Gasoline generators fully utilize various gases or harmful gases as fuel, converting waste into treasure, ensuring safe and convenient operation, offering high cost-effectiveness, low emissions, and being suitable for cogeneration of heat and electricity, among other advantages. The market prospects are very promising.
Our country boasts abundant natural gas resources. In comparison to the substantial natural gas reserves, the proportion of natural gas in our primary energy consumption is relatively low, indicating a significant potential for increase in the future.
In China, due to the influence of gas supply, gas power generation is still in its infancy. Large-scale gas power generation as distributed energy stations is still a ways off. Small-scale gas power generation is primarily found in oil fields, gas fields, and at airports, hotels, etc. It is expected that with increasingly abundant gas supply and expanding supply areas, gas power generation will see rapid development in the coming years.
Advantages:
The gas power generation set boasts a wide range of output power, high reliability in start-up and operation, excellent power generation quality, lightweight, compact size, simple maintenance, and low frequency noise. Generally, it has the following four advantages:
1. Excellent power generation quality
Due to the generator set's operation involving only rotational movement, the electronic control responds quickly, ensuring exceptional stability. The generator produces a high precision of output voltage and frequency with minimal fluctuations. Under sudden 50% and 75% load changes, the set operates extremely stably, outperforming the electrical performance metrics of diesel generator sets.
High startup performance, high success rate of startup
After a successful cold start, it takes only 30 seconds to reach full load, whereas international regulations stipulate that a diesel generator must be loaded within 3 minutes of a successful start. Gas turbine generator sets ensure a high start-up success rate under any environmental temperature and climate conditions.
Low noise and minimal vibration
Due to the high-speed rotation of the gas turbine, its vibration is extremely low, and its low-frequency noise is superior to that of diesel generator sets.
Four, the combustible gas used is a clean and inexpensive source of energy.
Such as gas, Platycodon gas, etc., power generation sets fueled by them are not only reliable and cost-effective but also transform waste into treasure, without causing pollution.
Noise Abatement:
The gas-powered generator set consists of a gas engine, a generator, a control cabinet, and other components, with the gas engine and generator mounted on a single steel chassis. The set runs on a variety of combustible gases such as natural gas, associated gas from oil wells, coal mine gas, water gas, refining by-products, coke oven gas, and blast furnace gas, offering quick startup and good economic performance. Particularly due to the demand for high-quality urban living, gas generator sets have been widely used in telecommunications, post offices, banks, libraries, hotels, and other departments as backup power sources. Early gas generator sets were designed for mining conditions, and the noise produced during operation typically ranges from 95 to 110 dB(A). The GB 3096-93 Urban Area Environmental Noise Standard has strict regulations on noise levels in urban areas, with daytime levels for Category 2 areas (residential, commercial, and industrial mixed zones) set at 60 dB(A), and nighttime levels at 50 dB(A); for Category 1 areas (residential and cultural and educational institutions), daytime levels are 55 dB(A), and nighttime levels are 45 dB(A). The noise generated during operation of the set causes significant noise pollution in urban environments, affecting people's normal work and life, and limiting the widespread application of gas generator sets. This article proposes a set of rectification measures for the noise pollution issue associated with gas generator sets, aiming to reduce the set's noise and promote the wider use of gas generator sets.
1. Source Analysis
Gasoline engine noise is the primary source of noise in a gas power generation set. Gasoline engine noise can be categorized into aerodynamic noise, combustion noise, mechanical noise, exhaust noise, and vibration noise. Aerodynamic noise mainly includes air vibration noise caused by intake and exhaust as well as fan rotation, which directly propagates into the air. The pressure vibration formed by combustion inside the cylinder, radiating outward through the cylinder head and the body, is called combustion noise; the impact noise from the piston to the cylinder sleeve, and the impact vibration noise from moving parts such as the valve train and injection system, are collectively referred to as mechanical noise. During operation, exhaust gases are ejected at high speed from the exhaust valve, enter the muffler along the exhaust manifold, and then排出 into the atmosphere through the tailpipe. Exhaust noise is the main noise of the engine, usually about 15 dB(A) higher than the main engine noise, followed by combustion noise, mechanical noise, fan noise, and intake noise.
