Gas exchanger device for a gas boiler

Comfort and energy savings in our homes depend on having well-insulated and heated spaces. The gas boiler is one of the most important parts of a heating system. Contemporary gas boilers integrate cutting-edge technologies to optimize performance and reduce their ecological footprint. The gas exchanger device is one such example of technology that has become more popular.

The essential components of gas boilers are gas exchangers, which transmit heat from the combustion process to the water that runs through the heating system. By ensuring that as much heat is captured and used within the system as possible, this process enables the efficient use of energy. Gas exchangers effectively capture and transfer heat, which lowers energy costs and carbon emissions.

The ability of a gas exchanger device to promote heat exchange between the hot gases generated during combustion and the water circulating within the boiler system is central to its operation. Gas exchangers are typically constructed from premium materials like aluminum or stainless steel and are meant to survive harsh conditions and high temperatures. This robustness guarantees longevity and dependability in functioning, offering homeowners comfort.

The energy efficiency that gas exchanger devices provide is one of their main benefits. The efficiency of gas boilers is greatly increased by gas exchangers, which capture heat that would otherwise be lost through flue gases. This is in line with initiatives to lower energy use and fight climate change, in addition to saving money for homeowners.

Additionally, gas exchanger devices are essential for improving gas boiler systems’ safety. Through efficient containment and direction of combustion gases, they reduce the possibility of carbon monoxide leaks, guaranteeing occupant safety within. This feature emphasizes how crucial it is to maintain safety standards by performing routine maintenance and inspections on gas exchangers.

Device and principle of operation of a double -circuit gas boiler

Here you will find out:

Boilers with dual-circuit heating have gained popularity because they are small and convenient. They provide hot water while simultaneously keeping you warm at home. That is, there is no longer any need to purchase a separate water heater or heating appliance. What is the dual-circuit gas boiler’s basic working principle and what components make up this apparatus? This will be covered in our review.

Double -circuit gas boiler

You must comprehend the device of a gas double-circuit boiler in order to comprehend the basic principles of its operation. It is made up of numerous independent modules that switch to the dowry contour and heat the coolant in the heating circuit. You can rely on the equipment to operate without issue thanks to the coordinated efforts of all its parts. You can comprehend the working principle of a double-circuit boiler by being familiar with its mechanism.

Since all we need to know is the main nodes’ appointment, we won’t be considering the double-circuit boiler accurate to the screw device. Within the boiler, we shall discover:

The hot water’s contour and heating are controlled by two separate circuits in the model.

• A burner located in an open or closed combustion chamber – This is the heart of any heating boiler. It heats the coolant and generates heat for the operation of the dowry circuit. To ensure accurate support for a given temperature, it is endowed with a system of electronic flame modulation;
• Combustion chamber – it contains the above burner. It can be open or closed. In a closed combustion chamber (or rather, above it) we will find a fan that is responsible for air injection and for removing combustion products. It is he who is a source of quiet noise when the boiler is turned on;
• Circulation pump – provides forced circulation of the coolant through the heating system and when operating the DOS circuit. Unlike the combustion chamber fan, the pump is not a noise source and works as silently as possible;
• A three -way valve – it is this thing that is responsible for switching the system to the generation mode of hot water;
• The main heat exchanger – in the device of a double -circuit wall -mounted gas boiler, it is located above the burner, in the combustion chamber. Here, the coolant used in the heating circuit or in the hydraulic power plant to heating water occurs;
• Secondary heat exchanger – It is in it that hot water is preparing ;
• Automation – it controls the parameters of the equipment, checks the temperature of the coolant and hot water, controls modulation, turns on and disconnects various nodes, controls the presence of flame, fixes errors and performs other useful functions.

Nozzles for connecting gas, hot and cold water pipes, and the heating system are located in the lower portion of the housings.

Double heat exchangers are used in some gas double-circuit boiler models. However, the fundamentals of work are essentially unchanged.

