RS20210169A1 - BIO FIREPLACE WITH AUTOMATIC COMBUSTION CONTROL - Google Patents

Abstract

Bio fireplace with automatic combustion control consists of assemblies: of tank (1) with peristaltic pump (2), of preheater (3), of evaporator (4), of burner (8) and electronic equipment that enables management and control of the bioethanol combustion process. The operation of the device is enabled and controlled by a microprocessor (15) which is connected to a peristaltic pump (2), an ultrasonic fuel level sensor (16), electric heaters (5, 6), a sensor (31) for the presence of ethanol vapors, a sensor (32) for controlling the horizontality of the device and sensor (33) for controlling mechanical shocks, i.e. impacts. The device has a preheater (3) positioned below the burner (8) so that the copper capillary tube (22), which supplies fuel to the evaporator (4) for preheating liquid bioethanol, uses the heat of the burner (8), thus reducing the need to engage electric heaters (5, 6), that is, it enables the operation of the bio fireplace at ambient temperature. In the burner (8) there is a perforated aluminium tube (26) that enables the even distribution of steam in the combustion chamber, which then, during the combustion of oxygen, creates a laminar diffuse flame along its entire length.

Description

BIOFIREPLACE WITH AUTOMATIC COMBUSTION CONTROL

FIELD OF TECHNOLOGY TO WHICH THE INVENTION RELATES

The field of technology to which the invention relates, generally speaking, falls within the field of heating, i.e. fireplaces, and specifically relates to a biofireplace that uses bioethanol as fuel.

According to the International Patent Classification (IPC, 2020.01), the subject matter of the invention is classified and designated by the primary classification symbol F24C 5/02, which defines liquid fuel stoves and cookers with vaporizing burners, as well as the secondary classification symbol F23D 5/04, which refers to burners in which liquid fuel vaporizes into a partially enclosed combustion space, with or without chemical transformation of the vaporized fuel, and F23N 5/00, which defines combustion control systems.

TECHNICAL PROBLEM

The technical problem solved by the present invention is the following: how to constructively solve a fireplace that uses bioethanol with a concentration of 97-99% as fuel, in which a microprocessor with PWM width modulation is used for optimization for complete combustion of alcohol vapors, which during operation allows preheating of the vapor before entering the burner with minimal engagement of electric heaters, which is safe in cases of impact, i.e. mechanical shocks, the occurrence of the presence of carbon monoxide and carbon dioxide, as well as in the event of a power outage of electronic components of the system, an unforeseen absence of flame, and in addition is characterized by a reduced flame temperature, and thus the oxidation of atmospheric nitrogen (NO and NO<2>) and which is more economical in terms of saving electricity, and is easily adaptable in terms of design to the forms and requirements for modern aesthetic interior design.

STATE OF THE ART

Bioethanol fireplaces have a much greater variability in shape and technical characteristics compared to other heating devices, because they are used for reheating. Their main purpose is decorative, so their design is often more important than their operating properties. Some general characteristics are common to them, so we can classify them into several categories:

- Table “lamps”, used as decorative accessories mainly in hotel rooms, restaurants, offices. They are usually used for a short time, so that people are exposed to their emissions only on certain occasions. The technology of the burners is extremely simple, and generally consists of a simple metal container with one or more slits on top, while the aesthetic characteristics of their design are adapted to the requirements of the user. The flame is generally completely open or only partially protected by small glass walls. The reference power for this type of device is less than 2 kW, and their typical capacity is less than 1 liter.

- Fireplace-like appliances are similar in size, appearance and use to wood-burning fireplaces. Their appearance may resemble a classic fireplace or they may have a modern design, but they are always characterized by some kind of frame surrounding the flame zone, with one or more burners. They often contain decorative elements to simulate wood logs. The reference power for this type of appliance is around 4 kW, and their typical capacity is between 2 and 5 liters.