2. Modified Design
Based on the working principle of gas-powered generator sets, it's difficult to reduce noise at the source, so the focus is mainly on effectively blocking the noise transmission paths. The core of noise reduction technology is to utilize the natural attenuation of sound waves during propagation to reduce the noise pollution area. Specific methods to lower noise include: sound absorption, sound insulation, and altering the direction of noise propagation. In practical engineering applications, usually only one method is used. This article adopts a combined approach using all three methods and proposes a new composite noise reduction technology for gas-powered generator sets.
(1) Combination muffler
The original silencer primarily relied on resistive noise reduction, consuming high power and yielding unsatisfactory noise reduction. After careful consideration, a three-stage composite noise reduction technology was applied to transform the silencer into a new composite type. The main components of this composite silencer include the spray noise reduction and vibration damping chamber, porous noise reduction housing, sound-absorbing and heat-insulating layer, and sound-absorbing resonance plates. The noise energy from the sound source is fully dissipative against resistance as it passes through the first-stage spray noise reduction and vibration damping chamber. The second-stage porous resistive noise reduction housing eliminates most high-frequency noise, enhancing the silencer's adaptability to high frequencies. It also contains sound-absorbing material within the chamber, which fully absorbs and redirects noise, thereby maximizing noise energy consumption. The third stage is a specially designed exhaust pipe with resonance plates, further reducing noise through the vibration of thin plates. Tests have shown that the new silencer outperforms the original in terms of noise reduction, frequency range (mainly the frequency range of the noise reduction peak), and resistance loss. Additionally, the silencer is appropriately sized, has good structural rigidity, is easy to install, and has the function to suppress regenerative noise. The rear sound-absorbing and noise-insulating layer also has corrosion resistance, effectively overcoming low-temperature dew point corrosion of smoke gases, thus extending the service life of the silencer.
(2) Two-stage Vibration Damping Pads
Effective methods for controlling mechanical and combustion noise involve vibration isolation for the unit. Composite vibration-damping pads are installed between the gas engine, generator, and steel chassis, as well as high-efficiency vibration-damping rubber pads between the chassis and the foundation. After two-stage vibration isolation, not only is the vibration of the unit effectively isolated, but the operation of the unit becomes more stable, and the overall noise is significantly reduced.
(3) Muffler Exhaust Duct
Fan noise is composed of rotational noise and vortex noise. Rotational noise is caused by the periodic disturbances generated by the rotating fan blades cutting through the airflow. Vortex noise is a series of swirling flows formed by the separation of boundary layers across the rotating blade cross-section, resulting from gas slip or separation, which radiates a non-stable flow noise. The exhaust duct is directly connected to the outside, with a high air velocity, and the noise from the airflow, fan, and mechanical sources is radiated through this channel. To control the noise from the fan and exhaust duct, a silencing exhaust duct is designed. This silencing exhaust duct is longer and consists of a guide vane slot and an exhaust noise reduction chamber. The working principle of the exhaust noise reduction chamber is similar to that of a resistive silencer. The noise reduction effect can be improved by changing the absorbent material (altering the sound absorption coefficient of the material), adjusting the thickness of the absorbent material, the length and width of the exhaust duct, and other parameters.
(4) Muffler Inlet Duct
The unit operates within an enclosed room. Broadly speaking, the intake system encompasses the air intake channel of the unit and the engine's intake system. Both the intake and exhaust channels are directly connected to the outside, with high air flow rates causing noise from both the air currents and the unit's operation to radiate outward. The noise from the engine's intake system is generated by pressure fluctuations caused by the periodic opening and closing of the intake valves, typically occurring within the low-frequency range below 500 Hz. Two silencer intake channels are installed on the room's walls, serving as both the intake for the room and the engine. Due to the negative pressure caused by exhaust, cold air naturally enters the room through the silencer intake channels, effectively expelling the heat emitted by the unit. This ensures that there is an adequate supply of fresh air within the room.
