CN212511100U

CN212511100U - Energy-saving system suitable for no backheating boiler

Info

Publication number: CN212511100U
Application number: CN202022125750.5U
Authority: CN
Inventors: 邹小刚; 张知翔; 周飞; 车宏伟; 李楠; 薛宁; 李文锋; 申冀康; 姬海民
Original assignee: Xian Thermal Power Research Institute Co Ltd; Xian Xire Boiler Environmental Protection Engineering Co Ltd
Current assignee: Xian Thermal Power Research Institute Co Ltd; Xian Xire Boiler Environmental Protection Engineering Co Ltd
Priority date: 2020-09-24
Filing date: 2020-09-24
Publication date: 2021-02-09
Anticipated expiration: 2030-09-24

Abstract

The utility model discloses an economizer system suitable for no backheat boiler for no backheat system's boiler flue gas waste heat recovery utilizes, this system is including the import pipeline, import shutoff valve, frequency conversion booster pump, check valve, shutoff valve, energy-saving appliance, export pipeline and the export shutoff valve that communicate in proper order, is used for adjusting the recirculation valves of energy-saving appliance import temperature, and main road governing valve. The recirculation valve bank includes a shutoff valve, a regulator valve, a shutoff valve, and a bypass valve. The energy-saving system is arranged in front of a deaerator of the boiler. Temperature measuring points are arranged at a flue gas side inlet and a flue gas side outlet of the energy saver and at a water side inlet and a water side outlet of the energy saver and are remotely transmitted to a boiler centralized control system, and the variable-frequency booster pump and the regulating valve carry out negative feedback regulation control through a set value and an actual value. The utility model discloses make no backheat boiler break away from the restriction that the refrigerant temperature is low, when the flue gas waste heat is retrieved to the degree of depth, effectively avoid the economizer to receive the hot side and take place to corrode, improved boiler efficiency, have apparent economic benefits.

Description

Energy-saving system suitable for no backheating boiler

Technical Field

The utility model belongs to the technical field of the boiler is energy-conserving, concretely relates to economizer system suitable for no backheat boiler can be used to the boiler flue gas waste heat degree of depth utilization of no backheat system.

Background

With the continuous deepening of the policy of energy conservation and emission reduction in China, the energy saver is widely applied. The energy saver absorbs and utilizes heat in flue gas at the tail of the boiler through a refrigerant, wherein the main refrigerant comprises water and air. The flue gas at the tail part of the boiler contains corrosive gas, and when the temperature of the flue gas is reduced to be lower than the dew point temperature, the corrosive gas is condensed on the surface of a heat exchange tube, so that the heat exchange tube is corroded, even leaked, and the reliability of an energy saver and the safety of a unit are seriously influenced. The normal temperature air is generally about 20 ℃, and is directly used as a refrigerant of the energy saver, which can cause flue gas condensation and corrosion. For a boiler without a regenerative system, most of boiler feed water is directly subjected to thermal deoxidization by desalted water and then enters a boiler economizer. Normal-temperature desalted water is arranged in front of the deaerator, the water temperature is about 20 ℃, and the desalted water directly used as an economizer refrigerant can cause flue gas condensation and corrosion. The water temperature behind the deaerator is about 104 ℃, the water temperature is too high when the deaerator is directly used as a coolant of the energy saver, the smoke temperature can only be reduced to about 124 ℃ under the condition of ensuring reasonable heat exchange end difference, and the energy saver is large in size and has insignificant energy-saving benefit. Therefore, when no regenerative boiler is provided with no deep energy saver at present, the exhaust gas temperature is about 150 ℃ generally, and some exhaust gas temperatures even reach 180 ℃, so that the unit efficiency is low and the economical efficiency is poor.

Disclosure of Invention

An object of the utility model is to overcome above-mentioned prior art's shortcoming, provide an economizer system suitable for there is not backheat boiler, this system makes no backheat boiler break away from the restriction that the refrigerant temperature is low, and the flue gas waste heat is retrieved to the degree of depth, and automatically regulated economizer entry temperature and export smoke temperature effectively avoid the economizer to receive the hot side to corrode, improve unit efficiency simultaneously by a wide margin.

