SI9200062A - Special central heating furnance - Google Patents

Abstract

The boiler design allows for more intensive cooling chamber flames as part of a refrigerated door, specially shaped insert made of fireproof sheet metal and an additional thin cooled wall in the firebox. Water is fed / discharged into / through the hoses by flexible hoses. Cooled the chamber on the inside of the door enclosing part of the flame, firebox with perimeter partitions and extra chilled walls increase heat transfer at unchanged external dimensions of the boiler and reduce ΝΟχ emission during combustion due to more intense cooling the flames. The solution is technologically simple and easily doable. The welds must be waterproof.

Description

DESCRIPTION OF THE INVENTION

Special boiler for central heating

TECHNICAL FIELD OF THE INVENTION

The invention relates to the field of heating engineering and within the scope of the construction of district heating boilers. It is intended for gas or liquid fuel boilers, and part of the invention can also be used on solid fuel boilers.

According to the international patent classification, the invention belongs to the following groups:

F 22 B 37/00,

F 24 H 1/22,

01 F,

G 01 K,

G 01 L,

G 01 N.

TECHNICAL PROBLEM

The invention is based on the problems encountered in district heating boilers:

- how to reduce heat losses of boilers and thereby increase efficiency,

- how to increase the heat transfer in the firebox without changing the dimensions of the fireboxes,

- how to increase the rate of flame cooling,

- how to reduce NOx emissions from combustion due to flame temperatures above 1200 ° C (cause of forest acid rain) and thus the environmental burden of the environment,

- how to reduce soot and carbon monoxide CO emissions from boiler houses and thereby ecologically burden the environment,

- how to reduce the maintenance costs of boilers caused by the deposits on the surfaces of boiler combustion due to unburnt sulfur from the fuel.

-2STATUS OF TECHNOLOGY

The modern design of the boiler must allow for complete combustion or. low CO carbon monoxide emissions since carbon black, unburnt CnHm hydrocarbons and N0x nitrogen oxides). In addition, it must also comply with the regulations on minimum efficiency, maximum permissible exhaust gas temperature and maximum allowable losses of boiler heat to the environment. Emission of carbon monoxide CO, carbon black and unburnt CnHm hydrocarbons can be controlled by modern burners, and N0x nitrogen oxides are generated by the high flame temperature and the relatively long residence time of the combustion gas (combustion products) in the flame. For this reason, modern boiler structures need to be adapted to maximize combustion, minimize flame temperature and keep the combustion gas in hot flame zones as short as possible.

Problems also arise due to the formation of unburned sulfur linings on the combustion walls, which reduces the efficiency and increases the cost of maintaining the boilers. Another type of problem arises because of the boiler door, which in most cases is passive or. with their surface they do not participate in the process of heat transfer in the boiler and are therefore thermally insulated on the inside with a special filler which has to withstand temperatures up to 1000 ° C and above. The doors also serve as a flue gas invert chamber, which is directed from the firebox, e.g. into the stack of smoke pipes. The flue gases on the inside of the door transfer some of the heat to the door filler, resulting in heat loss to the surroundings because the outside surface of the door is heated above the temperature of the heat carrier (most often water) in the boiler. In most boilers, the door from the outside is also not noticed or. isolated. Due to high temperature loads, door fillers are subject to aging and eventually start to fall off, which means the boiler is out of operation, heat supply disruptions and additional maintenance costs. The problem of doors is growing with the power of boilers or. with their size.

-3 DESCRIPTION OF THE TECHNICAL PROBLEM SOLUTION

Assistance with the present invention is provided in solving the problems arising from central heating boilers for gaseous and liquid fuels, especially for higher power boilers and partly for solid fuel boilers, which helps to solve these problems in a relatively inexpensive, simple and efficient way.

The invention is intended as a boiler construction which allows additional cooling of the flame and increases the heat transfer within the boiler.

