CN215982646U

CN215982646U - Direct spray humidification type low-nitrogen energy-saving recovery system

Info

Publication number: CN215982646U
Application number: CN202122303070.2U
Authority: CN
Inventors: 张海清; 李航; 董俊; 吴玉娇
Original assignee: SIPPR Engineering Group Co Ltd
Current assignee: SIPPR Engineering Group Co Ltd
Priority date: 2021-09-23
Filing date: 2021-09-23
Publication date: 2022-03-08
Anticipated expiration: 2031-09-23

Abstract

The utility model discloses aThe direct spray humidification type low-nitrogen energy-saving recovery system comprises a gas boiler, a low-nitrogen burner, an energy saver, a spray smoke heat recoverer, a spray air heating humidifier, a fan, a conveying water pump, a water return pump and a plate heat exchanger; the smoke exhaust port of the gas-fired boiler is communicated with the inner cavity of the spray-type smoke heat recoverer through an energy saver, and smoke in the spray-type smoke heat recoverer is cooled by cooling water sprayed by a first spray pipe and then is exhausted to the atmosphere from a chimney at the top of the spray-type smoke heat recoverer; one path of the heated cooling water is sent into a second spray pipe in the spray type air heating humidifier through a first conveying water pump, and the other path of the heated cooling water is sent into the plate type heat exchanger through a second conveying water pump. The utility model solves the problems of reduced output and reduced thermal efficiency of the gas boiler caused by FGR technology, and the gas boiler and the low-nitrogen burner can reach NOx lower than 30mg/Nm without any modification³The emission standard of (1).

Description

Direct spray humidification type low-nitrogen energy-saving recovery system

Technical Field

The utility model relates to a combustion system of a gas boiler, in particular to a direct spray humidification type low-nitrogen energy-saving recovery system.

Background

In order to reduce nitrogen oxides in the tail gas of a gas boiler, at present, an FGR (flue gas recirculation) technology is mostly adopted, namely, part of the tail gas of the boiler is introduced to flow back into a boiler furnace, so that the purposes of increasing the flow velocity of the flue gas in the furnace and reducing the nitrogen concentration, the oxygen concentration and the temperature in the furnace are achieved to inhibit the production of the nitrogen oxides; meanwhile, an independent indirect heat exchange condensation type energy saver is adopted to reduce the temperature of the tail gas, and heat recovery is realized. The defects of the method are as follows: 1. introducing boiler tail gas to flow back into a boiler hearth, so that the amount of fuel and air entering the hearth is reduced, the heat exchange efficiency is reduced, the steam production of the boiler is reduced, and the heat efficiency is reduced; 2. the combustion flame is unstable, and the CO content is high; 3. condensed water is generated in the back-burning flue gas and can corrode a combustor; 4. when the boiler operates at low load, the emission of nitrogen oxides reaching the standard cannot be ensured; 5. the boiler and the heat recovery device are two devices, the control is complex, and the occupied area is large.

Disclosure of Invention

The utility model aims to provide a direct spraying humidification type low-nitrogen energy-saving recovery system to reduce nitrogen oxides in boiler tail gas emission and improve the heat efficiency of a gas boiler.

In order to achieve the purpose, the utility model adopts the following technical scheme:

the utility model relates to a direct spray humidification type low-nitrogen energy-saving recovery system which comprises a gas boiler, a low-nitrogen burner, an energy saver, a spray smoke heat recoverer, a spray air heating humidifier, a fan, a conveying water pump, a water return pump and a plate heat exchanger, wherein the gas boiler is connected with the low-nitrogen burner through the energy saver; the gas-fired boiler smoke outlet is communicated with the inner cavity of the spray-type flue gas heat recoverer through the energy saver, the energy saver is used for cooling flue gas and then sending the cooled flue gas into the spray-type flue gas heat recoverer, and the flue gas in the spray-type flue gas heat recoverer is cooled by cooling water sprayed by a first spray pipe and then discharged to the atmosphere from a chimney at the top of the spray-type flue gas heat recoverer; one path of the heated cooling water is sent into a second spray pipe in the spray type air heating humidifier through a first water conveying pump to heat the temperature of combustion-supporting air of a gas-fired boiler entering the spray type air heating humidifier, the heated combustion-supporting air is sent into the low-nitrogen burner from an air supply pipeline and a fan at the top of the spray type air heating humidifier, and the cooled cooling water is sent into the first spray pipe through a water return pump; and the other path of the water is conveyed into the tube pass of the plate heat exchanger through a second water conveying pump, exchanges heat with soft water in the shell pass of the plate heat exchanger, cools the soft water, and then conveys the soft water into the first spraying pipe, and the heated soft water is conveyed to a deaerator of the gas boiler.

Furthermore, a smoke exhaust bypass pipeline is arranged between the outlet of the economizer and the chimney, and a smoke exhaust electric butterfly valve is arranged on the smoke exhaust bypass pipeline.

Furthermore, a combustion-supporting air bypass pipeline is arranged between a combustion-supporting air inlet of the spray type air heating humidifier and the air supply pipeline, and a combustion-supporting air electric butterfly valve is arranged on the combustion-supporting air bypass pipeline.

The utility model has the advantages that the problems of reduced output and reduced thermal efficiency of the gas boiler caused by FGR technology are solved, and the gas boiler and the low-nitrogen combustor can reach the NOx lower than 30mg/Nm without any modification³The emission standard of (1). The overall heat efficiency of the gas boiler system is improved, the overall efficiency of the gas boiler system is improved by 5-8%, and the operation is safer and more stable.

