A diesel generator is a device that uses diesel as fuel, converts the chemical energy of diesel into mechanical energy through an internal combustion engine, and then converts the mechanical energy into electrical energy through a generator. Diesel generators are widely used in our daily lives, such as hospitals, factories, data centers, construction sites, remote areas, etc.

In this article, SMAT will introduce you to diesel engine generators from multiple aspects.

What is the best diesel generator?

The generator sets we often talk about are usually diesel generator sets, which are mainly composed of diesel engine + alternator. Diesel generator is a complete set of mechanical equipment that converts other forms of energy into electrical energy.

Diesel generator is a kind of power generation device, which is suitable for places where with power supply use as backup power source and where without power supply use as main power source.

Composition of diesel generator set

Diesel generator is a complete set of mechanical equipment that converts other forms of energy into electrical energy. It consists of multiple components such as power system control system, silencer system, shock absorption system, exhaust system, etc.

1. Diesel engine: As a power source, it converts the heat energy generated by diesel combustion into mechanical energy. Common brands include CUMMINS generator diesel, WEICHAI, etc.

2. Generator: Connected to the diesel engine, it converts the mechanical energy output by the diesel engine into electrical energy.

3. Control system: used to monitor and control the operating status of the generator set. Common brand SMARTGEN

4. Cooling system: usually water cooling or air cooling is used to ensure that the diesel engine works within a suitable temperature range.

5. Base and fuel tank: The base is made of thickened steel plate, and the silent generator set is equipped with a base fuel tank.

6. Lubrication system: Provide lubrication for the moving parts of the diesel engine to reduce friction and wear. It is mainly composed of oil pump, oil filter, oil pan, etc.

7. Fuel system: responsible for storing, transporting and injecting diesel. Including fuel tank, fuel pump, injector and other parts.

8. Circuit breaker: overload protection, short circuit protection, Chint brand

9. Filter element: diesel filter element, oil filter element, air filter element, filter diesel, oil, air.

How does a diesel generator work?

A diesel generator generates power by burning diesel in a diesel engine, which drives the generator to generate electricity.

The working process of a diesel generator is as follows: diesel burns and expands in the engine cylinder, pushing the piston movement to convert into the rotational mechanical energy of the crankshaft, driving the generator rotor to rotate at high speed: the rotor magnetic field cuts the stator coil to generate electromagnetic induction, thereby outputting AC power, and adjusting the voltage and frequency through the control system, ultimately providing stable power for the equipment.

Classification of diesel generator sets

1. Classification by purpose:

Common generator sets: used as common power sources in some places with high requirements for power supply continuity, such as hospitals, data centers, communication base stations, etc. This type of generator set usually needs to operate stably for a long time, and has high requirements for its reliability, power generation quality and degree of automation.

Diesel standby generator: mainly used as an emergency power supply when the city power is outage. Commonly used in factories, office buildings and other places, it is in standby state when the city power is normal. Once the city power is interrupted, it can be quickly started and put into operation to ensure the normal operation of important equipment. The start-up time of the standby generator set is required to be short, and it should generally reach the rated operating state within 15-30 seconds.

2. Basic types

How to install a diesel generator?

1. Site selection: Choose a well-ventilated, dry, flat place away from flammable and explosive items. Avoid installing in low-lying and water-logged places to prevent rainwater from backflowing and damaging the equipment. At the same time, ensure that there is enough space around to facilitate the operation, maintenance and repair of the equipment.

2. Foundation installation: In order to reduce the impact of vibration on the equipment and the surrounding environment, a solid foundation needs to be built for the diesel generator set. The size and bearing capacity of the foundation should be determined according to the model and weight of the generator set. The foundation surface should be flat and the horizontal error should not exceed the specified value. Our generator sets will be shipped with shock-absorbing pads.

3. Electrical connection: Correctly connect the output cable of the generator to the electrical equipment or distribution cabinet, ensure that the cable specifications meet the rated current requirements of the generator set, and the connection is firm and well insulated. At the same time, grounding protection should be done well, and the metal casing of the generator set should be reliably connected to the grounding system. The grounding resistance should meet the requirements of relevant standards and is generally not greater than 4Ω to ensure the safety of personnel and equipment.

