Hot water boiler includesElectric hot water boiler、Oil fired hot water boiler、Gas fired hot water boilerandCoal fired hot water boilerWait, hot water boiler is used to produce hot waterboilerIt refers to a kind of thermal equipment that uses the heat energy released by fuel combustion or other heat energy (such as electric energy, solar energy, etc.) to heat water to the rated temperature.The boiler defined in the Regulations on Safety Supervision of Special Equipment refers to the equipment that uses various fuels, electricity or other energy sources to heat the liquid contained to certain parameters and export heat energy to the outside.Its scope is specified as pressure steam boiler with volume greater than or equal to 30L;The outlet water pressure is greater than or equal to 0.1MPa (gauge pressure), and the rated power is greater than or equal to 0.1MwPressure hot water boiler；Organic heat carrier boiler。Extracted from Regulations on Safety Supervision of Special Equipment of the People's Republic of China
Chinese name
hot-water boiler
Foreign name
Hot water boiler
Classification
Electric hot water boiler, oil fired and gas-fired hot water boiler
Hot water boilers can be divided intoElectric hot water boiler、Oil fired hot water boiler、Gas fired hot water boiler, coal-fired hot water boiler, etc;According to whether it is pressure bearing or not, it can be divided into normal pressure hot water boiler and pressure bearing hot water boiler. The "hot water boiler" we usually refer to normal pressure hot water boiler. Because of its safe operation, people use this kind of normal pressure hot water boiler for bathing or heating.
Tubular
Assembling computerwater boiler All functions of the controller are stored on an intelligent chip, realizing the intellectualization, digitization, automation and humanization of the boiler. The boiler intelligently controls the water temperature, so that the water temperature heating can be stopped automatically;The large font on the screen shows the water temperature, and the boiler water temperature is clear at a glance.2. The boiler water temperature can be set at will from 10 ℃ to 100 ℃. The boiler can not only supply hot water for bathing, but also provide boiled water for drinking. It can be used for two purposes.3. The top of the furnace body is equipped with an air vent. The boiler is under no pressure and has no explosion risk. The whole machine is also equipped with overheat protection (when the water temperature in the furnace is too high, the heating tube automatically stops working and beeps an alarm, secondary overheat protection (when the temperature of the boiler shell exceeds 105 ℃, the secondary circuit is automatically cut off)Protection against dry burning and water shortage (when the boiler water is lower than the very low water level, the boiler stops working and gives a buzzer alarm) and other safety protections.[1]
Drum type
In the early days, most of the hot water boilers, such as drum type hot water boilers, were refitted from steam boilers, and the boiler water was naturally circulated in the boiler.To guaranteeBoiler water circulationIt is safe and reliable, and requires that the boiler should have a certain height, so this type of boiler is larger, and its steel consumption and cost are relatively increased.However, because this type of boiler has a large water output capacity and can maintain natural circulation, when the system circulating pump stops suddenly, it can effectively prevent the boiler water from vaporizing.It is also for this reason that natural circulation hot water boiler develops rapidly in China.[1]
purpose
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Hot water boiler is mainly used for heating and bathing.Hot water boiler passes throughHot water circulating pumploopthermal insulation water tankThe hot water of the water tank can be heated repeatedly to achieve the purpose of bathing;The hot water boiler circulates the hot water of the heating pipeline through the hot water circulating pump, and can meet people's heating requirements through the radiator (radiator);Hot water boiler and hot water circulating pump together with heat exchanger can realize dual functions of bathing and heating.[1]
Structure principle
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For the natural circulation hot water boiler, the inlet and outlet water are connected from the top of the upper drum, and the inlet water is led by the inlet distribution pipe to the front and side lower headers, and then heated up by the inlet water wall pipe.The front and rear ends of the upper drum are equipped with water baffles at the boundary between the falling and rising water flow. The water baffles only partition the lower half of the drum cross section.For forced circulation, the inlet water is connected to the lower header at the front end, rising from the front water-cooled wall tube to the upper drum (the front water-cooled wall downcomer is canceled at this time), then turning into the side water-cooled wall tube downcomer to the side lower header, and then distributing the side water-cooled wall tube to rise to the upper drum, and then descending from the front convection tube bundle to the lower drum, finallyThere are several circuitous processes between the lower drum and water flows out from the rear end of the upper drum.Forced circulation boilerThere is no economizer.[1]
characteristic
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Electric hot water
1. Microcomputer hot water boiler controller with built-in backlightLCD screenThe operation status of the boiler is clearly visible on the display.All operations can be easily completed by pressing keys,Boiler controllerIts super display function and control function are complete.