You’ll see that the gas column’s device is identical except for the lack of a heating circuit.

We discovered the mechanism of a wall-mounted, double-circuit gas boiler; at first glance, it appears a little confusing, but the challenges vanish if you comprehend the placement of specific nodes. The resemblance to a gas flow water heater, which still has a burner and heat exchanger, is evident here. Everything else is extracted from single-circuit wall-mounted boilers. The fact that there is an expansion tank, a circulation pump, and a security group integrated into the binding is unquestionably advantageous.

When examining the setup and working principle of a gas double-circuit boiler, it is important to keep in mind that the coolant and water from the DHW contour are never combined. Through a different pipe that is connected to the heating system, the coolant is poured into the heating system. A portion of the coolant is circulating through the secondary heat exchanger, preparing hot water. But that is a topic for a bit later on.

In the realm of heating and insulating your home, understanding the gas exchanger device for a gas boiler is crucial. This component plays a pivotal role in the efficiency and safety of your heating system. Essentially, a gas exchanger is responsible for transferring heat from the burnt gas to the water that circulates through your boiler, ensuring your home stays warm during chilly days. It works by capturing the heat produced during combustion and transferring it to the water, which is then pumped through your radiators or underfloor heating system. This process not only maximizes the energy extracted from the gas but also minimizes waste, making your heating system more eco-friendly and cost-effective in the long run. Understanding how this device operates can empower homeowners to make informed decisions about their heating systems, ultimately leading to improved comfort, efficiency, and savings.

The principle of operation of a double -circuit gas boiler

We will now start dissecting the basic idea behind how a gas double-circuit boiler operates. We now know why each node and module exists, and this information will help us comprehend how all of this gear functions. We’ll examine the idea of work in two ways:

• In heating mode;
• In hot water generation mode.

Your home is heated by the boiler when it is in heating mode.

We observe right away that operating in two modes is not feasible. To address this, double-circuit boilers have a three-way valve that directs a portion of the coolant to the dowry circuit circuit. First, let’s examine the principle of operation during the heating process. Next, we will investigate the operation of the technique in hot water supply mode.

A double-circuit boiler functions similarly to a standard flow heater when it is in the heating mode. When the burner is first turned on, it works for a while to raise the temperature in the heating circuit to a certain point. Upon reaching the required temperature range, the gas supply will be cut off. Should an air temperature sensor be installed within the residence, its readings will be considered by the automation.

In double-circuit boilers, a weather-dependent automation that regulates street air temperature may also have an impact on a gas burner’s performance.

The coolant, which is forcing the heating system into forced mode, is heated by the heat from the operating burner. In order to guarantee that water passes through the main heat exchanger normally, the three-way valve is in this position. There are two methods for removing combustion products: independently or with the use of a unique fan that is housed in the double-circuit boiler’s upper section. The state of the DHW system is disconnected.

Work in hot water supply mode

The hot water supply circuit initiates at the moment the tap crane handle is turned. The three-way valve, which shuts off the heating system, is activated by the emerging water current. A gas burner is lit simultaneously (assuming it was disconnected at the time). The tap starts to flow hot water after a short while.

The heating circuit is totally shut off when switching to the hot water supply mode.

Let’s examine how the hot water contour operates theoretically. As previously stated, its inclusion results in the heating system or DHW being the only thing that operates in this situation. governs the entire three-way valve. He directs a portion of the hot coolant toward the secondary heat exchanger; the secondary has no flame. The heat exchanger starts to heat the water passing through it when the coolant acts on it.

Due to the usage of a tiny coolant circulation circle, the scheme is a little bit complicated. Although there is no such thing as the best operating principle, double-circuit gas boilers with independent heat exchangers can claim regular maintenance. What characteristics distinguish boilers with integrated heat exchangers?

• A simpler structure;
• High probability of scale formation;
• Higher efficiency in DIA.

