Boiler flue gas heat energy recycling system

Abstract

The utility model belongs to the technical field of energy recycling, and particularly relates to a boiler flue gas heat energy recycling system which is mainly used for recycling flue gas heat energy of a steam boiler. Comprising a steam boiler, a heat storage water tank, a first-stage energy saver and a second-stage energy saver, the front end of the first-stage energy saver is connected with the steam boiler, and the rear end of the first-stage energy saver is connected with the heat storage water tank through a pipeline; and the second-stage energy saver is connected with the heat storage water tank through a return pipe. According to the novel boiler flue gas heat energy recycling system, temperature control and liquid level control of heat energy recycling are achieved, components are reasonably controlled, a control module for boiler flue gas heat energy utilization is formed, the flue gas emission temperature is reduced, meanwhile, the utilization rate of boiler fuel is increased, and energy is saved.

Description

Technical Field

[0001] The utility model belongs to the technical field of energy recovery and utilization, and particularly relates to a boiler flue gas heat energy recovery and utilization system, which is mainly used for recovering the heat energy of steam boiler flue gas. Background Art

[0002] Steam boilers emit a large amount of flue gas during combustion. The flue gas contains a large amount of heat which is discharged along with the flue gas, thus causing the thermal efficiency of the boiler to decrease and resulting in low utilization rate of natural gas energy.

[0003] Today, energy is in short supply. On the basis of constantly seeking renewable energy, how to improve the utilization rate of non-renewable energy and save its usage is a topic that is constantly being studied. Therefore, improving the energy utilization rate of non-renewable energy can not only reduce the production cost of production enterprises and enhance the competitiveness of enterprises in the market, but also better meet the requirements of energy conservation and emission reduction.

[0004] The existing boiler exhaust system usually uses a first-stage economizer, and the flue gas still contains a large amount of heat that cannot be effectively utilized. Utility Model Content

[0005] In view of the above deficiencies in the prior art, the technical problem to be solved by the utility model is: to provide a boiler flue gas heat energy recovery and utilization system, which solves the problem that the flue gas discharged by the existing steam boiler contains a large amount of heat energy which cannot be effectively utilized.

[0006] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0007] A boiler flue gas heat energy recovery and utilization system comprises a steam boiler, a heat storage tank, a primary economizer and a secondary economizer, wherein the front end of the primary economizer is connected to the steam boiler, and the rear end of the primary economizer is connected to the heat storage tank via a pipeline; the secondary economizer is connected to the heat storage tank via a reflux pipe.

[0008] Furthermore, in order to facilitate water supply to the steam boiler, a boiler feed water pump is provided on a section of the pipeline close to the heat storage tank. When the boiler has demand, water is supplied to the boiler through the boiler feed water pump.

[0009] Furthermore, in order to further increase the temperature difference between the flue gas and the water side, improve the heat exchange efficiency, and ensure maximum utilization of thermal energy, a circulating heating pump, a circulating heating control valve, and a water supply control valve are installed between the secondary economizer and the heat storage tank.

[0010] Furthermore, in order to ensure that water resources are not wasted, a liquid level sensor is provided on the heat storage tank, and the liquid level sensor is interlocked.

[0011] Furthermore, in order to prevent the water inlet selection of the secondary economizer, the water supply control valve and the circulating heating control valve are interlocked;

[0012] When the water level in the hot water storage tank is low, open the water supply control valve, close the circulating heating control valve and the circulating heating pump, and give priority to using the softened water with a lower temperature to enter the secondary energy saver;

[0013] When the water level in the heat storage tank reaches the set value, in order to prevent the tank from overflowing and wasting water resources, the water replenishment control valve is closed, the circulating heating control valve and the circulating heating pump are opened, and the water in the heat storage tank is circulated between the secondary energy saver.

[0014] Furthermore, in order to facilitate the control of the boiler feed water pump, the circulating heating control valve and the make-up water control valve, the circulating heating pump, the boiler feed water pump, the circulating heating control valve and the make-up water control valve are all electrically connected to the control system.

[0015] Furthermore, the number of the steam boilers is greater than or equal to one.

[0016] In summary, due to the adoption of the above technical solution, the beneficial technical effects of the utility model are:

[0017] A boiler flue gas heat energy recovery and utilization system has a liquid level sensor on the hot water storage tank, which is interlocked with the water supply control valve to ensure that water resources are not wasted. The water supply control valve and the circulating heating control valve are interlocked to ensure the water inlet selection of the secondary economizer. When the water level in the hot water storage tank is low, the water supply control valve is opened, the circulating heating control valve and the circulating heating pump are closed, and the softened water with a lower temperature is preferentially used to enter the secondary economizer, thereby increasing the temperature difference between the flue gas and the water side, improving the heat exchange efficiency, and ensuring the maximum utilization of heat energy;

[0018] When the water level in the heat storage tank reaches the set value, in order to prevent the water tank from overflowing and wasting water resources, the water supply control valve is closed, the circulating heating control valve and the circulating heating pump are opened, and the water in the heat storage tank is circulated between the secondary economizer to further increase the temperature of the heat storage tank and utilize the flue gas heat to a higher extent.

[0019] A boiler flue gas heat energy recovery and utilization system has temperature control and liquid level control for heat energy recovery. With reasonable control components, a boiler flue gas heat energy utilization control module is formed. While further reducing the flue gas emission temperature, the utilization rate of boiler fuel is improved, saving energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the overall structure of the utility model.

