Flue gas recirculation system for gas heaters of GPM-PTPG type

Abstract

FIELD: energy.SUBSTANCE: invention relates to the recirculation of combustion products during fuel combustion in gas heaters. A method for recirculating flue gases in gas heaters of the GPM-PTPG type, which consists of heating the air entering the burner device by removing part of the flue gases into the mixing zone of the burner device. A chimney with a damper is mounted on the inspection hatch for the condition of the smoke tubes and at the inlet of the air damper of the burner device, ensuring the discharge of flue gases into the burner device due to the ejection created by the natural draft of the burner device of the gas heater.EFFECT: increase in the energy efficiency of the GPM-PTPG type gas heater by implementing the RDG system and reducing heat losses q2 without the use of additional and energy-dependent equipment.1 cl, 1 dwg

Description

[0001] The invention relates to the field of energy, in particular to the recirculation of combustion products during fuel combustion in gas heaters.

[0002] Currently, gas heaters (hereinafter referred to as GH) are used at compressor and gas distribution stations (hereinafter referred to as GDS) to heat and automatically maintain the set gas temperature before throttling [1]. A common type of GH is the GPM-PTPG manufactured by Gazprommash Plant LLC. The advantages of this type of GH are operational stability, energy independence, and the ability to operate at very low ambient temperatures. However, they have a comparatively low efficiency (82%) for modern devices. [3] This is due to the type of burner device, which is an atmospheric burner. And also with the design of the heat generator, which has 2 flue gas passes, which prevents complete heat removal. The placement of gas heaters at existing GDS, outdoors in the open air, also leads to additional losses and a decrease in the efficiency (hereinafter referred to as COP).

[0003] One of the methods for increasing the efficiency of thermal power plants is flue gas recirculation (hereinafter referred to as FGR).

[0004] A device for flue gas recirculation is known (Patent 1509575 Russian Federation, IPC F23N 9 / 08. Method for recirculating flue gases and system for implementing it / R.K. Rieder - No. 4368462; declared 29.12.1987; published 23.09.1989) [3]. The main part of the combustion products, having transferred heat to the convective surfaces, leaves the boiler, and a part of the combustion products is directed through the selection unit to the suction section and is fed by a fan to the discharge section of the recirculation line. A tubular heat exchanger is located in this section, through which water flows. On the heat exchanger, the gas is cooled to a temperature below the dew point temperature with the formation of condensate, which is fed to the furnace 1 with the flow of recirculation gases. Reducing the temperature of recirculation gases below their dew point temperature will reduce the intensity of nitrogen oxide formation, and the utilization of heat from condensed steam will increase the boiler efficiency by 0.5%.

[0005] The disadvantages of this device are its complex design and the use of a fan, which is energy-dependent. This device is also intended for use in heating boiler units, which requires indoor installation, meaning it is not exposed to freezing temperatures.

[0006] Another method for recirculating a portion of flue gases is known (Patent 2 137 046 Russian Federation, IPC F22B 31 / 08, F22D 1 / 02, F22D 1 / 36, F23L 15 / 00. Method for increasing the efficiency of a power plant and device for implementing it / Martin Kienbeck - No. 94043813 / 06; declared 09.12.1994; published 10.09.1999) [4], which consists of heating the air supplied to the steam generator for burning fuel due to the fact that part of the heat contained in the flue gas of the steam generator is returned. This recovery is accomplished using recuperative or regenerative heat transfer devices, such as tubular or plate heat transfer devices or rotary air heaters. By partially utilizing the heat contained in the flue gases to preheat combustion air, the efficiency of the power plant is increased.

[0007] The disadvantage of this method is the complexity of the design, which requires the installation of additional equipment in the form of heat exchangers or air heaters.

[0008] The aim of the invention is to increase the energy efficiency of the GPM-PTPG type PG by implementing the RDG system.

[0009] The technical result is an increase in the energy efficiency of the GPM-PTPG type PG by implementing the RDG system and reducing heat losses q2 without the use of additional and energy-dependent equipment in the form of a fan.

[0010] The technical result is achieved by installing a metal flue gas duct with a damper in one or more smoke tube inspection hatches and at the burner air damper inlet. This damper directs a portion of the flue gases into the burner mixing zone through ejection created by the natural draft of the gas preheater burner. The mixing zone is the section of the flue gas duct where the flue gases mix with atmospheric air. Due to the ejection of air into the burner, flue gases enter the mixing zone. This heats the air supplied to the burner, reducing heat loss with the exhaust gases. The diameter of the flue gas duct in the smoke tube inspection hatches and the diameter of the mixing zone flue gas duct are selected depending on the size of the SG.

[0011] The essence of the invention is explained in Fig., where:

[0012] 1 – metal chimney, 2 – mixing zone, 3 – smoke tube inspection hatches, 4 – electromagnetic valves, 5 – air damper, 6 – damper, 7 – thermometer, 8 – ball valves.

[0013] The invention works as follows:

[0014] Fuel gas is supplied to the burner device by opening the electromagnetic valves 4 and ball valves 8. The direction of the fuel gas is indicated by indicator arrows on the pipeline.

[0015] Air supply is realized by shifting the opening / closing of the air damper 5 on the burner device.

[0016] One or more smoke tube inspection hatches 3 are mounted on one side of chimney 1 and on the other side of the air damper 5 on the burner assembly. A portion of the flue gases is withdrawn through an opening in one or more smoke tube inspection hatches 3 and passes through chimney 1 to mixing zone 2. Flue gases are withdrawn by air ejection created by mixing zone 2. In mixing zone 2, the flue gases mix with atmospheric air. The temperature in chimney 1 is recorded using thermometer 7. The flow of flue gases can be shut off if necessary using damper 6.

[0017] As a result, air is ejected into the burner, causing flue gases to enter the mixing zone. This heats the air supplied to the burner, reducing heat loss with the exhaust gases and increasing the efficiency of the SG.

[0018] This solution has been successfully tested at Gazprom Transgaz Ufa LLC.

Claims

A method for recirculating flue gases in gas heaters of the GPM-PTPG type, consisting of heating the air entering the burner device by removing a portion of the flue gases into the mixing zone of the burner device, characterized in that a chimney with a damper is mounted on the inspection hatch for the condition of the smoke tubes and at the inlet of the air damper of the burner device, ensuring the removal of flue gases into the burner device due to ejection created by the natural draft of the burner device of the gas heater.

Images