- Stove-like appliances, usually sold and used as auxiliary heating devices, are often similar to pellet stoves and may have electronic controls for automatic on and off, power regulation or thermostats, and forced convection for more efficient diffusion of warm air. The reference power for this type of device is around 5 kW, and their typical capacity is greater than 3 liters with the possible presence of an auxiliary fuel tank.

Bioethanol used as fuel is a chemical compound with well-known chemical and physical properties; the names ethanol, bioethanol or simply alcohol refer to ethanol products. Most alcohol fireplaces are designed to burn liquid ethanol. The process of ethanol combustion is a chemical reaction expressed as follows:

СН<3>CH<2>OH 3О<2>→ 2CO<2>+ 3Н<2>О

This stoichiometric equation gives the theoretical amount of oxygen required for the complete oxidation of ethanol, which is three molecules of oxygen, two molecules of carbon dioxide and three molecules of water. This is a theoretical ratio, while in practice, in order to achieve a good and complete combustion process, the device needs to be adapted to the specific environment or location. In addition, it is also important to keep in mind that the oxidant most often used is not pure oxygen, but air, which is composed of 21% oxygen and about 79% nitrogen. Nitrogen “dilutes” the combustion products and reduces the combustion temperature, and is also responsible for the formation of nitrogen oxides, which are formed at high flame temperatures, even if the fuel does not contain nitrogen. In principle, manufacturers expect complete combustion of the fuel, the products of which should be “only” carbon dioxide (SO<2>) and water. In fact, taking into account the poor design of the burner, the typical absence of fans that promote forced ventilation or the imperfection of the device to check the degree of mixing of air and fuel vapor in the core of the device, various pollutants can appear due to incomplete combustion conditions.

A review of available patent documentation and other professional literature, as well as available technical and promotional literature from a large number of companies specializing in the production of biofireplaces, found the following:

In the American application US 8622053 published on 07. 01. 2014. under the title "Burner and its method of operation", a device is shown that uses alcohol vapor as fuel, the volumetric flow of which is constant, and thus the flame height is constant depending on the previously set value. In this device, the amount of liquid phase in the evaporator directly depends on the amount of liquid phase in the tank, because they are connected by the principle of connected vessels. Therefore, the amount of steam changes with the emptying of the tank, which affects the flame height (the flow of generated alcohol vapor is not constant). In this device, the amount of generated steam depends exclusively on the volumetric flow through the pump, because all the liquid phase supplied to the evaporator is generated in steam, where the volumetric flow is defined by the user and it regulates the flame height.

Unlike the previously described technical solution, the present invention contains a much more efficient technical solution for obtaining steam from bioethanol, which implies that the conversion from liquid bioethanol to the gaseous phase is carried out under controlled conditions. In addition, in order to increase the efficiency of the device, the preheater is designed in such a way that, in addition to increasing the temperature of the bioethanol, it also has the function of cooling the burner itself, thereby ensuring a lower temperature of the device itself.

In the European patent application EP 2549182 published on 13. 11. 2013 under the title "Liquid fuel fireplace", a burner with two tanks is shown that has a heater positioned outside the evaporator and heats the preheater vessel in which there is a larger amount of liquid phase. According to this solution, it is also envisaged to connect an additional external tank with fuel during the operation of the device, without this affecting the functionality and flame height. The assembly of this device also includes cooling fans placed inside the thermal protectors. This solution is complex and requires a complicated construction of fireplace protection in case of unforeseen problems. Connecting an additional external tank creates a problem with the functionality or flame height of the device. In addition to being significantly simpler and significantly smaller in size, the present invention also allows the connection of an external tank, without affecting the functionality and height of the flame, i.e. the laminarity of steam combustion.

