阅读说明：本技术 一种利用热一次风调温装置降低排烟温度的系统 (System for reducing exhaust gas temperature by utilizing hot primary air temperature adjusting device ) 是由 张知翔 赵锋 姬海民 徐党旗 薛宁 魏铜生 张广才 于 2021-09-17 设计创作，主要内容包括：本发明公开了一种利用热一次风调温装置降低排烟温度的系统,冷一次风管与一次风暖风器的风侧入口相连通,一次风暖风器的风侧出口与热一次风调温装置的风侧入口相连通,热一次风调温装置的风侧出口与热一次风管相连通；调温水路系统与热一次风调温装置的水侧相连通,冷凝结水管与烟气冷却器的水侧入口相连通,烟气冷却器的水侧出口与热凝结水管及一次风暖风器的水侧入口相连通,一次风暖风器的水侧出口与烟气冷却器的水侧入口相连通,该系统能够在不掺配冷风的前提下实时调整热一次风温,提高系统运行的安全性和经济性。(The invention discloses a system for reducing exhaust gas temperature by utilizing a hot primary air temperature adjusting device.A cold primary air pipe is communicated with an air side inlet of a primary air heater, an air side outlet of the primary air heater is communicated with an air side inlet of the hot primary air temperature adjusting device, and an air side outlet of the hot primary air temperature adjusting device is communicated with a hot primary air pipe; the temperature-adjusting waterway system is communicated with the water side of the hot primary air temperature-adjusting device, the condensation water pipe is communicated with the water side inlet of the flue gas cooler, the water side outlet of the flue gas cooler is communicated with the hot condensation water pipe and the water side inlet of the primary air heater, and the water side outlet of the primary air heater is communicated with the water side inlet of the flue gas cooler.)

1. A system for reducing the exhaust gas temperature by using a hot primary air temperature adjusting device is characterized by comprising a cold primary air pipe, a primary air warm air device (4), a hot primary air temperature adjusting device (2), a hot primary air pipe, a temperature adjusting waterway system, a condensation water pipe, a flue gas cooler (3) and a hot condensation water pipe;

the cold primary air pipe is communicated with an air side inlet of the primary air heater (4), an air side outlet of the primary air heater (4) is communicated with an air side inlet of the hot primary air temperature adjusting device (2), and an air side outlet of the hot primary air temperature adjusting device (2) is communicated with the hot primary air pipe;

the temperature-adjusting waterway system is communicated with the water side of the hot primary air temperature-adjusting device (2), the condensation water pipe is communicated with the water side inlet of the flue gas cooler (3), the water side outlet of the flue gas cooler (3) is communicated with the hot condensation water pipe and the water side inlet of the primary air heater (4), and the water side outlet of the primary air heater (4) is communicated with the water side inlet of the flue gas cooler (3).

2. The system for reducing the exhaust gas temperature by using the primary hot air temperature adjusting device according to claim 1, wherein a primary hot air temperature adjusting device inlet air door (15) is arranged at an air side inlet of the primary hot air temperature adjusting device (2), and a primary hot air temperature adjusting device outlet air door (16) is arranged at an air side outlet of the primary hot air temperature adjusting device (2).

3. The system for reducing the exhaust gas temperature by using the hot primary air temperature regulating device according to claim 1, further comprising a cold primary air bypass damper (5) and a hot primary air bypass damper (6), wherein an inlet of the hot primary air bypass damper (6) is communicated with an air side outlet of the air preheater (1), and an outlet of the hot primary air bypass damper (6) is communicated with a hot primary air pipe; the inlet of the cold primary air bypass air door (5) is communicated with the cold primary air pipe, and the outlet of the cold primary air bypass air door (5) is communicated with the hot primary air pipe.

4. The system for reducing the temperature of the discharged smoke by using the primary hot air temperature regulating device according to claim 1, further comprising a hot smoke pipe, wherein the hot smoke pipe is communicated with an external dust remover sequentially through the smoke side of the air preheater (1) and the smoke side of the smoke cooler (3).

5. The system for reducing the temperature of flue gases with a hot primary air attemperating device according to claim 1, characterized in that a booster pump (12) is arranged at the water side inlet of the flue gas cooler (3).

