system is used in motor cycles, scooters and aero plans. 

Water Cooling: It is the indirect method of cooling the engine The various cooling systems used are shown in below figure. Water after circulating in water jackets (passages around the cylinder, combustion chamber valves etc.) goes as waste or in recirculation method of cooling water is continuously circulated through water jackets. Water takes up the heat and leaves for radiator where it is cooled for recirculation.  

In stationary diesel engine plants the water cooling systems are as follows: 

1. Open or Single Circuit System:  In this system pump draws the water from cooling pond and forces it into the main engine jackets. Water after circulating through the engine return to the cooling pond. 

2. Closed or Double Circuit System: In this system raw water is made to flow through the heat exchanger when it takes up the heat of jacket water and returns back to the cooling pond. 

Heat lost by water cooling is about 25 to 35%. The amount of heat lost is called jacket loss. The rate of flow of water should be so adjusted that the outlet temperature of cooling water does not exceed 60’c and rise in temperature of cooling water is limited to 11’c the water used for cooling purposes should be free from impurities. Water cooling methods permit uniform cooling. Water cooling creates troubles in very cold weather. Cooling efficiency is reduced due to scaling in the pipes, jackets and radiator. Engine efficiency affected by power needed to drive the water pump and radiator fan. 

Closed system of cooling is mostly used in power stations. A closed cooling system comprises the following equipment. 

1. A surge tank. 

2. Soft water circulating pump. 

3. Soft water circulation pipe. 

3. Soft water heat exchanger or cooler. 

4. Raw water softening plant. 

5. Raw water circulation pump. 

6. Raw water circulation pipe. 

7. Raw water cooling arrangement such as cooling tower. 

8. Thermometer for measuring inlet and outlet temperatures. 

9. Temperature regulator to control the Excessive jacket temperature. 

10. Safety device to control the excessive jacket temperature. 

This system shown is in use soft water for jack cooling. The hot jacket water from the engine is passed through cooler (heat exchanger) where it is cooled with the help of raw water. 

The raw water in turn is cooled by cooling towers.  

What is Bulk Email: Definition, Examples, Tips

A bulk email could be a selling message sent by a whole to multiple recipients right away. It aims to market a business, sell goods, and develop relationships. when registering with SendPulse, you'll be able to send bulk emails for completely free.

Contents

Types of Bulk Emails

What is a bulk email service?

How to Send Bulk Emails for complimentary

How to Send Bulk Emails while not Spamming and obtaining Blacklisted

Bulk Email Examples

Bulk Email Best Practices

References

Today, marketers choose to use bulk email services to deliver necessary messages with marginal effort. in contrast to junk emails sent while not the recipients’ permission, bulk emails square measure legal selling campaigns since the recipients take receive them. However, if bulk email selling isn't properly managed, users could think about it spam, and consequently, it should hurt sender name. once making and causation bulk email campaigns, keep in mind to stick to the CAN-SPAM Act to avoid penalties and losses to your business.

Types of Bulk Emails

Newsletters

Promotional emails

Acquisition emails

Retention emails

Newsletters. A news report is a wonderful approach of keeping subscribers within the loop regarding what’s occurring with a business. In most cases, newsletters offer insights, notifications, or guides to customers during a bid to assist them higher perceive a specific service or product.

Promotional emails. Bulk emails square measure effective at promoting sales, attracting customers with offers and deals, and building whole awareness. These emails can even be wont to recommend acceptable merchandise to existing and prospective customers.

Acquisition emails. These square measure messages sent to amass new customers, directed at prospects on an inventory UN agency have nevertheless to convert. they'll be wont to share special offers to convert potential customers to create a procurement.

Retention emails. These mass emails square measure typically sent to existing shoppers to encourage them to stay getting from your company. They aim to spice up a brand’s client loyalty.

