Method for analyzing absolute energy efficiency and relative energy efficiency of compressed air system

Abstract

The invention relates to a compressed air system operation monitoring technology, and aims to provide a method for analyzing absolute energy efficiency and relative energy efficiency of a compressed air system. For a compressed air system running in a single-machine form, the gas production rate of a compressor running in a single machine and the corresponding running power are measured under thestate of appointing the value of the gas flow; meanwhile, influence factors during operation of the compressor are monitored; the absolute energy efficiency of the compressor is defined, and the absolute energy efficiency of the compressor, which changes along with the running time, and the numerical value change curve of each influence factor are drawn in the same coordinate system; and the influence on the absolute energy efficiency of the compressor is corrected according to the definition of the user side on the gas standard state in combination with the monitoring result of each influencefactor to obtain the absolute energy efficiency data of the compressor in the corresponding state. According to the method, through absolute energy efficiency analysis under the corresponding state conditions, the actual unit consumption and the change rule of the given single machine under different production and environment working conditions can be visually analyzed on the basis of the corresponding chart form.

Description

technical field [0001] The invention relates to a compressed air system operation monitoring technology, in particular to an analysis method for the absolute energy efficiency and relative energy efficiency of the compressed air system. Background technique [0002] In metallurgy, non-ferrous metals, steel, chemical and petrochemical industries, compressed air is an important energy source, and its system is a typical nonlinear dynamic system, whose operation is directly affected by changing environmental conditions and production load intensity. The language is complex and changeable. For such a complex system, the parameters that can be monitored by traditional design, operation and maintenance are a series of coupled process parameters, such as compressor discharge pressure, flow rate, discharge temperature, compressed air temperature at all stages of inlet and outlet, and motor voltage. , Motor current, motor power, inlet guide vane opening, bypass valve closing, etc. ...

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Problems solved by technology

The problem with these parameters is that they are all coupling parameters, and it is difficult to judge the operating status of the system based on one of them, especially the energy efficiency status.

The problems existing in this system are manifested in the following aspects: 1) The analysis of the whole station lacks the basis for single machine analysis; 2) The compressed air station is composed of different compressors, and the operating time ratio of different equipment is different, which will lead to the failure of the air compressor station. There are differences in the operating characteristics of the system, and the system cannot characterize this change process; 3) Compression heat energy recovery rate η w In the expression of , the numerator involves the values ​​of the inlet pressure and the header pressure, which change in real time (instantaneous and total energy consumption are contradictory, instantaneous is power, total energy consumption is electricity, and power is variable), while the value of the denominator is a certain The power consumption of a period of time, there is a contradiction between these two concepts; 4) Compression heat energy recovery rate η w The expression of is equivalent to the shaft power of an isothermal process, and under the corresponding working conditions, the power of the motor should also consider the characteristics of the motor, that is, the conversion efficiency of the motor under different load intensities, and the analysis of this effect is lacking in the formula; 5) The introduction of waste heat recovery efficiency actually contradicts GB19153

The problem of waste heat recovery should be analyzed separately. Considering GB19153, access to waste heat recovery must be super-level energy efficient, but this is parallel to the operating efficiency of the compressor itself

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