CN100453888C - Correction methods of online fluid system - Google Patents

Abstract

The invention relates to a method for correcting the online fluid system, comprises that 1, selecting the node of online fluid system, measuring the fluid pressure; 2, measuring the power of power device; 3, checking the tube of system; 4, measuring the character of tubes; 5, replacing the power device. The invention can improve the efficiency of power device 10% higher than general condition, reduce energy consumption more than 40%, and prolong the service life of fluid transmitter.

Description

A kind of method for correcting error of online fluid system

Technical field

The invention belongs to FLUID TRANSPORTATION or circulatory system technical field, particularly a kind of method for correcting error of online fluid system.

Background technique

The FLUID TRANSPORTATION or the circulatory system are widely used in such as major works fields such as building air-conditioner device, coolings, and its power consumption is huge.At present, ubiquity dynamic power machine and unreasonable, the unscientific problem of system matches in the FLUID TRANSPORTATION or the circulatory system, promptly is commonly called as the phenomenon of " low load with strong power ", causes the significant wastage of the energy, increases huge cost expenditure for engineering application units.

Be that example illustrates below with the central air-conditioning system.Central air-conditioner is widely used in mansion, hotel, restaurant etc., and it comfortable the time, also is the main dissipative system in the building for people life brings.Central air-conditioner essence is that a kind of that refrigerator compresses, expands refrigerant or concentrate, evaporates put, endothermic process.System water is mediated, and by the exchange of cold/heat and with cold/heat delivery each air conditioner end equipment to building, mediates with wind then, carries out cold/exchange heat, and the coldest/heat delivery is to building space.The cold that refrigerator produces drains into outdoor by the cooling tower pectinid cooling that another cooling water system is delivered to roof.The continuous circulation of said process constitutes central air-conditioning system.

The energy consumption of central air-conditioning system mainly contains following three bulks: 1, refrigerator Driven Compressor or add the energy consumption of heat medium; 2, air-conditioning water pump water send cold/heat to overcome the energy consumption of resistance to water-flow; 3, air-conditioning draught fan wind send cold/heat to overcome the energy consumption of distinguished and admirable resistance.

In construction project, the conventional design of central air conditioning water system and selection water pump are by the most unfavorable processing condition design and coupling, but the actual motion of central air-conditioning system is to adopt one or more refrigerator to make up operation by the refrigeration duty requirement that changes; Simultaneously, when the design dosage, refrigerator has the surplus capacity of 100-200% again, and this must be in big flow, poor efficiency, the operation down of high power consumption state with regard to making the water pump of selecting with the most unfavorable processing condition design, cause operation water pump and system performance not to match, the power consumption of significant wastage water pump.

In view of the water pump of central air-conditioning system has big surplus capacity, people come energy-conservation by control startup-shutdown time and main frame temperature.Occur for the previous period adopting the pump variable frequency adjusting method to come energy efficient, power saving rate is at 20-40%, and the water pump actual operating efficiency is at 40-60%, the power consumption 3-5% of frequency variator own, in addition, when pump rotary speed reduced, its efficient also will reduce by the likelihood relation, therefore adopt single energy-saving and frequency-variable scheme, system energy consumption is still than higher.So, seek a kind of actual load operation power coupling to online fluid system, from the energy consumption problem of power source solution " low load with strong power ", be technical problem to be solved by this invention.

Summary of the invention

The invention discloses a kind of method for correcting error of online fluid system, its objective is and utilize this method for correcting error that the online FLUID TRANSPORTATION or the circulatory system are realized the optimum condition operation.

For achieving the above object, the technical solution used in the present invention: a kind of method for correcting error of online fluid system, online fluid system is implemented following correction step successively:

1. be chosen at the node of linear flow system, measuring fluid pressure;

2. the power of measuring system dynamic power machine;

3. the problem of diagnostic system pipeline existence addresses these problems by the minimum principle of motion water system resistance;

4. draw characteristic curve of pipeline, determine the optimal operating condition point;

5. the dynamic power machine of replacing system.

The method for correcting error of described online fluid system, hydrodynamic pressure adopt pressure gauge or vacuum gauge that the equipment and the pipeline turnover mark of system are pressed measurement.

The method for correcting error of described online fluid system, dynamic power machine are pump or fans, and the operate power of pump or fan (N) adopts wattmeter to measure, or measure electric current I, voltage U, power factor Cos Φ, calculate as follows: $N=\sqrt{3}\mathrm{IUCos\Φ}.$

The method for correcting error of described online fluid system, the design power of the pump or fan of system layout and operate power are compared, and determine the optimal working point of pump or fan, by principle of optimality displacement pump or fan.

