WHAT IS DIESEL GENERATOR?
The generator consists of two main sections as the part that creates mechanical energy and alternator. Diesel, gasoline and natural gas engines are commonly preferred to provide the mechanical energy. Alternatively, wind power, water or steam turbine can be used. In today’s world, the most common products are manual generators, diesel and gasoline automatic generator, welding generators, three-phase generator and monophasic generators.
The alternator is a rotating electrical machine that transforms rotational mechanical energy to electric energy. The system coupled with the diesel engine is a diesel generator. Diesel engine used as the driver source operates with diesel fuel and transforms chemical energy to mechanical rotation energy. Electric energy generated by the diesel generator can control devices such as fuse, contactor, switch (circuit breaker) and induce load supply. Additionally, there are control and alarm units that measure and monitor the important parameters of the generator.
WHAT ARE SYNCHRONOUS GENERATOR SYSTEMS? WHAT ARE THE ADVANTAGES?
EMSA JENERATÖR R&D group develops special projects to solve the high power diesel engine problems around the world and to provide benefits to its customers with necessary work against the high cost. With multiple generator synchronous systems, the user can eliminate the high costs and be dependent on a single generator. Our expert team plans and develops the projects in line with the needs and desires of the customers. First, the power and number of required generators are determined and the synchronous system is created for a suitable scenario. The generator can be divided into continuous synchronous, power back-up and fault back-up synchronous based on the synchronous system usage purpose. According to the project details, discontinuous or continuous (soft transition) can be applied when returning to grid energy.
Control panel created for the synchronous system control has all the values and derived values in a generator. With electronic control relays, the generator can be manufactured by considering all protection systems and details in a generator.
WHAT IS ALTERNATOR AND ITS WORKING PRINCIPLE?
In 1831, Michael FARADAY discovered that when the magnetic field passing through a wire is changed, this change led to electric current generation on that wire. If this wire is rotated with external power, this rotation energy is converted into electric energy. After this invention of FARADAY, simple manual generator systems were developed and these systems form the basis for the electricity generators. In 1892, an alternator that generates alternating current was invented by Nicola TESLA. Alternators work with electromagnetic induction principle. Electromagnetic induction leads to electric current when the magnetic field passing through a wire is changed. If this wire is rotated with external power, this (rotation kinetic) energy is converted into electric energy. Rotation kinetic energy changes the magnetic fields around the conductors with rotor rotation and an electrical current is generated. The magnetic field of the rotor can be obtained with a current that will be transferred with induction. Brushless alternators can be divided into two as a main and exciting system based on alternator operation principle. The main rotor which is the mobile part of the main system is formed by poles changing with rotor revolution number. Main poles of the rotor are rotated at motive unit revolution. Direct current is necessary to have a magnetic current on the poles. Direct current in the main poles is supplied by an exciting system. While the operating principles of the exciting system and main system are the same, poles and windings are inverted. In the exciting system, poles are on immobile exciting stator and windings are on rotating exciting rotor. Current from the auxiliary windings independent of the main stator is rectified in the voltage regulator and flowed to pole windings of the exciting stator. Three-phase alternating current is created on the coils on the exciting rotor that cuts the magnetic field from the poles. Alternating current is rectified on the rotation bridge diodes on the rotor and transferred to the main rotor (main poles) as direct current. When the load is applied to the brushless alternators, automatic voltage regulator (AVR) is used to prevent voltage drop and to keep the voltage at the desired level.
WHAT IS DIESEL ENGINE?
Diesel is an internal combustion engine type that operates with fuels ejected to the compressed air. This engine was invented as large power is needed in technical terms. German companies played an important role to develop this engine. First diesel engines in the highway transport were used since 1922. While the diesel engines in the naval sector started in 1910, the engines that can be used in the small boats were only manufactured starting from 1929. After this date, 40-50 horsepower land vehicle engines were manufactured. At the beginning of the World War II, while the diesel engines were used in railroad transportation, tractors, construction machines, ships and different areas of the industry, gasoline engines were preferred for low-power requirements. The diesel engine was invented by German engineer and inventor Rudolf Diesel.
He has invented an engine using ammonium vapour before the diesel engine, but the engine exploded in the first operation and he almost got killed. He was hospitalised for months. In 1887, after Gottlieb Daimler and Karl Benz invented the car engine, he started their work on the invention of the diesel engine.
