CN106153128A - Compressor flow based on gas temperature rise and efficiency measurement instrument - Google Patents

Abstract

The invention discloses a kind of compressor flow based on gas temperature rise and efficiency test instrument, including thermometer, Pressure gauge, transformer, analog-digital converter, data processor and display, wherein thermometer is arranged on the import and export of blower fan, importing and exporting at blower fan and install Pressure gauge near blower fan, transformer is arranged on motor power line.The holding wire of thermometer, Pressure gauge and transformer is connected with analog-digital converter, and analog-digital converter is connected with processor by data wire, and processor is connected with display by data wire simultaneously.

Description

Compressor flow based on gas temperature rise and efficiency measurement instrument

Technical field

The present invention relates to the test instrumentation of compressor flow and efficiency.

Background technology

In production technology, it is possible to determine that the flow of blower fan produces for optimized production process, raising with efficiency accurately Efficiency and reduction fan energy consumption have critically important effect.

Existing frequently-used compressor flow measuring instruments is based on velocity field method, i.e. in certain of the import or export air channel of blower fan Individual position, uses gridding method to utilize the measurement devices such as pitot tube to go out at this gas dynamic pressure of every bit on duct cross-section, then profit The speed v of this point is calculated with bernoulli principle_i, recycling following formula calculates the volume flow of gas in this cross section:

$V=\frac{\underset{i=1}{\overset{n}{\Σ}}{v}_i}{n}S---\left(1\right)$

Area of section is measured in S is air channel in formula.

According to the compressor flow measured, the following formula that usually uses of fan efficiency calculates:

$\mathrm{\η}=\frac{V\mathrm{\Δ}p}{W}---\left(2\right)$

In formula, V is the volume flow of blower fan, and Δ p is that blower fan import and export total head is poor, and W is the shaft power inputing to blower fan.

Use said method, be more accurate when fan air channel flow field is more uniform.But many times produce In order to reduce floor space during system design, often structure comparison is compact, causes air channel how curved, and straight length is short, so test cuts There is bigger speed difference in the choose requirement that can not meet accurately measurement, such as measurement cross section in face, or there is whirlpool local Or backflow phenomenon, bring bigger error all can to the measurement of flow and efficiency, relative error is even more than more than 10%.

Summary of the invention

The deficiency existed for prior art, it is desirable to provide a kind of compressor flow based on gas temperature rise and efficiency Measuring instruments.

The technical solution used in the present invention is:

A kind of compressor flow based on gas temperature rise and efficiency measurement instrument, by measuring the temperature of blower fan import and export gas Degree, ambient pressure and blower fan inlet and outlet pressure, measure the power of input motor simultaneously, by measuring gas temperature rise solving equation Method calculate flow and the efficiency of blower fan.

The principle of the invention is clear and definite, and simple in construction, precision is higher.

Accompanying drawing explanation

Accompanying drawing is the system schematic of the present invention.

Detailed description of the invention

The present invention is described in further detail below in conjunction with the accompanying drawings.

Description of reference numerals is as follows:

1 motor power line 2 current transformer 3,4,10,13,14,19,24 holding wire

5 analog-digital converter 6,8 data wire 7 processor 9 display

11 atmospheric pressure measurement device 12 fan outlet 15,20 pressure gauges

16,17 temperature measuring equipment 18 fan inlet 21 blower fan 22 motor

23 voltage transformers

In embodiment as depicted, temperature measuring equipment 17 is installed in fan inlet 18, and pressure gauge 20 is pacified It is loaded on the wall of fan inlet 18.Temperature measuring equipment 16 is installed in fan outlet 12, and pressure gauge 15 is installed on On the wall of fan outlet 12.Atmospheric pressure measurement device 11 is arranged near blower fan 21.Current transformer 2 and voltage transformer 23 are arranged on the power line 1 of motor 22.Current transformer 2, temperature are surveyed by holding wire 3,4,10,13,14,19,24 respectively Amount device 16, atmospheric pressure measurement device 11, pressure gauge 15, temperature measuring equipment 17, pressure gauge 20 and Voltage transformer 23 is connected on analog-digital converter 5, and analog-digital converter 5 is connected on processor 7 through data wire 6, processor 7 Link together with display 9 through data wire 8.