It is evident that the drawbacks and benefits are closely related, although distinct heat exchangers are valued more. Although there is no scale in this case, the structure is fairly complex. Please be aware that the coolant flow along the heating circuit stops when the hot water is operating. That is, its continuous operation may cause the premises’ thermal balance to be violated.

The double-circuit boiler enters the expectation mode (or instantly turns on the heating of a slightly cooled coolant) as soon as the tap is closed, activating the three-way valve. The machinery will remain where it is until we open the crane once more in this mode. Depending on the boilers being used, certain models can perform as high as 15–17 l/min.

Once you have figured out the gas double-circuit boiler’s operating principle, you will be able to comprehend each node’s function and even independently comprehend repair issues. The device appears extremely complex at first glance, and its intricate internal design is cause for admiration—after all, the creators succeeded in creating nearly flawless heating apparatus. boilers with two circuits, like those made by Vaillant. They actively replace two devices at once by producing hot water and heating buildings for a variety of uses. Additionally, you can eliminate the need for a floor boiler and save space thanks to their compact design.

The principle of operation of a double -circuit gas boiler, equipment and types

A double-circuit gas boiler is a device that supplies the hot water supply and heating circuit, or the coolant 2 circuit (rice, 1). Anyone who has a double-circuit gas boiler in their home should be familiar with its operating principle. It’s important to remember this device’s primary functions:

• Ensuring the heating system by the coolant and further maintenance of temperature in the system;
• Hot water supply, that is, providing a house with hot water for household needs.

Rice. 1 The double-circuit system’s operation

Principle of operation

A double-circuit boiler warms the heat exchanger’s coolant. The thermostat, which activates a double-circuit boiler when the coolant temperature drops below a predetermined threshold, is responsible for the entire heating process. The thermostat activates the circulation pump and issues a command. The coolant in the reverse pipeline starts to move as a result of the pump starting up. This causes the coolant, which has been heated in the heat exchanger, to start moving through the system.

The gas device starts off with a low power and increases to its maximum during the heating process. However, the boiler reaches the appropriate temperature when the operating mode is selected. Automation regulates this process, and when it reaches a very high temperature, it shuts off the boiler, preventing gas from entering the burner.

Rice. Dual-circuit boiler with two walls.

The thermal energy that is released when gas burns heats up the heat exchanger. As a result, the heat exchanger is already above the combustion chamber, which has the burner below.

As soon as a теплоноситель в системе отопления повторит заданного температурного режима, горелка постепенно затухает, а потом газ и вовсе не поступает. Furthermore, according to the new thermostat team, the double-circuit gas boiler is in standby mode.

A three-way valve is used to handle the double-circuit unit’s second function, which is to supply hot water. As water enters the secondary heat exchanger—which is intended for hot water—he covers the path that the coolant takes into the heating system. The primary is below this heat exchanger. The double-circuit boiler continues to heat the radiator coolant after the three-way valve closes, which is activated during the tap crane’s opening.

Gas boilers can be ignited using one of two methods:

• Electric – this type of ignition is in the devices that work from electricity. Thanks to the control node, such a rod occurs in automatic mode;
• Piezorozzhig – inexpensive boilers are equipped with this type of ignition, this is an energy -dependent system. Pinking comes from pressing the button on the case. At the same time, the smell is constantly on.

3. The floor-mounted dual-circuit boiler

Work of the contour of the hot water

A double-circuit boiler’s summertime feature is that it can be used as a gas column. How does a summertime double-circuit gas boiler operate? Following the tap crane’s opening, the boiler is turned on from the waiting state. The pressure relay closing is to blame for this.

No more than 2.5 liters of water are required for this. The automation command causes ignition, which progressively increases the gas supply. Additionally, a three-way valve overlaps the heating circuit in response to the crane opening. Moreover, water is supplied to the secondary heat exchanger from the primary heat exchanger, where it is heated.

The device operates at reduced power and only modifies even heating once the water in the heat exchanger reaches the required temperature. A one-degree drop in temperature triggers the gas burner.