He started to work on the limitations of thermodynamics and fuel efficiency. For example, 85-90% of the energy in steam engines was wasted. He started to work on designing a higher efficiency Carnot cycle engine. In 1893, he published a theory on “a rational thermal engine design instead for the steam engine and currently known combustion engines”. His theory was patented. Between 1893-1897, the director of MAN AG Augsburg Heinrich von Buz gave him a chance to test and develop his ideas about his new engine and Rudolf Diesel managed to invent the first diesel engine. He patented his new engine in Germany, the US and other countries and he established Diesel Engine Manufacturing Company. Diesel Engine Operating Principle Diesel engine is an internal combustion engine. Air is filled to the cylinder when the piston is moving down. This air is compressed when the piston is moving up. The compression rate is higher than the gasoline (between 1.12 and 1.25) and the air temperature rise above 500°C. When the piston is near the flat spot, the injector nozzle sprays fuel to the cylinder. When the fuel is mixed with heated air due to compression, the fuel is combusted. Since diesel starts to combust from 80°C, the fire risk is lower than gasoline. Diesel engines can be adapted to different fuel types including vegetable oils, gas and gasoline. However, the most common fuel type is diesel produced from raw petroleum.
WHAT ARE THE MAIN COMPONENTS OF THE GENERATOR?
1- Connector Box
3- Turbo Charge
4- Exhaust Output
5- Control Panel
6- Lifting Lug
7- Grounding Point
8- Vibration Isolators
HOW TO CHOOSE GENERATOR LOCATION?
For a safe installation, choosing a suitable generator location is important. You need to consider the warnings in the manual for correct and complete installation. For more information, you can contact Emsa generator. You need to consider the following factors when choosing and mounting area for the generator and follow the necessary implementation steps.
- Sufficient Clean Air Suction,
- Sufficient Hot Air Discharge,
- Suitable Exhaust Gas Discharge,
- Levelled Concrete Base Construction or Levelled Concrete Area Identification,
- Protection Against Undesired Weather Conditions (Sun, Heavy Rain and Snow etc.)
- Protection Against Negative Environmental Conditions (Excessive Dust, Humidity, Dampness etc.)
- Leaving At Least 1 Meter Gap Around the Generator for Operation, Designing Entrance Door By Considering Possible Re-Location of the Generator from Installation Area.
- Installation area should be selected in a way to avoid any workplace accidents caused by slipping and falling due to surface coating or oil discharge.
If the installation will be in the open area, the generator set should be protected from weather conditions and cabin-type generator should be used.
WHAT SHOULD THE SURFACE AND PLATFORM BE FOR GENERATOR?
Generators can be placed on soil, building, steel construction and platform surfaces. Placing the generator set on a concrete base is the most preferred implementation. The concrete base should be designed to withstand the weight of the generator set. The height should be 200-300 mm. It is necessary to leave more than 250mm area around the generators. Please consult an expert for more details. The generator installation surface should withstand all types of dynamic forces due to static weight and engine operation weight. If there is water accumulation risk in the selected surface area, the concrete base height should be increased depending on the risk.
THINGS TO BE CONSIDERED FOR COOLING AND VENTILATION
Engine and alternator dissipate heat and increases the ambient temperature. The increased temperature has negative effects on generator operation. Therefore, sufficient ventilation is needed to keep the engine and alternator cool. The airflow should be as shown in Figure 7. The air should enter the generator room from the alternator side, pass above the engine and inside the radiator and exit the room with the help of a bellows-type flexible tarpaulin from tent canvas. If the tarpaulin is not used to discharge the hot air from the room, hot air would dissipate inside the generator room and decrease the cooling efficiency.
It is important to avoid sharp edges in the radiator hot air discharge channel or chimney (Figure 8). Router organisation should be planned to rotate the exhausted air (Figure 7).
HOW SHOULD THE EXHAUST SYSTEM BE?
The purpose of the engine exhaust system is to discharge the dangerous or discomforting exhaust fume outside the room and to decrease the noise. Suitable exhaust silencer should be put on the exhaust pipe to decrease the engine noise level.
- It is dangerous to breath engine exhaust gas. All generator gases inside closed areas should be discharged outside the room with standard-compliant impermeable pipes.
- Keep the hot exhaust silencer and exhaust pipe away from flammable materials and make sure to store that safely for the safety of the personnel.
- When exhaust systems are designed, back pressure should not exceed the backpressure value specified by the engine manufacturer. Excessive back pressure will lead damage to the engine. To decrease the backpressure, exhaust pipes should be as short and flat as possible. Every pipe elbow should have a curve at least 1.5 times larger than the pipe inner diameter. Using a pipe with 1 inch larger pipe diameter in every 6 meters or 3 pipe elbows would be suitable to decrease exhaust backpressure.
- To prevent transferring the engine vibration to the exhaust pipe system and the building and for heat-induced expansion, a flexible connection between the exhaust manifold and exhaust pipe system should be used.
- To prevent the weight of the exhaust pipe to be on the engine manifold and turbocharging output, the pipe should be supported from surrounding structures (especially ceiling). The weight of the exhaust system should be on the building. Tension device can be used for this purpose.
- The parts of the exhaust system inside the generator system should be isolated to decrease the noise level and dissipated heat. Silencer and exhaust pipes should be placed away from flammable materials.
