- Español
- Português
- русский
- Français
- 日本語
- Deutsch
- tiếng Việt
- Italiano
- Nederlands
- ภาษาไทย
- Polski
- 한국어
- Svenska
- magyar
- Malay
- বাংলা ভাষার
- Dansk
- Suomi
- हिन्दी
- Pilipino
- Türkçe
- Gaeilge
- العربية
- Indonesia
- Norsk
- تمل
- český
- ελληνικά
- український
- Javanese
- فارسی
- தமிழ்
- తెలుగు
- नेपाली
- Burmese
- български
- ລາວ
- Latine
- Қазақша
- Euskal
- Azərbaycan
- Slovenský jazyk
- Македонски
- Lietuvos
- Eesti Keel
- Română
- Slovenski
- मराठी
- Srpski језик
Thermal Machine efficiency
2021-08-27
1. Any machine that can use the energy released when fuel is burned to do mechanical work is called a heat engine.
2. During the working process of the heat engine, the heat released when the fuel in the heater (high temperature heat source) burns is not all absorbed by the working substance (working fluid), and the working fluid gets only part of the heat from the heater It is converted into mechanical work, and the rest is discharged with the working fluid and passed to the condenser (low temperature heat source). Part of the mechanical work done by the working fluid is lost due to overcoming the friction of the parts. According to the working characteristics of the heat engine, the use and loss of heat in the heat engine will be explained below.
Combustion efficiency
It refers to the ratio of the heat obtained by the working fluid from the heater to the heat released when the fuel is burned. If expressed by ηC, the fuel combustion efficiency can be written as ηC=Q1/Q.
Thermal efficiency
It refers to the ratio of the heat converted into mechanical work in the working part of the heat engine and the heat obtained by the working fluid from the heater. If expressed by η, then η=W/ Q1=( Q1-Q2) / Q1=1- Q2/ Q1.
It is obvious from the formula that the larger Q1 and the smaller Q2, the higher the thermal efficiency. This is the main part of the heat engine efficiency, and it indicates the degree of heat utilization in the heat engine.
Mechanical efficiency
It refers to the ratio of the heat required to drive the shaft to do the work and the heat converted into mechanical work during the working process of the heat engine. If expressed by ηm, then ηm=Q3/(Q1-Q2), etc., that is, η=Q useful/Q total .
2. During the working process of the heat engine, the heat released when the fuel in the heater (high temperature heat source) burns is not all absorbed by the working substance (working fluid), and the working fluid gets only part of the heat from the heater It is converted into mechanical work, and the rest is discharged with the working fluid and passed to the condenser (low temperature heat source). Part of the mechanical work done by the working fluid is lost due to overcoming the friction of the parts. According to the working characteristics of the heat engine, the use and loss of heat in the heat engine will be explained below.
Combustion efficiency
It refers to the ratio of the heat obtained by the working fluid from the heater to the heat released when the fuel is burned. If expressed by ηC, the fuel combustion efficiency can be written as ηC=Q1/Q.
Thermal efficiency
It refers to the ratio of the heat converted into mechanical work in the working part of the heat engine and the heat obtained by the working fluid from the heater. If expressed by η, then η=W/ Q1=( Q1-Q2) / Q1=1- Q2/ Q1.
It is obvious from the formula that the larger Q1 and the smaller Q2, the higher the thermal efficiency. This is the main part of the heat engine efficiency, and it indicates the degree of heat utilization in the heat engine.
Mechanical efficiency
It refers to the ratio of the heat required to drive the shaft to do the work and the heat converted into mechanical work during the working process of the heat engine. If expressed by ηm, then ηm=Q3/(Q1-Q2), etc., that is, η=Q useful/Q total .
Heat engine efficiency η=c×m×△t/mq
Previous:Types of Thermal Machine