6. The system for reducing the temperature of exhausted smoke by using the primary hot air temperature regulating device according to claim 1, wherein the temperature regulating waterway system comprises a water outlet pipe, a water inlet pipe, a water flow regulating system, a primary air temperature regulating device inlet water temperature regulating valve (11), n-stage low-pressure heaters (13) and n + 1-stage low-pressure heaters (14);

the water inlet pipe is communicated with an inlet of a primary air temperature adjusting device inlet water temperature adjusting valve (11) and an inlet of an n-stage low-pressure heater (13), a water side inlet of a hot primary air temperature adjusting device (2) is communicated with an outlet of the primary air temperature adjusting device inlet water temperature adjusting valve (11) and an outlet of the n-stage low-pressure heater (13), a water side outlet of the hot primary air temperature adjusting device (2) is communicated with an inlet of an n + 1-stage low-pressure heater (14), an outlet of the n-stage low-pressure heater (13) is communicated with an inlet of a water flow adjusting system, an outlet of the water flow adjusting system is communicated with an inlet of the n + 1-stage low-pressure heater (14), and an outlet of the n + 1-stage low-pressure heater (14) is communicated with a water outlet pipe.

7. The system for reducing the temperature of exhaust gas by using a primary hot air temperature regulating device according to claim 6, wherein the water flow regulating system comprises a condensate main path gate valve (7), a condensate bypass regulating valve (9), a condensate bypass regulating valve inlet gate valve (10-1), a condensate bypass regulating valve outlet gate valve (10-2) and a condensate bypass regulating valve bypass gate valve (8);

the outlet of the n-stage low-pressure heater (13) is communicated with the inlet of the condensed water bypass regulating valve bypass gate valve (8), the inlet of the condensed water main path gate valve (7) and the inlet of the condensed water bypass regulating valve inlet gate valve (10-1), the outlet of the condensed water bypass regulating valve inlet gate valve (10-1) is communicated with the inlet of the condensed water bypass regulating valve outlet gate valve (10-2) through the condensed water bypass regulating valve (9), and the outlet of the condensed water bypass regulating valve outlet gate valve (10-2), the outlet of the condensed water bypass regulating valve bypass gate valve (8) and the outlet of the condensed water main path gate valve (7) are communicated with the inlet of the n + 1-stage low-pressure heater (14).

8. System for reducing the exhaust gas temperature with a hot primary air temperature regulating device according to claim 1, characterized in that the water temperature T at the water side outlet of the hot primary air temperature regulating device (2)_W2＝T₂₀-30, wherein T₂₀The saturated water temperature is the saturated water temperature under the water side outlet pressure of the hot primary air temperature adjusting device (2);

temperature of water at water inlet of hot primary air temperature adjusting device (2)Wherein, C₁The specific heat capacity of the air at the air inlet of the primary hot air temperature adjusting device (2), m is the mass flow of the air at the air inlet of the primary hot air temperature adjusting device (2), and T is_A1For regulating the air temperature, T, at the inlet of the hot primary air (2) at the air side_A2For the air temperature L at the outlet of the hot primary air temperature adjusting device (2) on the air side_{Temperature regulation}For the flow of condensed water at the water side inlet of the hot primary air temperature regulating device (2), C₂For hot primary air temperature regulation device (2) water sideThe specific heat capacity of the condensed water at the inlet;

T_W2≥T_{n +1 into}，T_{n +1 into}The water temperature of the water side inlet of the n + 1-stage low-pressure heater (14);

the water flow L of the water side of the hot primary air temperature adjusting device (2)_{Temperature regulation}＝0.6*L_{Condensed water}Wherein L is_{Condensed water}Is the main condensate flow.

9. The system for reducing the temperature of exhaust fumes using a hot primary air temperature regulating device according to claim 3, wherein when L is_{Temperature regulation}≥0.6*L_{Condensed water}By decreasing T_W1Regulating L_{Temperature regulation}(ii) a When T is_W1＝T_{n is into}And L is_{Temperature regulation}Greater than 0.6 x L_{Condensed water}When the wind is in use, the hot primary air bypass air door (6) is opened to adjust L_{Temperature regulation}When this time T_A2When the air quantity is larger than the design value, the cold primary air bypass air door (5) is opened to adjust T_A2Wherein, T_{n is into}The water temperature is the water temperature at the inlet of the n-stage low-pressure heater (13).