- To prevent rainwater from the open exhaust output, flap-type rain valves can be used in different implementations.
- Each generator should have its own exhaust system. Generator exhaust outputs cannot be connected with a single exhaust pipe.
- Exhaust material should be a metal pipe.
HOW SHOULD THE FUEL SYSTEM BE?
TUsing clean and high-quality fuel will increase the engine lifecycle and ensure safe operation. It is suitable to use pre-filters between engine recording filters and fuel transfer pump. Water and dispersion filters must be included in the transfer pump line. Sparks, flames and smoking near the fuel must be prohibited. Fuel supply in a diesel engine could be as follows.
1.Directly from the fuel tank on the chassis
2.From prismatic or cylindrical external fuel tank outside the chassis
Another important factor for a diesel engine is to use fuel without water or foreign particle. Impurities inside the fuel might damage the fuel injection system. The water inside the fule might lead to rusting or corrosion on the fuel hardware parts.
HOW VIBRATION CAN BE DECREASED?
To minimise the vibration transferred to the surface, generators sets are equipped with rubber dampeners.
These dampeners consist of a group between the engine/alternator leg and the chassis, and another group between the chassis and the ground.
Also, flexible areas shall be provided on connection points of the generator set such as air duct, exhaust installation and fuel installation. Thus, damages caused by vibration during initial operation, operation and stopping shall be prevented.
HOW DOES CONTROL SYSTEM OPERATE?
Emsa Generators have generator control units that can be controlled remotely with programmable microprocessor and monitors and enable protection for all measurement values and warnings with messages. Control systems allow the operation and stopping of the generator and monitoring of operating conditions and output voltage. Control systems enable flexible usage for changing conditions with programmable parameters. All generators with control panels on Smart 500 model has default remote access property. This enables regular information flow and archiving via GSM modem. Thus, while unnecessary service cost is decreased for the customers, problems can be solved without occurring.
HOW ARE TRANSFER PANELS USED?
Transfer panels are used for controlling the output power of the generator and to transfer the power safely. Generator sets that cut-in automatically have contactors and motor switch on the panels. In these systems, switching components are controlled by the generator control unit on the transfer panel. In manual generator sets, inverter switch is used with a thermic-magnetic circuit breaker in the power output to control the output power.
WHAT ARE GENERATOR STANDARDS?
ISO 8528 series standards include 11 standards under “Reciprocating Internal Combustion Engine Driven Alternating Current Generating Sets” the main title.
These standards first published by ISO in 1993 were published by TSE (Turkish Standard Institution) on April 2004 under TS ISO 8528 code as Turkish Standards.
ISO 8528 standards include various properties for nominal value and performance of the generator groups consisting of the reciprocating internal combustion engine, alternating current, control equipment, connection hardware and auxiliary equipment.
Internal Combustion Engines with Piston
EN 12601 "Reciprocating internal combustion engine driven generating sets - Safety" standard has been published by European Committee for Standardisation or Comité Européen de Normalisation (CEN) in 2001. EN 12601 under “Machinery Safety Directive” determining the CE marking and CE Compliance Declaration implementations are the main product safety standards for Generator Groups. EN 12601 standard has been commissioned in our country on March 2003 by TSE as TS EN 12601 “Reciprocating Internal Combustion Engine Driven Generator Group-Safety” standard.
WHAT ARE SYNCHRONOUS GENERATOR SYSTEMS? WHAT ARE THE ADVANTAGES?
Emsa Generator provides significant advantages over a single generator with the same power with its synchronous systems formed by creating multiple lower capacity generators. Synchronisation panels designed by Emsa Generator engineers and technology offers an integrated solution for the customer. Emsa Generator showed its experience, technical expertise and difference in generating large powers by synchronising multiple generators that present low-cost systems that can work under different scenarios. Systems built by synchronising generators with lower power rather than one single large power generator brings certain advantages. Synchronous systems,
- Flexible usage,
- Reliable system,
- Easy service and maintenance,
- Low cost,
- Longer service life with equal ageing,
- Uninterrupted maintenance,
- Low initial investment cost,
- Easy delivery and spare part supply.
Synchronous Systems for Prime Power
If there is no grid electricity, two or more generators constantly supply the loads synchronously and these loads are shared based on the generator power. The generator is cut-in and cut-out depending on the load level of the business and to enable economic use.
Synchronous Systems for Stand-by
If grid energy is outside the voltage and frequency values, two or more generators supply the loads synchronously for their power ratio. When the grid power is back, loads are transferred discontinuously.
