Combustion heating system and working method for alternative recovery of thermal energy cycles

Abstract

The application discloses a combustion heating system and a working method for alternately recycling thermal energy, comprising two sets of combustion devices and thermal energy recycling devices arranged in an upper-lower corresponding mode, and an automatic control system, wherein each set of the thermal energy recycling device is provided with a heat storage body, the bottom of the heat storage body is provided with a ring of thermal energy circulation holes, each ring of the thermal energy circulation holes is correspondingly provided with a flame outlet of the combustion device, the automatic control system controls the two combustion devices to alternately combust and heat, the thermal energy circulation holes corresponding to the combustion device for combustion and heating transport the hot gas stored in the heat storage body to the flame outlet for mixing, and the flue gas is transported from another corresponding thermal energy circulation hole to the heat storage body to absorb and store waste heat energy. The combustion device is provided with the thermal energy circulation hole, so that the flame ejected by the combustion device can be more completely combusted, two sets of devices can efficiently and continuously recycle thermal energy, the loss of thermal energy of combustion tail gas emission is reduced, the utilization rate of combustion thermal energy is high, and energy saving and cost reduction are facilitated.

Description

Technical Field

[0001] This invention relates to the field of heating system technology, and in particular to a combustion heating system and its working method that features alternating heat energy recycling. Background Technology

[0002] Currently, traditional heating devices are generally used in the textile, food processing, and hardware processing industries to heat heat-conducting materials and raw materials. These devices are mostly direct-fired gas systems, which carry away a large amount of heat during combustion, resulting in significant energy waste. Therefore, it is necessary to design reasonable waste heat recovery systems for these applications to recover this heat energy and improve thermal efficiency.

[0003] Chinese patent publication number CN108800957A, entitled "Energy-Saving Combustion and Waste Heat Recovery System for Rapid Aluminum Melting Furnace," discloses a waste heat recovery system comprising a first regenerator, a second regenerator, and a reversing device. This system allows one regenerator to store waste heat generated by combustion in the melting furnace, while the other regenerator preheats the combustion-supporting gas in the holding furnace, alternating according to a preset time cycle. This effectively solves the problems of low waste heat recovery efficiency and difficulty in waste heat recovery in existing technologies. The structure uses a portion of the flue gas extracted by the circulating fan after waste heat recovery in the regenerator as supplementary gas, which is then sent into the holding furnace through a flue gas burner to further dilute the combustion-supporting gas preheated in the regenerator and maintain flue gas balance between the main and auxiliary flues. However, this equipment is only suitable for the aluminum melting furnace industry and cannot be applied to other heat-conducting materials or raw material heating and processing scenarios. Moreover, this waste heat recovery system and pipeline structure are complex. Some of the flue gas that has undergone waste heat recovery in the heat storage chamber contains impurities. These impurities and high-temperature flue gas can easily cause damage to components such as the three-way valve, flue gas burner, heat preservation burner, induced draft fan, circulating fan, and blower. These components require frequent maintenance and replacement, which is not conducive to use and needs to be improved. Summary of the Invention

[0004] To address the aforementioned problems, the present invention aims to provide a combustion heating system and its operating method that features alternating heat energy recovery. This system comprises two or more sets of improved combustion devices and waste heat recovery devices, resulting in a simpler and more reliable system structure. It can efficiently and reliably recover heat energy in an alternating manner, achieving high utilization of combustion heat energy and facilitating energy saving and cost reduction. Furthermore, the present invention has a wide range of applications and is easy to deploy and install in a modular and flexible manner.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A combustion heating system with alternating heat energy recovery includes two sets of combustion devices and heat energy recovery devices arranged vertically and vertically, as well as an automatic control system. Each heat energy recovery device is equipped with a heat storage body, and the bottom of the heat storage body is provided with a ring of heat energy circulation holes. Each ring of heat energy circulation holes is provided with a flame outlet of the combustion device. The automatic control system controls the two combustion devices to alternately burn and heat. During combustion, the heat energy absorbed and stored in the heat storage body above the combustion device is returned to the flame outlet through the heat energy circulation holes for mixing and heating. The combustion flue gas is transported from the other heat energy circulation hole to the other heat storage body to absorb and store the residual heat.