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

an energy-saving system suitable for a non-regenerative boiler, which is used for recycling the waste heat of flue gas of the non-regenerative boiler, comprises a main path regulating valve 17 arranged on a desalting water pipeline in front of a deaerator 18 of a non-regenerative boiler 19, an inlet pipeline 1 and an outlet pipeline 7 which are communicated with the demineralized water pipeline in parallel, an energy saver 6 arranged between the inlet pipeline 1 and the outlet pipeline 7, wherein the inlet pipeline 1 is communicated with a water side inlet of the energy saver 6, the outlet pipeline 7 is communicated with a water side outlet of the energy saver 6, an inlet shutoff valve 2, a variable frequency booster pump 3, a check valve 4 and a shutoff valve 5 which are sequentially arranged on the inlet pipeline 1, an outlet shutoff valve 8 arranged on the outlet pipeline 7, a water side inlet water temperature measuring point 14 arranged at the water side inlet of the energy saver 6, an inlet smoke temperature measuring point 15 arranged at the smoke side inlet of the energy saver 6 and an outlet smoke temperature measuring point 16 arranged at the smoke side outlet of the energy saver 6, and the smoke side inlet and outlet of the energy saver 6 are communicated with a smoke pipeline before a chimney after the non-regenerative boiler 19 enters; still including the recirculation valves 9 that are used for adjusting the import temperature of energy-saving appliance 6, recirculation valves 9 is including setting gradually the first shutoff valve 10 of branch road, governing valve 11 and the second shutoff valve 12 of branch road on the first branch road of intercommunication inlet pipeline 1 and outlet pipeline 7 and setting up the bypass valve 13 on the second branch road of intercommunication inlet pipeline 1 and outlet pipeline 7, and wherein first branch road and second branch road and the intercommunication point of inlet pipeline 1 all are located between inlet shutoff valve 2 and the frequency conversion booster pump 3, and first branch road and second branch road and the intercommunication point of outlet pipeline 7 all are located the upper reaches of outlet shutoff valve 8.

The economizer 6 directly adopts desalted water as a refrigerant of the economizer 6.

The regulating valve 11 and the main path regulating valve 17 are electric regulating valves or pneumatic regulating valves and have remote and local control functions; the water temperature at the water inlet of the energy saver 6 is realized by automatically controlling the opening of the regulating valve 11 by the boiler centralized control system.

The flue gas temperature at the flue gas side outlet of the energy saver 6 is realized by automatically controlling the frequency of the variable-frequency booster pump 3 by the boiler centralized control system.

The smoke temperature of the smoke side outlet of the energy saver 6 is set to 80-90 ℃, the exhaust gas temperature of the non-regenerative boiler 19 is reduced to 80-90 ℃, and compared with the exhaust gas temperature of the conventional non-regenerative boiler, the exhaust gas temperature of the non-regenerative boiler is more than 120 ℃, the residual heat of the smoke gas is deeply recycled to heat the desalted water entering the deaerator 18.

The control method of the energy-saving system suitable for the non-regenerative boiler is characterized in that when the system is not operated, the inlet shutoff valve 2, the outlet shutoff valve 8, the shutoff valve 5, the branch first shutoff valve 10 and the branch second shutoff valve 12 are kept fully closed, the bypass valve 13 is fully opened, and the opening degree of the main path regulating valve 17 is 0%; when the system operates, the inlet shutoff valve 2, the outlet shutoff valve 8, the shutoff valve 5, the branch first shutoff valve 10 and the branch second shutoff valve 12 are kept fully opened, the bypass valve 13 is fully closed, the opening degree of the main path regulating valve 17 is 50%, and the opening degree of the regulating valve 11 is 50%; setting the water temperature of the water side inlet of the energy saver 6 to be 65-75 ℃, monitoring the water temperature of the water side inlet of the energy saver 6 by the water temperature measuring point 14 in real time, increasing the opening degree of the regulating valve 11 when the actually measured water temperature of the water side inlet is lower than a set value, so as to increase the amount of recirculated water entering the energy saver 6, raising the water temperature of the water side inlet of the energy saver 6 to the set value, and reducing the opening degree of the regulating valve 11 when the actually measured water temperature of the water side inlet is higher than the set value, so as to reduce the amount of recirculated water entering the energy saver 6 and reduce the water temperature of the water side inlet; setting the flue gas temperature at the flue gas side outlet of the energy saver 6 to be 80-90 ℃, monitoring the flue gas temperature at the outlet of the energy saver 6 in real time by an outlet flue gas temperature measuring point 16, increasing the frequency of the variable-frequency booster pump 3 when the actually measured flue gas temperature at the flue gas side outlet is higher than a set value, so as to increase the rotating speed of the variable-frequency booster pump 3, increase the water flow of the energy saver 6, reduce the outlet flue gas temperature of the energy saver 6 to the set value, and reduce the frequency of the variable-frequency booster pump 3 when the actually measured flue gas temperature at the flue gas side outlet is lower than the set value, so as to reduce the rotating speed of the variable-frequency booster pump; when the regulating valve 11 needs to be overhauled in the operation process of the system, the branch first shutoff valve 10 and the branch second shutoff valve 12 are closed, the bypass valve 13 is opened, and after the overhaul is finished, the branch first shutoff valve 10 and the branch second shutoff valve 12 are restored to be fully opened, and the bypass valve 13 is fully closed.