European patent application EP 2028420 published on 25. 01. 2012 under the title "System for automatic supply of liquid fuel to stoves", shows a device with a system for automatic filling of the stove with liquid fuel used in household heating stoves, especially fireplaces, which has a control unit with fuel quality sensors and sensors located in the supply system that provide additional system safety. The device is powered by an air pump, the efficient operation of which requires absolute tightness in the tank itself, which is a short-term and unsafe solution. In addition, the liquid phase of the fuel is supplied to the burner itself, where the transition from the liquid phase of the fuel to alcohol vapor takes place. In this case, there is direct contact between the liquid phase and the flame, which is an unsafe solution. The flame is extinguished by a movable lid that physically blocks the supply of oxygen. After the combustion process stops, alcohol vapor remains in the device, which is also problematic from a safety perspective.

According to the solution in question, there is no safety flaw of this type, since there is no direct contact between the liquid fuel and the flame, i.e. only alcohol vapor is supplied to the burner.

Utility model CN 211502903 U published on 15.09.2020. under the title "Module for supplying fuel to an alcohol stove and a device for its combustion", shows a device intended for use as a stove in households, where this solution structurally contains three pumps that ensure the supply of liquid to the burner. The fact that the transition from the liquid phase to alcohol vapor is carried out in the burner itself represents the essential difference between this and the subject invention. Namely, the fuel mixture is obtained by dispersing the liquid phase inside the burner itself, which is a major drawback of this stove from a safety perspective, and which is overcome by the subject invention.

Polish patent application PL 222427 W1 published on 29. 07. 2016 under the title "Burner for a liquid fuel biofireplace and its control system" shows a device that has the shape of a profiled tube and in the upper part contains a chamber open at the top, with only one closed chamber below the profiled tube, which is a space for steam distribution and fuel evaporation. Like the subject invention, this stove contains a fuel dosing pump, and in the upper part it has connectors for draining excess fuel in case of emergency. Under the burner in the closed chamber is located a control system connected via WiFi to an information manipulator. This solution is unsafe because in the event of a power outage or problems in the device's operating system, in the liquid evaporation chamber and in the burner itself, the process of converting liquid fuel into alcohol vapor continues until the heater cools down. This means that the alcohol vapor is retained in the device itself and represents a flammable mixture, which is problematic from a safety perspective. In addition, according to this invention, in the event of an increase in the flow rate of the metering pump, heated fuel may return to the storage tank, resulting in the dissipation of thermal energy and an increase in the temperature of the fuel in the tank itself. The constructive solution of the biofireplace in question avoids such a failure, because in the event of a power failure, the system is automatically closed by an electromagnetic valve, so the amount of alcohol vapor formed in the evaporator does not increase, and at the same time, a valve is opened that returns the liquid and gaseous phases of the fuel to the tank.

The difference between these inventions is that according to the technical solution of patent PL 222427 V1, the heater is located below the burner itself, which means that during the combustion of the steam its temperature is constantly increasing and thus the increased temperature is transferred to the device. The subject invention provides that the heating of the liquid fuel is carried out in a capillary tube in the preheater which, during operation, takes over the heat of the burner, the temperature of which is consequently reduced. This results in a reduction in the use of electrical energy necessary for the complete conversion of liquid bioethanol into a gaseous state in the evaporator.

The published patent application EP 3211304 A1 dated 30. 08. 2017, entitled "Bioethanol stove", presents a simple solution for a stove that uses bioethanol as fuel, which is fed directly into the burner in a liquid state. The mixture obtained in this way cannot have diffusion, laminar combustion, but the flame will be swirling with a tendency to transition to turbulent depending on the amount of oxygen supplied. In addition, a disadvantage of this stove is the operation of the device at lower ambient temperatures, because the carburetor at low temperatures cannot provide a mixture for complete combustion. The problem arises because the flame comes into contact with the liquid phase of the fuel, which endangers the safety of the user. In addition, the return pump returns the heated fuel to the tank, which increases the temperature of the device itself. The design solution of the device in question avoids all of the above shortcomings.