Method for correcting error of the present invention can be used for the various online FLUID TRANSPORTATION or the circulatory system, as the FLUID TRANSPORTATION or the circulatory systems such as central air-conditioning system, metallurgy, iron and steel, oil.

Make because of strong vibration that inflow-rate of water turbine causes, big noise, poor efficiency, high-power unfavorable operating mode operation by method for correcting error of the present invention and to be improved or to eliminate, improve the efficient of dynamic power machine, dynamic power machine operates steadily, phenomenons such as no hot, vibration, noise make the dynamic power machine of the online FLUID TRANSPORTATION or the circulatory system be in the operation of optimum condition state.

The realization of deviation correcting technology scheme of the present invention has solved the power matching problem of " low load with strong power " in the online FLUID TRANSPORTATION or the circulatory system, dynamic power machine efficient exceeds 10% than routine, it is also little than intrinsic to take up space, and energy consumption declines to a great extent, and energy-saving effect reaches more than 40%; Simultaneously, the life-span of the FLUID TRANSPORTATION or the circulatory system prolongs.

Description of drawings

Fig. 1 is that the central air conditioning water system of the embodiment of the invention detects schematic representation.

Fig. 2 is mechanical water pump characteristic and characteristic curve of pipeline figure.

Embodiment

Below in conjunction with accompanying drawing embodiments of the invention are elaborated.

As shown in Figure 1, 2, by of the rectify a deviation processing of following five steps to certain online central air conditioning water system.

1, adopt pressure gauge or vacuum gauge that the equipment and the pipeline of central air conditioning water system are carried out hydrodynamic pressure mensuration.

(1) water-in and water-out node a, the b of water pump 2 in the selecting system measure water pump and press H into and out of mark ₁, H ₂, draw pump head H=H then ₂-H ₁, look into pump characteristic, obtain water flow Q.

(2) choose heat-exchange device 3 into and out of node c, d, measure heat-exchange device and press into and out of mark, try to achieve the heat-exchange device internal resistance of operation.

(3) measure the pond 1 of open system and the geometry discrepancy in elevation Δ H of cooling tower 4.

2, measure water pump operation power N.

Directly measure with wattmeter, perhaps, obtain as follows according to measuring electric current I, voltage U, power because of table Cos Φ: $N=\sqrt{3}\mathrm{IUCos\Φ}---\left(\mathrm{KW}\right)$

3, diagnosis water system pipeline existing problems: valve leak, system short-circuit, plugged filter, close valve operation etc., address these problems by the most minimum principle of operation water system resistance for preventing the water pump overload.

4, paint characteristic curve of pipeline, determine the optimal operating condition point.

According to hydrodynamic equations, the total head of water pump or water system drag overall H are:

$H=\underset{n=1}{\overset{n}{\mathrm{\Σ}}}\mathrm{hn}+\mathrm{\ΔH}+\frac{v^2}{2g}---\left(M\right)$

In the formula:

For water system along journey drag overall (M)

How much lifts (M) of Δ H water pump

Be dynamic resistance (M)

Wherein, gravity acceleration g=9.8 meter per seconds ², the pipeline flow velocity is pressed the V=1-2 meter per second, therefore, and actual dynamic resistance

Be worth very for a short time, when systems engineering designs, can ignore.

Water system square is directly proportional along journey drag overall and water flow, that is:

$\underset{n=1}{\overset{n}{\mathrm{\&Sigma;}}}\mathrm{hn}={\mathrm{<figure-callout\; id="2"\; label="KQ"\; filenames="C20071006687300111.png"\; state="\{\{state\}\}">KQ</figure-callout>}}^2$

In the formula: K is a constant, and is only relevant with the water system characteristic.

So, water pump total head or water system drag overall H=KQ ²+ Δ Ho

Obtain the characteristic of system pipeline by actual measurement water pump total head or water system drag overall, how much lifts of water pump.

H=KQ ²+ Δ H is a water system pepeline characteristic equation, and the parabola by water pump operation point is the characteristic curve of pipeline, as shown in Figure 2.Satisfy the optimal working point that C point on the characteristic curve of pipeline of water system requirement water flow is water pump operation.

5, water-change pump more.

Press optimal working point (flow Q _A, lift H _C) select water pump to replace the water pump that original system is installed.

As shown in Figure 2, the X curve is the characteristic curve of pump of original system design and installation, and the Y curve is system's correction back characteristic curve of pipeline, and the Z curve is the high efficiency energy saving pump performance curve of installing after method for correcting error of the present invention is handled; P is the power curve of original system water pump, and P ' is the power curve of correction back water pump; O is the efficiency curve of original system water pump, and O ' is the efficiency curve of correction back water pump.

