According to the theory of hydrodynamics, the flow process of gas will be accompanied by loss. For example, after the gas flows through the throttling device, the pressure of the air flow will be reduced accordingly, that is, they lose the active work of the fan. Because all this happens in the process of gas conveying by the fan, that is, the energy of the fan is wasted.

風(fēng)機(jī)工況點(diǎn)是風(fēng)機(jī)在某一轉(zhuǎn)速下的性能曲線與管網(wǎng)阻力特性線的交點(diǎn)。風(fēng)機(jī)實(shí)際運(yùn)行時(shí)，并非永遠(yuǎn)停留在設(shè)計(jì)工況點(diǎn)上。它將隨用戶的需求或外界條件的變化而變化，也就是風(fēng)機(jī)實(shí)際上處于變工況下工作。要想使風(fēng)機(jī)的風(fēng)壓或風(fēng)量達(dá)到某一目標(biāo)值，就需要對(duì)風(fēng)機(jī)或管網(wǎng)進(jìn)行為人為地控制，亦稱調(diào)節(jié)。通過有效地調(diào)節(jié)，實(shí)現(xiàn)在保證風(fēng)機(jī)能夠穩(wěn)定工作的條件下，既要滿足生產(chǎn)對(duì)流量或壓力的要求，又能限度地節(jié)能。簡(jiǎn)言之，調(diào)節(jié)的目的就是滿足性能要求，擴(kuò)大（穩(wěn)定）工況，實(shí)現(xiàn)節(jié)能，防止喘振。

The operating point of the fan is the intersection of the performance curve of the fan at a certain speed and the resistance characteristic line of the pipe network. During the actual operation of the fan, it does not always stay at the design working condition point. It will change with the needs of users or changes in external conditions, that is, the fan actually works under variable working conditions. In order to make the air pressure or air volume of the fan reach a certain target value, it is necessary to artificially control the fan or pipe network, also known as regulation. Through effective regulation, it can not only meet the requirements of production for flow or pressure, but also save energy to a certain extent under the condition that the fan can work stably. In short, the purpose of regulation is to meet the performance requirements, expand (stabilize) working conditions, save energy and prevent surge.

風(fēng)機(jī)采用不同的調(diào)節(jié)方式都可達(dá)到同一目的，但節(jié)能效果各不相同。

Different adjustment methods of fan can achieve the same purpose, but the energy-saving effects are different.

根據(jù)理論分析及實(shí)踐證明，可得出如下4個(gè)方面的結(jié)論。

According to theoretical analysis and practical proof, the following four conclusions can be drawn.

⑴對(duì)于鼓風(fēng)機(jī)和壓縮機(jī)，出口節(jié)流調(diào)節(jié)方式耗功最多。盡管相對(duì)流量Qr（實(shí)際流量Q與設(shè)計(jì)流量Q0之比）減少時(shí)，功率亦相應(yīng)減少。如當(dāng)Q=0.65Q0時(shí)，所對(duì)應(yīng)的功率減少到原來的80%左右，但與其它調(diào)節(jié)方式相比，耗能仍居重要位置。

(1) for blowers and compressors, the outlet throttling regulation mode consumes the most power. Although the relative flow QR (the ratio of actual flow Q to design flow Q0) decreases, the power also decreases accordingly. For example, when q = 0.65q0, the corresponding power is reduced to about 80%, but compared with other regulation methods, energy consumption still occupies an important position.

⑵如果相對(duì)流量變化不大時(shí)（或稱調(diào)節(jié)深度小時(shí)），幾種調(diào)節(jié)方式耗功差別不大。即調(diào)節(jié)方式對(duì)節(jié)能效果影響不大，甚至不僅不節(jié)能，反而因調(diào)節(jié)裝置的存在多耗功（如液力耦合器）。

(2) if the relative flow changes little (or the regulation depth is small), there is little difference in power consumption among several regulation modes. That is, the regulation mode has little impact on the energy-saving effect, or even does not save energy, but consumes more power due to the existence of the regulation device (such as hydraulic coupler).

⑶一般來說，調(diào)節(jié)深度越大，節(jié)能效果越顯著。因此，要慎重選擇調(diào)節(jié)方式，以期獲得效益。

(3) generally speaking, the greater the adjustment depth, the more significant the energy-saving effect. Therefore, we should carefully choose the regulation mode in order to obtain benefits.

⑷變速調(diào)節(jié)曲線接近理想曲線。所以，變速調(diào)節(jié)方式優(yōu)越，特別是采用變頻電動(dòng)機(jī)調(diào)速的節(jié)能方案為好，但需要增設(shè)變頻裝置。對(duì)于中小容量的變頻調(diào)速建議積極試用；由于大容量高電壓變頻調(diào)速裝置價(jià)格較高，應(yīng)結(jié)合具體情況，綜合比較，決定取舍?？傊?，既要考慮調(diào)節(jié)性能，也要考慮設(shè)備初投資、可靠性及經(jīng)濟(jì)性等，全 面評(píng)價(jià)調(diào)節(jié)方式的優(yōu)劣。

(4) the speed regulation curve is close to the ideal curve. Therefore, the variable speed regulation mode is superior, especially the energy-saving scheme of variable frequency motor speed regulation is better, but the variable frequency device needs to be added. It is recommended to actively try out frequency conversion speed regulation with small and medium capacity; Due to the high price of high-capacity and high-voltage variable frequency speed regulation device, the choice should be determined by comprehensive comparison in combination with specific conditions. In short, we should not only consider the regulation performance, but also consider the initial investment, reliability and economy of the equipment, and comprehensively evaluate the advantages and disadvantages of the regulation mode.