Patent application WO 2013107455 A2 published on 25. 07. 2013 under the title “Electronically controlled burner” shows a device consisting of at least one fuel tank connected to an evaporation accelerator, the heating of which is achieved by a heater, a flame carrier and an ignition element. The device contains a burner whose operation is controlled electronically. In the central part of the burner, a sprayer is located, by means of which the bioethanol vapor is delivered to the burner, on the upper plate of which there are openings where combustion takes place. The disadvantage of this solution is that due to the use of a ball that regulates the operation of the sprayer, frequent downtime occurs. This is avoided by a simple solution of an evaporator with a perforated tube through whose openings the bioethanol vapor exits, evenly distributed in the burner.

DISCLOSURE OF THE ESSENCE OF THE INVENTION

The subject invention completely solves the previously defined technical problem.

The essence of the invention is reflected in the fact that in accordance with the inventive idea, a biofireplace has been constructed, consisting of assemblies: a tank with a peristaltic pump, a preheater, an evaporator, a burner and electronic equipment that enables management and control of the bioethanol combustion process, which uses a microprocessor with PWM width modulation to optimize the combustion of alcohol vapors, which enables economical preheating of the vapor that goes to the burner, and is safe in cases of mechanical shocks or impacts, the presence of carbon monoxide and carbon dioxide, as well as in the event of a power failure of the electronic components of the system, an unforeseen absence of flame, and is also characterized by a reduced flame temperature and oxidation of atmospheric nitrogen (NO and NO<2>), greater efficiency, i.e. saving electricity, and is easily adaptable to forms and requirements for modern aesthetic interior design.

The essence of the invention is also the construction of a preheater that raises the temperature of liquid bioethanol before it enters the evaporator, which reduces the use of electric heaters to a minimum, since the heat generated as a by-product of the combustion of bioethanol vapor in the burner is used to heat the bioethanol. This is achieved by positioning the preheater directly below the burner, with a copper capillary tube inserted into the groove in the preheater housing, which extends axially along the entire lower surface of the burner, effectively absorbing the heat of the burner, which simultaneously lowers its temperature and reduces the flame temperature, which results in a reduction in the oxidation of atmospheric nitrogen NO and NO<2>.

The novelty of the invention is also the construction of the burner, which ensures an optimal ratio of fuel and air and their mixing, thereby achieving maximum combustion efficiency with minimal occurrence of by-products that otherwise occur as a result of incomplete combustion. The burner is designed in such a way that the flame created in it is uniform along its entire length, and combustion is laminar and diffusional and does not have to be manually controlled.

The essence of the invention is also the installation of a microprocessor whose primary role is to control the flame height by digitally regulating the speed of the stepper motor of the peristaltic dosing pump, whereby the microprocessor allows defining limit values of CO<2> and CO concentrations, at which the device automatically turns off.

The novelty of the invention is also reflected in the optimization of the evaporator operation by automatically correcting the heater activation, thereby maintaining a constant temperature necessary for the complete conversion of liquid bioethanol into steam.

The device according to this invention has several advantages, of which several of the most important are listed below:

- using PWM pulse width modulation drastically reduces electricity consumption;

- during operation, the device largely enables the conversion of liquid bioethanol into steam without the use of a heater;

- by using a digital signal, the noise effect is minimized, which is a great advantage over analog control;

- it is completely safe, and in addition, it is easy to maintain without the use of special tools and does not require special training for operators.

BRIEF DESCRIPTION OF THE DRAWING IMAGE

In order to facilitate understanding of the invention, the inventor refers, for example only, to the attached drawings of the application and where:

- Figure 1 is a schematic diagram of the connection of the assemblies that make up the fireplace in question;

- Figure 2 shows an axonometric view of the preheater with the capillary tube protection plate open, viewed from below;

- Figure 3 shows an axonometric view of the bottom plate of the preheater;

- Figure 4, presents an axonometric view of an evaporator without a lid with a capillary tube in a side view;

- Figure 5, presents an axonometric view of the evaporator without a lid and without a capillary tube in a side view;

- Figure 6, presents an axonometric view of the evaporator cover in side view; - Figure 7, presents an assembled view of the evaporator in axonometric view from the side; - Figure 8, presents an axonometric view of the burner in top view;

- Figure 9 shows the side view of the burner;

- Figure 10 shows the burner's top view;

- Figure 11 shows the appearance of the burner in cross-section A-A.