[0007] Furthermore, the combustion device is provided with a gas inlet and an auxiliary gas inlet. The gas inlet is connected to a gas control valve through a gas inlet pipe, and the auxiliary gas inlet is connected to an auxiliary gas control valve through an auxiliary gas inlet pipe. The combustion device is also provided with an automatic igniter and a flame detector. The gas control valve, auxiliary gas control valve, automatic igniter, and flame detector are connected to the automatic control system.

[0008] Furthermore, the vertical cross-section at the flame outlet is waist-shaped, and the thermal energy circulation holes are arranged around the waist-shaped flame outlet.

[0009] Furthermore, a fire-gathering ring is provided on the outer side of the flame outlet, and the fire-gathering ring has a fire-gathering slope that gradually converges towards the outlet direction.

[0010] Furthermore, the heat recovery device is provided with an airflow channel that can exchange heat energy with the heat storage body. The heat storage body can absorb the heat energy of the flue gas discharged into the airflow channel through the heat energy circulation hole, or heat the airflow in the airflow channel with the absorbed and stored heat energy and then return it to the flame outlet through the heat energy circulation hole.

[0011] Furthermore, a four-way reversing valve is provided between the two sets of heat recovery devices. The two ends of the four-way reversing valve are respectively connected to the top of the heat recovery device. The lower end of the four-way reversing valve is connected to the air input device, and the upper end of the four-way reversing valve is connected to the flue gas outlet. Each set of heat recovery devices is equipped with a temperature sensor. The four-way reversing valve, the air input device, and the temperature sensor are also connected to the automatic control system.

[0012] The working method of the combustion heating system with alternating heat energy recovery and circulation described above includes the following steps:

[0013] S1. The automatic control system controls the first combustion device to ignite and start working. The airflow input by the air input device is blown in through the four-way reversing valve, the first heat storage body, and the first heat energy circulation hole. After being compressed and mixed with the gas flame ejected from the first flame outlet, it is blown towards the heating area to generate a high-temperature flame. The flue gas after combustion enters the second heat storage body through the second heat energy circulation hole. The second heat storage body purifies the flue gas and absorbs and stores the waste heat of the flue gas. The filtered flue gas is then discharged through the four-way reversing valve and the exhaust port.

[0014] S2. After the temperature sensor detects that the temperature in the second heat storage body has reached the set value, it controls the first combustion device to stop working and starts the second combustion device to take over. At the same time, the four-way reversing valve is reversed. The airflow input by the air input device is blown into the second heat storage body and the second heat energy circulation hole through the reversed four-way reversing valve. After being compressed and mixed with the gas flame ejected from the flame outlet, it is blown towards the heating area to generate a high-temperature flame. The flue gas after combustion enters the first heat storage body through the first heat energy circulation hole. The first heat storage body purifies the flue gas and absorbs and stores the waste heat of the flue gas. The filtered flue gas is then discharged through the four-way reversing valve and the exhaust port.

[0015] S3. After the temperature sensor detects that the temperature in the first heat storage body has reached the set value, it controls the second combustion device to stop working and then starts the first combustion device to take over the work, and so on in a cycle.

[0016] Furthermore, the four-way reversing valve is provided with a reversing valve plate and a driving mechanism. In step S1, the lower air inlet of the four-way reversing valve is connected to the top pipe of the first heat recovery device, and the upper exhaust port of the four-way reversing valve is connected to the top pipe of the second heat recovery device. In step S2, after the four-way reversing valve reverses, the lower air inlet of the four-way reversing valve is connected to the top pipe of the second heat recovery device, and the upper exhaust port of the four-way reversing valve is connected to the top pipe of the first heat recovery device.

[0017] The present invention has the following beneficial effects:

[0018] 1. This invention involves setting up two or more sets of combustion devices and heat recovery devices arranged vertically and vertically, with heat circulation holes connected to the heat recovery devices around the flame outlet of the combustion devices. When the combustion devices are working, the corresponding heat circulation holes output hot air towards the flame outlet, making the flame emitted by the combustion devices burn more thoroughly and improving heating efficiency and heating speed. Meanwhile, another heat circulation hole outputs flue gas towards another heat storage body, and the waste heat of the flue gas is absorbed and stored by the heat storage body. This can greatly reduce the heat energy carried away by the combustion exhaust gas. The two sets of devices can efficiently and continuously recover heat energy alternately, resulting in high utilization of combustion heat energy and promoting energy saving and cost reduction. Furthermore, this invention can be widely used in conjunction with heating furnaces and drying furnaces in industries such as textiles, food processing, and hardware processing. It has a wide range of applications and is easy to deploy and install in a modular and flexible manner.