LUBRICATION 

Frictional forces causes wear and tear of rubbing parts of the engine and thereby the life of the engine is reduced. This requires that some substance should be introduced between the rubbing surfaces in order to decrease the frictional force between them. Such substance is called lubricant. The lubricant forms a thin film between the rubbing surfaces and prevents metal to metal contact. The various parts of an I.C. engine requiring lubrication are cylinder walls and pistons, big end bearing and crank pins small end bearing and gudgeon pins, main bearing cams and bearing valve tappet and guides and timing gears etc. The functions of a lubricant are as follows

• It reduces wear and tear of various moving parts by minimizing the force of friction and ensures smooth running of parts. 

• It helps the piston ring to seal the gases in the cylinder. 

• It removes the heat generated due to friction and keeps the parts cool. 

The various lubricants used in engines are of three types: 

1. Liquid Lubricants. 

2. Solid Lubricants. 

3. Semi-solid Lubricants. 

Liquid oils lubricants are most commonly used. Liquid lubricants are of two types: 

(a) Mineral Oils 

(b) Fatty oils. 

Graphite, while lead and mica are the solid lubricants. Semi solid lubricants or greases as they are often called are made from mineral oils and fatty oils. 

A Rood lubricant should possess the following properties: 

• It should not change its state with change in temperature. 

• It should maintain continuous films between the rubbing surfaces. 

• It should have high specific heat so that it can remove maximum amount of heat. 

• It should be free from corrosive acids. 

The lubricant should be purified before it enters the engine. It should be free from dust, moisture, metallic chips, etc. The lubricating oil consumed is nearly 1% of fuel consumption. The lubricating oil gets heated because of friction of moving parts and should be cooled before recirculation. The cooling water used in the engine may be used for cooling the lubricant. Nearly 2.5% of heat of fuel is dissipated as heat which is removed by the Lubrication oil. 

Lubricating oil is purified by following four methods: 

1. Settling, 

2. Centrifuging, 

3. Filtering,

4. Chemical reclaiming. 

The centrifuging widely used gives excellent purification when properly done. 

The figure shows the lubricating oil external circuit. 

ENGINE STARTING METHODS 

Spark ignition engines are used mainly in smaller size where compression ratio to be our come in cranking is only 5 to 7. Hand and electric motor (6 - 12 V, DC) cranking are practical. Diesel engines are difficult to be started by hand cranking because of high compression required and therefore mechanical cranking system is used. 

The various methods used for the starting of diesel engine are as follows: 

Compressed Air System: Compressed air system is used to start large diesel engines. In this system compressed air at a pressure of about 20 kg per sq. cm is supplied from an air bottle the engine an inlet valve through the distributor or through inlet manifold. 

Electric Starting: Electric starting arrangement consists of an electric motor which a drives pinion which engages a toothed 11 on engine flywheel. Electric power supply for the motor is made available by a small electric generator driven from the engine in case of small plants a storage battery of 12 to 36 volts is used to supply power to the electric motor. 

The electric motor disengages automatically after the engine has started. The advantages of electric starting are its simplicity and effectiveness. 

Starting by an Auxiliary Engine: In this method a small petrol engine is connected to the main engine through clutch and gear arrangements. Firstly, the clutch is disengaged and petrol engine is started by hand. Then clutch is gradually engaged and the main engine is cranked for starting. Automatic disengagement of clutch takes place after the main engine has started.

STARTING PROCEDURE 

Actual process of starting the engine differs from engine to engine. Some common steps for starting the engine are as follows:

• Before starting the engine it is desirable to check fuel system, lubricating system and cooling water supply. 

• Depending upon the method of starting a check for the same is essential. If air starting is used the pressure of air should be checked and also the air system should be checked for possible leakage. The storage battery should be checked if electric motor is used for starting. 

• There should be no load on the engine. 

• Crank the engine and run it at slow speed for a few minutes and again check the working of various systems such as fuel, lubricating oil system etc.

The speed of the engine should be gradually increased till it synchronizes with the bus bars. Then connect the generator to the bus and finally increase the engine speed so that it takes up desired load. 

STOPPING THE ENGINE 

The engine should not be stopped abruptly. Top stop the engine the speed should be decreased gradually until no power is delivered by the alternator. Then the engine is disconnected from the bus bars and is allowed to run idle for some time. 

