The hot water boiler belongs to the heat source of heating, ventilation and air conditioning heat load. The pressure hot water boiler can supply both low temperature water and high temperature hot water. Another typical feature of pressurized hot water boilers is that the circulating water pump of the heating system generally uses a clean water pump, which pumps the return water of the system project to the boiler. It must overcome the system circulation resistance and maintain a certain pressure in the boiler to ensure that hot water does not vaporize at high temperatures. Hot water boiler is an important heat supply equipment in the national economy.
In this guide, we’ll teach you everything you need to know about your hot water boiler: what is the hot boiler, how they work, how to choose a new one, how to maintain them and replace them.
Topics
1. What is a hot water boiler?
2. How they work
3. Application
4. Types
5. Pros and cons
6. How to calculate the required thermal power
7. Costs
8. Maintaining
9. Conclusion
1. What is The Hot Water Boiler?
Hot water boilers include electric hot water boilers, oil-fired hot water boilers, gas hot water boilers, coal-fired hot water boilers, etc. Hot water boilers are boilers that produce hot water. They use the heat energy released by fuel combustion or other heat energy (such as electrical energy). , solar energy, etc.) a thermal energy device that heats water to a rated temperature.
2. How do Hot Water Boilers Work?
The boiler body uses the combustion fuel to continuously release heat. The high-temperature flue gas generated during combustion can transfer heat to the heating surface of the boiler through the principle of heat transmission, and the temperature itself decreases gradually, and finally discharged through the chimney. Hot water boilers are mainly used for heating and bathing. The hot water boiler circulates the hot water in the thermal insulation water tank through the hot water circulation pump, and heats the hot water in the water tank repeatedly to achieve the purpose of bathing; the hot water boiler circulates the hot water in the heating pipe through the hot water circulation pump, and passes through the radiator (radiator) which can meet people's heating requirements; hot water boilers and hot water circulation pumps combined with heat exchangers can realize the dual functions of bathing and heating.
3. Application
Hot water boilers are mainly used for heating and bathing. The hot water boiler circulates the hot water in the heat preservation water tank through the hot water circulation pump, and heats the hot water in the water tank repeatedly to achieve the purpose of bathing; the hot water boiler circulates the hot water in the heating pipe through the hot water circulation pump and passes through the radiator. It can meet people's heating requirements; hot water boilers and hot water circulation pumps combined with heat exchangers can realize the dual functions of bathing and heating.
4. Types of Hot Water Boilers
★ Electric Hot Water Boiler
Electric hot water boilers are also called electric heating boilers, electric heating boilers, electric heating boilers, electric bath boilers, electric bath boilers, etc. Electric hot water boilers are designed using the latest electric heating technology and control systems to produce hot water to meet the needs of heating or supplying daily life and bathing. Fully automatic environmentally friendly boiler for hot water.
★ Gas Hot Water Boiler
Gas hot water boiler is a type of hot water boiler. Gas hot water boiler uses gas (such as natural gas, liquefied petroleum gas, city gas, biogas, etc.) as fuel. It heats water through the burner to achieve heating and provide living and bathing purposes. Hot water boilers are highly intelligent, fast heating, low noise, and dust-free. They are an economical and popular boiler type that is very suitable for China's national conditions.
★ Coal Hot Water boiler and Biomass Hot Water Boiler
Thermal power: 0.7-14MW, Rated working pressure: 1.0-1.25MPa
The coal boiler hot water and biomass hot water boiler are a single-drum boiler in structure. Water wall pipes are installed on the left and right sides of the furnace, and a wing-shaped flue is formed. Threaded smoke pipes are arranged inside the boiler drum, and movable grates with minimal coal leakage are used, reasonable structure, high thermal efficiency, greatly saving energy consumption.
5. Pros & Cons for Hot water Boilers
Electric hot water boiler
Pros: Easy to install and operate, lower upfront cost, high energy efficiency, safer than gas
Cons: Higher utility costs, slow to heat, won’t work during a power outage
Gas hot water boiler
Pros: Quick-heating, low utility costs, can work during power outage
Cons: More expensive up front, harder to install (needs gas lines and venting), potential safety issues with flammable gas
Coal & biomass hot water boiler
Pros: Easy to abtain, but propane burns cleaner as well
Cons: Takes up a lot of space and is not friendly to the environment
6. Figure out how much thermal power of hot water boiler you need
If you want to know the question "How to calculate the thermal power of a hot water boiler", you must first solve a question, what is the thermal power of a hot water boiler? Thermal power (symbol represented by Q, unit is megawatt (MW)) represents the rated heat supply of the hot water boiler. The rated heat supply of the hot water boiler refers to: the long-term continuous operation of the hot water boiler on the premise of ensuring safety. , the effective heat supply of hot water output per hour.