[0021] In the figure: steam boiler 1, hot water storage tank 2, primary energy saver 3, secondary energy saver 4, circulating heating pump 5, boiler feed water pump 6, circulating heating control valve 7, water supply control valve 8, control system 9, pipeline 10, return pipe 11, liquid level sensor 12. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical solution and advantages of the utility model more clear, the utility model is further described in detail in combination with the embodiments below. It should be understood that the specific embodiments described here are only used to explain the utility model, and are not used to limit the utility model.

[0023] Example 1

[0024] In this embodiment, Figure 1 As shown, a boiler flue gas heat energy recovery and utilization system includes a steam boiler 1, a hot water storage tank 2, a primary economizer 3 and a secondary economizer 4, wherein the front end of the primary economizer 3 is connected to the steam boiler 1, and the rear end of the primary economizer 3 is connected to the hot water storage tank 2 through a pipeline 10; the secondary economizer 4 is connected to the hot water storage tank 2 through a return pipe 11. The number of the steam boilers 1 is greater than or equal to 1.

[0025] Example 2

[0026] In this embodiment, Figure 1 As shown, a section of the pipeline 10 near the hot water storage tank 2 is provided with a boiler feed water pump 6. When the boiler has a demand, water is supplied to the boiler for use through the boiler feed water pump 6. During the operation of the boiler, the heat in the flue gas is fully absorbed and utilized by the primary economizer 3 and the secondary economizer 4 through heat energy recovery, and softened water is used to fully absorb and utilize the heat, and then sent to the hot water storage tank for storage through tap water pressure. When the boiler has a demand, water is supplied to the boiler for use through the boiler feed water pump 6, thereby saving energy.

[0027] Example 3

[0028] In this embodiment, Figure 1 As shown, in order to further increase the temperature difference between the flue gas and the water side, improve the heat exchange efficiency, and ensure the maximum utilization of thermal energy, a circulating heating pump 5, a circulating heating control valve 7, and a water replenishment control valve 8 are installed between the secondary economizer 4 and the hot water storage tank 2. In order to ensure that water resources are not wasted, a liquid level sensor 12 is provided on the hot water storage tank, and the liquid level sensor 12 is interlocked with the circulating heating pump 5.

[0029] In order to ensure the water inlet selection of the secondary economizer 4, the water supply control valve 8 and the circulating heating control valve 7 are interlocked;

[0030] When the water level in the heat storage tank is low, the water replenishment control valve 8 is opened, the circulating heating control valve 7 and the circulating heating pump 5 are closed, and the softened water with a lower temperature is preferentially used to enter the secondary economizer; when the water level in the heat storage tank reaches the set value, in order to prevent the water tank from overflowing and wasting water resources, the water replenishment control valve 8 is closed, the circulating heating control valve 7 and the circulating heating pump 5 are opened, and the water in the heat storage tank 2 is circulated between the secondary economizer 4, so as to further increase the temperature of the heat storage tank and utilize the flue gas heat to a higher extent.

[0031] Example 4

[0032] In this embodiment, Figure 1 As shown, in order to facilitate the control of the circulating heating pump 5, the boiler feed water pump 6, the circulating heating control valve 7 and the make-up water control valve 8, the circulating heating pump 5, the boiler feed water pump 6, the circulating heating control valve 7 and the make-up water control valve 8 are all electrically connected to the control system 9.

[0033] The above description is a preferred embodiment of the utility model and is not intended to limit the utility model. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the utility model should be included in the protection scope of the utility model.

Claims

1. A boiler flue gas heat recovery system, comprising a steam boiler (1), a hot water storage tank (2), a primary economizer (3) and a secondary economizer (4), characterized in that: The front end of the first-stage economizer (3) is connected to the steam boiler (1), and the rear end of the first-stage economizer (3) is connected to the hot water storage tank (2) via a pipeline (10); the second-stage economizer (4) is connected to the hot water storage tank (2) via a return pipe (11).

2. A boiler flue gas heat recovery and utilization system according to claim 1, characterized in that: A boiler feed water pump (6) is provided on a section of the pipeline (10) close to the hot water storage tank (2). When the boiler has a demand, water is supplied to the boiler through the boiler feed water pump (6).

3. A boiler flue gas heat recovery and utilization system according to claim 1, characterized in that: A circulating heating pump (5), a circulating heating control valve (7) and a water supply control valve (8) are installed between the secondary energy saver (4) and the hot water storage tank (2).

4. The boiler flue gas heat recovery system according to claim 1, characterized in that: The hot water storage tank is provided with a liquid level sensor (12), and the liquid level sensor (12) is interlocked with the circulating heating pump (5).

5. The boiler flue gas heat recovery system according to claim 3, characterized in that: The water supply control valve (8) and the circulation heating control valve (7) are interlocked; When the water level in the hot water storage tank is low, the water replenishment control valve (8) is opened, the circulating heating control valve (7) and the circulating heating pump (5) are closed, and the softened water with a lower temperature is preferentially used to enter the secondary energy saver; When the water level in the hot water storage tank reaches a set value, the water supply control valve (8) is closed, and the circulating heating control valve (7) and the circulating heating pump (5) are opened to circulate the water in the hot water storage tank (2) and the secondary energy saver (4).

6. A boiler flue gas heat recovery and utilization system according to claim 5, characterized in that: The circulating heating pump (5), the boiler feed water pump (6), the circulating heating control valve (7) and the water supply control valve (8) are all electrically connected to the control system (9).

7. The boiler flue gas heat recovery system according to claim 1, characterized in that: The number of the steam boilers (1) is greater than or equal to one.

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