DETAILED DESCRIPTION OF THE INVENTION

The subject invention relates to a biofireplace with automatic combustion control and, as can be seen from the figures of the attached drawing, it consists of the following assemblies: tank 1 with peristaltic pump 2, preheater 3, evaporator 4, burner 8 and electronic equipment that enables management and control of the bioethanol combustion process.

The tank 1 is in the shape of a hollow square, made of stainless steel - inox, with an opening 19 on the upper side to which a hose 49 is connected for filling fuel from a bottle 50 using a peristaltic pump 17. The tank 1 is connected by a pipe 20 to the suction part of a peristaltic pump 2, the pressure part of which is connected to the preheater 3 via a pipe 21. The tank 1 contains an ultrasonic fuel level sensor 16 that monitors information about the amount of fuel at all times and forwards it to the microprocessor 15. The bioethanol used for the biofireplace in question has a concentration of 97-99%.

The subject invention provides for the use of a microprocessor 15 that works with digital signals, so that the control of the combustion process is fully automated and digitalized. The main function of the microprocessor 15 is to monitor changes in the parameters of the combustion process control in real time and to manage the executive peripherals (such as the peristaltic pump and the preheater), in order to maintain constant operation without changing the required flame height. In this way, a uniform flame is obtained along the entire length of the burner 8 with complete, laminar and diffuse combustion. The microprocessor 15 also allows for the definition of temperature limit values, CO<2> or CO concentration, at which the device is automatically switched off. Today, there are a large number of different types of microprocessors on the market and they are constantly being improved. Since the operation of the microprocessor 15 is well known in the prior art, for the purpose of easier understanding of the invention and for better clarity, only its mode of operation is given in the detailed description.

The preheater 3, as can be seen from Figures 2 and 3, which serves to raise the temperature of liquid bioethanol before entering the evaporator 4, according to this invention, is positioned below the burner 8 and consists of a thermally insulated aluminum housing closed on the upper side by an aluminum plate 25 with a circular opening 46 and a groove 37 into which a copper capillary tube 22 is inserted. In order to prevent heat loss and unnecessary heating of the device itself, the housing of the preheater 3 is closed by an aluminum plate 34 on which an opening 45 is made in accordance with the opening 46. An inlet 48 is passed through these openings through which the bioethanol vapor enters the burner 8. This position of the preheater 3 reduces the use of electrical energy required for the operation of the evaporator 4, because in optimal conditions the thermal energy burner 8, located above the preheater 3, is sufficient to convert liquid bioethanol into steam without using heaters 5, 6. After establishing the operating temperature of the burner 8, in the preheater 3, the heating of the copper capillary tube 22 is carried out only by the heat generated by the operation of the burner 8.

It should be noted that in this way, the heat transfer of the burner 8 is carried out while simultaneously reducing the flame temperature, i.e. reducing harmful combustion by-products, which is proportional to the oxidation of atmospheric nitrogen NO and NO<2>.

The power control of the heaters 5, 6 is done by PWM (Pulse Width Modulation). Digital control of analog circuits drastically reduces the cost of the control system and achieves significant energy savings. Today's microcontrollers generally have built-in PWM peripherals, which further simplifies implementation. The main advantage of using PWM is that the signal remains digital all the way from the processor to the receiver, so that DA conversion is not required. By using a purely digital signal, the noise effect is minimized, which is a great advantage compared to analog transmission and PWM control of the dosing pump motor. Microprocessors and PWM modulators are well known in the state of the art and their operation is not explained in particular detail.