STARTING AIDS 

Starting aids may be used during cold weather to obtain quicker starting of the engine. Ethyl ether is mostly used as such aid. Glow plugs another starting aid. Glow plug forms a local hot spot thus imitating the combustion of fuel even if the compression temperature of air in sufficient. 

FUEL SUPPLY 

The fuels used in I.C. engines are in liquid form. They HIP preferred because of their high calorific value and case of storage and handling. The storage of oil fuel is simpler than the solid I n. I the amount of fuel to be stored depends upon the service hour’s unit vary for different installations. Bulk storage and engine day I hold the engine fuel. The fuel delivered to the power plant is received in storage tanks. Pumps draw the oil from storage tanks and supply it is the smaller day tanks from where the oil is supplied to the engine as shown in figure. 

The fuel oil used should be free from impurities. Efforts should he made to prevent contamination of the fuel. An important step is to reduce the number of times the fuel is handled. Greater amount OF impurities settle down in the storage tank and remaining impurities are removed by passing the oil through filters. Storage tank may be located above the ground or underground. But underground storage tanks are preferred. It is provided with coils, heated by steam or hot water to reduce for viscosity and to lower the pumping cost. Main hole is provided FIN internal access and repair. Vent pipe is provided to allow the tank to breathe as it is filled or emptied. Level indicator measures the quantity of oil in the tank, and an overflow line is provided to control the quantity of oil. 

A generating station during which high speed diesel (HSD) is employed as fuel and diesel is employed because the first cause for the generation of electricity is understood as High Speed Diesel (HSD) power station . High speed diesel power station is suitable for little and medium outputs. it's used as central power plant for smaller power supplies and as a standby plant to hydro-electric power plants and steam power plants. The diesel power plants are commonly used where fuel prices or reliability of supply favors oil over coal, where water system is restricted , where loads are relatively small, and where electric line service is unavailable or is out there at too high rates. High speed diesel power plants in common use have capacities up to about 5 MW. This is one quite Diesel power station but there's used smaller engine than diesel power station .

APPLICATIONS OF HSD power station

1. They are quite suitable for mobile power generation and are widely utilized in transportation systems consisting of rail roads, ships, automobiles and aero planes.

2. They can be used for little electric power generation in capacities.

3. They can be used as standby power plants.

4. They can be used as peak load plants for a few other sorts of power plants.

5. Industrial concerns where power requirement are small.

6. HSD power plants become more economical thanks to their higher overall efficiency.

HSD POWER PLANTS IN BANGLADESH

There are two methods of cooling the I.C. Engines. 

1. Air cooling 

2. Water cooling. 

Air Cooling: It is a direct method of cooling. In air cooled engine fins are cast on the cylinder head and cylinder barrel to increase its exposed surface of contact with air. Air passes over fins and carried away heat, with it. Air for cooling the fins may be lined from a blower or fan driven by the engine. Air moment relative to engine may be used to cool the engine as in case of motor cycle’s engine. About 13 to 15% of heat is lost by this method. It own air cooling system. Simplicity and lightness are the ad shows not as effective as water cooling. The rate of cooling depends upon the velocity, quantity and temperature of cooling air and size of surface being cooled. 

The position of valves, Fins and head in air cooling system. This system is used in motor cycles, scooters and aero plans. 

Water Cooling: It is the indirect method of cooling the engine The various cooling systems used are shown in below figure. Water after circulating in water jackets (passages around the cylinder, combustion chamber valves etc.) goes as waste or in recirculation method of cooling water is continuously circulated through water jackets. Water takes up the heat and leaves for radiator where it is cooled for recirculation.  

In stationary diesel engine plants the water cooling systems are as follows: 

1. Open or Single Circuit System:  In this system pump draws the water from cooling pond and forces it into the main engine jackets. Water after circulating through the engine return to the cooling pond. 

2. Closed or Double Circuit System: In this system raw water is made to flow through the heat exchanger when it takes up the heat of jacket water and returns back to the cooling pond. 

Heat lost by water cooling is about 25 to 35%. The amount of heat lost is called jacket loss. The rate of flow of water should be so adjusted that the outlet temperature of cooling water does not exceed 60’c and rise in temperature of cooling water is limited to 11’c the water used for cooling purposes should be free from impurities. Water cooling methods permit uniform cooling. Water cooling creates troubles in very cold weather. Cooling efficiency is reduced due to scaling in the pipes, jackets and radiator. Engine efficiency affected by power needed to drive the water pump and radiator fan. 

