1. What is a vacuum hot water boiler?
Answer: The so-called vacuum hot water boiler is also called a vacuum phase change hot water boiler. It refers to a boiler that heats cold water through phase change heat when the internal medium pressure of the boiler is lower than atmospheric pressure during normal operation.
2. What is the composition and structure principle of a vacuum hot water boiler?
Answer: The vacuum hot water boiler body is divided into upper and lower parts. The structure of the lower part is similar to that of a three-pass wet-back shell steam boiler, that is, the heating surface composed of the furnace bladder and the flue; The first half is a vacuum chamber (negative pressure steam chamber), and a tubular steam-water heat exchanger is installed in the space to heat the circulating water flowing through the heat exchanger. Operating principle: When the vacuum hot water boiler is running, the heat medium water in the furnace body absorbs the heat energy released by fuel combustion under vacuum negative pressure, boils and vaporizes into low-temperature steam. The low-temperature steam rises and encounters the system circulating water in the stainless steel heat exchanger, and is heated. The circulating water is sent to users for heating or sanitary hot water. The water vapor itself is cooled and condensed into water droplets, which fall to the water surface of the heating medium and are heated again, thus completing the entire cycle. The heat medium water continuously performs the cycle of "boiling == evaporation == condensation == heat medium water" in the closed body, so there is no need to replenish condensed water and there is no danger of empty burning. Vacuum hot water boilers utilize steam-water condensation heat exchange. Among all heat exchange conditions, the steam-water condensation heat transfer coefficient is the highest.
1. What is a vacuum hot water boiler?
Answer: The so-called vacuum hot water boiler is also called a vacuum phase change hot water boiler. It refers to a boiler that heats cold water through phase change heat when the internal medium pressure of the boiler is lower than atmospheric pressure during normal operation.
2. What is the composition and structure principle of a vacuum hot water boiler?
Answer: The vacuum hot water boiler body is divided into upper and lower parts. The structure of the lower part is similar to that of a three-pass wet-back shell steam boiler, that is, the heating surface composed of the furnace bladder and the flue; and the upper part is similar to the three-pass wet-back shell steam boiler. The first half is a vacuum chamber (negative pressure steam chamber), and a tubular steam-water heat exchanger is installed in the space to heat the circulating water flowing through the heat exchanger. Operating principle: When the vacuum hot water boiler is running, the heat medium water in the furnace body absorbs the heat energy released by fuel combustion under vacuum negative pressure, boils and vaporizes into low-temperature steam. The low-temperature steam rises and encounters the system circulating water in the stainless steel heat exchanger, and is heated. The circulating water is sent to users for heating or sanitary hot water. The water vapor itself is cooled and condensed into water droplets, which fall to the water surface of the heating medium and are heated again, thus completing the entire cycle. The heat medium water continuously performs the cycle of "boiling == evaporation == condensation == heat medium water" in the closed body, so there is no need to replenish condensed water and there is no danger of empty burning. Vacuum hot water boilers utilize steam-water condensation heat exchange. Among all heat exchange conditions, the steam-water condensation heat transfer coefficient is the highest.
3. What is a vacuum state?
Answer: The vacuum state does not mean that the absolute pressure is zero. As long as it is lower than the external air pressure, it can be called "vacuum". For example: when a vacuum boiler is running, the shell of the boiler is evacuated by the vacuum device and maintains a pressure of about -0.03MPa, which means the absolute pressure of the medium in the boiler is about 0.07MPa.
4. What is vacuum degree?
Answer: Vacuum degree refers to the degree of dilution of gas in a vacuum state, usually expressed by "high vacuum degree" and "low vacuum degree". A high vacuum degree means "good" vacuum degree, and a low vacuum degree means "poor" vacuum degree. The degree of vacuum value indicates that the actual value of the system pressure is lower than the atmospheric pressure, that is, the degree of vacuum = atmospheric pressure - absolute pressure. International standard unit of vacuum: Pascal (Pa).
