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Research Status and Development Trend of Marine Gasoline Generators
Gasoline generator is a kind of power generation equipment with a very wide range of uses and very important status. It has been widely used in various sectors of the national economy. For example, most shipbuilding power stations, mobile power stations and various emergency power stations are made up of gasoline generators. Gasoline generators are technology-intensive products that involve specialized technologies such as internal combustion engines, motors, and automatic controls. With the development of the national economy, while the demand for gasoline generators has increased year by year, the requirements for the functions and technical performance of gasoline generators are also increasing.
Gasoline generators are so widely used because they have outstanding advantages that other units do not have: They are compact in structure, economical, and easy to maintain for generator sets that match high-pressure, medium-speed gasoline engines. Easy maintenance, less operator needed, small amount of maintenance during standby; quick start, and can reach full power quickly, the start-up time of gasoline engine is generally only a few s, can be fully loaded within 1min under emergency condition , Full load within 15~30min under normal condition; Easy to realize automation; Vibration, noise, etc. can be effectively controlled; High reliability and so on. Therefore, mobile power stations equipped with gas-fired generators will receive more and more attention, especially modern warfare is also inseparable from power, camping lighting, command, control, communications, artillery systems, systems, airports, bases, etc. also need power. So the prospect of gasoline generators is very good.
Due to the obvious gap between domestic units and foreign advanced units in terms of mechanical performance, electrical performance, operating performance, reliability, daily maintenance and service life, China has introduced foreign models of marine gasoline engines (such as Cummins) since the 1980s. MWM, etc.), generators (such as Stanford, Siemens, etc.), air circuit breakers and electricity meters and other production technologies to meet the needs of the domestic shipbuilding industry.
At present, there are major problems with marine gasoline generators in China:
(1) The level of scientific research, design, trial production and production of gasoline generator equipment lags behind, and there is a lack of unified leadership among various scientific research and production units and the 26th volume and the 4th issue of August 2004 ship science and technology SHIPSCIENCE AND TECHNOLOGY V.26, No. 4Aug., 2004 coordination, serious technology; even some units for the immediate interests, repeated introduction of complete sets of gasoline generator equipment, leading to repeated investment, resulting in the loss of state assets and unnecessary economic losses.
(2) Gasoline generators have many types of miscellaneous items, which have a low level of standardization and serialization. They have poor commonality between different products, poor quality of basic parts and spare parts, poor integration, and difficulty in installation and maintenance. Compared with foreign advanced air-conditioners, gasoline engines have large gaps in economy, dynamics, structural compactness, reliability, durability, vibration and noise; and generators are compact in structure, versatile in parts, dynamic and stable. The differences in performance, reliability service life, and electromagnetic compatibility of the state regulators are also significant.
(3) Slow application of new technologies and new processes. New technologies and new processes zui can improve the dynamics and economy of gasoline engines, reduce vibration noise and exhaust gas content, and improve product quality and longevity, such as multi-valve air intake system, lean combustion, electronically controlled injection, and pressurized intercooling technology. And so on, not only can improve the compression ratio, improve the intake air quality, reduce the intake resistance, make the combustion more fully, increase the output power of the gasoline engine, reduce the fuel consumption rate, and can improve the emission and reduce the smoke in the exhaust gas.
(4) Gasoline engines and generators used in marine generators introduced in the 1980s have been digested and absorbed by enterprises, and have increased the degree of localization and increased the proportion of self-made parts. However, they have neglected the basis of digestion and absorption. To improve and innovate, the product performance and quality have remained at the same level for many years. However, with the continuous development of new products and new models in foreign countries, the original imported products have lost market competitiveness.
(5) Among the electrical equipment for marine gasoline generators, electronics and electrical components are one of the weak points of the zui, which affects the performance and reliability of power generation, distribution and control devices. This is a problem that should be addressed in China today. . Since the gasoline engine is composed of three parts: a gasoline engine, a generator and an automatic control device, the development and improvement of any part of the technical level can promote the development of other aspects, thereby improving the overall performance of the gasoline generator. Therefore, these three parts The level of technology between them is mutually reinforcing and mutually reinforcing.