The burner assembly 8, as can be seen from Figures 8, 9, 10 and 11, consists of an aluminum housing 28 that is open on the top side and firmly connected to the preheater 3 on the bottom side via the top plate 25. A perforated aluminum tube 26 of square cross-section is axially inserted into the housing 28. The perforation of the tube 26 is made with circular openings 27, the diameter and arrangement of which are calculated in such a way as to enable uniform distribution of steam and the creation of a laminar diffuse flame along the entire length of the burner 8. The housing 28 represents a chamber in which alcohol vapors are mixed with oxygen from the air, and complete combustion is achieved by dosing the fuel with a peristaltic pump 2 in a value defined by the maximum allowable flow rate regulated by the microprocessor 15. In the center of the longer side of the burner housing 28, an opening is made into which the spark igniter 9 is inserted vertically from the side. At the entrance to the aluminum tube 26 of the burner, a temperature sensor 18 is installed, which provides information to the microprocessor 15 that the appropriate temperature of the alcohol vapor has been reached, i.e. that the alcohol vapor has entered the burner 8 and that initial ignition can be performed, thus starting the combustion process.

The fuel from the preheater 3 flows through the capillary tube 22 into the evaporator assembly 4, which consists of a metal housing 35 in the shape of a hollow square, in the centers of whose shorter sides are threaded flanges 44, into which mutually separated heaters 5, 6 are demountably, axially fixed, with the heater 5 being located at the inlet of the evaporator 4, while the heater 6 is located at the outlet of the rectifier 4. A capillary tube 23 is spirally wound along the entire length of the heaters 5, 6, in which the liquid fuel is converted into steam, which, via the electromagnetic valve 7, flows into the perforated aluminum tube 26 located in the combustion chamber of the burner 8. The electromagnetic valve 7 is normally open and its function is to immediately close the steam supply to the burner 8 in the event of irregularities in the operation of the system. and information about improper and unsafe operation is delivered to the microprocessor 15. From Figures 4 and 5, it can be seen that temperature sensors 11, 12 are located in the evaporator housing 35, where sensor 11 measures the fuel temperature on the part of the capillary tube 23 around the heater 5, while sensor 12 measures the fuel temperature on the part of the capillary tube 23 around the heater 6 at the outlet from the evaporator 4. The optimal temperature for the operation of the biofireplace is achieved by PID regulation, the function of which is to heat the bioethanol with the heaters 5, 6 close to the point of transition to ethanol vapor, in cases when this is not achieved by the operation of the preheater 3, which is the case when starting the device or the first few minutes of operation, when the thermal energy of the burner 8 has not been transferred to the preheater 3. After measuring the temperature of the bioethanol, the temperature sensors 11, 12 deliver the read data to the microprocessor 15, which, through The PWM control 14 controls the power of the heaters 5, 6 in order to obtain a temperature of about 70° C at which the liquid bioethanol is completely converted into steam. The optimally preheated bioethanol steam, via the insulated capillary tube 23, reaches the inlet 48 passed through the openings 45, 46. In order to prevent heat loss and possible unnecessary heating of the entire device, the sides of the housing 35 are insulated on both sides with a layer 36 of mineral wool. The evaporator cover 38, Figures 7 and 8, is made of the same material as the housing 35, has a “P” profile shape and is equal in dimensions to the upper open surface of the housing 35. Vertical tubular outlets 39, 40 are provided at both ends of the housing 35, through which the ends of the pipes 22, 23 are passed. In order to prevent heat losses, the outlets 39, 40 are filled with rock wool 43, and the capillary tube 23 is insulated with liquid ceramic. Four washers 41 are positioned on the upper edges of the longer sides of the housing 35, with the help of which the cover 38 is secured with screws through the openings 42.