Technical Field

The invention belongs to the technical field of generator sets, and relates to a system for reducing exhaust gas temperature by using a hot primary air temperature adjusting device.

Background

The air preheater is an important component of coal-fired boiler, and it utilizes hot flue gas to heat cold air for combustion into hot air so as to reduce exhaust gas temperature and raise heat efficiency of boiler. The air for boiler combustion is divided into primary air and secondary air, and the primary air is mainly used for conveying pulverized coal and improving oxygen required in the initial stage of combustion. However, the coal type of the domestic boiler is greatly changed, so that the temperature of the air-powder mixture at the outlet of the coal mill is greatly changed, and even the risk of deflagration exists. For the design coal with high water content, the design temperature of the hot primary air is high, when the design coal burns the coal with low water content, a certain amount of cold air needs to be blended to reduce the temperature of the hot primary air, at the moment, the cold primary air quantity passing through the air preheater is reduced, the exhaust gas temperature of the boiler is increased, and the thermal efficiency of the boiler is reduced.

At present, a low-temperature economizer is mainly added at an inlet of a dust remover, and condensed water of a regenerative system is used for reducing the exhaust gas temperature of the boiler, but the method has low heat utilization efficiency and limited coal saving amount.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provides a system for reducing the temperature of exhaust smoke by using a hot primary air temperature regulating device, which can regulate the temperature of hot primary air in real time on the premise of not blending cold air and improve the safety and the economical efficiency of system operation.

In order to achieve the purpose, the system for reducing the exhaust gas temperature by utilizing the hot primary air temperature adjusting device comprises a cold primary air pipe, a primary air heater, a hot primary air temperature adjusting device, a hot primary air pipe, a temperature adjusting water path system, a condensation water pipe, a flue gas cooler and a hot condensation water pipe;

the cold primary air pipe is communicated with the air side inlet of the primary air heater, the air side outlet of the primary air heater is communicated with the air side inlet of the hot primary air temperature adjusting device, and the air side outlet of the hot primary air temperature adjusting device is communicated with the hot primary air pipe;

the temperature-adjusting waterway system is communicated with the water side of the hot primary air temperature-adjusting device, the condensation water pipe is communicated with the water side inlet of the flue gas cooler, the water side outlet of the flue gas cooler is communicated with the hot condensation water pipe and the water side inlet of the primary air heater, and the water side outlet of the primary air heater is communicated with the water side inlet of the flue gas cooler.

An inlet air door of the hot primary air temperature adjusting device is arranged at an air side inlet of the hot primary air temperature adjusting device, and an outlet air door of the hot primary air temperature adjusting device is arranged at an air side outlet of the hot primary air temperature adjusting device.

The system also comprises a cold primary air bypass air door and a hot primary air bypass air door, wherein an inlet of the hot primary air bypass air door is communicated with an air side outlet of the air preheater, and an outlet of the hot primary air bypass air door is communicated with a hot primary air pipe; the inlet of the cold primary air bypass air door is communicated with the cold primary air pipe, and the outlet of the cold primary air bypass air door is communicated with the hot primary air pipe.

The hot flue gas pipe is communicated with an external dust remover sequentially through the flue gas side of the air preheater and the flue gas side of the flue gas cooler.

The water side inlet of the flue gas cooler is provided with a booster pump.

The temperature-adjusting waterway system comprises a water outlet pipe, a water inlet pipe, a water flow adjusting system, a primary air temperature adjusting device inlet water temperature adjusting valve, an n-grade low-pressure heater and an n + 1-grade low-pressure heater;

the inlet pipe is communicated with the inlet of a primary air temperature adjusting device inlet water temperature adjusting valve and the inlet of an n-grade low-pressure heater, the water side inlet of a hot primary air temperature adjusting device is communicated with the outlet of the primary air temperature adjusting device inlet water temperature adjusting valve and the outlet of the n-grade low-pressure heater, the water side outlet of the hot primary air temperature adjusting device is communicated with the inlet of an n + 1-grade low-pressure heater, the outlet of the n-grade low-pressure heater is communicated with the inlet of a water flow adjusting system, the outlet of the water flow adjusting system is communicated with the inlet of the n + 1-grade low-pressure heater, and the outlet of the n + 1-grade low-pressure heater is communicated with a water outlet pipe.