A is former design pump operating point: flow Q _A, lift H _A, pump shaft power N _A, pump efficiency η _A

The actual conditions point that measures system is B: flow Q _B, lift H _B, pump shaft power N _B, pump efficiency η _B

As shown in Figure 2: intrinsic high-lift pump is actual to be in low lift, big flow, poor efficiency, the operation of high power consumption state, when serious even burn motor.

Detect by system, analyze and cause the reason of high energy consumption and carry out optimal design, by system's actual conditions operation, pass through H=KQ again by the actual measurement parameter ²+ Δ H formula obtains the characteristic curve of pipeline of water system, and the flow on the curve is design discharge Q _AThe C point be water system optimum condition (Q _A, H _C) operating point, be equipped with at last and be in optimal working point operation, most effective water pump, be high efficiency energy saving pump, the operating conditions of this pump is: flow Q _A, lift H _C, air horsepower N _C, efficiency eta _C

Among Fig. 2, O, H _B, B, Q _B, O institute region is the energy consumption of former design water pump operation, O, H _C, C, Q _C, O institute region handles the energy consumption of the energy-efficient pump operation of installing the back for adopting method for correcting error of the present invention, the two difference is energy consumption of saving.

Test one: certain building adopt two 1,000,000 kilocalories/time the TRANE screw-type water chiller, join three IS 150-125-400B 30KW refrigerant pumps, three IS 200-150-400C 45KW coolant pumps, the design objective of original system and actual measurement operating mode such as table 1.

Table 1: water pump design objective and actual operating mode are relatively

Handle by method for correcting error of the present invention, change the water pump of original system, select two ALB 125/26B15KW refrigerant pumps, two ALB 150/26A 22KW coolant pumps.Actual operating mode was as shown in table 2 after the design objective of water pump was handled with correction.

Table 2: the design objective of high efficiency energy saving pump and the operating conditions of actual measurement

The heating in this building is shared with the refrigeration water pump, and calculated with 2400 hours year working time, and after method for correcting error of the present invention was handled, annual total amount of electricity saving was 167520 degree, and electricity price can be saved 117264 yuan of the electricity charge every year by 0.7 yuan/degree.

Test two:

Two 355KW coolant pump operations are joined by the blast-furnace cooled water system that certain factory is 40 cubic metres.

After method for correcting error of the present invention is handled, join two 220KW coolant pump operations, power saving rate 44.69%, 315.8 degree that per hour economize on electricity, annual economize on electricity 272.88 ten thousand degree are counted 150.08 ten thousand yuan.

Test three:

Certain the configuration 75KW of power plant pump operating cycle.

After method for correcting error of the present invention is handled, join the 37KW pump operating cycle, power saving rate 57.5%, 46 degree that per hour economize on electricity, 35.88 ten thousand degree can economize on electricity every year.

Test four:

The air-conditioning of certain company, cooling water system five 90KW coolant pumps operation under unified central planning.

After method for correcting error of the present invention is handled, join five 55KW coolant pump operations, power saving rate 47.1%, 212 degree that per hour economize on electricity, 1,900,000 degree that can economize on electricity every year are counted 1,240,000 yuan.

Test five:

200 tons in certain factory/time circulating fluidized bed boiler join two 1000KW induced draught fans operations, the actual measurement operate power is 2X 548.5KW, the operational efficiency of blower fan is 33%, after handling, adopts method for correcting error of the present invention a 550KW induced draught fan, the operate power of design is 352.4KW, per hour economize on electricity 744.6 the degree, the power saving rate of blower fan is 67.88%, the operational efficiency 70% of blower fan.

Claims (4)

1, a kind of method for correcting error of online fluid system is characterized in that: online fluid system is implemented following correction step successively:

1. be chosen at the node of linear flow system, measuring fluid pressure;

2. the power of measuring system dynamic power machine;

3. the problem of diagnostic system pipeline existence addresses these problems by the minimum principle of motion water system resistance;

4. draw characteristic curve of pipeline, determine the optimal operating condition point;

5. the dynamic power machine of replacing system.

2, the method for correcting error of online fluid system according to claim 1 is characterized in that: hydrodynamic pressure adopts pressure gauge or vacuum gauge that the equipment and the pipeline turnover mark of system are pressed measurement.

3, the method for correcting error of online fluid system according to claim 1, it is characterized in that: described dynamic power machine is a pump or fan, the operate power of pump or fan adopts wattmeter to measure, or measures electric current I, voltage U, power factor Cos Φ, calculates as follows: $N=\sqrt{3}\mathrm{IUCos\&Phi;},$ N is the operate power of pump or fan.

4, the method for correcting error of online fluid system according to claim 3 is characterized in that: the design power of the pump or fan of system layout and operate power are compared, and determine the optimal working point of pump or fan, by principle of optimality displacement pump or fan.

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