Condensation and convection devices

Gas boilers with double circuits can operate on two philosophies:

The gas convection unit works on the basic principle of releasing steam produced during gas combustion, which is then expelled via the combustion product removal system. Condensation models, however, operate in a different way. They have a second combustion chamber that is used to collect the spent vapors from burning fuel. After reaching a specific temperature there, they continue to heat the secondary heat exchanger. The hot water circuit is intended for use with the secondary heat exchanger.

The boiler operates on the convection principle, which is becoming more and more manageable. There is very little possibility of corrosion developing because the steam enters the chimney and no condensate forms inside. Because condensation boilers have a second combustion chamber in their design, they have an efficiency indicator above.

The design of a double -circuit device

The double-circuit gas boiler device (rice. 4) has three main nodes that are present in all variants of the device:

Additionally, the gas heating unit’s corpus, which has a layer of thermal insulation on it, is unaltered.

Rice. 4 Design of a double-circuit gas boiler

A gas burner is a structure that has nozzles inside and is perforated all the way around. Nozzles distribute and serve gas to create a consistent flame. There are various kinds of burners available:

• One -stage – this burner is arranged, so it cannot be adjusted, it works in the same mode;
• Two -stage – this device has 2 position adjustment positions;
• Modulated – the power of such a burner can be adjusted, due to this, boilers are more economical to consume fuel.

Exchanger of heat. Two heat exchangers are found in double-circuit gas devices.

• Primary – in it the coolant for the heating circuit is heated. Made of steel or cast iron;
• Secondary is a heat exchanger in which water is heated for a hot water supply contour. It usually affects the temperature slightly less than the primary, so it can be made of materials such as copper, stainless steel, etc.D.

Rice. 5 The double-circuit gas device’s primary heat exchanger

An automation node manages how a gas device operates. It consists of a sensor network and an electronic circuit. The electronic circuit’s double-circuit boiler, which either switches the device’s operating mode or turns it off, is verified by sensors.

An apparatus required for a forced-circulation heating system is the circulation pump. This is a constituent element of a system that depends on energy. The appropriate pressure indicator is provided by such a pump.

The following options for the combustion system of combustion products:

• natural traction. In this case, combustion products are removed into a chimney, which should rise above the roof by at least 1 meter;
• forced traction. Boilers with such a system have a fan in the design for the output of combustion products into a coaxial chimney (pipe in the pipe). Such boilers are called turbocharged.

Tank expansion. When a теплоноситель reaches extremely high temperatures, it becomes unstable and eventually breaks down, resulting in a расширительный бак. Depending on the power of the boiler and the volume of coolant in the system, the tank’s capacity may vary.

The combustion chamber has the appearance of a thermally insulated metal container. The main heat exchanger is located above it, and a burner is located at the bottom. A gas device’s combustion chamber can be:

Since a gas double-circuit device with an open camera draws its combustion air directly from the room where it is installed, it may be energy-dependent. It is advised to install these units in boiler rooms, which are specially designated spaces. They must be set up in accordance with all the guidelines, which include having windows and adequate ventilation. Carbon dioxide will be released by a double-circuit boiler with an open combustion chamber that is low in air.

A gas double-circuit device with a closed camera is one that uses a coaxial chimney to draw air for combustion from the street. The unique design of the coaxial gases allocation system, or the "pipe in the pipe," serves as its foundation (rice, 6). In other words, a larger diameter pipe contains a smaller diameter pipe. Products that burn pass through a small pipe and a large air fence to enter a gas boiler. The coaxial chimney has the benefit of being able to be installed both vertically and horizontally.

6 pipes (a pipe inside a pipe) for the coaxial chimney

Energy -dependent and energy -dependent boilers

Energy-dependent dual-circuit gas boilers operate essentially on the same principles as other energy-dependent boilers. Electricity-powered parts are what make them function. This includes a fan to remove combustion products, automation (full adjustment of the aggregate robot), and a circulation pump. The operation of energy-dependent double-circuit units has certain drawbacks:

• Such equipment is sensitive to voltage drops in the network, so you need to additionally purchase a voltage stabilizer;
• If there are no accidents on the line of the mains and light, then the boiler will not function. In this case, you need to get a generator or uninterrupted power supply.