Closed system of cooling is mostly used in power stations. A closed cooling system comprises the following equipment. 

1. A surge tank. 

2. Soft water circulating pump. 

3. Soft water circulation pipe. 

3. Soft water heat exchanger or cooler. 

4. Raw water softening plant. 

5. Raw water circulation pump. 

6. Raw water circulation pipe. 

7. Raw water cooling arrangement such as cooling tower. 

8. Thermometer for measuring inlet and outlet temperatures. 

9. Temperature regulator to control the Excessive jacket temperature. 

10. Safety device to control the excessive jacket temperature. 

This system shown is in use soft water for jack cooling. The hot jacket water from the engine is passed through cooler (heat exchanger) where it is cooled with the help of raw water. 

The raw water in turn is cooled by cooling towers.  

What is Bulk Email: Definition, Examples, Tips

A bulk email could be a selling message sent by a whole to multiple recipients right away. It aims to market a business, sell goods, and develop relationships. when registering with SendPulse, you'll be able to send bulk emails for completely free.

Contents

Types of Bulk Emails

What is a bulk email service?

How to Send Bulk Emails for complimentary

How to Send Bulk Emails while not Spamming and obtaining Blacklisted

Bulk Email Examples

Bulk Email Best Practices

References

Today, marketers choose to use bulk email services to deliver necessary messages with marginal effort. in contrast to junk emails sent while not the recipients’ permission, bulk emails square measure legal selling campaigns since the recipients take receive them. However, if bulk email selling isn't properly managed, users could think about it spam, and consequently, it should hurt sender name. once making and causation bulk email campaigns, keep in mind to stick to the CAN-SPAM Act to avoid penalties and losses to your business.

Types of Bulk Emails

Newsletters

Promotional emails

Acquisition emails

Retention emails

Newsletters. A news report is a wonderful approach of keeping subscribers within the loop regarding what’s occurring with a business. In most cases, newsletters offer insights, notifications, or guides to customers during a bid to assist them higher perceive a specific service or product.

Promotional emails. Bulk emails square measure effective at promoting sales, attracting customers with offers and deals, and building whole awareness. These emails can even be wont to recommend acceptable merchandise to existing and prospective customers.

Acquisition emails. These square measure messages sent to amass new customers, directed at prospects on an inventory UN agency have nevertheless to convert. they'll be wont to share special offers to convert potential customers to create a procurement.

Retention emails. These mass emails square measure typically sent to existing shoppers to encourage them to stay getting from your company. They aim to spice up a brand’s client loyalty.

LUBRICATION 

Frictional forces causes wear and tear of rubbing parts of the engine and thereby the life of the engine is reduced. This requires that some substance should be introduced between the rubbing surfaces in order to decrease the frictional force between them. Such substance is called lubricant. The lubricant forms a thin film between the rubbing surfaces and prevents metal to metal contact. The various parts of an I.C. engine requiring lubrication are cylinder walls and pistons, big end bearing and crank pins small end bearing and gudgeon pins, main bearing cams and bearing valve tappet and guides and timing gears etc. The functions of a lubricant are as follows

• It reduces wear and tear of various moving parts by minimizing the force of friction and ensures smooth running of parts. 

• It helps the piston ring to seal the gases in the cylinder. 

• It removes the heat generated due to friction and keeps the parts cool. 

The various lubricants used in engines are of three types: 

1. Liquid Lubricants. 

2. Solid Lubricants. 

3. Semi-solid Lubricants. 

Liquid oils lubricants are most commonly used. Liquid lubricants are of two types: 

(a) Mineral Oils 

(b) Fatty oils. 

Graphite, while lead and mica are the solid lubricants. Semi solid lubricants or greases as they are often called are made from mineral oils and fatty oils. 

A Rood lubricant should possess the following properties: 

• It should not change its state with change in temperature. 

• It should maintain continuous films between the rubbing surfaces. 