5. Why is the heating medium water in a vacuum hot water boiler heated in a vacuum state?
Answer: Water has different boiling temperatures under different pressures. Under an atmospheric pressure (0.1Mpa), the boiling temperature of water is 100°C, while under a pressure of 0.8Kpa, the boiling temperature of water is 100°C. The boiling temperature is 4°C. Vacuum hot water boilers work within the pressure range of vacuum degree 2.67Kpa ~ 66.6 Kpa, and the corresponding saturation temperature is 15℃ ~ 85℃. Therefore, in a vacuum state, the heat medium water easily boils and vaporizes.
6. The origin of vacuum hot water boiler?
Answer: The basic principle of vacuum hot water boiler was born in 1972 at Zurich University of Technology.
In 1975, Japan's TAKUMA Company developed a vacuum hot water boiler based on this principle and obtained an invention patent. Later, it was gradually promoted around the world, but mainly in Asian countries. There are well-known vacuum boiler manufacturers in Japan and South Korea such as TAKUMA and Qingdong. In the late 1980s, some domestic manufacturers developed vacuum hot water boilers. However, due to technical problems, they were mainly unable to solve the problem of the electrochemical reaction of water and iron in the boiler in a sealed vacuum state to generate incompatible gases, which caused the vacuum degree to continue to decrease. The problem has not been promoted. In the late 1990s, domestic boiler manufacturers began to produce vacuum boilers.
7. What are the main differences between imported vacuum hot water boilers and domestic products?
Answer: The core difference lies in the different vacuum devices: imported products use a vacuum pump and its control system to form and control vacuum, while domestic products use a mechanical check valve to form and control it. its vacuum.
8. What is the key technology of vacuum hot water boiler?
Answer: The key technology of the vacuum boiler is to keep the vacuum degree stable for a long time and the leakage rate is extremely small.
9. How to form a vacuum state in a vacuum hot water boiler?
Answer: Air extraction method: A special vacuum pump is used in the factory to forcefully evacuate the sealed tank of the vacuum boiler to form a vacuum state. Some manufacturers use the boiling method: first add a certain amount of clean water into the boiler to a certain water level, close all the boiler valves except the exhaust valve, start the furnace and raise the temperature to the saturation temperature of the heating medium water under the working pressure, and wait for it to dissolve in the working fluid. After all the air inside is exhausted, close the exhaust valve to form a vacuum state.
10. What is the cause of vacuum failure?
Answer: When the vacuum hot water boiler leaves the factory, the inside of the boiler is in a vacuum state. However, during the operation of the vacuum boiler, the vacuum degree will be destroyed for the following reasons:
First : Furnace body leakage: Quality defects in welds, sealing parts, and steel materials.
Second: The generation of non-condensable gas (cannot be prevented): A chemical reaction will occur between the heating medium water and the furnace body (steel plate), releasing a non-condensable gas (H2). The gas will directly affect the vacuum degree of the vacuum boiler. However, the chemical reaction also forms a protective film (iron hydroxide) on the surface of the steel plate, which hinders the chemical reaction. According to experience, this chemical reaction will stop within 2 to 3 years of boiler operation.
11. How to prevent vacuum damage?
Answer: 1. For furnace leakage, the detection of the production process is very important. Vacuum boilers use "helium mass spectrometry leak detection" during the production process, mainly including parts leak detection. There are three types: (dissolving plug), semi-finished product leak detection (furnace body welding part) and complete machine leak detection. The detection accuracy is high (helium molecule level), the detection is thorough, and it is completely preventable.
2. During the operation of the vacuum boiler, the non-condensable gas must be extracted, which is called vacuuming.
12. Why does a vacuum hot water boiler need to be evacuated during operation?
Answer: When non-condensable gas is generated inside the vacuum boiler, the pressure will rise accordingly, which is the so-called vacuum destruction. The non-condensable gas generated inside the vacuum boiler has a serious impact on the heat transfer efficiency. When the volume content of non-condensable gas reaches 0.2%, the thermal efficiency is reduced by 20 to 30%, the outlet water temperature cannot be increased, and the boiler output is reduced. Therefore, when the vacuum boiler is running, the non-condensable gas must be extracted.