The operating principle of the device in question, shown schematically in Figure 1, is as follows: when starting the device, the microprocessor 15 gives a command to the peristaltic pump 2 to fill the evaporator 4 with liquid bioethanol. At the same time, the heaters 5, 6 convert the liquid bioethanol into steam. When the temperature sensors 11, 12 deliver information to the microprocessor 15 that the temperature at which the bioethanol steam is created has been reached, the high-voltage spark igniter 9 performs the initial ignition, thereby starting the combustion process. The burner 8 is equipped with a flame detection sensor 10 that controls the success of the ignition, i.e. whether it is necessary to restart the igniter 9, which is defined by the microprocessor 15. The described process includes the method of starting the device. Once the combustion of bioethanol has begun in the burner 8, the operating mode continues by transporting the fuel from the tank 1 using a peristaltic pump 2 mounted on a pipe 20 to the preheater 3, which uses the heat energy generated by the combustion of bioethanol vapor in the burner 8 so that the liquid fuel enters the evaporator 4 preheated. The heat energy generated by the operation of the burner 8 spreads to the evaporator 4 and is sufficient to convert the liquid bioethanol into vapor without turning on the heaters 5, 6. At the beginning of the device's operation, the fuel temperature is equal to the ambient temperature, so at lower temperatures, the operation of the heaters 5, 6 is necessary to start the device. When the device switches to continuous operation, the heaters 5, 6 are turned off and the fuel is preheated, i.e. the transition from the liquid to the gaseous state is performed using the heat generated by heating the space around burner 8. The process of stabilizing the system operation is regulated by the microprocessor 15 via temperature PID regulation (with a minimum deviation from the initial set temperature equilibrium parameters), thereby achieving a uniform process of liquid fuel evaporation. During the operation of the device, the temperature sensors 11, 12 deliver information to the microprocessor 15, which controls the operation of the heaters 5, 6 in order to achieve the optimal operating temperature of bioethanol vapor of about 70° C. The resulting bioethanol vapor from the evaporator 4, through the insulated capillary tube 23, reaches the inlet 48, passed through the openings 45, 46 and welded to the aluminum tube 26 of the burner, and then passes through the openings 27 and, after ignition, burns in the burner housing 8. The circular openings 27 are designed to ensure uniform distribution of vapor along the entire burner 8, as a result of which the flame is uniform along its entire length. The combustion chamber in the housing 28 allows for optimal mixing of alcohol vapor with oxygen from the air, resulting in laminar diffusion combustion.

Regular shutdown of the system is carried out by means of a microprocessor 15 command, in which the normally open solenoid valve 7 loses voltage and closes the fuel flow into the capillary tube 23, as a result of which combustion in the burner 8 almost instantly ceases, and all remaining steam in the aluminum tube 26 also burns out. At the same time, the normally closed solenoid valve 24 installed on the tube 29 loses voltage and opens the return line, after which the remaining steam in the system returns to the tank 1, where it cools and turns into a liquid state. In this way, the retention of alcohol vapor in the system and the creation of overpressure are avoided.

Forced shutdown of a biofireplace due to a power outage is manifested by the loss of power to all electronic devices in the fireplace. As a result, the normally open solenoid valve 7 loses voltage, closes, interrupting the flow of alcohol vapor to the burner 8, and the combustion process is interrupted. The process of forced shutdown, in a physical sense, is almost the same process as with regular shutdown of the system.

The forced shutdown of the biofireplace due to irregularities in operation is managed by the microprocessor 15, whose operation is based on monitoring parameters, such as the presence of carbon monoxide using the sensor 30 that detects its presence, then the presence of ethanol vapors inside the device itself using the sensor 31, the horizontality of the device using the sensor 32 and mechanical shocks or impacts using the sensor 33 (tilt sensor). Problems in operation can occur for an unknown reason (the flame has gone out), which is registered by the flame presence sensor 10, which sends a signal to the igniter 9 via the microprocessor 15 to restart the initial ignition process. The initial ignition process is time-limited and after a certain time, if a continuous combustion process is not established, the microprocessor 15 performs a forced shutdown of the system. Monitoring the operation of the device is enabled by the display 47.