2. The ceramic electric heating tube type hot water boiler adopts the electric heating mode of "water and electricity separation", which completely separates the electric heating tube from the boiler water. The boiler is safe to use and convenient to repair and replace the heating tube;The stainless steel electric heating tube type hot water boiler adopts the "immersion" electric heating mode. The boiler water rises quickly and has high efficiency. The heating tube is flange connected to the furnace body, which is easy to clean and replace.
3. Users can set the water temperature at any time between 30 ℃ and 90 ℃. The boiler can automatically supply heat to the heating cycle system or provide users with hot water for bathing and living according to the user's requirements.
4. Step by step time-sharing input method is adopted for high-power boiler to control the heating group. The heating group can be input or stopped randomly according to the load change, significantly reducing the impact on the power grid.At the same time, the number of heating sections can also be started and stopped manually, so that users can adjust the power of the boiler by themselves.
5. The control system controls the start and stop of the circulating pump according to the boiler water temperature.The hot water circulating pump stops when the boiler water temperature reaches the set upper limit, and starts when the water temperature is lower than the set lower limit.
6. The interior of the hot water boiler for bathing and domestic use has undergone anti-corrosion treatment. The furnace body is not easy to rust and corrosion, the boiler has a long service life, and the hot water quality is clean and sanitary.High grade centrifugal glass fiber wool multi-layer insulation, less heat loss, energy saving and consumption reduction;The famous white color plate is beautifully packaged, with beautiful appearance and corrosion resistance.
7. The boiler has electric leakage protection function (the control system automatically cuts off the boiler power supply after detecting the electric leakage of the power supply appliance), dry burn prevention extremely low water level protection function (when the water level is lower than the set minimum limit water level, immediately shut down and alarm), furnace overheating protection function (when the temperature of the boiler shell exceeds 105 ℃, immediately shut down and alarm, and automatically start the boiler after the temperature is normal)Temperature sensorAbnormal protection function (the control system continuously detects the sensor condition, immediately shuts down and gives an alarm), abnormal protection function of power supply voltage (automatically cuts off power when the power supply is abnormal, and automatically recovers operation after it is normal), and open phase protection function of heating module (shuts down protection after monitoring the lack of phase of heating module).
8. The top of the boiler is equipped with an exhaust port which is connected with the atmosphere. The inner tank is not under pressure. The boiler works under normal pressure, without explosion risk, and completely eliminates potential safety hazards.
9. Symmetrical design of water outlet and return outlet (double inlet and double outlet), suitable for quick connection and installation;The electromechanical integration of the boiler is compact and reasonable, and the transportation is very convenient.[1]
Fuel (gas)
1. Equipped with imported brand burners, it is highly automated. It can automatically purge according to the controller command, automatically ignite electronically, automatically burn, and automatically adjust the proportion of air oil (gas). The performance is safe and stable, and the combustion effect is good.AndFlameout protection deviceTo ensure safe operation.
2. All functions of the computer type hot water boiler controller are magically stored on a smart chip. The boiler starts with one button and operates at full automatic time and temperature. Users can set the start and stop time of the boiler. After the setting is completed, there is no need for special personnel to be on duty, which saves time and effort.
3. Flame retardant spoiler is inserted in the fire tube to slow down the smoke exhaust speed, strengthen heat transfer, and lower the temperature of smoke discharged from the smoke chamber, so as to reduce heat loss and save fuel.
4. The water temperature is displayed in large font, which is convenient to master the operating conditions of the boiler and system. The water temperature can be set at will from 10 ℃ to 90 ℃. The boiler automatically heats the system or provides users with hot water for living and bathing.
5. The control system controls the start and stop of the circulating pump according to the boiler water temperature. The hot water circulating pump starts when the boiler water reaches the set upper limit water temperature, and stops when the water temperature is lower than the set lower limit water temperature.