13． What is the most advanced way to maintain vacuum?
Answer: The most advanced vacuum maintenance method of the vacuum hot water boiler is the patented technology of Japan TAKUMA Company - the temperature difference type fully automatic intelligent air extraction device, which is a completely intelligent and fully automatic air extraction device. device. The control system diagnoses and pumps air on its own as needed, without the need for human control.
14. What does the temperature difference automatic air extraction device consist of?
Answer: Non-condensable gas tank, vacuum check valve, three-way valve, two-way valve, vacuum pump, exhaust pipe, temperature sensor and control system, etc. (see the drawing on the first page) .
15． How does the temperature difference automatic air extraction device work?
Answer: Working principle: When non-condensable gas is generated inside the unit, the non-condensable gas (hydrogen) gradually accumulates in the gas collection tank during operation. Since the non-condensable gas does not participate in heat exchange, the collection tank The temperature of the gas tank slowly decreases. When the temperature difference between the temperature of the gas collecting tank and the temperature of the heat medium water reaches 10 degrees, the control system issues an instruction to operate the air pump.
When the non-condensable gas is pumped away, the negative pressure steam reaches the gas collecting tank. The temperature of the gas collecting tank rises and the temperature difference becomes smaller. The control system issues a command to stop the air pump, and the air pump stops.
16. What is heat medium water?
Answer: Thermal medium water is a kind of clean water that has been specially treated to remove impurities, oxygen and soften in the manufacturing factory. It is poured once during production and can be recycled during operation. Generally, it is not necessary unless there are special circumstances. Raise.
17. What is the material of the heat exchanger in the vacuum hot water boiler?
Answer: The heat exchanger in the boiler uses SUS304 stainless steel tubes. This pipe is not easy to scale, has high heat transfer efficiency, does not rust, and is better than ordinary heat exchange pipes in terms of water quality and flow rate restrictions.
18. What are the main features of vacuum hot water boilers?
Answer: ① No installation supervision is required, it can be used after installation; ②. One machine can be used for multiple purposes, saving investment; ③. No corrosion, no cracks, no scars, no pipe bursts, and long life; ④ High efficiency Energy saving, low operation and management costs; ⑤. High safety performance.
19. What is the national regulatory policy on vacuum boilers?
Answer: In May 2002, the General Administration of Quality Supervision, Inspection and Quarantine issued the National Quality Inspection Pot Letter No. 288, which clearly stipulates the use of vacuum boilers: Vacuum phase change boilers have low pressure due to their medium circulation system Atmospheric pressure, so no explosion accidents will occur. Manufacturing companies should manufacture vacuum phase change boilers in accordance with standards, and bear the legal responsibility of informing users (including boiler installers) of safe use and ensuring that the boiler system is always in a vacuum state during use. The installation unit of the vacuum phase change boiler is responsible for the installation quality meeting the installation requirements of the manufacturing enterprise. After installation, vacuum phase change boilers that meet the above requirements do not need to be confirmed by the boiler and pressure vessel safety supervision agency of the quality and technical supervision administrative department, nor do they need to go through registration procedures for use.
20． Does a vacuum hot water boiler require annual inspection during its service life? Does the user need to pay annual inspection fees?
Answer: There is no need to apply for installation, inspection, boiler room project approval, or annual inspection (pay the annual inspection fee).
21. How does a vacuum boiler supply heating hot water and domestic hot water at the same time?
Answer: A vacuum hot water boiler plus a set of heat exchange coils can provide heating hot water and domestic hot water at the same time. However, since heating is a continuous operation, it is a relatively stable load, while hot water supply is an intermittent supply, which is a highly variable load. In order to meet the operation of domestic hot water supply, bypass method is generally adopted on the heating circulating water pipe. Or add a water storage tank to domestic hot water.