METHOD OF INDUSTRIAL OR OTHER APPLICATION OF THE INVENTION

Industrial production of the subject invention is absolutely possible in factories for the production of stoves, cookers and fireplaces, and even in well-equipped mechanical workshops.

The invention is suitable for mass production and its application is particularly recommended in cases where supplementary heating is required in living, working and leisure areas.

The application of the invention is particularly recommended in buildings and spaces that need to meet high aesthetic criteria.

Given its ecological characteristics, the device can be used to equip spaces occupied by people of all ages.

Claims (5)

PATENT APPLICATION 1. Biofireplace with automatic combustion control consisting of a tank (1) with a peristaltic pump (2), an evaporator (4), a burner (8) and electronic equipment for operation management and control, characterized in that the tank (1) with an ultrasonic fuel level sensor (16) is made of stainless steel - inox with an opening (19) to which a hose (49) is connected for filling fuel from a bottle (50) using a peristaltic pump (17), connected by a pipe (20) to the suction part of the peristaltic pump (2) whose pressure part is via a pipe (21), connected to a preheater (3) whose outlet part is a pipe (22) connected to a spiral copper capillary tube (23) of the evaporator (4) whose outlet is connected to a perforated pipe (26) of the burner (8). 2. Biofireplace with automatic combustion control, according to claim 1, characterized in that the preheater (3) consists of a thermally insulated aluminum housing positioned below the burner (8), the upper side of which is closed by an aluminum plate (25) on which a circular opening (46) and a groove (37) are made in which a copper capillary tube (22) is inserted, protected on the lower side by an aluminum plate (34) on which an opening (45) is made in accordance with the opening (46) through which the inlet (48) is passed. 3. Biofireplace with automatic combustion control, according to claim 1, characterized in that the evaporator (4) is a metal housing (35) in the shape of a hollow square, in which threaded flanges (44) are made in the centers of the shorter sides, axially, oppositely arranged rod heaters (5, 6) are removably fixed, wherein the heater (5) is located at the inlet of the evaporator (4), while the heater (6) is located at the outlet of the rectifier (4), and in that a capillary tube (23) is spirally wound around the heater (5, 6) along its entire length, and in that temperature sensors (11, 12) are made in the evaporator housing (35), and in that all sides of the evaporator housing (35), on the inside and outside, are insulated with a layer (36) of mineral wool, and in that the evaporator cover (38) is made of the same material as the housing (35), which in cross-section has the appearance of a "P" profile and is equal in dimensions to the upper open surface of the evaporator housing (35), with vertical tubular outlets (39, 40) filled with rock wool (43) on its upper side, through which the ends of the capillary tube (23) insulated with liquid ceramic are passed, and in that four washers (41) are positioned on the upper edges of the longer side walls of the housing (35), by means of which the cover (38) is fixed with screws through the openings (42). 4. Biofireplace with automatic combustion control, according to claim 1, characterized in that the burner (8) is made of an aluminum housing (28), with its entire lower surface open and connected to the preheater (3) by a solid connection with the upper plate (25), wherein an aluminum tube (26), perforated with circular openings (27), of square cross-section, is axially inserted into the housing (28) of the burner (8), on the lower side of which an inlet (48) is welded, and in that an opening is made in the center of the longer side (28) of the burner (8) into which a spark igniter (9) is inserted vertically, laterally, while a temperature sensor (18) is installed at the entrance to the aluminum tube (26). 5. Method of operation of a biofireplace with automatic combustion control, according to claim 1, characterized in that the operation and control of the biofireplace, based on data from sensors (10, 16, 30, 31, 32, 33), is controlled by a microprocessor (15) connected to a peristaltic pump (2), electrovalves (7, 24) and heaters (5, 6), whereby the control is performed by PWM (Pulse Width Modulation).