IS 13980 : 1995 Acceptance tests on industrial boilers - Code of practice

1 Scope

1.1 Purpose

The purpose of this code is to establish procedures forconducting acceptance tests on industrial steam generating unitsand hot water boilers of the water tube type with capabilitieslarger than 25 tonnes FA 100�C of steam per hour,generally as envisaged in Fig. 1. The standard applies to unitsburning solid fuels fired by hand or by mechanical stokers orpulverized fuel firing equipment as well as liquid or gaseous fuel.It does not apply to packaged boilers which are, to a large extent,shop assembled. It also does not apply to dual fired or waste heatunits which require a more specialized for of dry and wet gas heatloss measurement. The code lays the procedure to determine:

a) gross thermal efficiency,

b) rating of the units, and

c) other relating operating parameters such as steam temperatureand control range.

1.2 Methods of Testing

Instructions are given for two acceptable methods of testingsteam boilers to determine efficiency. One method is the directmeasurement of input and output, hereinafter referred to as theinput-output method. The other method is the direct measurement ofheat losses and is hereinafter referred to as the heat loss method.The method followed in conducting the test shall be clearly definedin the report. The generating units shall preferably be tested byheat loss method, as the errors involved are too large to controlin large installation by input-output method.

1.2.1 The input-output method requires the accurate measurementof the quantity and high heat value of the fuel, heat credits andthe heat absorbed by the working fluid or fluids.

1.2.2 The heat loss method requires the determination of losses,heat credit and ultimate analysis and high heat value of the fuel.To establish the capacity at which the losses occur it is necessaryto measure either the input or output.

1.2.3 Throughout this code input is defined as high heat valueof the fuel plus the heat added from other sources such as sensibleheat in fuel and air, heat atomizing steam, as applicable.

1.2.4 The output is defined as the heat absorbed by the workingfluid or fluids.

1.3 Capacity

Rating of steam boilers is defined as the evaporation in kg ofsteam per hour delivered at defined operating parameters at whichthe efficiency is guaranteed or kW absorbed by the working fluid orfluids. Rating of hot water heaters is defined on the heat absorbedby water and the heat of any steam (hat may be generated (kW).

1.4 Efficiency

The efficiency of steam boiler determined within the scope ofthis code is the gross thermal efficiency and is defined as theratio of heat absorbed by the working fluid or fluids to the heatinput as defined in 1.2.3. This definition disregards theequivalent heat in the power required by the auxiliary apparatusexternal to the envelope (see Fig. 1).

1.4.1 Efficiency for the two methods is expressed Thisequations:

a) Input-Output Method

Efficiency (percent) = - Output/Input X 100

= Heat absorbed by working fluid or fluids/Heat in fuel + Heatcredits X 100

b) Heat Loss Method

Efficiency (percent)

= 100 - Heat losses/Heat in fuel + Heat credits X 100

1.5 Abbreviated Efficiency Test

It is recognized that for acceptance testing of small heatingand industrial swam boiler a simplified test is the only practicalapproach.

An abbreviated efficiency test considered only the major losses,and the chemical heat in the fuel as input.

Although the abbreviated tests procedure ignores the minorlosses, and the heat credits, the test procedures for obtaining themajor items will be the same as specified, for the sizes of boilerunits and therefore, the contents of this code should be read andunderstood prior to running a simplified efficiency test. Whereheat losses are to be adjusted to compensate for variations infuel, or changes in inlet air temperature, as would be done inverifying an efficiency guarantee, the procedure given in Section 7for collection of standard or guarantee conditions of the codeshould be followed.

Figure 2 gives relationship between input, output, heat creditsand losses.

1.6 Fuels

Both the heat loss and the input-output method of this codeapply to boiler units operating with either solid, liquid orgaseous fuels.

1.6.1 This code will apply only when tests are run using asingle fuel.

1.6.2 Where tests have to be made using a combination of fuels,it will be necessary to establish test procedure and calculationsbased on guiding principles and general intent of this code.

1.7 Test Reports

A typical summary sheet for abbreviated efficiency test andother parameters are given in this section (see page 8).

2 References

IS 436 : Part 1 : Sec 1 : 1964 Methods for samplingof coal and coke: Part 1 Sampling of coal,Section 1 Manualsampling

IS 436 : Part 2 :1965Methods for sampling of coal and coke:Part 2 Sampling of coke

IS 1350 : Parts 1 to5Methods for test for coal and coke

IS 1447 :1966Methods of sampling of petroleum and itsproducts

IS1448Methods of test for petroleum and itsproducts

IS 2952 : Part 2 :1975Recommendations for methods ofmeasurement of liquid flow by means oforifice plates and nozzles:Part 2 Compressible fluids

IS 3624 :1987Pressure and vaccum gauges

SP 26 :1983ISI steam tables in SI Units