The water flow regulating system comprises a condensed water main path gate valve, a condensed water bypass regulating valve inlet gate valve, a condensed water bypass regulating valve outlet gate valve and a condensed water bypass regulating valve bypass gate valve;

the outlet of the n-stage low-pressure heater is communicated with the inlet of the condensed water bypass regulating valve bypass gate valve, the inlet of the condensed water main path gate valve and the inlet of the condensed water bypass regulating valve inlet gate valve, the outlet of the condensed water bypass regulating valve inlet gate valve is communicated with the inlet of the condensed water bypass regulating valve outlet gate valve through the condensed water bypass regulating valve, and the outlet of the condensed water bypass regulating valve outlet gate valve, the outlet of the condensed water bypass regulating valve bypass gate valve and the outlet of the condensed water main path gate valve are communicated with the inlet of the n + 1-stage low-pressure heater.

Water temperature T at water side outlet of hot primary air temperature regulator_W2＝T₂₀-30, wherein T₂₀The saturated water temperature is the saturated water temperature under the water side outlet pressure of the hot primary air temperature adjusting device.

Water temperature at water inlet of hot primary air temperature regulatorWherein, C₁The specific heat capacity of air at the air inlet of the hot primary air temperature regulating device is shown, m is the mass flow of the air at the air inlet of the hot primary air temperature regulating device, and T is_A1For regulating the air temperature, T, at the inlet of the hot primary air attemperator_A2For the air temperature at the outlet of the hot primary air temperature-regulating device at the air side, L_{Temperature regulation}For the flow of condensate at the water side inlet of the hot primary air temperature control device, C₂The specific heat capacity of condensed water at the water side inlet of the hot primary air temperature regulating device is shown;

T_W2≥T_{n +1 into}，T_{n +1 into}The water temperature at the water side inlet of the n + 1-stage low-pressure heater is obtained;

the hot primary air adjusts the temperatureWater flow L of the water side of the device_{Temperature regulation}＝0.6*L_{Condensed water}Wherein L is_{Condensed water}Is the main condensate flow.

When L is_{Temperature regulation}≥0.6*L_{Condensed water}By decreasing T_W1Regulating L_{Temperature regulation}(ii) a When T is_W1＝T_{n is into}And L is_{Temperature regulation}Greater than 0.6 x L_{Condensed water}Then, the hot primary air bypass air door is opened to adjust L_{Temperature regulation}When this time T_A2When the air quantity is larger than the design value, the cold primary air bypass air door is opened to adjust T_A2Wherein, T_{n is into}Is the water temperature at the inlet of the n-stage low-pressure heater.

The invention has the following beneficial effects:

when the system for reducing the exhaust gas temperature by using the hot primary air temperature regulating device is in specific operation, the hot primary air temperature regulating device is additionally arranged on the hot primary air channel, the hot primary air temperature is reduced by the temperature regulating water path system, and the mixing amount of cold air at the inlet of the coal mill is reduced, so that the primary air quantity passing through the air preheater is increased, the exhaust gas temperature of a unit is reduced, the boiler efficiency is improved, meanwhile, the cold primary air in the primary air heater is heated by using hot water output by the flue gas cooler, the air temperature at the outlet of the primary air heater is increased to more than 70 ℃, the hot primary air temperature is increased, the energy saving amount of the temperature regulating water path system is further improved, the cold end wall temperature of the air preheater is also increased, and the operation environment of the air preheater is improved.

Drawings

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

Wherein, 1 is an air preheater, 2 is a hot primary air temperature adjusting device, 3 is a flue gas cooler, 4 is a primary air heater, 5 is a cold primary air bypass air door, 6 is a hot primary air bypass air door, 7 is a condensed water main path gate valve, 8 is a condensed water bypass adjusting valve bypass gate valve, 9 is a condensed water bypass adjusting valve, 10-1 is a condensed water bypass adjusting valve inlet gate valve, 10-2 is a condensed water bypass adjusting valve outlet gate valve, 11 is a primary air temperature adjusting device inlet water temperature adjusting valve, 12 is a booster pump, 13 is an n-grade low-pressure heater, 14 is an n + 1-grade low-pressure heater, 15 is a hot primary air temperature adjusting device inlet air door, and 16 is a hot primary air temperature adjusting device outlet air door.