[0019] 2. In this invention, a ring of heat energy circulation holes is provided around the flame outlet of each of the two combustion devices, directly connecting the airflow channel at the bottom of the heat storage body to it. The air input device is located at the lower end of the four-way reversing valve outside the heat recovery device, so that there is no need to install valves, fans or other equipment components between the combustion device and the heat recovery device. The system structure is simpler and more reliable, less prone to damage during use, and reduces operation and maintenance costs.

[0020] 3. The vertical cross-section of the combustion device body and its flame outlet in this invention is waist-shaped, which makes the combustion heating surface wider. It is easy to set more heat energy circulation holes around the flame outlet, which facilitates the compression and mixing of the combustion flame and the hot air flow blown back by the heat energy circulation holes. After compression and mixing, it is burned again, the combustion is more complete, and a higher temperature flame is generated, thereby effectively improving the combustion efficiency. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the combustion heating system with alternating heat energy recovery according to the present invention.

[0022] Figure 2 A three-dimensional schematic diagram of the flame outlet section of a combustion heating system that performs alternating heat energy recycling.

[0023] Figure 3 This is a three-dimensional schematic diagram of the combustion device of the present invention.

[0024] Figure 4 This is a schematic diagram of the combustion device of the present invention in the direction of the flame outlet.

[0025] Figure 5 This is a cross-sectional schematic diagram of one of the cyclic working states of the system of the present invention.

[0026] Figure 6 This is a cross-sectional schematic diagram of the second cyclic working state of the system of the present invention.

[0027] Explanation of reference numerals in the attached figures:

[0028] 1. Combustion device; 11. Flame outlet; 12. Gas inlet; 13. Combustion-supporting gas inlet; 14. Automatic igniter; 15. Flame detector; 2. Heat recovery device; 21. Heat storage body; 22. Heat circulation hole; 3. Automatic control system; 4. Flame concentrator; 41. Flame concentrator slope; 5. Four-way reversing valve; 6. Air input device; 7. Temperature sensor. Detailed Implementation

[0029] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments:

[0030] See Figure 1-6 As shown, a combustion heating system with alternating heat energy recovery includes two sets of combustion devices 1 and heat energy recovery devices 2 arranged vertically and vertically, as well as an automatic control system 3. In large heating systems, three or more sets of combustion devices 1 and heat energy recovery devices 2 can be installed to facilitate continuous alternating combustion and heat recovery. Each set of heat energy recovery devices 2 is equipped with a heat storage body 21, which includes heat storage bricks or heat-absorbing carbon, etc., and can work stably at high temperatures with a specific heat capacity of 1.2 or higher. It can filter and purify combustion flue gas to achieve low-temperature and low-pollution emissions. The heat storage body 21 is provided with an airflow channel to facilitate circulating heat energy exchange with the heat storage body 21. The bottom of the heat storage body 21 is provided with a ring of heat energy circulation holes 22. The heat energy circulation hole 22 is provided with a flame outlet 11 corresponding to the combustion device 1. The heat storage body 21 can absorb the heat energy of the flue gas discharged into the airflow channel through the heat energy circulation hole 22, or heat the airflow in the airflow channel with the absorbed and stored heat energy and then send it back to the flame outlet 11 through the heat energy circulation hole 22. The automatic control system 3 controls the two combustion devices 1 to burn and heat alternately. When the combustion device 1 is working, the heat energy absorbed and stored in the heat storage body 21 above the combustion device 1 is sent back to the flame outlet 11 through the heat energy circulation hole 22 to be mixed and heated together. The combustion flue gas is transported from another heat energy circulation hole 22 to another heat storage body 21 to absorb and store the residual heat. A four-way reversing valve 5 is provided between the two sets of heat recovery devices 2. The two ends of the four-way reversing valve 5 are respectively connected to the top of the heat recovery device 2. The lower end of the four-way reversing valve 5 is connected to the air input device 6. The air input device 6 includes a fan or a compressed air supply device. The upper end of the four-way reversing valve 5 is connected to the exhaust port. Each set of heat recovery devices 2 is equipped with a temperature sensor 7.