• It should have high specific heat so that it can remove maximum amount of heat. 

• It should be free from corrosive acids. 

The lubricant should be purified before it enters the engine. It should be free from dust, moisture, metallic chips, etc. The lubricating oil consumed is nearly 1% of fuel consumption. The lubricating oil gets heated because of friction of moving parts and should be cooled before recirculation. The cooling water used in the engine may be used for cooling the lubricant. Nearly 2.5% of heat of fuel is dissipated as heat which is removed by the Lubrication oil. 

Lubricating oil is purified by following four methods: 

1. Settling, 

2. Centrifuging, 

3. Filtering,

4. Chemical reclaiming. 

The centrifuging widely used gives excellent purification when properly done. 

The figure shows the lubricating oil external circuit. 

ENGINE STARTING METHODS 

Spark ignition engines are used mainly in smaller size where compression ratio to be our come in cranking is only 5 to 7. Hand and electric motor (6 - 12 V, DC) cranking are practical. Diesel engines are difficult to be started by hand cranking because of high compression required and therefore mechanical cranking system is used. 

The various methods used for the starting of diesel engine are as follows: 

Compressed Air System: Compressed air system is used to start large diesel engines. In this system compressed air at a pressure of about 20 kg per sq. cm is supplied from an air bottle the engine an inlet valve through the distributor or through inlet manifold. 

Electric Starting: Electric starting arrangement consists of an electric motor which a drives pinion which engages a toothed 11 on engine flywheel. Electric power supply for the motor is made available by a small electric generator driven from the engine in case of small plants a storage battery of 12 to 36 volts is used to supply power to the electric motor. 

The electric motor disengages automatically after the engine has started. The advantages of electric starting are its simplicity and effectiveness. 

Starting by an Auxiliary Engine: In this method a small petrol engine is connected to the main engine through clutch and gear arrangements. Firstly, the clutch is disengaged and petrol engine is started by hand. Then clutch is gradually engaged and the main engine is cranked for starting. Automatic disengagement of clutch takes place after the main engine has started.

STARTING PROCEDURE 

Actual process of starting the engine differs from engine to engine. Some common steps for starting the engine are as follows:

• Before starting the engine it is desirable to check fuel system, lubricating system and cooling water supply. 

• Depending upon the method of starting a check for the same is essential. If air starting is used the pressure of air should be checked and also the air system should be checked for possible leakage. The storage battery should be checked if electric motor is used for starting. 

• There should be no load on the engine. 

• Crank the engine and run it at slow speed for a few minutes and again check the working of various systems such as fuel, lubricating oil system etc.

The speed of the engine should be gradually increased till it synchronizes with the bus bars. Then connect the generator to the bus and finally increase the engine speed so that it takes up desired load. 

STOPPING THE ENGINE 

The engine should not be stopped abruptly. Top stop the engine the speed should be decreased gradually until no power is delivered by the alternator. Then the engine is disconnected from the bus bars and is allowed to run idle for some time. 

STARTING AIDS 

Starting aids may be used during cold weather to obtain quicker starting of the engine. Ethyl ether is mostly used as such aid. Glow plugs another starting aid. Glow plug forms a local hot spot thus imitating the combustion of fuel even if the compression temperature of air in sufficient. 

FUEL SUPPLY 

The fuels used in I.C. engines are in liquid form. They HIP preferred because of their high calorific value and case of storage and handling. The storage of oil fuel is simpler than the solid I n. I the amount of fuel to be stored depends upon the service hour’s unit vary for different installations. Bulk storage and engine day I hold the engine fuel. The fuel delivered to the power plant is received in storage tanks. Pumps draw the oil from storage tanks and supply it is the smaller day tanks from where the oil is supplied to the engine as shown in figure. 

The fuel oil used should be free from impurities. Efforts should he made to prevent contamination of the fuel. An important step is to reduce the number of times the fuel is handled. Greater amount OF impurities settle down in the storage tank and remaining impurities are removed by passing the oil through filters. Storage tank may be located above the ground or underground. But underground storage tanks are preferred. It is provided with coils, heated by steam or hot water to reduce for viscosity and to lower the pumping cost. Main hole is provided FIN internal access and repair. Vent pipe is provided to allow the tank to breathe as it is filled or emptied. Level indicator measures the quantity of oil in the tank, and an overflow line is provided to control the quantity of oil. 