The operation principle of this embodiment is, utilizes temperature measuring equipment 17 and pressure gauge 20 by fan inlet 18 The temperature of gas with pressure measxurement out, utilizes temperature measuring equipment 16 and pressure gauge 15 by the temperature at fan outlet 12 Degree with pressure measxurement out, utilizes atmospheric pressure measurement device 11 to be measured by the environment atmospheric pressure near blower fan, simultaneously Utilize current transformer 2 with voltage transformer 23 by the input current of motor 22 with voltage measurement out.Survey at above-mentioned parameter After measuring, after measurement signal is converted to digital signal by analog-digital converter 5, it is input to processor by data wire 6 In 7, the flow of blower fan 21 out and is shown on the display 9 with efficiency calculation by processor 7 through utilizing energy method.

The principle of this energy method is, after neglecting blower fan surface radiating, the gas temperature rise flowing through blower fan 21 is absorbed Energy and fan outlet 12 at gas kinetic energy and fan inlet 18 gas kinetic energy difference and motor 22 should be equal to Output, it may be assumed that

$W=c_{p}m(T_2-T_1)+\frac{1}{2}m(v_2^2-v_1^2)---\left(3\right)$

In formula: W is the output of motor 22, c_pFor the specific heats of gases, m is gas mass flow, T₂、T₁It is wind respectively The thermodynamic temperature of gas, v at machine outlet 12 and fan inlet 18₂For gas average speed, v at fan outlet 12₁Enter for blower fan Gas average speed at mouth 18, wherein:

$v_1=\frac{m}{S_1{\mathrm{\ρ}}_1}---\left(4\right)$

$v_2=\frac{m}{S_2{\mathrm{\ρ}}_2}---\left(5\right)$

S in formula₁For fan inlet 18, area of section at pressure gauge 20, S are installed₂For fan outlet 12, pressure is installed Area of section at measurement apparatus 15.

Gas density ρ uses following formula to calculate:

$\mathrm{\ρ}=\frac{p+p_0}{RT}---\left(6\right)$

In formula p be pressure gauge 21,15 measure fan inlet 18, meter pressure at fan outlet 12, p₀ Environment atmospheric pressure near blower fan 21 out measured by atmospheric pressure measurement device 11, R is gas constant, and T is gas Thermodynamic temperature.

So, formula (6) is substituted in formula (4), formula (5), then formula (4), formula (5) are substituted in formula (3), further according to motor Current value, magnitude of voltage, power factor and the efficiency value of 22 calculate output, by solving formula (3) about the one of flow Individual cubic equation just can by blower fan 21 flow rate calculation out.After calculating the flow of blower fan, fan efficiency can also be held very much Easy calculates.

If fan inlet 18 is in ambient air, then the v in formula (3) can be made₁=0.

Owing to the temperature field at fan inlet 18 and fan outlet 12 and the static pressure field of force are relatively uniform, especially temperature field is very Uniformly, so Novel air measurement instrument certainty of measurement proposed by the invention is higher, when measuring high-head blower fan 21, such as When blower fan 21 pressure head is more than 5kPa, measuring relative error and can control within 5%, pressure head is the highest, and certainty of measurement is the highest, when When pressure head is more than 15kPa, measures relative error and can control within 1.5%.

The present invention is not limited to above-mentioned embodiment, and anyone can draw other various forms under the enlightenment of the present invention Product.Though but in its shape or structure, make any change, technical scheme as the every and present invention is same or like, all Within its protection domain.

Claims (3)

1. a compressor flow based on gas temperature rise and efficiency measurement instrument, it is characterised in that include temperature measuring equipment, pressure Force measuring device, atmospheric pressure measurement device, current transformer, voltage transformer, analog-digital converter, data processor and aobvious Showing device, wherein the import of blower fan and outlet are respectively mounted temperature measuring equipment and pressure gauge, and atmospheric pressure measurement device is pacified Being contained in position near blower fan, electric current and voltage transformer are arranged on motor power line, temperature measuring equipment, pressure measxurement dress Put, the holding wire of atmospheric pressure measurement device, current transformer and voltage transformer is connected with analog-digital converter, and modulus turns Parallel operation is connected with processor by data wire, and processor is connected with display by data wire simultaneously.

Compressor flow based on gas temperature rise the most according to claim 1 and efficiency measurement instrument, it is characterised in that at wind Pressure gauge and temperature measuring equipment are installed in machine near exit air channel.

Compressor flow based on gas temperature rise the most according to claim 1 and efficiency measurement instrument, it is characterised in that at wind Pressure gauge and temperature measuring equipment are installed in air channel near machine import.