22． Is a vacuum hot water boiler a big investment?
Answer: Although the price of the vacuum boiler host is higher than that of ordinary hot water boilers, the use of vacuum hot water boilers can save a lot of investment in auxiliary equipment: plate heat exchangers, volumetric heat exchangers, primary circulation pumps, soft water Processing equipment and expansion water tanks can also save corresponding pipeline installation fees, auxiliary power capacity expansion fees, system control fees, etc. The overall investment is still lower than that of ordinary hot water boiler systems.
23. What is the return on investment?
Answer: Since the normal service life of a vacuum hot water boiler is more than twice that of an ordinary hot water boiler (reaching a semi-permanent life), the investment return period is long and the equipment depreciation rate is low, it is suitable for customers who need long-term use. .
24. Why is the service life of vacuum hot water boiler more than twice that of traditional boiler?
Answer: Traditional boilers have their own fatal weaknesses, which determine their short service life. In order to solve the fatal weakness that affects the life of traditional boilers, vacuum hot water boilers use high-purity heat medium water to be sealed inside the boiler, without contact with air, and there will never be oxygen corrosion. The boiler heats external hot water through a heat exchanger, and the furnace and smoke pipe are only in contact with the heat medium water, which completely eliminates the generation of scale and can maintain high-efficiency operation for many years; the system circulation return water does not mix with the heat medium water in the boiler, and the smoke exhaust Stable, no condensation water is generated, completely solving the phenomenon of condensation corrosion and greatly extending the life of the boiler. The service life of the vacuum hot water boiler is more than 20 years.
25. What is the Achilles heel of traditional hot water boilers?
Answer: At present, most of the boilers used for heating and hot water in my country are still traditional hot water boilers (normal pressure or pressurized hot water boilers), but their service life is often not long, and some only last three to five years. It was scrapped. The reason was not the manufacturing quality of the boiler itself, but the unavoidable corrosion and scaling during use:
①. Oxygen corrosion: During the construction and decommissioning period of traditional boilers, Without protective measures, the atmosphere will invade the pot. Because the atmosphere contains oxygen and moisture. This causes oxygen corrosion. The pits caused by oxygen corrosion will accelerate corrosion in the future operation process; in the entire system during the outage period. Especially in areas where water easily accumulates and cannot be drained off, if there are residues and water slag on the surface, the corrosion will be more serious than in normal operation.
②. Return water condensation corrosion: The heating cycle return water temperature in northern my country is designed to be 75°C, but in actual use it is often 50°C or even lower. At this time, the water vapor in the flue gas will condense. It turns into liquid water and mixes with the SO2 and NOX produced by combustion to form strong acid that seriously corrodes the chimney, smoke chamber and smoke pipe. The red rusty water flowing out of the rear smoke chamber of the boiler is caused by corrosion. Even imported boilers are no exception to this kind of corrosion. In severe cases, the boiler will be worn out in about three years.
③. Scaling of the main body furnace and smoke pipe: Many hot water boilers directly heat external hot water, and the quality of the water directly affects the life of the boiler. After hot water is heated, scale will continue to precipitate and deposit on the furnace and smoke pipes, causing the heat transfer resistance to increase and the boiler efficiency to decrease. When scale accumulates to a certain extent, the furnace and smoke pipes will be burned through, causing the boiler to be scrapped.
26. Are the water quality requirements for vacuum hot water boilers the same as those for traditional boilers?
Answer: The water quality requirements of the vacuum hot water boiler system are not as strict as those of traditional boilers. Vacuum hot water boilers use corrosion-resistant stainless steel heat exchangers and have low water quality requirements.