Commonly used capacities of hot water boiler thermal power: 0.7, 1.4, 2.8, 4.2, 7, 10.5, 14, 29, 46, 58, 70, 116MW. So, how to calculate the thermal power of hot water boiler?
1. 10,000 calories = 10,000 kilocalories (Kcal) = 10,000,000 calories (cal) = 41858518.2 Joules (j);
2. 10,000 kcal ≌ 11.6 kilowatt (Kw) Example: A 24 kilowatt (Kw) boiler is approximately equal to a 20,000 kcal boiler;
Calculation formula for heat consumption required to heat 1t of water to 40℃: 1T×1000L×40℃=40000kcal
Example: For example, if the user needs 5t of water per hour, then the required thermal power of the gas hot water boiler is 5tX40000Kcal=200000Kcal.
3. Let’s take a look at the relationship between the thermal power and heat supply of gas hot water boilers.
The calculation formula for the amount of heat (provided or lost): Q=cm△t, where c=specific heat capacity of the medium (if the medium is water, c=4200K/kg), m=medium mass, △t=medium temperature difference (discharge There is a temperature difference between heat absorption and heat absorption).
Example: How much heat is needed to heat 1 ton of hot water from 0℃ to 40℃ in one hour?
Q=cm△t=4200*1000*40=168000J (joule)≈40000cal (kilocalorie)
It takes 1,000 calories to increase the temperature of one ton of water by one degree. For example, if the user needs 5 tons of 40°C water per hour, then the required heating value of the gas hot water boiler is 5tX40000Kcal=200000Kcal.
7. Cost
It is important to know how much an industrial hot water boiler replacement costs because it will allow you to be prepared for the cost of installation and maintenance.
If you need to replace an industrial hot water boiler, there are 2 factors to consider. The first thing to consider is the size of the replacement boiler, for example if you have a 3.5MW hot water boiler and want something similar then you could expect to pay around $25,000 to $45,000 depending on the manufacture, model and configuration. Conversely, if you replace your old 3.5MW boiler with a new one that has twice the capacity (10 tons), the cost will be around $45,000 to over $75,000+. Secondly, you must consider the material and labor costs for dismantling old equipment and installing new equipment, which vary according to local charges.
8. Hot Water Boiler Maintenance
When you buy a boiler and put it into use, it is necessary to know how to maintain it in daily use. Because correct maintenance can effectively prolong the service life of the boiler, but also prevent some accidents. Next, CN Boiler will give you a detailed introduction to the daily maintenance of some boilers for your reference.
★ Hot Water Boiler Operation Period Notes
1) Boiler room should be clean and tidy. Other sundries shouldn't be put in boiler room.
2) Pay attention to indoor lighting, water gauge and pressure gauge should have good lighting, and stoker can see clearly. Often patrol around the boiler, and check if the boiler and auxiliary parts are normal.
3) There can't be pounding water on the ground of boiler foundation in case of foundation corrosion caused by moisture.
★ Hot Water Boiler Daily Maintenance
In boiler daily use, inspection, testing, measurement and record job should be done well to know and master the equipment state and timely solve existing problems
1) Daily inspection
Daily inspection items see below:
Contents Requirements
Valve instrument system: Including pressure gauge, water level gauge, safety valve, blowdown device, steam valve, water valve,etc. Performance meets the requirements and the valve switch is in good condition.
Automatic control system: Including test,
control, alarm and interlock of combustion, water level and pressure Performance status meets the requirements.
Water supply system: including water level of soft water tank, feed water temperature, water softener equipment, etc In the normal state.
Combustion system: Including equipment like feeding device, grate, furnace wall, slag extractor,etc
See our Daily maintenance
Ventilation system: Including FD fan, ID fan, air damper, flue gas duct,etc. Fan operation, damper opening, smooth air duct flow, no air leakage.
2) Test, measurement and recording
a. Test: Regularly do water level measurement and test of alarm interlocking device, automatic water supply equipment and other devices to ensure that automatic control equipment work well.
b. Measurements:hot water boiler standard equipment has testing items like hot water temperature, furnace pressure load, air damper opening or fan rotate speed, furnace temperature and flue gas temperature,and be regularly checked and maintained the correctness of these measuring instrument.
c. Record: Record boiler daily operation and analyze and solve the problems.
3) Daily maintenance
The stoker should regularly check and test the temperature and pressure safety alarm interlock protection device to confirm that it can work. If the alarm and interlock protection device is damaged, it should be repaired in time. The boiler can only be operated after the repair.