A generating station during which high speed diesel (HSD) is employed as fuel and diesel is employed because the first cause for the generation of electricity is understood as High Speed Diesel (HSD) power station . High speed diesel power station is suitable for little and medium outputs. it's used as central power plant for smaller power supplies and as a standby plant to hydro-electric power plants and steam power plants. The diesel power plants are commonly used where fuel prices or reliability of supply favors oil over coal, where water system is restricted , where loads are relatively small, and where electric line service is unavailable or is out there at too high rates. High speed diesel power plants in common use have capacities up to about 5 MW. This is one quite Diesel power station but there's used smaller engine than diesel power station .

APPLICATIONS OF HSD power station

1. They are quite suitable for mobile power generation and are widely utilized in transportation systems consisting of rail roads, ships, automobiles and aero planes.

2. They can be used for little electric power generation in capacities.

3. They can be used as standby power plants.

4. They can be used as peak load plants for a few other sorts of power plants.

5. Industrial concerns where power requirement are small.

6. HSD power plants become more economical thanks to their higher overall efficiency.

HSD POWER PLANTS IN BANGLADESH

There are two methods of cooling the I.C. Engines. 

1. Air cooling 

2. Water cooling. 

Air Cooling: It is a direct method of cooling. In air cooled engine fins are cast on the cylinder head and cylinder barrel to increase its exposed surface of contact with air. Air passes over fins and carried away heat, with it. Air for cooling the fins may be lined from a blower or fan driven by the engine. Air moment relative to engine may be used to cool the engine as in case of motor cycle’s engine. About 13 to 15% of heat is lost by this method. It own air cooling system. Simplicity and lightness are the ad shows not as effective as water cooling. The rate of cooling depends upon the velocity, quantity and temperature of cooling air and size of surface being cooled. 

The position of valves, Fins and head in air cooling system. This system is used in motor cycles, scooters and aero plans. 

Water Cooling: It is the indirect method of cooling the engine The various cooling systems used are shown in below figure. Water after circulating in water jackets (passages around the cylinder, combustion chamber valves etc.) goes as waste or in recirculation method of cooling water is continuously circulated through water jackets. Water takes up the heat and leaves for radiator where it is cooled for recirculation.  

In stationary diesel engine plants the water cooling systems are as follows: 

1. Open or Single Circuit System:  In this system pump draws the water from cooling pond and forces it into the main engine jackets. Water after circulating through the engine return to the cooling pond. 

2. Closed or Double Circuit System: In this system raw water is made to flow through the heat exchanger when it takes up the heat of jacket water and returns back to the cooling pond. 

Heat lost by water cooling is about 25 to 35%. The amount of heat lost is called jacket loss. The rate of flow of water should be so adjusted that the outlet temperature of cooling water does not exceed 60’c and rise in temperature of cooling water is limited to 11’c the water used for cooling purposes should be free from impurities. Water cooling methods permit uniform cooling. Water cooling creates troubles in very cold weather. Cooling efficiency is reduced due to scaling in the pipes, jackets and radiator. Engine efficiency affected by power needed to drive the water pump and radiator fan. 

Closed system of cooling is mostly used in power stations. A closed cooling system comprises the following equipment. 

1. A surge tank. 

2. Soft water circulating pump. 

3. Soft water circulation pipe. 

3. Soft water heat exchanger or cooler. 

4. Raw water softening plant. 

5. Raw water circulation pump. 

6. Raw water circulation pipe. 

7. Raw water cooling arrangement such as cooling tower. 

8. Thermometer for measuring inlet and outlet temperatures. 

9. Temperature regulator to control the Excessive jacket temperature. 

10. Safety device to control the excessive jacket temperature. 

This system shown is in use soft water for jack cooling. The hot jacket water from the engine is passed through cooler (heat exchanger) where it is cooled with the help of raw water. 

The raw water in turn is cooled by cooling towers.