Detailed Description

The invention is described in further detail below with reference to the accompanying drawings:

referring to fig. 1, the system for reducing the exhaust gas temperature by using the hot primary air temperature adjusting device of the present invention includes a cold primary air pipe, a primary air heater 4, a hot primary air temperature adjusting device 2, a hot primary air pipe, a temperature adjusting water path system, a condensation water pipe, a flue gas cooler 3, and a hot condensation water pipe; the cold primary air pipe is communicated with the air side inlet of the primary air heater 4, the air side outlet of the primary air heater 4 is communicated with the air side inlet of the hot primary air temperature adjusting device 2, and the air side outlet of the hot primary air temperature adjusting device 2 is communicated with the hot primary air pipe; the temperature-adjusting waterway system is communicated with the water side of the hot primary air temperature adjusting device 2, the condensation water pipe is communicated with the water side inlet of the flue gas cooler 3, the water side outlet of the flue gas cooler 3 is communicated with the heat condensation water pipe and the water side inlet of the primary air heater 4, and the water side outlet of the primary air heater 4 is communicated with the water side inlet of the flue gas cooler 3.

An inlet air door 15 of the hot primary air temperature adjusting device is arranged at an air side inlet of the hot primary air temperature adjusting device 2, and an outlet air door 16 of the hot primary air temperature adjusting device is arranged at an air side outlet of the hot primary air temperature adjusting device 2.

The invention also comprises a cold primary air bypass air door 5 and a hot primary air bypass air door 6, wherein the inlet of the hot primary air bypass air door 6 is communicated with the air side outlet of the air preheater 1, and the outlet of the hot primary air bypass air door 6 is communicated with a hot primary air pipe; the inlet of the cold primary air bypass air door 5 is communicated with the cold primary air pipe, and the outlet of the cold primary air bypass air door 5 is communicated with the hot primary air pipe.

The invention also comprises a hot flue gas pipe, wherein the hot flue gas pipe is communicated with an external dust remover sequentially through the flue gas side of the air preheater 1 and the flue gas side of the flue gas cooler 3.

A booster pump 12 is arranged at the water side inlet of the flue gas cooler 3.

The temperature-adjusting waterway system comprises a water outlet pipe, a water inlet pipe, a water flow adjusting system, a primary air temperature adjusting device inlet water temperature adjusting valve 11, an n-stage low-pressure heater 13 and an n + 1-stage low-pressure heater 14; the water inlet pipe is communicated with an inlet of a primary air temperature adjusting device inlet water temperature adjusting valve 11 and an inlet of an n-stage low-pressure heater 13, a water side inlet of a hot primary air temperature adjusting device 2 is communicated with an outlet of the primary air temperature adjusting device inlet water temperature adjusting valve 11 and an outlet of the n-stage low-pressure heater 13, a water side outlet of the hot primary air temperature adjusting device 2 is communicated with an inlet of an n + 1-stage low-pressure heater 14, an outlet of the n-stage low-pressure heater 13 is communicated with an inlet of a water flow adjusting system, an outlet of the water flow adjusting system is communicated with an inlet of the n + 1-stage low-pressure heater 14, and an outlet of the n + 1-stage low-pressure heater 14 is communicated with a water outlet pipe.

The water flow regulating system comprises a condensed water main path gate valve 7, a condensed water bypass regulating valve 9, a condensed water bypass regulating valve inlet gate valve 10-1, a condensed water bypass regulating valve outlet gate valve 10-2 and a condensed water bypass regulating valve bypass gate valve 8; the outlet of the n-stage low-pressure heater 13 is communicated with the inlet of the condensed water bypass regulating valve bypass gate valve 8, the inlet of the condensed water main path gate valve 7 and the inlet of the condensed water bypass regulating valve inlet gate valve 10-1, the outlet of the condensed water bypass regulating valve inlet gate valve 10-1 is communicated with the inlet of the condensed water bypass regulating valve outlet gate valve 10-2 through the condensed water bypass regulating valve 9, and the outlet of the condensed water bypass regulating valve outlet gate valve 10-2, the outlet of the condensed water bypass regulating valve bypass gate valve 8 and the outlet of the condensed water main path gate valve 7 are communicated with the inlet of the n + 1-stage low-pressure heater 14.