27. Why can vacuum boilers save energy?
Answer: ① Radiant heat loss: The furnace body is a sealed vacuum container, which has good thermal insulation performance and small radiant heat loss. ②Heat exchange efficiency: The thermal efficiency of the steam-water heat exchanger in the furnace body is 10 times that of the water-water heat exchanger. ③ Thermal inertia and low load performance: The boiler is small in size, has less heat medium water, and has a small heat capacity. Therefore, the thermal inertia is small and it is sensitive to load changes. After the boiler is turned on, hot water will be available in 5 to 8 minutes. ④No scale - energy saving
28. Why will vacuum hot water boilers never explode?
Answer: Vacuum hot water boilers will never explode. The furnace body works in a vacuum state and is not a pressure vessel; the furnace body is sealed with a certain amount of heat medium water and will not burn empty under any condition; the body is equipped with multiple self-protection devices (anti-overheating, anti-freezing, insufficient waterproof level, anti-pressure Too high, anti-shock, insufficient gas and fuel supply, etc.
29. Does the vacuum hot water boiler save floor space?
Answer: The vacuum hot water boiler uses a high-load combustion method. , the length of the combustion chamber is shortened, the structure is compact, the body volume is significantly smaller, the product is easy to transport and install, and multiple units can be installed side by side, occupying a small area; the reduction of boiler auxiliary equipment reduces the area occupied by the auxiliary equipment, thus saving overall space in the boiler room. Floor space. The vacuum hot water boiler room saves 30-50% of the floor space than the traditional boiler room. 30. Does the use of vacuum hot water boiler need to increase the tonnage?
Answer: No. Both vacuum hot water boilers and traditional hot water boilers are heat source supply equipment. The output (tonnage) of the boiler is the ability of the boiler to provide heat per unit time. Both traditional boilers and vacuum boilers are relatively the same. The load requirements and tonnage selected are the same.
31. What are the disadvantages of vacuum hot water boilers?
Answer: It cannot provide hot water above 90℃.
32. Is the vacuum hot water boiler suitable for use in radiator heating systems?
Answer: The design temperature of the heating medium of the radiator hot water heating system is generally based on thermal comfort requirements and system operation. The water supply temperature should not exceed 95°C to ensure that the heating medium does not vaporize under normal pressure conditions. In the past, the supply and return water temperature was often 95°C/70°C. However, in recent years, according to domestic and foreign standards. According to advanced experience in heating, appropriately lowering the temperature of the heating medium is beneficial to improving comfort, so vacuum hot water boilers generally use 80/60°C to meet the inlet and outlet water temperature requirements of 80/60°C when designing the radiator heating system.
Nowadays, even if the design water temperature is 95/70°C for residences heated by urban heating networks or community centralized boiler rooms, when the design outdoor temperature is reached, the operating water temperature generally only needs to be about 70/55°C to ensure the design indoor temperature. Because the main factors that determine the efficiency of the heat sink are the heat dissipation area of ??the heat sink and the flow rate of the medium inside the heat sink (which has little to do with the temperature of the medium), and the same amount of circulating water with the same temperature difference carries the same amount of heat. Vacuum hot water boilers differ from traditional boilers (95/70°C) in the radiator heating system, mainly in that the room heating time is 4 to 5 minutes slower than traditional boilers.
33. Is the vacuum hot water boiler suitable for use in air conditioning and heating systems?
Answer: In traditional central air-conditioning system, chiller + fuel (gas) hot water boiler is a preferred cold and heat source solution. In summer, a centrifugal (screw) chiller is used to provide cold water at 7?C~12?C, and in winter, a fuel (gas) hot water boiler is used to provide hot water at 50?C~60?C. Since the vacuum hot water boiler uses negative pressure steam for indirect heating, the heat exchanger can withstand the higher water pressure of the system. Therefore, the vacuum hot water boiler can be widely used in large and medium-sized air conditioning projects as a heat source in winter, and it has certain advantages in renovation projects. advantages.
34． Vacuum hot water boiler approval in fire protection design?
Answer: Due to the particularity of the working principle of the vacuum hot water boiler, its body is similar to an evaporation coil in a heat exchanger, air handler or refrigeration unit, and only its fuel delivery system ( Oil storage tanks, daily oil tanks, oil pipeline systems or gas pipeline systems) shall be designed in accordance with fire protection design requirements. As for the location of the machine room where the vacuum hot water boiler is located, the design of the vacuum hot water boiler system in the machine room shall be approved by the fire protection design. .