[0031] The combustion device 1 is provided with a gas inlet 12 and an auxiliary gas inlet 13. The gas inlet 12 is connected to a gas control valve through a gas inlet pipe, and the auxiliary gas inlet 13 is connected to an auxiliary gas control valve through an auxiliary gas inlet pipe. The combustion device 1 is also provided with an automatic igniter 14 and a flame detector 15. The gas control valve, auxiliary gas control valve, automatic igniter 14, flame detector 15, four-way reversing valve 5, air inlet device 6, and temperature sensor 7 are connected to the automatic control system 3. The vertical cross-section of the flame outlet 11 is oblong, and the heat circulation holes 22 are arranged around the oblong flame outlet 11. A flame concentrating ring 4 is provided on the outside of the flame outlet 11. The flame concentrating ring 4 has a flame concentrating slope 41 that gradually narrows towards the outlet direction; this facilitates the convergence of the hot gas flow and the combustion flame ejected from the flame outlet 11, thereby improving combustion efficiency.

[0032] The working method of the combustion heating system with alternating heat energy recovery and circulation described above includes the following steps:

[0033] S1. The automatic control system 3 controls the first combustion device 1 to ignite and start working. The airflow input by the air input device 6 is blown in through the four-way reversing valve 5, the first heat storage body 21, and the first heat energy circulation hole 22. It is compressed and mixed with the gas flame ejected from the first flame outlet 11 and blown towards the heating area to generate a high-temperature flame. The flue gas after combustion enters the second heat storage body 21 through the second heat energy circulation hole 22. The second heat storage body 21 purifies the flue gas and absorbs and stores the waste heat of the flue gas. The filtered flue gas is then discharged through the four-way reversing valve 5 and the exhaust port.

[0034] S2. After the temperature sensor 7 detects that the temperature in the second heat storage body 21 has reached the set value, it controls the first combustion device 1 to stop working and starts the second combustion device 1 to take over. At the same time, the four-way reversing valve 5 is reversed. The airflow input by the air input device 6 is blown into the second heat storage body 21 and the second heat energy circulation hole 22 through the reversed four-way reversing valve 5. After being compressed and mixed with the gas flame ejected from the flame outlet 11, it is blown towards the heating area to generate a high-temperature flame. The flue gas after combustion enters the first heat storage body 21 through the first heat energy circulation hole 22. The first heat storage body 21 purifies the flue gas and absorbs and stores the waste heat of the flue gas. The filtered flue gas is then discharged through the four-way reversing valve 5 and the exhaust port.

[0035] S3. After the temperature sensor 7 detects that the temperature in the first heat storage body 21 has reached the set value, it controls the second combustion device 1 to stop working and then starts the first combustion device 1 to take over the work, and so on in a cycle.

[0036] See the diagram of the cyclic operation. Figure 5-6 As shown, attached Figure 5-6Hide the fire circle 4 in the middle.

[0037] Furthermore, the four-way reversing valve 5 is provided with a reversing valve plate and a driving mechanism. The driving mechanism includes an electric mechanism or a pneumatic actuator. In step S1, the lower air inlet of the four-way reversing valve 5 is connected to the top pipe of the first heat recovery device 2, and the upper exhaust port of the four-way reversing valve 5 is connected to the top pipe of the second heat recovery device 2. After the four-way reversing valve 5 reverses in step S2, the lower air inlet of the four-way reversing valve 5 is connected to the top pipe of the second heat recovery device 2, and the upper exhaust port of the four-way reversing valve 5 is connected to the top pipe of the first heat recovery device 2.

[0038] The above description is merely a specific embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made based on the content of the present invention specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A combustion heating system with heat energy cycle alternate recovery, comprising two sets of combustion device (1) and heat energy recovery device (2) arranged in correspondence with each other, and an automatic control system (3), characterized in that: Each set of said heat energy recovery device (2) is provided with a heat storage body (21), the bottom of the heat storage body (21) is provided with a circle of heat energy circulation holes (22), each circle of said heat energy circulation holes (22) is correspondingly provided with the flame outlet (11) of said combustion device (1), said automatic control system (3) controls two said combustion devices (1) to alternate combustion and heating, the heat energy absorbed and stored in the corresponding heat storage body (21) above the said combustion device (1) during combustion is returned to the said flame outlet (11) through the said heat energy circulation hole (22) for mixed heating, the combustion flue gas is transported from another said heat energy circulation hole (22) to another said heat storage body (21) to absorb and store the residual heat; said combustion device (1) is provided with a gas inlet (12) and a combustion supporting gas inlet (13), said gas inlet (12) is connected with a gas control valve through a gas inlet pipe, said combustion supporting gas inlet (13) is connected with a combustion supporting gas control valve through a combustion supporting gas inlet pipe, said combustion device (1) is also provided with an automatic igniter (14) and a flame detector (15), said gas control valve, combustion supporting gas control valve, automatic igniter (14) and flame detector (15) are connected with said automatic control system (3) for control; said heat energy recovery device (2) is provided with an air flow channel capable of circulating heat energy exchange with the heat storage body (21), said heat storage body (21) can absorb the heat energy of the flue gas discharged into the air flow channel through said heat energy circulation hole (22), or heat the air flow in the air flow channel after absorbing and storing the heat energy, and then reversely return to said flame outlet (11) through said heat energy circulation hole (22).