The water side inlet water temperature measuring point 14, the inlet smoke temperature measuring point 15 and the outlet smoke temperature measuring point 16 transmit the measured temperatures to the boiler centralized control system, and the boiler centralized control system controls the variable-frequency booster pump 3 and the regulating valve 11 to perform automatic negative feedback regulation control through a temperature set value and an actual value.

Compared with the prior art, the utility model discloses following beneficial effect has:

an economizer system suitable for no backheat boiler in the course of the work, set for economizer flue gas side outlet smoke temperature and be 80 ℃ -90 ℃ and water side inlet temperature and be 65 ℃ -75 ℃. The frequency of frequency conversion booster pump follows economizer export smoke temperature, sets for minimum frequency and is 20%, when actual export smoke temperature is higher than when setting for export smoke temperature value, improves frequency conversion booster pump frequency, when actual export smoke temperature is less than when setting for export smoke temperature value, reduces frequency conversion booster pump frequency. The regulating valve opening follows the water side inlet water temperature of the energy saver, when the actual water side inlet water temperature is higher than the set water side inlet water temperature value, the regulating valve opening is reduced, and when the actual water side inlet water temperature is lower than the set water side inlet water temperature value, the regulating valve opening is increased. And the system can run automatically after being started. The system can not only prevent the low-temperature corrosion of the energy saver, but also realize the deep energy saving of the non-regenerative boiler, improve the unit efficiency and have remarkable economic benefit.

Drawings

Fig. 1 is the system diagram of the utility model, wherein 1 is the inlet pipeline, 2 is the import shutoff valve, 3 is the frequency conversion booster pump, 4 is the check valve, 5 is the shutoff valve, 6 is the economizer, 7 is the outlet pipeline, 8 is the export shutoff valve, 9 is the valves of recirculating valve, 10 is the first shutoff valve of branch road, 11 is the governing valve, 12 is the second shutoff valve of branch road, 13 is the bypass valve, 17 is main road governing valve, 18 is the oxygen-eliminating device, 19 is no backheat boiler. The energy-saving system is arranged in front of a deaerator of the boiler. In the figure, 14 is a water side inlet water temperature measuring point, 15 is an inlet smoke temperature measuring point, and 16 is an outlet smoke temperature measuring point.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings:

referring to fig. 1, an economizer system suitable for no backheat boiler, including inlet pipe 1, import shutoff valve 2, frequency conversion booster pump 3, check valve 4, shutoff valve 5, energy-saving appliance 6, export pipeline 7 and export shutoff valve 8, including the valve group 9 that recycles that is used for adjusting 6 import temperatures of energy-saving appliance to and main road governing valve 17. The recirculation valve group 9 comprises a bypass first shut-off valve 10, a regulating valve 11, a bypass second shut-off valve 12 and a bypass valve 13. The energy-saving system is arranged in front of the deaerator 18 of the non-regenerative boiler 19, and the refrigerant of the economizer 6 directly takes normal-temperature desalted water. A water side inlet water temperature measuring point 14 is arranged at a water side inlet of the energy saver 6, an inlet smoke temperature measuring point 15 is arranged at a smoke side inlet, an outlet smoke temperature measuring point 16 is arranged at a smoke side outlet, and a smoke side inlet and a smoke side outlet of the energy saver 6 are communicated with a smoke pipeline before a back-feeding chimney of a non-regenerative boiler 19.

The inlet pipeline 1 is connected with an inlet of the energy saver 6, the outlet pipeline 7 is connected with an outlet of the energy saver 6, an inlet and an outlet of the recirculation valve bank 9 are respectively connected with an outlet and an inlet of the energy saver, the inlet shutoff valve 2 and the variable-frequency booster pump 3 are sequentially arranged at the middle position of the inlet pipeline 1 along the water flow direction, and the variable-frequency booster pump 3 is positioned behind the interface of the recirculation valve bank 9 and the inlet pipeline 1. The water flow rate in the inlet pipeline 1, the outlet pipeline 7 and the recirculation valve group 9 is not more than 2.5m/s, and the pipe diameter with a proper specification is selected according to the water flow rate. The flow speed of the flue gas in the economizer 6 is not more than 12m/s, and a proper section is designed according to the flow speed of the flue gas. The regulating valve 11 and the main path regulating valve 17 can be electric regulating valves or pneumatic regulating valves, and have remote and local control functions. The control of the variable frequency booster pump 3 and the recirculation valve group 9 is controlled by a boiler centralized control system.