4. Pipeline connection: For water-cooled generator sets, the cooling water pipeline should be connected to ensure smooth circulation of the coolant without leakage. The pipeline connection of the fuel system should be tight to prevent fuel leakage. At the same time, a fuel filter should be installed to filter impurities in the fuel. In addition, the exhaust pipe should be as short as possible and avoid sharp turns to reduce exhaust resistance. At the same time, heat insulation and silencing treatment should be done to reduce the impact of exhaust noise and temperature on the surrounding environment.

How to maintain diesel generators?

1. Daily inspection:

Before and after starting and stopping the generator every day, check whether the appearance of the generator set is damaged, whether the connecting parts are loose, whether the coolant and oil levels are within the normal range, and whether the fuel tank is sufficient. During operation, pay close attention to the various parameters on the control panel, such as water temperature, oil temperature, oil pressure, voltage, frequency, etc., and deal with abnormalities in time.

2. Regular maintenance:

(1) Air filter: Regularly clean or replace the air filter element to ensure smooth engine air intake and prevent dust and other impurities from entering the cylinder and aggravating engine wear. Generally, it should be cleaned every 200-300 hours of operation, and the filter element needs to be replaced every 1000-1500 hours of operation.

(2) Oil filter: Replace the oil filter according to the specified operating time to ensure the cleanliness of the oil. Usually, the oil filter is replaced every 200-300 hours of operation, and the oil is replaced at the same time.

(3) Fuel filter: Regularly replace the fuel filter to remove moisture and impurities in the fuel and ensure the normal operation of the fuel system. Generally, the fuel filter should be replaced every 500-800 hours of operation.

(4) Coolant: Regularly check the concentration and level of the coolant, and add or replace the coolant in time according to the usage. Generally, the coolant should be replaced every 2-3 years, and the cooling system should be cleaned at the same time to prevent scale and rust.

(5) Battery: For generator sets with electric start, regularly check the electrolyte level and voltage of the battery, keep the battery clean, and prevent the pole from oxidation. If the battery is found to be low, it should be charged in time. Generally, the battery is charged and discharged every 3-6 months.

(6)Other parts: Regularly check the tension of the belt, and replace it in time if it is worn or aged; check whether the terminal of the generator is loose or oxidized, and if there is a problem, it should be dealt with in time; clean the equipment thoroughly, remove dust, oil, etc., and maintain a good operating environment for the equipment.

Performance indicators of diesel generator sets

1. Rated power: refers to the maximum power that the generator set can continuously output for a long time under rated conditions, in kilowatts (kW) or megawatts (MW). It is an important indicator to measure the power generation capacity of the generator set. Users should reasonably select a generator set with a suitable rated power according to the actual power demand.

2. Rated voltage: The line voltage output by the generator set during normal operation. Common ones in the Philippines are 440V, 480V, 230V, etc. Different electrical equipment has specific requirements for voltage, so the rated voltage of the generator set needs to match the electrical equipment.

3. Rated frequency: The frequency in the Philippines is 60HZ, and the diesel generator set should ensure that the output frequency is stable at 60Hz at the rated speed. Unstable frequency will affect the normal operation of electrical equipment, such as motor speed fluctuations, abnormal operation of electronic equipment, etc.

4. Power factor: It indicates the ratio of active power (KW) to apparent power (KVA). The power factor of a general diesel generator set is 0.8. The higher the power factor, the more effective work is done in the electric energy output by the generator set, and the higher the utilization rate of electric energy.

5. Fuel consumption rate: refers to the amount of fuel consumed by the generator set for every 1kW·h of electric energy output, in g/(kW·h). The fuel consumption rate reflects the fuel economy of the generator set and is one of the important cost factors that users need to consider when selecting and using the generator set. The fuel consumption rates of generator sets of different models and different powers are different. Generally, the larger the power, the lower the fuel consumption rate.

6. Voltage regulation rate: indicates the degree of fluctuation of the output voltage of the generator set when the load changes, usually expressed as a percentage. A good voltage regulation rate can ensure that the electrical equipment can obtain a stable voltage supply under different load conditions, and the voltage regulation rate is generally required to be within ±5%.

7. Frequency regulation rate: refers to the degree of fluctuation of the output frequency of the generator set when the load changes, also expressed as a percentage. The frequency regulation rate reflects the frequency response ability of the generator set to load changes, and the frequency regulation rate is generally required to be between ±1% – ±2% to ensure the normal operation of the electrical equipment.