Q:What is the relationship between pressure, temperature and specific volume of steam?
A:Steam is widely used because steam is easy to distribute, transport and control. Steam can be used not only as a working fluid for generating electricity, but also for heating and process applications.
When the steam supplies heat to the process, it condenses at a constant temperature, and the volume of the condensed steam will be reduced by 99.9%, which is the driving force for the steam to flow in the pipeline.
The steam pressure/temperature relationship is the most basic property of steam. According to the steam table, we can get the relationship between steam pressure and temperature. This graph is called a saturation graph.
In this curve, steam and water can coexist at any pressure, and the temperature is the boiling temperature. Water and steam at boiling (or condensing) temperature are called saturated water and saturated steam, respectively. If saturated steam does not contain saturated water, it is called dry saturated steam.
The steam pressure/specific volume relationship is the most important reference for steam transmission and distribution.
The density of a substance is the mass contained in a unit volume. Specific volume is volume per unit mass, which is the reciprocal of density. The specific volume of steam determines the volume occupied by the same mass of steam at different pressures.
The specific volume of steam affects the selection of steam pipe diameter, redundancy of steam boiler, distribution of steam in heat exchanger, bubble size of steam injection, vibration and noise of steam discharge.
As the pressure of steam increases, its density will increase; conversely, its specific volume will decrease.
The specific volume of steam means the properties of steam as a gas, which has certain significance for the measurement of steam, the selection and calibration of control valves.
| Model |
NBS-FH-3 |
NBS-FH-6 |
NBS-FH-9 |
NBS-FH-12 |
NBS-FH-18 |
| Power
(kw) |
3 |
6 |
9 |
12 |
18 |
| Rated pressure
(MPA) |
0.7 |
0.7 |
0.7 |
0.7 |
0.7 |
| Rated steam capacity
(kg/h) |
3.8 |
8 |
12 |
16 |
25 |
| Saturated steam temperature
(℃) |
171 |
171 |
171 |
171 |
171 |
| Envelop dimensions
(mm) |
730*500*880 |
730*500*880 |
730*500*880 |
730*500*880 |
730*500*880 |
| Power supply voltage(V) |
220/380 |
220/380 |
220/380 |
220/380 |
380 |
| Fuel |
electricity |
electricity |
electricity |
electricity |
electricity |
| Dia of inlet pipe |
DN8 |
DN8 |
DN8 |
DN8 |
DN8 |
| Dia of inlet steam pipe |
DN15 |
DN15 |
DN15 |
DN15 |
DN15 |
| Dia of safty valve |
DN15 |
DN15 |
DN15 |
DN15 |
DN15 |
| Dia of blow pipe |
DN8 |
DN8 |
DN8 |
DN8 |
DN8 |
| Water tank capacity
(L) |
14-15 |
14-15 |
14-15 |
14-15 |
14-15 |
| Liner capacity
(L) |
23-24 |
23-24 |
23-24 |
23-24 |
23-24 |
| Weight (kg) |
60 |
60 |
60 |
60 |
60
|