6. HorizontalOil fired and gas-fired hot water boilerIt is a three return full wet back structure, and adopts the design of large furnace and group of smoke pipes to increase the radiant heat absorption of furnace and effectively save energy and reduce consumption.Threaded smoke pipe andCorrugated furnace linerThe heat transfer effect is greatly enhanced and the fuel consumption is greatly saved.
7. The whole machine is also equipped with overheat protection (when the water temperature in the boiler is too high, the burner automatically stops working and beeps an alarm, secondary overheat protection (when the boiler shell temperature exceeds 105 ℃, the secondary circuit is automatically cut off), dry burning water shortage protection (when the boiler water is below the extremely low water level, the boiler stops working and beeps an alarm)Boiler leakage protection (the control system will automatically cut off the power supply after detecting electrical leakage and short circuit).
8. The boiler is designed according to the normal pressure structure, and the boiler is in a non pressure state, without any safety hazard.
9. AdvancedCentrifugal glass woolMulti layer thermal insulation, famous white color steel plate as outer packaging, less heat loss, beautiful and rust resistant.[1]
2. The boiler is designed according to normal pressure, and the top of the boiler body is equipped with an air vent. The boiler operates under no pressure, and the combustion operation is safe and reliable.Atmospheric hot water boilerIt can be installed in any place where it is used, and is not limited by the various levels of annual monitoring procedures, so it has been developed rapidly in recent years.
3. The vertical coal-fired atmospheric hot water boiler is mainly composed of shell head, furnace liner, furnace liner top, lower seal ring, cupola tube and horizontal water pipe. The combustion chamber is arranged in the furnace liner. The fuel is burned on the fixed grate with natural ventilation. The flue gas scours the horizontal water pipe in the furnace liner horizontally and is discharged into the atmosphere through the cupola tube and chimney.
4. VerticalCoal fired hot water boilerThe furnace is of water-cooled bent pipe structure, surrounded by furnace liner, with large heating area, high thermal efficiency, energy saving and consumption reduction;The shell adopts elliptical head, and the grate adopts cast iron round grate, which is durable and has a long service life.
5. The horizontal coal-fired hot water boiler is a single drum longitudinal type in structure. Water wall tubes are installed on the left and right sides of the furnace, and wing shaped flues are formed. Threaded smoke tubes are arranged in the drum. The movable grate with little coal leakage is adopted, which is reasonable in structure, high in thermal efficiency, and greatly saves energy consumption.
6. The horizontal coal-fired atmospheric hot water boiler adopts a three pass water fire tube structure with a single drum arranged longitudinally. The furnace is densely covered with smooth tube water wall tubes on both sides, and the design structure is reasonable and compact;With large heating area, long flue gas flow, good heat transfer effect and low exhaust gas temperature, it has high thermal efficiency, low operating cost and more economical use.
7. HorizontalCoal fired boilerAfter the fuel is burned on the grate, the flame passes through the low wall to the burn out chamber, from the burn out chamber to the front smoke box through the wing flue on both sides, then from the smoke tube bundle to the rear smoke chamber, and then is pumped by the induced draft fan and discharged into the atmosphere through the chimney, which can not only prevent the bottom of the boiler shell from being exposed to the high temperature radiation of the furnace, but also reduce the smoke temperature at the inlet of the high temperature tube plate. In addition, with the help of the return water injection, there is no dead water zone at the bottom of the drum,It can also effectively prevent the tube sheet from scaling and furnace bottom bulge due to supercooling and boiling, and the flue gas can be diverted to the flue gas chamber for dust removal, which also reduces the original dust concentration.
8. For vertical coal-fired atmospheric hot water boiler, all pipes in the heating area are straight pipes with sufficient cleaningHandhole deviceIt is convenient for manual mechanical cleaning of dirt and internal inspection.The upper part of the horizontal coal-fired atmospheric hot water boiler is equipped with a sufficiently large manhole, through which personnel can enter the furnace body, greatly facilitating the inspection and maintenance of the boiler.