Continuous Parallel Operation
Continuous parallel working with the grid could have advantages for the consumer if the electrical energy distribution firm has different tariff throughout the day and higher price tariff is applied if the determined power is exceeded or energy restrictions are imposed on the consumer due to insufficient infrastructure. There are a few different operation methods for parallel operation. First one is baseload peak lopping method when the determined active load is supplied by the generator system under the desired power factor and by the grid for the remaining load. This method is popular among cogeneration systems where a constant load is preferred. Another implementation is the true peak lopping method where the power from the grid is limited and the power above this limit is supplied by the generator. This operation method is used when the tariff price above a certain power limit is extremely high or power that can be taken from the grid is limited.
HOW CAN I SUPPLY ORIGINAL SPARE PARTS FOR THE GENERATOR?
You can supply all the parts for your Emsa generator from Emsa Head Office or regional dealers. Additionally, you can inform Emsa and get an offer for your spare part demands for every engine, alternator and generator brands.
WHEN SHOULD YOU MAKE GENERATOR MAINTENANCE AND CONTROL?
You need to follow the maintenance schedule on Maintenance and User Handbook sent with the generator. Additionally, you might need to increase the maintenance and control frequency for factors such as operating frequency and duration, load, fuel-oil quality, ambient temperature, dusty-dirty environment etc. The user is liable for maintenance, control and timely replacement of corroded materials (engine oil, filters, V-bet, anti-freeze etc.). Necessary maintenance should be applied by the authorised service specified on the maintenance schedule after first 6 months or first 50 operation hours (whichever is reached first) and later, after 12 months or in every 150 operation hours (whichever is reached first). Additionally, the operator should check fuel, oil and cooling water levels every day and operate the generator once in every 15 days for 10-15 minutes to check any oil, fuel, water leakage and abnormal vibration. You can contact Emsa regional dealers or Emsa Call Centre for safe, correct and economic generator maintenance and control.
WHAT HAPPENS IF I OPERATE THE GENERATOR UNDER LOW LOAD?
If the generator is operated under low load, the lifecycle will decrease and serious damaged might occur.
This is especially more important in larger power.
Minimum permitted load for standby generators is 30% of the standby power. If the generator is operated under no-load or low load, there might be:
- Corrosive damage on engine parts
- Decreased greasing quality due to thinning in greasing oil
- White smoke
- Oil or liquid leakage in the exhaust and air suction system
- Carbon accumulation on cylinder covers or exhaust manifold.
WHAT HAPPENS IF THE GENERATOR IS OVERLOADED?
The generator set tag specifies the suitable operation categories (Standby, Prime). Using above these operating conditions will lead to the following problems:
- Decreased engine life,
- Overheating in the engine,
- Increased engine erosion,
- Overhearing on alternator windings, isolation vulnerabilities
- Thinning in greasing oil and decreased oil pressure
WHAT DOES GENERATOR GUARANTEE COVER?
Emsa products are guaranteed for part and manufacturing errors. Please look at the document that comes with your product or consult to your sales representative for guarantee duration and scope details.
WHAT IS RPM?
This is the rotation of the generator set in 1 minute. Generally, engine and alternators are manufactured for 1500 rpm or 3000 rpm for 50Hz, 1800 rpm or 3600 rpm for 60Hz.
DOES GENERATOR MAKE NOISE?
Generators make noise due to exhaust, engine body and fans. Emsa noise isolation cabins offer the optimum solution by maximum noise control.
HOW CAN YOU DETERMINE THE REQUIRED GENERATOR POWER?
Determining the generator set power requires expertise and it is connected to various factors. You can contact Emsa expert engineers or regional dealers for more information.
WHAT DOES STANDBY / PRIME / CONTINUOUS MEAN?
- Standby Power: The power to operate for a limited time under variable load. Total of 200 hours per year operation is possible under a 70% load value. It is used as a back-up power when there are grid energy cuts. There is no overloading.
- Prime Power: The power to operate constantly under variable load. The average load value should be 70%. 10% overloading is possible for 1 hour every 12 hours.
- Continuous Power: The power to operate constantly under constant load. The average load value could be 100%. There is no overloading.
These concepts are explained in detail in international ISO8528 standard and this standard is accepted as TS ISO 8528 in Turkey. All engine and alternator manufacturers manufacture their products to meet these values. These concepts define the operation category of a generator.
HOW LONG CAN A GENERATOR WORK WITH ONE FULL FUEL TANK?
The fuel consumption of the generators depends on load status. Emsa designs fuel tanks to enable the generator to work at least 8 hours under full-load. This time will increase as the load decreases. Additionally, special chassis that enables more fuel storage can be manufactured and used in special projects.
WHICH PRECAUTIONS ARE NEEDED IF THE GENERATOR WILL NOT BE USED FOR A LONG TIME?
Generators must be tested under load at least once in every 15 days by the operator for 10 minutes. If the generator will not be used for a long time, storage in the “Maintenance and User’s Handbook” should be done by the authorised service. After long-term storage, authorised service should commission the generator. This is also related to the scope of guaranty.