Shangneng ZWNS vacuum hot water boiler principle introduction
Water has a boiling point of 100°C at 1 bar. Below 1 bar pressure, the boiling point of water is less than 100 °C. The pressure is 0.7 bar, the boiling point is 90° C.; the pressure is 0.3 bar, the boiling point is 70° C.; the pressure is 0.1 bar and the boiling point is 40° C.
The closed chamber of the vacuum hot water boiler is vacuum evacuated to form a vacuum chamber. The combustion causes the heat medium water to boil in the vacuum chamber to generate negative pressure water vapor, the steam condenses outside the heat exchanger tube, and the tube cold water is heated and heated. To the user, water vapor condenses to form water droplets and flows back to the heat medium water, which is heated and vaporized again. This completes the entire cycle, and the normal operating pressure of the boiler is less than 0.7 bar. Heat medium water is high-purity water treated with special treatment such as descaling, deoxidation, etc. It is filled by the factory before it is shipped. When it is used, closed circulation (vaporization-condensation-vaporization) inside the boiler does not increase or decrease. It is within the service life of the boiler. No need to add or replace.
At present, the company's vacuum hot water boiler is divided into three types: ZWNS-Y fuel, ZWNS-Q gas, and ZWNS-D electric heating vacuum hot water boiler.
Fig.1 Schematic diagram of ZWNS type vacuum hot water boiler
Fig. 2 ZWNS vacuum hot water boiler section
1, five security protection
Shangneng vacuum hot water unit adopts dual control of pressure and temperature to run the unit. Compared with the conventional vacuum hot water unit (only with temperature control), the safety performance is greatly improved. In addition, the vacuum hot water unit has five more safety protection devices to ensure the safe operation of the unit:
1.1 over temperature alarm:
When the temperature of the thermal media exceeds the set alarm temperature (set point 98°C), the burner will automatically stop and alarm.
1.2 Overpressure alarm:
When the pressure inside the unit reaches the set pressure (set value 5KPa), the burner automatically stops and alarms.
1.3 Thermal Media Water Level Abnormal Protection Device:
When the unit heat medium water is lower than the set water level, it will automatically stop and alarm.
1.4 Gas Leakage Alarm:
When the unit is running, the Rialdo gas leak detection device of the Italian Rial Road is constantly monitoring the gas content in the air. When the gas leakage reaches a certain value, the gas intake solenoid valve automatically shuts down and alarms.
1.5 mechanical explosion-proof device:
The unit body is equipped with safety explosion-proof devices, explosion-proof valve diaphragm detonation pressure 0.01MPa, if the unit pressure exceeds the initiation pressure, the explosion-proof membrane automatically breaks, to the crew diarrhoea pressure.
2, safe and reliable
The inside of the unit is in a vacuum and oxygen-free state, and the boiler body will not be damaged due to corrosion; the inside of the unit will never scale, and it can run efficiently for many years; in order to ensure long-term reliable operation of the unit, the vacuum hot water unit is composed of static components (steel plates, steel pipes, etc.) ) With the use of domestically produced high-quality materials, all other operating components are imported products, which have reliable performance and extremely low failure rates.
3, environmental protection and emission reduction
The RIELLO gas-fired combustion engine of Italy's Riyal Road, which is equipped with an upper vacuum water heater, is characterized by complete mixing, high combustion efficiency, and low NOx emission. The unit hearth adopts a wet-back three-return structure and complete combustion with a combustion efficiency of over 99.99%. This can fundamentally ensure that the unit operates in compliance with the most demanding environmental protection requirements.
The discharge of the smoke from the vacuum hot water unit complies with GB13271-2001 "National Class 1 Regional Atmospheric Pollution Discharge Standards".
4, high efficiency and energy saving
4.1. Unit design: Heat transfer water and heat transfer tubes are designed to have a heat transfer temperature difference of 10°C, which effectively reduces the operating temperature of the thermal medium water and saves energy consumption of the complete machine;
4.2. Unit structure: The upper energy vacuum hot water unit hearth adopts a wet back type three-pass combustion structure, complete combustion, increased heat transfer area, improved thermal efficiency, and the exhaust gas CO content is almost 0 (national standard is 1000PPM), combustion efficiency Up to 99.99%; The smoke tube adopts the patented technology of internal and external fin internal thread high-efficiency heat-exchanging smoke tube, which greatly reduces the temperature of exhaust smoke and improves the thermal efficiency; The whole machine adopts front and rear full wet back structure, and the surface temperature is low, compared with ordinary dry back type Boiler energy-saving 2%; the whole machine adopts high temperature rubber-plastic insulation, good heat preservation performance, less heat loss, thermal efficiency up to 94%.
4.3 Control System: The control system adopts double control of pressure and temperature, the control sensitivity is increased by 50%, the number of times the low-load burner is on and off is reduced by 35%, and the pre-purge energy is reduced by 35%; the temperature of the hot water outlet is linked with the temperature of the hot water. The control of the burner (used in a single circuit) can save more than 5% of the energy consumption compared to the temperature control of the heat medium water, and achieve a total energy saving of more than 2% in the system.
1、Using pressure and temperature to control the unit operation, there are five safety protection devices and the operation process is safe;
2. The inside of the unit is in a state of vacuum and oxygen-free. The boiler body will not be damaged due to corrosion and the inside will never scale. It can run efficiently for many years and is very reliable;
3. The combustion efficiency is over 99.99%. The supporting Rialdo Rialdo gas-fired combustion engine has the features of complete mixing, high combustion efficiency and low NOX emission, and actively responds to the national energy saving and environmental protection call.
4. The whole machine has low energy consumption and high thermal efficiency. It uses its own patents and is trustworthy.