9、Boiler bodyCompact layout, small floor area, convenient transportation, quick delivery, short installation cycle, low installation cost, less user investment, and fast recovery.[1]
Scope of application
Hot water boilers are widely used for heating, bathing and domestic hot water in hotels, schools, hotels, residential areas and other enterprises and institutions.[1]
Boiler fuel
Boiler fuels can be divided into four categories: solid fuels -Bituminous coal, anthracite,lignite, peat, oil shale, sawdust, bagasse, rice bran, etc.Liquid fuel - heavy oil, residual oil,diesel oilEtc.Gas fuel - natural gas, city gas,Liquefied petroleum gasEtc.New fuel - electric energy, light energy, etc.[1]
Advantages and disadvantages
Atmospheric boilerAlso called pressureless hot water boiler, it means that the top of the boiler is open to the atmosphere and does not bear the static pressure of the water column of the heating system.It is quite an "open type hot water tank".water circulating pumpIt can only be installed on the main hot water supply pipe, and check valve and flow regulating valve should be installed, so the circulating water pump does not play the role of circulating water, but plays the role of pressurized water, which is actually a pressurized water pump, just like the cold water booster pump in the water supply project. The water in the reservoir is pumped to the water tower, and then delivered to the user by gravity.[1]
advantage
(1) There is no explosion risk, so supervision and inspection may not be carried out.
(2) It is unnecessary to consider the pressure relief of boiler room
(3) Save steel and simplify process
(4) Discard the boiler for reuse.
(5) Cancel the make-up water pump.
(6) Power failure protection is good.
(7) Durable
(8) Save users' investment[1]
shortcoming
(1) Circulating energy consumption of the system.
(2) Low static pressure at the inlet of circulating water pump.
(3) The inlet water temperature of the circulating water pump is high.
(4) The boiler water is in direct contact with the atmosphere.[1]
Safe use
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Anticorrosion
The causes of boiler corrosion are analyzed as follows:
1. Do not control the make-up water volume.Article 100 of the safety supervision regulations for hot water boilers stipulates that "the leakage of the hot water system is generally not more than 1% of the water capacity of the system", but some units mistakenly believe that with a hot water boiler, it is convenient to use hot water, and the hot water of the system is used for bathing, washing clothes, etc. A 2.8MW hot water boiler makes up nearly 100 tons of water every day.
2. The "Low pressure boiler water quality standard" (hereinafter referred to as the standard) is not carefully implemented.The standard clearly stipulates that when the water supply temperature is ≤ 95 ℃, the PH value of circulating water should be controlled to reach 10~12, which is a very important indicator, but some units do not implement it.However, these units pay more attention to the hardness of make-up water, and some have specially installed mobile bed water treatment to meet the needs of make-up softened water. They mistakenly supply hot water boilers according to the steam boiler water standard, and think that if the softened water is qualified, it will not scale and corrosion.
3. Users whose heating network pipeline installation is unqualified and whose circulating water cannot be delivered to the end of the system.In order to avoid freezing, some users increase the number of times they discharge air, which makes the drainage hot and cool. As a result, the amount of leakage increases.
4. The constant pressure of expansion water tank and boiler is inconsistent.The expansion water tank of a unit is located on the fourth floor, its height is less than 15m, but the constant pressure of the boiler is 2.5kg/cm2. As a result, the stoker often makes up water in order to maintain the working pressure index of 2.5kg/cm2, and the water overflows into the trench, which costs both water and coal.
5. Shutdown without maintenance.After the heating period, the boiler was shut down, and the temporary workers were dismissed. Some boilers were filled with softened water, and some boilers were exposed to the atmosphere, lacking necessary maintenance.The above situation clearly shows that the corrosion of hot water boiler is caused by the user's lack of knowledge of hot water heating, especially a large amount of make-up water, which not only replenishes a large amount of dissolved oxygen, but also because of the large amount of make-up water and overload operation of water treatment equipment, the unqualified water with high chloride content is often replenished into the system to ensure the amount of make-up water,When the PH value of boiler water is only 7~8, hydrogen ion, oxygen ion, chloride ion, etc. are very active as corrosion media.As the PH value of boiler water is low and the concentration of hydrogen ions is high, hydrogen will conduct cathodic reaction under ulcer corrosion. When there is dissolved oxygen in the water, the presence of chloride will greatly increase the corrosion rate of iron. This is because water chloride ions are easily absorbed by the oxide film on the metal surface and replace the oxygen ions in the oxide film, thus forming soluble chlorides and damaging the oxide film,So that the metal surface continues to be corroded.
