(1) The supporting equipment of diesel generator set is relatively simple, with few auxiliary equipment, small size and light weight. Compared with the hydropower generator set that needs to build a dam and the steam generator set that needs to be equipped with a boiler, fuel storage and water treatment system, the diesel generator set has the advantages of small floor space, fast construction speed and low investment cost. The commonly used diesel generator set adopts independent configuration method, while the standby generator set or emergency generator set is generally used in conjunction with power transformation and distribution equipment. At the same time, the diesel generator set does not need sufficient water (the cooling water consumption of diesel engine is 34 ~ 52l/(kW h), which is only 1/11 of that of steam turbine generator set), so the installation location of the generator set is flexible.
(2) Diesel engine is the thermal engine with the highest thermal efficiency at present, and its effective thermal efficiency is 31% ~ 46%, that of high-pressure steam turbine is about 21% ~ 41%, and that of gas turbine is about 21% ~ 31%, so the fuel consumption of diesel generator set is low.
(3) Generally, it only takes a few seconds to start a diesel engine, and it can run at full load within 1min in an emergency; Under normal working conditions, it reaches full load in about 5-41s, while it usually takes 3-4h for the steam power plant to reach full load from start-up. The shutdown process of diesel engine is also very short, and it can be started and stopped frequently, so diesel generator set is very suitable as emergency generator set or standby generator set.
(4) The operation technology of diesel generator set is relatively simple, which is easy for general operators to master, requires few operators, and is easy to maintain during standby.
(5) The diesel engines in diesel generator sets are generally four-stroke, water-cooled, medium and high-speed internal combustion engines. The fuel is non-renewable diesel or renewable energy such as ethanol, biodiesel, compressed natural gas (CNG) and liquefied petroleum gas (IPG) is mixed with diesel to save energy and protect the environment. The emissions from diesel engine combustion are mainly HC and PM (particles), which pollute the environment and make the exhaust noise loud. Nevertheless, compared with hydropower, wind power, solar energy and other renewable energy sources, nuclear power and thermal power generation, diesel generator sets have obvious advantages: the comprehensive cost of construction and power generation of diesel generator sets is the lowest.
(6) The diesel generator set has high power supply reliability and automation function; The emergency power station with complete functions has the functions of automatic starting, automatic loading, automatic fault alarm and automatic protection, and the generator set can run automatically without operators and can be unattended.
(7) Most diesel engines used for power generation by electric drilling rigs are variants of general-purpose or other diesel engines. Since the frequency of alternating current is fixed at 51Hz, the rotating speed of the diesel engines can only be 3111r/min, 1511r/min, 1111r/min, 751r/min, 375r/min and 311r/min, and most of them are 1511r/min. The output voltage of diesel generator set is 611V, the frequency is 51Hz, and the power factor cos=1.8. The power of diesel engine varies widely, and the power of diesel engine for power generation can vary from 1.5kW to thousands of kW. Usually, the diesel engine equipped with electric drilling rig has a single capacity of more than 1111kW.
(8) The oil collector has a certain power reserve, and the diesel engine for power generation generally runs under stable working conditions, with a high load rate. Emergency and standby power supplies are generally rated as 1.2h power, and common power supplies are rated as continuous power. The supporting power of the unit shall be deducted from the transmission loss and excitation power of the motor, and a certain power reserve shall be reserved. Therefore, the matching power of the unit should be divided by the matching ratio of diesel engine power.
(9) The diesel engine is equipped with a speed regulating device. In order to ensure the stability of generator output voltage frequency, high-performance speed regulating devices are generally installed, and speed fine-tuning devices are installed for units running in parallel and incorporated into the power grid.
(11) In order to reduce the vibration of the unit, shock absorbers or rubber shock absorbers are usually installed at the joints between the main components such as diesel engine, generator, water tank and electric control box and the base.