How to convert calorific value into temperature rise

This post was last edited by Qingcheng Jun on 2017-7-7 at 11:52. To select the objects to be evaluated, formulas are used. How do you think one can convert the relatively abstract concept of 10 kilometers into a more concrete figure in terms of minutes? Through one parameter: specific heat, with the unit of kJ/kg·K. 1 kJ is sufficient to raise the temperature of 1 kg of a substance by 1 K, that is, 1℃

What was said upstairs is very insightful and also completely correct. Work, power, and temperature all have different units; they are related to various parameters, media, and processes, and are all expressed in terms of temperature or temperature differences. This is probably what process designers are doing most of the time.

This post was last edited by arpcd on 2017-7-7 18:21. It’s actually the International System of Units that’s to blame. . . In China, the **official units used are those of the International System of Units, commonly known as the SI system. Leaving other units aside, the unit for heat is actually quite absurd. Middle school students know how to convert the thermal-work equivalent. In fact, heat and work were not originally measured in the same unit: heat was measured in calories, while work was measured in joules; the conversion between the two is what constitutes the thermal-work equivalent. The owner’s question can actually be clarified with the definition of this calorie unit. . . Look at the part marked in red, sigh. . . . . Just in terms of the unit of heat, from an educational perspective, the United States does the best – it’s the world leader after all; so why do they prefer to use calories? ? ? They still prefer to use imperial units rather than metric ones. . . Any American engineer or technician who has worked in this field will refer to heat in terms of calories or BTU, while using kilowatts to denote motor power. It doesn’t really matter which unit is used; what’s important is that it be used appropriately. . . Calories and kilocalories are the most appropriate units for measuring heat, as they are easy to remember and very convenient. . . As I recall, when technical professionals in Europe and the United States talk about calories, they hardly ever use units such as J or kJ; instead, they use calories and kilocalories. . . Since the unit of heat can only be expressed in calories, it is possible to explain its historical background clearly, which makes it easier for students to understand and remember. When the specific heat capacity of water is expressed in kilocalories, the value is 1, that is, 1 kcal/kg·°C. This is much easier to remember than 4.2 kJ/kg·°C. It’s simple to recall that raising the temperature of 1 kilogram of water by 1 degree requires 1 calorie; raising its temperature by 100 degrees requires 100 calories. It’s much more complicated to keep track of kilojoules. What are the calorific values of fuels such as liquefied petroleum gas, kerosene, and gasoline? ? ? You remember that 10,000 kcal/kg is sufficient for a preliminary estimate; 10,000 calories per kilogram – it’s easy to remember. . . In the fields of nutrition, medicine, and health, when it comes to heat energy, it is referred to as calories; an adult needs 2000 calories per day. How convenient that is – try converting that amount to kilojoules. . . . To be honest about our education system—using a common Sichuan saying: “It’s incomprehensible.” . . . It’s purely causing trouble for myself. . . .

This is about keeping up with international standards, similar to the effect of using English. It’s just a unit that isn’t used much in daily life.