The utility model discloses a working process does:

when the system does not operate, keeping the inlet shutoff valve 2, the outlet shutoff valve 8, the shutoff valve 5, the branch first shutoff valve 10 and the branch second shutoff valve 12 fully closed, fully opening the bypass valve 13, and keeping the opening degree of the main path regulating valve 17 at 0%; before the system is started, the system is filled with water, the smoke temperature of a smoke side outlet of the energy saver 6 is set to be 80-90 ℃ and the water temperature of a water side inlet is set to be 65-75 ℃, the opening degree of the regulating valve in the recirculation valve bank is set to be 50%, the opening degree of the main path regulating valve is set to be 50%, the inlet shutoff valve 2, the outlet shutoff valve 8, the shutoff valve 5, the branch first shutoff valve 10 and the branch second shutoff valve 12 are fully opened, and the bypass valve 13 is fully closed. And starting the variable-frequency booster pump when the temperature of the smoke at the smoke side inlet of the economizer is higher than 80 ℃, and setting the lowest frequency to be 20%. The water temperature is monitored in real time by a water side inlet water temperature measuring point of the energy saver 6, and when the actually measured inlet water temperature is lower than a set value, the boiler centralized control system increases the opening degree of the regulating valve 11 of the recirculation valve group 9, so that the recirculation water quantity is increased, the water side inlet water temperature of the energy saver 6 is increased to the set value, and vice versa. The smoke temperature is monitored by the smoke temperature measuring point at the outlet of the energy saver in real time, and when the actually measured smoke temperature at the outlet of the smoke side is higher than a set value, the frequency of the variable frequency booster pump 3 is increased by the boiler centralized control system, so that the rotating speed of the variable frequency booster pump 3 is increased, the water flow of the energy saver 6 is increased, and the smoke temperature at the outlet of the energy saver 6 is reduced to the set value, or vice versa. And after the system runs stably, the system is put into automatic operation.

Claims

1. An energy-saving system suitable for a non-regenerative boiler is characterized by being used for recycling flue gas waste heat of the non-regenerative boiler and comprising a main path regulating valve (17) arranged on a demineralized water pipeline in front of a deaerator (18) of a non-regenerative boiler (19), an inlet pipeline (1) and an outlet pipeline (7) which are communicated with the demineralized water pipeline in parallel, an economizer (6) arranged between the inlet pipeline (1) and the outlet pipeline (7), wherein the inlet pipeline (1) is communicated with a water side inlet of the economizer (6), the outlet pipeline (7) is communicated with a water side outlet of the economizer (6), an inlet shutoff valve (2), a variable-frequency booster pump (3), a check valve (4) and a shutoff valve (5) which are sequentially arranged on the inlet pipeline (1), an outlet shutoff valve (8) arranged on the outlet pipeline (7), and a water side inlet water temperature measuring point (14) arranged at a water side inlet of the economizer (6), an inlet smoke temperature measuring point (15) arranged at the inlet of the smoke side of the energy saver (6) and an outlet smoke temperature measuring point (16) arranged at the outlet of the smoke side, wherein the smoke side inlet and the smoke side outlet of the energy saver (6) are communicated with a smoke pipeline before a back-heating boiler (19) and a back chimney; still including being used for adjusting energy-saving appliance (6) import temperature's recirculation valves (9), recirculation valves (9) are including setting gradually first shutoff valve (10), governing valve (11) of branch road and branch road second shutoff valve (12) on the first branch road of intercommunication inlet pipeline (1) and outlet pipeline (7) and setting up bypass valve (13) on the second branch road of intercommunication inlet pipeline (1) and outlet pipeline (7), and wherein the communicating point of first branch road and second branch road and inlet pipeline (1) all is located between import shutoff valve (2) and frequency conversion booster pump (3), and the communicating point of first branch road and second branch road and outlet pipeline (7) all is located the upper reaches of export shutoff valve (8).

2. An economizer system for a regenerative-less boiler according to claim 1, characterized in that the economizer (6) uses directly demineralized water as the economizer (6) coolant.

3. The economizer system for a once-through boiler according to claim 1, characterized in that the regulating valve (11) and the main path regulating valve (17) are electric regulating valves or pneumatic regulating valves with remote and local control functions; the water temperature at the water side inlet of the energy saver (6) is realized by automatically controlling the opening of the regulating valve (11) by the boiler centralized control system.

4. The energy-saving system applicable to the non-regenerative boiler is characterized in that the flue gas temperature at the flue gas side outlet of the economizer (6) is realized by automatically controlling the frequency of the variable-frequency booster pump (3) through a boiler centralized control system.

5. The energy-saving system suitable for the non-regenerative boiler is characterized in that the smoke temperature of the smoke side outlet of the energy saver (6) is set to 80-90 ℃, the smoke temperature of the non-regenerative boiler (19) is reduced to 80-90 ℃, and the smoke waste heat is deeply recovered to heat the desalted water entering the deaerator (18).