11.    HEAT AND MATERIAL BALANCE
Fig. 1. Heat and Material Balance workbook with IN1, OUT1 and BAL sheets.
Heat balance calculations are usually carried out when developing new chemical processes and improving old ones（开发新化学反应或者改善老反应）, because no process can work if too much heat is released or if there is a lack of thermal energy to maintain the reaction temperature. This module calculates the real or constrained heat balances, with given mass-balances as the boundary conditions, but not the theoretical balances at equilibrium conditions.
The heat balance application always contains IN1, OUT1 and BAL sheets. A pair of IN and OUT sheets is called a Balance area, which may be considered equivalent to a control volume. A total number of 127 balance areas may be inserted, to create a multiple balance area workbook. Multiple balance area workbooks are explained in more detail in chapter 10. Multiple balance areas. For simplicity only the first balance area (IN1, OUT1) will be described in the following chapters.
The basic idea of the heat balance module is that the user specifies the IN1 and OUT1 species, temperatures and amounts and the Heat Balance module automatically calculates
the heat and material balances using the BAL sheet. The Heat balance module updates the calculated results on the BALANCE row at the bottom of the form each time the user changes the input data. Please do not modify the BAL sheet.
Since the program uses and creates new balance areas according to the name of the sheets, it is extremely important that reactor thenthe automatically created sheet names, i.e. the BAL, INx and OUTx sheets, should not be modified.
You can also add new sheets for other spreadsheet calculations using the Insert Sheet and Insert Excel Sheet selections in the menu. The other sheets work very much like MS Excel worksheets, for example, you can:
-    rename the sheet name by double clicking the sheet tab
-    type formulae into the cells
-    use similar cell references as in Excel
-    use most of the Excel functions
-    link the sheet to IN1 sheet using normal Excel cell references, for example, for converting elemental analysis of the raw material to amounts of the components.
-    use the heat balance calculation results in OUT1 sheet as the initial values for other spreadsheet calculations.
In addition the Heat Balance menu provides a wide range of Excel type features, such as: number, font, alignment and border formatting, defined names settings and cell protection. Because they are not necessarily needed in heat balance calculations, these features are not described here in detail.
The new heat balance module offers several ways to calculate heat and material balances:
1. The user types the input and output species, temperatures and amounts into the IN1 and OUT1 sheets respectively. This is a simple way to calculate heat and material balances and was available already in HSC 2.0. However, the problem with the old version was that the user had to manually maintain the material balance when the input feed changed.
2. Materials (species) are given as groups of substances, called streams. These streams can be the same as the phases, but they can also be a mixture of phases.
3. The output amounts can be linked with the input amounts with Excel type cell references, or vice versa.
11.1    Basic Calculation Procedure（基本计算程序）
The following procedure will describe the most simple way to calculate Heat Balance:
1. Introduce the input substances (raw materials), temperatures and amounts on the IN1 sheet. It is possible to either type amounts in kmol, kg or Nm3. It is advised to use kmol and kg because missing density data may cause inaccuracy with Nm3 units.
2. Introduce the output substances (products), temperatures and amounts on the OUT1 sheet. Type amounts in either kmol, kg or Nm3 as preferred.
3. When feeding additional energy (electricity) to the process, enter this amount into the To
tal column in the last empty row of the IN1 sheet. You can also type for example “Extra Heat” in the first column of this row, see Fig. 20. The Database module will convert the color of all “inert“ text in the first column to green, if this text is not identified in the database as a substance. Notice that:
1 kWh = 3.6 MJ = 0.8604 Mcal (th).
    However, the Balance module will automatically recalculate green text when changing units from the menu. If the green text cell contains a formula, it will automatically be changed according to the new unit. For example a change from °C to K will add “+ 273.15” to the end of the formula.

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