35. Where can the vacuum hot water boiler room be built in the building?
Answer: Vacuum hot water boilers can be placed in the basement, semi-basement or first floor of a building, as well as on the roof, to fully meet the needs of users in different situations.
36． What does a vacuum hot water boiler use as fuel?
Answer: The main fuels are oil (light diesel or heavy oil) and gas (natural gas, city gas, liquefied petroleum gas).
37． What is the combustion equipment of vacuum hot water boiler?
Answer: The vacuum hot water boiler is suitable for various combustion equipment. According to the needs, it can be equipped with advanced integral burners, such as Weishaupt imported from Germany, Black & Decker from Italy, Riello, etc. The integral burner has an adjustable flame shape and is suitable for any boiler, with little requirement for the size of the combustion chamber. At the same time, because the combustion tube and the combustion head are long and thin, the diameter of the flame stabilizing disk is small, the pressure behind the disk is large, the flame leaves the flame stabilizing disk, the heat load is small, and the service life is long. The suction port of the combustion fan of the burner is suspended in the air, and the air sucked in is relatively clean, which is conducive to complete combustion. The flange of the combustion tube is movable, making it easy to adjust the installation depth. At the same time, the blower and combustion tube are integrated, so the combustion noise is small. And its accessories are highly versatile.
38. The generation and prevention of boiler combustion noise?
Answer: Combustion noise mainly comes from the burner motor, air supply fan, and combustion chamber combustion noise. As the boiler output (tonnage) increases, the noise value increases, which is related to the boiler heat exchange method. Not big. There are also other noise-generating equipment (water pumps, etc.) in the boiler room. Therefore, the noise in the boiler room needs to be comprehensively prevented and controlled. Noise reduction methods include: adding silencer hoods and damping accessories to the burner (motor, fan, etc.), adding a diversion fan to the flue, adding sound-absorbing panels to the walls, soundproof doors for doors, etc. To ensure that the boundary noise indicators meet the standards.
39. Why do vacuum hot water boilers have low operating costs?
Answer: ⑴ The auxiliary machinery of the vacuum hot water boiler is reduced, and operating expenses such as electricity usage and maintenance costs are directly reduced.
⑵ The vacuum hot water boiler has a built-in heat exchanger, so the boiler body does not scale and the thermal efficiency does not decrease.
⑶ The heat exchanger in the vacuum hot water boiler directly heats the circulating water of the system. The volume of the boiler is small, the amount of heat medium water is small, and the heat capacity is also small. Therefore, the thermal inertia is small, and the partial load operation efficiency is high. The boiler operates at 50% to 75% load for 70% of its operating time. Therefore, when the vacuum hot water boiler is used, operating costs are greatly reduced.
⑷The thermal efficiency of the vacuum hot water boiler is 91%; the thermal efficiency of the traditional boiler is about 90%, and the efficiency of the plate heat exchanger is about 94%. The primary and secondary heat exchange systems formed by the connection of the two, The overall efficiency is 90%×94%=84.6%.
Therefore, the overall thermal efficiency of the vacuum hot water boiler is 6-7% higher than that of the primary and secondary heat exchange operations of the plate heat exchanger of the traditional hot water boiler. The increased efficiency leads to a reduction in fuel costs, thereby saving operating costs.
40． How to identify the thermal efficiency of vacuum hot water boiler?
Answer: The thermal efficiency of the boiler refers to the percentage of effective heat in the heat supplied by the fuel. Most of the heat fed into the boiler by the fuel is absorbed by the heating surface of the boiler, producing water vapor. This is the effective heat being utilized. The other part of the heat is lost, and this part of the heat is called heat loss. The vacuum hot water boiler operates at rated efficiency, and the exhaust smoke temperature is 185°C. The exhaust smoke temperature is lower than the national standard of 220°C, which means that the fuel combustion heat is absorbed by the system circulating water, and the thermal efficiency is higher than the national standard (87-88%) .