Drawings

FIG. 1 is a schematic diagram of the system of the present invention.

Detailed Description

The following describes embodiments of the present invention in detail with reference to the drawings, which are implemented on the premise of the technical solution of the present invention, and detailed embodiments and specific operation procedures are provided, but the scope of the present invention is not limited to the following embodiments.

The utility model relates to a direct spray humidification type low-nitrogen energy-saving recovery system which comprises a gas boiler 1, a low-nitrogen combustor 2, an energy saver 3, a spray flue gas heat recoverer 4, a spray air heating humidifier 5, a fan 6, a first conveying water pump 7.1, a second conveying water pump 7.2, a water return pump 8 and a plate heat exchanger 9.

The flue gas discharged by the gas boiler 1 is cooled to 120 ℃ by the economizer 3 and then sent to the spray type flue gas heat recoverer 4 to exchange heat with cooling water atomized by the first spray pipe, and the flue gas is cooled to 50 ℃ and then discharged to the atmosphere through the chimney 10; the water vapor in the flue gas is condensed to release a large amount of heat to be absorbed by cooling water, so that the temperature of the water is raised to 50-60 ℃.

The cooling water heated to 50-60 ℃ is conveyed to a second spray pipe in the spray type air heating humidifier 5 through a first conveying water pump 7.1, and is atomized and then carries out damp heat exchange with combustion air entering the spray type air heating humidifier 5, so that the nitrogen concentration and the oxygen concentration in the combustion air are reduced; the temperature of combustion air is raised to about 55 ℃, the humidity is increased to about 95%, the combustion air is sent into the low-nitrogen combustor 2 through the air supply pipeline 13 and the fan 6 and is sent into the hearth through the low-nitrogen combustor 2; the combustion-supporting air promotes the combustion reaction temperature to be reduced and the nitrogen concentration and the oxygen concentration to be simultaneously reduced in the hearth, thereby inhibiting the generation of nitrogen oxides and ensuring that the nitrogen oxide value is lower than 30mg/Nm³。

The temperature of the combustion air is increased, so that more heat is generated after the natural gas is combusted to heat the heat-carrying fluid of the gas boiler 1; soft water of the gas boiler 1 is conveyed to the first spray pipe in the spray type flue gas heat recoverer 4 again by the water return pump 8 to exchange heat with the flue gas.

The other path of the cooling water heated to 50-60 ℃ enters the tube pass of the plate heat exchanger 9 through a second conveying water pump 7.2 and exchanges heat with the water supplemented by the deaerator with the temperature of 20 ℃ in the shell pass of the plate heat exchanger 9, so that the temperature of the water supplemented (soft water) of the deaerator is increased, and the use amount of deaerated steam is reduced. Of course, the return water temperature of the heating pipe network can be heated, and the consumption of natural gas is reduced.

A smoke exhaust bypass pipeline 11 is arranged between the outlet of the economizer 3 and the chimney 10, and a smoke exhaust electric butterfly valve 12 is arranged on the smoke exhaust bypass pipeline 11. A combustion-supporting air bypass pipeline 14 is arranged between a combustion-supporting air inlet of the spray type air heating humidifier 5 and the air supply pipeline 13, and a combustion-supporting air electric butterfly valve 15 is arranged on the combustion-supporting air bypass pipeline 14. By controlling the combustion air electric butterfly valve 15 and the smoke exhaust electric butterfly valve 12, the direct spray humidification type low-nitrogen energy-saving recovery system can be closed by bypassing.

Claims

1. The utility model provides a direct spray humidification formula low nitrogen energy-saving recovery system which characterized in that: the system comprises a gas boiler, a low-nitrogen burner, an energy saver, a spray type flue gas heat recoverer, a spray type air heating humidifier, a fan, a conveying water pump, a water return pump and a plate heat exchanger;

the gas-fired boiler smoke outlet is communicated with the inner cavity of the spray-type flue gas heat recoverer through the energy saver, the energy saver is used for cooling flue gas and then sending the cooled flue gas into the spray-type flue gas heat recoverer, and the flue gas in the spray-type flue gas heat recoverer is cooled by cooling water sprayed by a first spray pipe and then discharged to the atmosphere from a chimney at the top of the spray-type flue gas heat recoverer; one path of the heated cooling water is sent into a second spray pipe in the spray type air heating humidifier through a first water conveying pump to heat the temperature of combustion-supporting air of a gas-fired boiler entering the spray type air heating humidifier, the heated combustion-supporting air is sent into the low-nitrogen burner from an air supply pipeline and a fan at the top of the spray type air heating humidifier, and the cooled cooling water is sent into the first spray pipe through a water return pump; and the other path of the water is conveyed into the tube pass of the plate heat exchanger through a second water conveying pump, exchanges heat with soft water in the shell pass of the plate heat exchanger, cools the soft water, and then conveys the soft water into the first spraying pipe, and the heated soft water is conveyed to a deaerator of the gas boiler.

2. A direct spray humidification low nitrogen energy saving recovery system as claimed in claim 1 wherein: a smoke exhaust bypass pipeline is arranged between the outlet of the economizer and the chimney, and a smoke exhaust electric butterfly valve is arranged on the smoke exhaust bypass pipeline.

3. The direct spray humidification low nitrogen energy saving recovery system of claim 1 or 2, wherein: and a combustion-supporting air bypass pipeline is arranged between a combustion-supporting air inlet of the spray type air heating humidifier and the air supply pipeline, and a combustion-supporting air electric butterfly valve is arranged on the combustion-supporting air bypass pipeline.