(1) Gasoline Generator Technology
At present, the reliability of gasoline generators used in power stations on the international market is constantly increasing, and it is developing toward the direction of no trouble before the overhaul period. The next is to improve the economy and power, and the fuel consumption rate of the units is required to reach below 210g/(kW#h). The unit has strong functions, high thermal efficiency, high cost performance, low maintenance cost, good compactness, small unit power weight and large power per unit volume; in addition, it constantly raises high requirements on environmental indicators, such as noise level of gasoline engine noise To achieve 96dB(A), the emission index has generally reached the European/European zero limit standard; it has good applicability and can work in harsh environments; it has good startability and can be quickly started at low temperatures and special occasions. Obviously, there is a big gap between the current domestic gasoline engine and the above major performance indicators.
The speed regulation characteristics of the governor unit of the power station directly affect the quality of the power supply, thereby affecting the performance of the controlled equipment, and also affect the reliability of the power plant unit operation, so the unit has special requirements for the speed regulation characteristics. With the ever-increasing standards for the frequency change rate of power plants, the foreign governors have used mechanical centrifugal flyweight governors, common hydraulic governors, dual-pulse hydraulic governors, and electrohydraulic regulators. Speed ​​to the full electronic governor, its advantages are high adjustment accuracy, speed adjustment, and the installation of electronic governor is very convenient, more superior performance, is the future direction and focus of development.
(2) Generator technology
Domestic generators, such as T2H, TFHX-, etc., are mostly phase excitation systems, and their steady state and dynamic voltage regulation characteristics are poor. In order to improve this performance, brushless excitation systems are being developed at home and abroad. Developed 50Hz, 60Hz general-purpose Class F insulation, small size, light weight, high efficiency brushless excitation generator, such as Siemens 1FC5 series generator 2, 4 pole generator after the power-weighted average efficiency of more than 93% . In order to improve the reliability of the excitation system, the rotor adopts the integral salient pole structure and good heat-conducting and thermosetting insulating plastics, and the integrity is good. The winding ends are short, and the overspeed performance can be further improved; the generator should be protected by open circuit and generally have a short circuit. Protection functions such as overload, undervoltage, etc., with the improvement of the protection characteristic requirements, are currently being developed for static release devices. H series and AH series circuit breakers introduced in China have electronic release devices and have proved to have higher protection characteristics. And accuracy and high reliability.
(3) Automatic Control Technology
In order to ensure that all components of the gasoline generator are in good working condition and further improve emergency functions and protection functions, the automatic control technology for gasoline generators should be vigorously developed. The basic electromechanical parameters of the original gasoline generator, such as lubricating oil pressure, cooling water temperature, speed, power and other indicators can not reflect the status of its work, and it is not suitable for automatic power station, automatic start, automatic parallel car, automatic monitoring, automatic solution. Column requirements, there must be more parameters, such as the starting equipment monitoring, cooling water pressure, exhaust temperature, gasoline generator 3 failed to start, the main switch 3 reclosing failure, control air pressure, generator winding temperature Detection, monitoring at the same time as car, automatic frequency regulator and voltage regulator monitoring. With the development of computer technology, it has provided new ideas and means for the development of gasoline generator automatic control technology. It has greatly improved the automation of gasoline generators, the perfection of protection functions and the rapidity of emergency functions. It can also be simpler and more reliable when it comes to the parallelization and modularization of gasoline generator power stations.
Computer controlled gasoline generator block diagram shown in Figure 1. It can be seen from the figure that the logic control signals originally completed by relays or digital circuits, as well as the signals originally from the individual regulators, are all input to the control computer through the A/D conversion module, and are centrally processed and controlled by the computer and input as required. The command, which outputs an appropriate signal, is converted by the D/A to the gasoline engine and generator actuators so that the unit can reach an ideal operating state. Under the fully automatic working mode, the microcomputer-controlled gasoline generator can be completed: (a) Automatic start-up of the gasoline generator; (b) Automatic setting and adjustment of operating parameters during operation, so that the unit runs in an ideal working condition; (c ) Auto-diagnosis and automatic processing of faults; (d) Auto-parallelization and automatic load distribution of the power station, automatic de-coupling. The realization of the computer-controlled gasoline generator plays an important role in improving the automation of the power station, the reliability of the power station, and the economical operation of the power station, and its application prospect is even broader.