Those who be in a factory is actual in moving process, the tolerance of frontal a system of fixed quotas for grain production that compresses a station via often can encountering air and differ actually with gas demand bigger, air reduces aircrew working load low, be in blame economy to run the condition of the area, the moving efficiency that brings about air to compress a station drops, create the waste of the sources of energy. Be aimed at afore-mentioned problems, the factory connects regular meeting to compress a station undertake to air energy-saving transform, pass those who adjust air compressor to provide a measure, change the means such as the air compressor with rated lesser capacity, make its work as far as possible in concentrated area, in order to achieve energy-saving goal.

Be in energy-saving in transformed process, want to undertake air compressor type selecting, always produce tolerance what should decide air compresses a station above all. As a result of the client side be not with tolerance completely changeless, put in constant wave motion however, run data through what check actually, how to decide to use tolerance interval reasonably, become air to compress a station energy-saving transform the problem that should solve above all. What if use gas interval,install is too big, criterion air compressor still is in inferior bear next moving, still the sources of energy is wasted; If use gas interval to had been installed small, empty atmospheric pressure shrinks the peak value requirement that the quantity of the biggest air feed of the station cannot satisfy production possibly to use gas, affect the normal production of the client side thereby, absolutely cannot take this.

The author is right in the job this kind of problem that encounter undertook reflection deep, set out from statistical viewpoint, the moving data that compresses a station to air undertakes an analysis, decide to use tolerance interval reasonably thereby, compress a station for air energy-saving transformed type selecting provided a basis. Undertake demonstrative through real case below.

The compressor of centrifugal type air that air of factory of some solar battery compresses a station to deploy 3 model to agree completely at present, 500kW of rated power of every air compressor, tolerance of frontal a system of fixed quotas for grain production is 70m^{3}/min. Its on Feburary 15, 2019 – 24 days of moving data see a table 1.

The basis runs data, produce tolerance on average what computation can reach this air compresses a station to be 138.56m^{3}/min, mean the biggest tolerance is 162.66m^{3}/min, instantaneous is the biggest tolerance is 160.70m^{3}/min.

Statistical knowledge tells us, standard deviation is to reflect a group of statistic index that measure data disperse level, the extent that points to statistical result to fluctuate up and down in the error inside certain period of time, it is one of important parameter of normal school.

To normal school, variable falls in (μ-1σ , μ+1σ ) the probability inside interval is 0.6827, variable falls in (μ-2σ , μ+2σ ) the probability inside interval is 0.9544, variable falls in (μ-3σ , μ+3σ ) the probability inside interval is 0.9974. In actual project application, the average of data of usable actual measurement replaces μ , standard deviation S replaces σ .

Standard deviation:

We have consideration to expressing 1 medium carry linage to occupy, compress a station clean is angrily the standard deviation S=9.60 M3/min of average discharge (the average flow that gives as a result of 24 days of computation is 107.66 M3/min, differ with other figure bigger, computation gives when standard deviation eliminate) . What choose the standard deviation air of 2 times to compress a station from this is the biggest produce tolerance to be:

The probability that produces tolerance to be less than 157.56m^{3}/min is 0.9544, and be in statistical on, produce probability to be maintained to be small probability incident under the incident of 0.05, reason holds this option reasonable.

From this, can compress a station to undertake as follows to this air energy-saving transform: Compressor of air of 2 when keep original centrifugal type is changeless, its always produce tolerance to be 140m^{3}/min, consider to certain abundant amount needs in actual process, change compressor of air of a centrifugal type not to have compressor of air of oily screw type for so, tolerance of frontal a system of fixed quotas for grain production is 30m^{3}/min, can satisfy manufacturing need.

Author brief introduction

Li Genchen, male, engineer, be graduated from university of Xi’an electron science and technology, electrician of Xi’an traffic university Master Cheng (reading) , currently hold the post ofgrand radical green can project of center of general affairs of production factory of science and technology manages an engineer of active system chairman, basically be in charge of energy-saving and relevant job.