In the present invention, the boiler door is designed to actively participate in the process of heat transfer in the boiler, thereby increasing the heating surface and thus the boiler output. The cost of maintaining the boilers is reduced because there is no need to replace the door filler. Due to the lower door temperature, the heat losses of the boiler to the surroundings are lower, thus increasing the efficiency. The temperature of the outer surface of the door is limited to the temperature of the water in the boilers and is reduced almost to the ambient temperature by the external isolation of the door. Because the inside of the door is fitted with a cooled chamber that surrounds a part of the flame, this allows the root of the flame to cool faster and, due to the difference in pressures between the interior of the chamber and the firebox, return the flue gas to the flame, further reducing its temperature and thus N0x emission.

In the present invention, a specially designed cartridge made of a flame retardant liner is mounted in the boiler firebox, thereby preventing the flame from contacting the cold walls of the firebox, allowing for more complete combustion. The cartridge allows to increase the speed of the flue gas in the firebox, thereby reducing the residence time of the flue gas in the zone of highest temperatures, thereby increasing the heat transfer.

In the present invention, an additional upright cooled wall is mounted in the firebox on which the flame splits and cools further which reduces N0x emissions and increases heat transfer.

The invention is fully applicable to gas or liquid fuel boilers and partly to solid fuel boilers.

-4 EXAMPLE OF A POSSIBLE DESIGN OF THE INVENTION

The invention is presented in Fig. 1, which represents a boiler for central heating in e.g. two-gas version with gaseous or liquid fuel.

The direction of travel of the heat exchanger - water 10 through the boiler is illustrated by arrows 15. The flue gases 5 exit the firebox 12, turn inside the door 4 into a stack of smoke pipes 11, from where they go into the outlet chamber 16 and further into the chimney. The door 1, which is enclosed on the outside by an insulating panel 2, opens 90 ° to one side.

Door 1 circulates water 10 coming into port 1 via pipe 19 leading from boiler return port 18 because there water is the coldest and flexible pipe 24. Water 10 exits port 1 through flexible pipe 23 and from boiler at port. 20. On the inside of the connections of the flow 20 and the return 18 of the boiler there are directing elbows 17 which allow a greater flow of water 10 through the door 1 and thereby equalize the water temperatures 10 in the boiler and door 1. The barrier 28 in the door 1 directs the circulation of water 10 port 1. To discharge water 10 from port 1, port 3 is located at the bottom of port 1.

On the inside of 4 of the door 1 there is a cooling chamber 6 surrounding the flame 25. Since inside the chamber 6 the flue gas velocity 5 is higher than in the firebox 12, the pressure in the chamber 6 is lower than in the firebox 12, which causes the effect of flue gas suction 5 outside the chamber 6 to the interior of the chamber 6. Consequently, a portion of the flue gas 5 is returned back 27 to flame 25, which reduces the temperature of the flame 25 and thus the N0x emission of nitrogen oxides, which is further reduced by the faster cooling of the flame 25 due to the additional cooling surfaces of the door 1 and chambers 6 on door 1. With additional cooled surfaces of door 1 and chamber 6, the heat transfer in the chimney 12 is further increased without increasing the external dimensions of the boiler. The inside diameter of the chamber 6 must be dimensioned according to the angle of scattering of the burner nozzles, and the length of the chamber 6 should be such that door 1 can be opened and combustion is not disturbed.

-5 Flame 25 is surrounded by a flame retardant insert 7 which prevents the flame 25 from touching the relatively cool walls of the firebox 12. Because the insert 7 is heated to a red grill, this allows more complete combustion at lower flame temperatures. Thus, the formation of soot and sulfur deposits on the walls 9 of the firebox 12 is greatly reduced, which leads to improved efficiency and reduced maintenance costs for the boilers. At the outlet of the insert 7 in front of the rear of the firebox 12, the flue gases 5 are turned into a channel 8 between the outer perimeter of the insert 7 and the inner walls 9 of the firebox 12. Since the flow cross section of the channel 8 is several times smaller than the flow cross section of the firebox 12 without the gasket 7, the flue gas 5 increases the velocity, thereby increasing the heat transfer in the firebox 12 and shortens the residence time of the flue gas 5 in the firebox 12. At the perimeter of the cartridge 7 there are gripping barriers 22 below which openings 21 may be located through which the flue gas portion 5 returns back 26 v. flame 25 thereby lowering the temperature of flame 25, leading to a reduction of N0x nitrogen oxide emissions. Barriers 22 also work in terms of increasing the heat transfer due to the turbulent effect.