To sum up, it is the key to cause corrosion of the hot water boiler and reduce the service life of the hot water heating system by over supplying water.[1]
The ideal hot water boiler operation system should be basically tight without leakage, and a fixed amount of water in the system circulates round and round, absorbing and releasing heat.After circulating, the dissolved oxygen in the water has been completely absorbed by iron and becomes oxygen free water, which will not cause serious corrosion to the boiler.It is reasonable that the leakage rate should not exceed 1% of the water capacity of the system in the regulations for hot water boilers.
In order to prevent corrosion of hot water boiler, the following recommendations are made:
1. For boilers whose water make-up rate exceeds the standard, it is necessary to find out the causes and treat the symptoms, cut off all drain taps, block all leakage, overflow, drip and leakage, increase the automatic vent valve of the system, and strictly manage the system to make the water make-up rate operate up to the standard.
2. A small amount of make-up water is inevitable, but the quality of make-up water should be paid attention to. It is better to supply deoxygenated water.The boiler water heated separately can use the waste heat of the tail flue to preheat the cold water (soft water) to 70 ℃~80 ℃, and then add appropriate amount of sodium phosphate and sodium sulfite into the boiler at the same time, which is beneficial but harmless to the boiler.
3. Strictly control the PH value of boiler water, and regularly test the PH value (two hours). When the PH value is lower than 10, increase the amount of sodium phosphate and sodium hydroxide for adjustment.
4. Do a good job of boiler shutdown maintenance.There are two methods: dry method and wet method. The dry maintenance method shall be adopted if the boiler is shut down for more than one month, and the wet maintenance method can be adopted if the boiler is shut down for less than one month.After the hot water boiler is out of service, it is better to use the dry method for maintenance. The water must be drained completely, and the moisture must be baked out with a small fire. Then add raw stone or calcium chloride, and add 2 kg~3 kg per cubic meter of boiler volume to ensure that the inner wall of the boiler is dry, so as to effectively prevent corrosion during the shutdown period.
5. The hot water boiler shall be shut down for comprehensive inspection and maintenance every 3-6 months after operation.[1]
Inspection items
Including the internal inspection and use preparation of the boiler, the inspection in the furnace and flue, the inspection of boiler accessories, the inspection of automatic control system, the inspection of auxiliary equipment, the inspection of combustion equipment, the inspection of auxiliary heating surface, and the inspection that must be done before the operation of the hot water boiler. We should not underestimate these inspections,It may cause very serious consequences because of our neglect.
Therefore, we must guard against mistakes and carefully check the following items before running the hot water boiler.
1. Including boiler internal inspection and use preparation.
2. Check the furnace and flue, and remove the ash and sundries in the furnace and flue.The regulating valve and gate of air duct and flue must be complete and tight, flexible in opening and closing, and accurate in opening and closing indication.
3. Inspection of boiler accessoriesSafety accessoriesWhether it is intact;Whether the cock rotates flexibly and is easy to use;All instruments and control devices shall be complete, good and clean.After passing the inspection, the pressure gauge cock shall be kept in working condition.
6. Inspection of combustion equipment and check whether the combustion equipment is in good condition;yesMechanical transmission systemThe test run of coal conveying system and mucking system is normal;The safety spring of the speed governing box shall be properly compressed and well lubricated;The indication of coal ram ruler is correct, the eagle iron is neat and intact, and the ballast flap is complete and flexible.
7. Check the auxiliary heating surface, and check whether the coupling of auxiliary equipment (induced draft fan, blower, water pump, etc.) is firmly connected;V-belt is properly tightened;The lubricating oil shall be good and sufficient;The cooling water is unblocked.After passing the inspection, install the safety cover, conduct the test run respectively, and pay attention to the current during idling.[1]
matters needing attention
① Keep the system pressure constant;The low-temperature hot water boiler is realized by the expansion tank installed at the highest position of the circulating systemHot water heating systemThe nitrogen constant pressure tank is commonly used as a measure;