2. A combustion heating system with alternating recovery of heat energy cycles according to claim 1, characterized in that: The vertical section at said flame outlet (11) is a waist hole shape, and said heat energy circulation hole (22) is arranged around the waist hole shaped flame outlet (11).

3. A combustion heating system with alternating recovery of heat energy cycles according to claim 2, characterized in that: The outside of said flame outlet (11) is provided with a flame gathering ring (4), said flame gathering ring (4) is provided with a flame gathering inclined surface (41) which gradually converges towards the outlet direction.

4. The combustion heating system of claim 1, wherein: A four-way reversing valve (5) is arranged between two sets of said heat energy recovery device (2), two ends of said four-way reversing valve (5) are respectively communicated with the top of said heat energy recovery device (2), the lower end of said four-way reversing valve (5) is connected with an air input device (6), and the upper end of said four-way reversing valve (5) is connected with an exhaust port; each set of said heat energy recovery device (2) is provided with a temperature sensor (7); the four-way reversing valve (5), air input device (6) and temperature sensor (7) are also connected with said automatic control system (3) for control.

5. The method of claim 4, wherein the method further comprises: determining a temperature of the working fluid; and adjusting the amount of heat energy provided to the working fluid based on the determined temperature of the working fluid. The method comprises the following steps: S1, the automatic control system (3) controls the first combustion device (1) to start working, the air input device (6) inputs the airflow through the four-way reversing valve (5), the first heat storage body (21), the first heat energy circulation hole (22) blows into, and the compressed mixed gas flame of the first flame outlet (11) blows to the heating place to produce high temperature flame, and the flue gas after combustion enters the second heat storage body (21) through the second heat energy circulation hole (22), the second heat storage body (21) purifies the flue gas and absorbs and stores the waste heat of the flue gas, and the filtered flue gas is discharged through the four-way reversing valve (5) and the smoke outlet; S2, after the temperature sensor (7) detects that the temperature in the second heat storage body (21) reaches the set value, the first combustion device (1) stops working, the second combustion device (1) is started to replace work, and the four-way reversing valve (5) is reversed, the airflow input by the air input device (6) blows into the second heat storage body (21) and the second heat energy circulation hole (22) through the reversed four-way reversing valve (5), and the compressed mixed gas flame of the flame outlet (11) blows to the heating place to produce high temperature flame, and the flue gas after combustion enters the first heat storage body (21) through the first heat energy circulation hole (22), the first heat storage body (21) purifies the flue gas and absorbs and stores the waste heat of the flue gas, and the filtered flue gas is discharged through the four-way reversing valve (5) and the smoke outlet; S3, after the temperature sensor (7) detects that the temperature in the first heat storage body (21) reaches the set value, the second combustion device (1) stops working, and the first combustion device (1) is started to replace work, and the cycle is alternately worked.

6. The method of claim 5, wherein the method further comprises: The four-way reversing valve (5) is provided with a reversing valve plate and a driving mechanism, the lower end air inlet of the four-way reversing valve (5) is communicated with the top pipeline of the first heat energy recovery device (2) in step S1, and the upper end smoke outlet of the four-way reversing valve (5) is communicated with the top pipeline of the second heat energy recovery device (2); after the four-way reversing valve (5) is reversed in step S2, the lower end air inlet of the four-way reversing valve (5) is communicated with the top pipeline of the second heat energy recovery device (2), and the upper end smoke outlet of the four-way reversing valve (5) is communicated with the top pipeline of the first heat energy recovery device (2).

Images