41． How much does it cost to operate a vacuum hot water boiler in winter?
Answer: The operating costs of vacuum hot water boilers are related to system functions, load size, heating area, usage time, etc. Taking the Beijing area as an example, based on the calculation of the average calorific value of 8500kcal/Nm3 after gas is delivered to the home, the theoretical operating cost of radiator heating in one heating season is approximately 18.02 yuan/m2. According to actual project usage statistics, the operating cost of a heating season is about 17 yuan/m2.
42． Is the vacuum hot water boiler easy to operate?
Answer: Boiler operators do not need to hold a certificate to operate. The boiler control panel adopts touch operation function for easy operation, and the body is equipped with multiple self-protection devices (anti-overheating, anti-freezing, insufficient waterproof level, anti-excessive pressure, anti-shock, anti-insufficient gas and fuel supply, etc.) to comprehensively prevent machine failure.
43. How does a vacuum hot water boiler ensure the safe operation of the boiler?
Answer: The vacuum hot water boiler is equipped with six safety protection devices to ensure the safe and stable operation of the boiler. The safety control devices specifically include: electrical protection devices, physical protection devices and destructive protection devices.
⑴Electrical protection device: ①. Combustion safety control device, ②. The heating medium water temperature control device can control the temperature and water level of the heating medium water inside the furnace body, ③. The pressure switch will actually act when the pressure in the furnace body rises abnormally, causing combustion to automatically stop.
⑵Physical protection device: ①. Overtemperature fuse. When the temperature is below 96°C, the fuse will definitely break and the combustion will stop automatically. ②. Low water temperature fuse. When the water level of the heating medium in the furnace is too low, causing the temperature to rise, the low water level temperature fuse is prevented from blowing and combustion automatically stops.
⑶ Destructive protection device: Dissolving plug, which will definitely dissolve below 98℃, releasing the steam in the furnace body into the atmosphere, so that the furnace body is not subject to abnormal pressure. The destructive protection device ensures that the unit will never be in danger of explosion when all electronic safety devices fail.
44. Can vacuum hot water boilers achieve remote control and network control?
Answer: The vacuum hot water boiler comes with a remote monitoring port and is equipped with a remote and network controller, which can control the boiler remotely and over the network. When multiple boilers are installed and used at the same time, the group control controller can be combined to realize group control of all boilers for centralized management, and use the climate compensation function to automatically control the number of startup boilers according to changes in load.
45. Will combustion produce carbon deposits? How to clean carbon deposits?
Answer: When fuel oil is burned as fuel, it will produce carbon deposits; gas is easy to burn and produces a trace amount of carbon deposits, but it is also necessary to clean up the carbon deposits in gas boilers every year. (Qingdong) Vacuum hot water boiler flue gas flow consists of a furnace and two flue gas returns. The space in the furnace can accommodate maintenance personnel to perform cleaning operations inside; the flue gas return path is composed of threaded smoke pipes. After opening the front smoke box cover and the rear maintenance flange cover, a steel brush can be used for convenient cleaning.
46. How to express the output of vacuum hot water boiler?
Answer: There are three ways to express the output of a boiler, namely kcal/h, tons/h (t/h), and megawatt (MW).
⑴Kcal/hour is an expression in metric units, which represents the heat supplied by the hot water boiler per hour.
⑵ "Ton" or "steam ton" is a popular term borrowed from steam boilers. It means that the heat supplied by the hot water boiler per hour is equivalent to turning a certain mass of water (usually expressed in tons) from 20℃ Heat absorbed and completely vaporized into steam.
⑶Megawatt (MW) is the unit of power in the International System of Units, and the basic unit is W (1MW=106W). This expression should be used in official documents.
The conversion relationship between the three expressions is as follows: 600,000 kcal/hour ≈ 1 steam ton/hour ≈ 0.7MW.
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