★ Hot Water Boiler Periodic Maintenance and Overhaul
1) If problems that need to be solved in daily maintenance and cannot be handled immediately are found but the boiler can keep running, confirm annual, quarterly or monthly maintenance plan to make regular maintenance.
2) Boiler runs for 2-3 weeks and following aspects should be checked once:
a. Carry out a comprehensive inspection and measurement of automatic control system equipment and instruments and important test instruments like water level and pressure and automatic control equipment should work normally.
b. Check convection tubes and economizer. If dust is found, it should be cleared. If there is no dust, extend the time of inspection and inspect once a month. If there is still no dust, time can be extended to 2 or 3 months. Meanwhile check if there is any leakage in welding joints of pipe ends. If there is leakage, it shall be repaired timely.
c. Make chain grate no-load rotate and check line by line if there are broken grate bars in front of sprocket shafts. If there are, the broken grate bars should be changed.
d.Check if the fan bearing oil level is normal and the cooling water pipe should be unblocked.
e. Check if front arch bricks are broken and fall off.
f. If there's leakage at water level gauges, vaves and piping flanges, it should be repaired.
3) Boiler should be comprehensively inspected and maintained after running for 3~6 months. In addition to do the various above-mentioned jobs, the following work should be done:
a. Water level electrodes of electrode type water level controller should be cleaned and after using for 6 months, pressure gauges should be re-inspected.
b. Open the top cover of the economizer, remove the ash outside the pipe, remove the elbow, and clean inner dirt.
c. Eliminate scale and sludge in drum, water-cooled wall tube and in two headers, and flush with clean water. Eliminate soot and furnace ash on water-cooled wall tube and drum fire surface.
d. Check the boiler internal and external like welding joint of pressure parts. If there's corrosion phenomenon of steel plate internal and external, serious defects should be repaired immediately if found. If the defects are not serious, they could be left to the next boiler stop and got repaired. If suspicious points are found, but they will not affect safety production, take notes for future reference.
e. Check if rolling bearing of ID fan is normal and check the wear degree of impeller and shell.
f. Clean dust in dust collector and wear condition. Each interface should be tight and no leakage after installed.
g. If necessary, furnace wall, its shell and insulation layer can be disassembled for thoroughly checking. If serious damages are found in certain parts, these parts should be repaired. At the same time, fill the inspection results and repair status into boiler safety and technology register book.
★ Hot Water Boiler Stop for Maintenance
Maintenance method for boiler not used for a long time: There are dry method and wet method. If boiler does not use more than one month, dry preservation should be used to maintain. If it is less than one month, wet preservation can be use to maintain.
Dry preservation
Drain boiler water after boiler stop, eliminate internal dirt thoroughly and flush clean. Use micro fire for furnace drying (note not to use big fire), put 10-30mm lump quick lime or anhydrous calcium chloride desiccant in disks separately, evenly put into the drum and its quantity is that: quick lime according to drum volume is 1-2kg/m3, anhydrous calcium chloride is 1-2kg/m3. Then close all manholes, hand holes and pipe valves and check once every two months. If it is found that desiccant is failure, it should be replaced. When boiler puts into operation again, desiccant and disks shall be taken out.
Boiler furnace and flue can also be put in some desiccant and close furnace door and the other doors and holes.
Wet preservation (suitable for short maintenance)
Drain boiler water after boiler stop, eliminate internal dirt thoroughly and flush clean. Re-inject treated alkaline water to the full, heat the boiler water to 105 ℃, let all air out of boiler, and then close all valves.
After boiler internal flushed clean, fill in alkaline solution to make metal surface formed alkaline protective film to prevent moisture. Wet preservation is suitable for short term furnace stop and its alkaline solution is sodium hydroxide or trisodium phosphate, or also can be the mixed solution of sodium hydroxide, trisodium phosphate and sodium sulfite. The dosage of sodium hydroxide or trisodium phosphate is different from putting condensate water or softened water.
To keep heating receiving surface dry, furnace should be dried by low fire periodically during maintenance. Open pumps periodically for water circulation to keep solution concentration is consistent.
Wet preservation can not be used in cold site to prevent boiler damage caused by freezing furnace water.
9. Conclusion
In conclusion, CN Boiler provides an efficient and reliable solution for your heating needs. With their high energy efficiency, rapid heating capabilities and ease of installation, these boilers are a top choice for homeowners and facility managers. With this introduction to hot water boilers, you can make an informed decision and enjoy the services of a comfortable and energy-efficient system.
If you want to learn about the detailed parameters and prices of hot water boilers, please contact us: at +0086 176-3856-3962.