The convection principle governs the natural circulation of coolant in energy-dependent boiler models. A larger diameter is required for such a pipe unit in the heating system to function normally. Additionally, the expansion tank needs to be open in this situation. Additionally, the heating system pipeline is made to include for proper circulation. Natural traction is the basis for the combustion product removal system’s operation. In order to do this, a chimney that is at least 4 meters tall is installed.

Because power-dependent devices have an open combustion chamber, they require continuous air flow. Therefore, the room should have regular ventilation. The fact that this double-circuit boiler continues to function even in the absence of electricity is, of course, its greatest benefit.

Baxi gas boiler: faults and how to fix them

Description of the work of a double -circuit gas boiler

Every manufacturer of gas heating installations offers modifications with an extra contour to prepare hot water for household needs. Understanding the system that a double-circuit gas boiler operates on will be helpful when purchasing a hot water unit for your house. This will assist you in making the best decision for your needs and operating environment.

The Navien double-circuit boiler apparatus

Varieties of gas double -circuit boilers

There are three types of double-circuit gas installations based on their device and mechanism of operation:

• used for heating water and coolant one common (bitter) heat exchanger;
• heating water for hydraulic devices in a separate high -speed overall heat exchanger;
• with a running heat exchanger and accumulative capacity.

Units with Bittermic heat exchanger

Complexly configured heat exchangers made of copper are installed in the first type of installations. Every pipe appears as it does in the figure.

In this instance, a double-circuit gas boiler works on the principle of heating water for hot water and heating two distinct tubes that are housed in one unit. According to the internal water for the hot water, a coolant runs along the outer tube for the heating system. The coolant and water flows in a single direction, organizing the movement of flows through passing. An automatic gas valve governs the operation of a gas regime that is situated beneath the heat exchanger. The following is the algorithm:

1. In heating mode, the water flowing through the outer tubes is heated to the temperature limited by the thermostat. Upon reaching this temperature, the gas valve turns off the burner, when cooled by the coolant, it turns on.
2. When one or several cranes of hot water in the house, its movement begins in the internal tubes of the heat exchanger, the circulation of the coolant in the heating system begins and the boiler operates in the dowry mode. The coolant moves through a small circle inside the boiler, transmitting its energy to the water in the inner tubes, the burner works constantly.
3. Когда краны ГВС в доме закрываются, циркуляция теплоносителя в системе отопления возобновляется.

The main benefit of the structure is that this work algorithm uses a double-circuit gas boiler without electricity. The second benefit is that installing a hot water unit is less expensive than installing a flow heat exchanger and storage capacity. One of the device’s minor drawbacks is its limited productivity. Usually, two to three average users are sufficient; if there are more, the water temperature will drop noticeably.

One other disadvantage is that joint use is inconvenient. Оогда открыт вентиль на кухне, а вы в это же время принимаете душ, то есть риск попасть под струю горячей воды после внезапного перекрытия кухонного крана. When someone opens the hot water faucet a lot while washing, it has the opposite effect and you end up with a cold shower.

The figure shows the operation scheme for the hotel’s installations.

Assembly device with a running heater

These gas boilers are not directly heated by the burner; instead, thermal energy is transferred "from water to water" through the presence of an extra heat exchanger, as previously mentioned. The diagram shows a thermostatic three-way valve that transfers coolant from the primary water heater to the secondary or heating system. These units typically have two expansion tanks installed—one for the coolant and the other for the hot water. They also typically have a circulation pump.

