1、 Quality requirements for generator sets

在沼氣發(fā)電過程中，沼氣發(fā)電機組對沼氣的成分、溫度、壓力、用量特別敏感，發(fā)電機組要求進氣系統(tǒng)必須保持空燃比的恒定和適度，避免空燃比過大，引起熄火；也要避免空燃比過小，引起溫度高及爆震?？杖急仁怯绊懻託獍l(fā)電機燃燒性能的重要因素之一，而沼氣溫度、壓力、成分的變化都會影響空燃比，因此，在選擇進行沼氣發(fā)電前，不對沼氣氣質(zhì)進行合理的把控，將導致發(fā)電機組無法正常運行，造成較大的經(jīng)濟損失。

In the process of biogas power generation, the biogas generator set is particularly sensitive to the composition, temperature, pressure, and dosage of biogas. The generator set requires the intake system to maintain a constant and moderate air fuel ratio to avoid excessive air fuel ratio, which may cause stalling; It is also necessary to avoid excessively low air fuel ratio, which can cause high temperature and detonation. The air fuel ratio is one of the important factors that affect the combustion performance of biogas generators, and changes in biogas temperature, pressure, and composition can all affect the air fuel ratio. Therefore, before choosing biogas power generation, not controlling the biogas quality reasonably will lead to the inability of the generator set to operate normally and cause significant economic losses.

1、沼氣質(zhì)量

1. Biogas quality

利用沼氣發(fā)電，要滿足沼氣發(fā)電機組對沼氣質(zhì)量的要求，《中大功率沼氣發(fā)電機組》(GBT29488-2003)、《沼氣電站技術(shù)規(guī)范》(NY/T1704-2009)對沼氣質(zhì)量的要求如下。

To use biogas for power generation, the first step is to meet the requirements of biogas power generation units for biogas quality. The requirements for biogas quality in the "Medium and High Power biogas power generation units" (GBT29488-2003) and "Technical Specifications for biogas power plants" (NY/T1704-2009) are as follows.

(1) 沼氣低位發(fā)熱值≥14MJ/Nm，相當于沼氣中甲烷體積分數(shù)不小于30%。沼氣中甲烷在30s內(nèi)的體積分數(shù)變化率不應超過2%，機組連續(xù)運行期間沼氣中甲烷體積分數(shù)變化率不超過5%。

(1) The low calorific value of biogas is ≥ 14MJ/Nm, which is equivalent to a methane volume fraction of no less than 30% in biogas. The change rate of methane volume fraction in biogas within 30 seconds should not exceed 2%, and the change rate of methane volume fraction in biogas during continuous operation of the unit should not exceed 5%.

(2) 沼氣溫度不高于50℃。

(2) The temperature of biogas shall not exceed 50 ℃.

(3) 沼氣發(fā)電機組對沼氣成分的具體要求如下表。

(3) The specific requirements for biogas composition of biogas generator units are shown in the table below.

注：沼氣體積的標準參比條件是101.3kPa，20℃；按照沼氣中所含硫成分全部轉(zhuǎn)化為硫化氫計算。

Note: The standard reference conditions for biogas volume are 101.3kPa, 20 ℃; Calculate based on the conversion of all sulfur-containing components in biogas into hydrogen sulfide.

①H2S對發(fā)電機組的影響

① The impact of H2S on generator sets

沼氣發(fā)電時沼氣中的H2S會對沼氣發(fā)電機組的進氣管道、增壓器、中冷器、火花塞、氣缸套、排氣管和消音器等造成嚴重腐蝕，從而影響機組壽命，所以沼氣在進入發(fā)電機組之前必須進行沼氣預處理，將H2S降到機組允許的范圍內(nèi)才能保證機組的可靠運行。

During biogas power generation, the H2S in the biogas can cause serious corrosion to the intake pipes, superchargers, intercoolers, spark plugs, cylinder liners, exhaust pipes, and silencers of the biogas generator set, thereby affecting the lifespan of the unit. Therefore, before biogas enters the generator set, biogas pretreatment must be carried out to reduce the H2S to the allowable range of the unit in order to ensure the reliable operation of the unit.

②水分對發(fā)電機組的影響

② The impact of moisture on generator sets

沼氣發(fā)電過程中，沼氣水分含量過大，會導致發(fā)電機組的進氣壓力損耗過大，嚴重情況下，會引起發(fā)動機功率波動、敲缸、停機等問題，嚴重地影響其使用壽命。其具體表現(xiàn)為：

In the process of biogas power generation, excessive moisture content in biogas can lead to excessive loss of intake pressure of the generator set. In severe cases, it can cause problems such as engine power fluctuations, cylinder knocking, and shutdown, seriously affecting its service life. Its specific manifestation is:

(a)發(fā)動機點火困難；

(a) Difficulty in engine ignition;

(b)降低燃燒室溫度，降低內(nèi)燃機效率；

(b) Reduce the temperature of the combustion chamber and reduce the efficiency of the internal combustion engine;

(c)水蒸氣等無功氣體的存在，會增壓和增大功耗；

(c) The presence of reactive gases such as water vapor can increase pressure and power consumption;

(d)水蒸氣與其他酸性物質(zhì)化合產(chǎn)生的中間產(chǎn)物，會對發(fā)電機組產(chǎn)生腐蝕，縮短使用壽命，降低可靠性。

(d) The intermediate products produced by the combination of water vapor and other acidic substances can corrode the generator set, shorten its service life, and reduce its reliability.

③粉塵對發(fā)電機組的影響

③ The impact of dust on generator sets

粉塵是發(fā)動機明確限制的雜質(zhì)，它主要影響在于：

Dust is a clearly restricted impurity in engines, and its main impact is:

(a)堵塞管路，流通不暢，加大壓損，增加運行費用；

(a) Blocking the pipeline, poor circulation, increased pressure loss, and increased operating costs;

(b)增大機械磨損，降低設備使用壽命。

(b) Increase mechanical wear and reduce equipment service life.