Samples of Direct Function Input in MS Excel
The samples below shows the use of ES_StableIF97 AddIn functions in MS Excel. Just like the built-in functions of MS Excel, ES_StableIF97 AddIn functions can be typed into Excel cells directly by the user or embedded(inserted in MS Excel) by ES_StableIF97 AddIn's own forms like the Function Wizard of MS Excel.
There are two Forms in ES_StableIF97 Addin for function embedding. One is the Function Form that assists the user to input ES_StableIF97 AddIn functions, and the other is the Unit Form that assists for the user to set the property units to be used in the Function Form and provides the way to embed the Unit Legend. Please refer to Example 1 : Numerical Consistency of ES_StableIF97 AddIn Steam Table Functions in Region 1 for actual application of the Forms.
Unit String Function
The picture below shows the Unit Legend embedded by ES_StableIF97 AddIn Unit Form.. In the Unit Legend, the unit string functions of ES_StableIF97 AddIn are used. In the picture, it is shown that the cell "B3" has the pressure unit string "ESStb_PUnitStr($C$3)", which shows pressure unit string for pressure unit number in the cell "C3". The other cells below the cell "B3" have respective unit string functions of ES_StableIF97 AddIn. The unit string functions are automatically embedded, if the user embeds the Unit Legend by the Unit Form.
Single Property Argument Steam Table Functions
Single property argument steam table functions are the functions that has one property given for other property calculation. The example shown below is the "ESStb_PSatbyT" function that calculates saturation pressure with temperature given.
The example function has the syntax of "ESStb_PSatbyT(Temp, TUN, PUN)". In the picture below, it is shown that the function in the cell "C17" has the temperature property argument as "500", the temperature unit number(TUN) as the cell address of temperature unit number, "C4", of the Unit Legend explained above, and the pressure unit number(PUN) as the cell address of pressure unit number, "C3", of the Unit Legend. This shows that the property argument(temperature) can be input directly by value and that the property units(TUN and PUN) can be connected with the Unit Legend.
The example function in the cell "C18" differs from the cell "C17" only in the temperature argument input by the cell address of "A18" instead of number "500". The cell "C19" differs from the cell "C18" in cell address type. The cell "C20" shows number input for all arguments instead of cell address input. It works, too.
The user can do all of the function embedding explained above by using the Function and Unit Forms very easily. The user does not need to type in the function into the cells for himself and does not need to remember the function syntax. The Forms provided in ES_StableIF97 AddIn perform the work on behalf of the user.
Dual Property Arguments Steam Table Functions
Dual property arguments steam table functions are the functions that has two properties given for other property calculation. The examples shown below are
The argument input type of the examples shown are same with those of Single Property Argument Steam Table Functions explained above. Only difference is that the property arguments given are two instead of one.
The last example shows that the entropy calculated by "ESStb_SbyTX" function is same with the given entropy in the "ESStb_XybTS" function example. That means the two steam table functions are consistent exactly.
Unit Conversion Functions
Unit conversion functions are the functions that convert property values from one unit to another unit. The example shown below is the "ESStb_DvtP" function that converts pressure from one unit to another unit. In the picture, it is shown that the function in the cell "D44" converts the pressure of "100" from the pressure unit number "2" to the pressure unit number in the cell "C3". Since the pressure unit number in the cell "C3" in this example is "2", the output pressure of the function is same with the source pressure "100". The pressure unit number "2" represents the "bar a" pressure unit. For property unit numbers, please refer to Unit Summary.
For the given property argument input into a cell, this type of input using unit conversion functions is useful, in case that the user wants the given property values to be changed automatically for the change of the unit numbers in the Unit Legend. If the user inputs the given pressure 100 bar a as "100" into the cell "D44" instead of using the pressure unit conversion function "ESStb_CvtP", it will not respond to the change of the pressure unit number in the Unit Legend cell "C3", and the user has to change for himself the pressure value "100" in the cell "D44" to a new value of new pressure unit.
If the pressure unit number in the cell of "C3" of the Unit Legend is changed to "6" representing the "psi a" pressure unit, the value in the cell "C44" will be changed to "1450.377"(psi a). 100 bar a = 1450.377 psi a. This change is shown in the cell "D46", where the OutputPUN is input directly as "6" instead of cell address.
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