In normal mode, the burner heats the main heat exchanger through which the coolant passes. When opening the hot water valve, one of the consumers, the flow sensor is triggered, sending the pulse of the control unit. He switches a three -way valve using an electric drive and the operation of a gas boiler completely goes into a hot water mode. The coolant from the main heater enters the secondary and gives its heat to the water heated for the hot water. The movement of flows here is organized towards each other for better heat transfer. As in the previous case, in the DHW mode, the supply to the heating system is turned off, the coolant moves from one heater to another using a circulation pump.

The drawbacks of gas water heaters that use the flow heating principle are identical to those of boilers that use a bittermic heat exchanger. Furthermore, without electricity, they are inoperable. The benefits can be divided into the following categories:

1. The possibility of accurate adjustment of hot water temperature at the output of the boiler.
2. The increased heating rate, due to which the period of time is reduced between the opening of the hot water valve and its flow to the consumer.
3. The secondary heater lasts longer than the Betermic heat exchanger.

Boilers with a running heater and accumulative built -in boiler

The hot water’s secondary heater is built into the unit to run in between the coolant’s heating and the hot water that builds up in Boyler. In other words, the burner continues to function for the purpose of heating water in hydroelectric power plants even after the coolant reaches the installed temperature. Similar to a typical fiber heater, the three-way valve simultaneously changes the coolant’s flow. In optimal mode, both circuits operate in alternation, and the boiler’s heated water immediately benefits the users. This double-circuit boiler installation is the least expensive of the three types.

Automation supports the set temperature of the coolant and water in the accumulative container, which can be scheduled for the following seven days. After that, the unit will heat the water to the appropriate temperature for the specified amount of time. The high cost of not having these gas boilers is offset by their increased efficiency and comfort when in use.

One of the common disadvantages of all double-circuit units is thought to be the heat exchangers’ propensity to settle on the scale’s working surfaces.

For long-lasting workDual-switch gas boilersIt is highly advised to plan for the heating system’s fueling and the filtration of cold water that is used to produce hot water.

To achieve this, mesh filters made of mud should be installed at the entrance to the unit that receives coolant and cold water from the return pipeline. Consequently, you must buy this kit before connecting a double-circuit gas boiler:

• 2 mesh filters;
• 4 balls of water for water;
• 1 ball valve for gas;
• 5 compounds with a rug nut (American);
• 2 Divids 90º.

The double-circuit gas boiler’s normal circuit, which connects it to the water supply, gas line, and heating system, is shown below. The elements are schematically depicted, and the proper way to install the mud is in a horizontal position, creating a threaded traffic jam. The filter will not function properly if installed vertically.

Gas Exchanger Function	The gas exchanger in a gas boiler is responsible for transferring heat from the combustion gases to the water in the boiler system.
Types of Gas Exchangers	Gas boilers can have different types of exchangers, including shell-and-tube, plate, or spiral designs, each with its own advantages and efficiency.

Purchasing a gas exchanger for your gas boiler can greatly improve the effectiveness and functionality of your heating system. By utilizing the heat that would otherwise be wasted from flue gases, these devices help to maximize energy utilization, which lowers utility costs and has a smaller environmental impact.

The capacity of a gas exchanger to recover heat from the exhaust gases created during combustion is one of its main benefits. The incoming cold water is then heated by this recovered heat before it enters the boiler. Because of this, the boiler runs more effectively and uses less fuel to reach the right temperature, saving you money and energy.

Furthermore, a gas exchanger helps create a heating system that is less harmful to the environment by lowering the quantity of heat lost via the flue. Increased efficiency results in lower carbon emissions, which helps you reduce your carbon footprint and make a positive impact on a cleaner, greener future.

Furthermore, a gas exchanger can frequently be retrofitted to an existing boiler system and is comparatively easy to install. As a result, homeowners can take advantage of increased efficiency without having to invest in pricey upgrades or major renovations.

To sum up, installing a gas exchanger device can be a useful and affordable way to improve the efficiency of your gas boiler. By recovering waste heat and increasing overall efficiency, these devices help you heat your home more sustainably while also saving money on energy bills.