In the invention, the primary air temperature at the air side outlet of the primary air heater 4 is higher than 70 ℃.

Water temperature T at water side outlet of hot primary air temperature adjusting device 2_W2＝T₂₀-30, wherein T₂₀The saturated water temperature is the saturated water temperature under the water side outlet pressure of the hot primary air temperature adjusting device 2.

Water temperature at water side inlet of hot primary air temperature regulator 2Wherein, C₁The specific heat capacity of the air at the air inlet of the hot primary air temperature adjusting device 2, m is the mass flow of the air at the air inlet of the hot primary air temperature adjusting device 2, and T is_A1For regulating the air temperature at the inlet on the wind side of the primary air-heating temperature regulating device 2, T_A2For the air temperature at the outlet of the hot primary air temperature control device 2 on the air side, L_{Temperature regulation}For the flow of condensate at the water side inlet of the hot primary air temperature control device 2, C₂The specific heat capacity of the condensed water at the water side inlet of the hot primary air temperature adjusting device 2;

T_W2≥T_{n +1 into}，T_{n +1 into}The water temperature at the water side inlet of the n + 1-stage low-pressure heater 14;

water flow L of water side of hot primary air temperature adjusting device 2_{Temperature regulation}＝0.6*L_{Condensed water}Wherein L is_{Condensed water}Is the main condensate flow.

When L is_{Temperature regulation}≥0.6*L_{Condensed water}By decreasing T_W1Regulating L_{Temperature regulation}(ii) a When T is_W1＝T_{n is into}And L is_{Temperature regulation}Greater than 0.6 x L_{Condensed water}When the hot primary air bypass air door 6 is opened, the L is adjusted_{Temperature regulation}When this time T_A2When the air quantity is larger than the design value, the cold primary air bypass air door 5 is opened to adjust T_A2Wherein, T_{n is into}The water temperature at the inlet of the n-stage low-pressure heater 13.

In order to prevent condensed water in the primary hot air temperature adjusting device 2 from vaporizing to cause pipeline vibration when the system is put into operation, the primary hot air bypass air door 6 is opened firstly, the inlet air door 15 of the primary hot air temperature adjusting device and the outlet air door 16 of the primary hot air temperature adjusting device are closed, water is injected into the primary hot air temperature adjusting device 2, and after the water injection of the system is completed, the inlet air door 15 of the primary hot air temperature adjusting device and the outlet air door 16 of the primary hot air temperature adjusting device are opened again to close the primary hot air bypass air door 6.

The specific working process of the invention is as follows:

the cold primary air passes through the primary air heater 4 and is heated to hot primary air with the temperature of more than 70 ℃, and the hot primary air enters the coal mill through the hot primary air temperature adjusting device 2;

the hot primary air temperature adjusting device 2 reduces the temperature of hot primary air by utilizing high-quality condensed water of the temperature adjusting water path system, meets the requirement of inlet air temperature of the coal mill, reduces the doping of cold primary air, improves the cold primary air quantity passing through the air preheater 1, reduces the smoke exhaust temperature of the outlet of the air preheater 1, and then improves the boiler efficiency. The hot flue gas becomes cold flue gas behind air heater 1, then enter into external dust remover after the cooling of gas cooler 3, the condensation water heats up through gas cooler 3 and becomes the hot condensate water, then divide into two the tunnel, wherein, discharge through the hot condensate pipe all the way, another way enters into the hot air heater 4 in the cold air of heating, the wind temperature with the hot air heater 4 exit of once improves to more than 70 ℃, in order to improve hot air temperature, then improve hot air attemperator 2's energy saving, can also improve air heater 1's cold junction wall temperature simultaneously, improve air heater 1's operational environment greatly.