A thin wall 14, which is cooled by the upstream water 10, is built into the firebox in comparison to the diameter of the firebox 12. In order to prevent direct contact with the flame 25 on the front, the wall 14 is lined with a fireproof insert 13, which may be from Samot. The lining 13 of the wall 14 in the firebox 12 distributes the flame 25, which is further cooled due to the cooled wall 14, reducing the N0x emission. The thickness and length of the wall 14 must be so selected that combustion is not disturbed.

The design of the boiler with chilled door 1 and chamber 6, combustion chamber 7 and additional cooled wall 14 is fully applicable for gas and liquid fuel boilers with fan burners. Version with chilled door 1 without chamber 6, without firebox 7 and additional cooling wall 14 for solid fuel boilers.

Claims (4)

PATENT APPLICATIONS 1) Special boiler for central heating, characterized by a cooled door, the embodiment of the cooled door consisting of a flexible pipe (23) for the discharge of the heat carrier or. water (10) from the door (1) to the flow connection (20) of the boiler and the flexible pipe (24) for supplying water (10) to the door (1) via the pipe (19) from the boiler return port (18). 2) Special central heating boiler characterized by a cooled chamber on the inside of the door (1) that encloses part of the flame and is part of the cooled door (1) of the boiler. 3) Special boiler for central heating, characterized by a cooled wall (14) with a protective cover (13) installed in the rear of the firebox (12). 4) Special boiler for central heating, characterized by a firebox (7) made of fire-resistant sheet with perimeter-mounted barriers (22) whereby the flue gas (5) in the firebox (12) travels in a duct (8) between the outer wall of the cartridge (7) and interior walls (9) fireboxes (12) -7 SUMMARY Special boiler for central heating The design of the boiler allows more intense cooling of the flame with the chamber, as part of a cooled door, a specially designed insert made of fireproof sheet metal and an additional thinly cooled wall in the firebox. Water is supplied / discharged to / from the door via flexible hoses. A cooled chamber on the inside of the door surrounding the flame partition, a combustion insert with perimeter bulkheads and additional cooled walls increase heat transfer at unchanged external boiler dimensions and reduce N0x emissions from combustion due to more intense flame cooling. The solution is technologically simple and easy to implement. Welds must be waterproof and welders must have an A-test. -8 INDICATING THE WAY TO BEST USE OF THE INVENTION The advantage of using refrigerated doors is given to higher and high power boilers, in which the door has a relatively large surface area and the effect of door cooling is greater. Cooled doors can also be used on boilers of small and small capacity. The version of the cooled door with the chamber on the door is applicable to boilers powered by gaseous and liquid fuels, and the implementation of the cooled door without the chamber on solid fuel boilers. The thickness of the sheet shall not be less than 4 mm. The welds must be waterproof. Welding in a protective atmosphere is preferred, and welders must have an A-test. The sheet must be well welded, and care must be taken to properly anchor the door leaf to prevent the sheet from inflating due to water pressure in the door. For maximum effect, the boiler door must be thermally insulated from the outside. Flexible pipes can withstand up to ten times more pressure than boiler walls and a large number of kinks, making them unproblematic for use on central heating boilers. The use of a fire-resistant steel insert is possible in all gas or liquid-fired central heating boilers with a fan burner, regardless of boiler power and size. The thickness of the sheet of the cartridge depends on the size of the cartridge but should not be less than 2.5 mm. Installation of the distribution wall in the firebox is possible in all gas-fired or liquid fuel-fired central heating boilers with a fan burner, regardless of boiler power and size. The thickness of the sheet shall not be less than 4 mm. The welds must be waterproof. The protective lining on the front of the wall can be made of chamotte or other fire resistant material. Welding in a protective atmosphere is preferred, and welders must have an A-test. The sheet must be well welded, and care must be taken to properly anchor the sheet to prevent the sheet from inflating due to water pressure.