A device for recovering and reusing waste heat from low-temperature exhaust gas of a glass melting furnace

Abstract

This utility model discloses a waste heat recovery and reuse device for low-temperature exhaust gas from a glass melting furnace, belonging to the field of heat recovery technology. The device includes a steel structure support, with an economizer fixedly installed inside. Several hot water heat exchangers are fixedly installed inside the economizer. A gas guide pipe is fixedly installed on the side of the economizer. One end of the economizer has an exhaust gas inlet connected to the exhaust gas outlet of the glass melting furnace, and the other end has an exhaust gas outlet. The hot water heat exchangers include an inlet pipe, one end of which is fixedly connected to an inlet manifold. Several heat exchange tubes are fixedly installed on the inlet manifold, and the other ends of the heat exchange tubes are jointly fixedly connected to a drain manifold, on which a drain pipe is fixedly installed. This device can significantly improve the waste heat exchange efficiency, increase the waste heat recovery rate of the low-temperature exhaust gas, and enhance the effect of waste heat recovery and reuse.

Description

Technical Field

[0001] This utility model relates to the field of heat recovery technology, and more specifically, to a device for recovering and reusing waste heat from low-temperature tail gas of a glass melting furnace. Background Technology

[0002] During the glass melting process, fuel combustion in a glass melting furnace releases a large amount of heat, of which about 40% is carried away by the flue gas. This flue gas typically leaves the furnace at a high temperature, but its temperature decreases significantly after being recovered and utilized by equipment such as waste heat boilers. When the flue gas temperature drops to around 200°C, it forms what is known as "low-temperature exhaust gas."

[0003] Currently, the commonly used methods for treating "low-temperature exhaust gas" generally involve simple waste heat recovery treatment, followed by the treatment of harmful substances in the "low-temperature exhaust gas". However, this method results in a low waste heat recovery rate in the "low-temperature exhaust gas".

[0004] Therefore, in view of this, we have studied and improved the existing structure to provide a low-temperature exhaust gas waste heat recovery and reuse device for glass melting furnaces, in order to achieve a more practical purpose. Utility Model Content

[0005] 1. Technical problems to be solved

[0006] In view of the problems existing in the prior art, the purpose of this utility model is to provide a waste heat recovery and reuse device for low-temperature tail gas of glass melting furnace, which can improve the waste heat exchange efficiency to a greater extent, improve the waste heat recovery rate of low-temperature tail gas, and enhance the effect of waste heat recovery and reuse.

[0007] 2. Technical Solution

[0008] To solve the above problems, the present invention adopts the following technical solution.

[0009] A device for recovering and reusing waste heat from low-temperature exhaust gas of a glass melting furnace includes a steel structure support. An economizer is fixedly installed inside the steel structure support. Several hot water heat exchangers are fixedly installed inside the economizer. A gas guide pipe is fixedly installed on the side of the economizer. An exhaust gas inlet is provided at one end of the economizer, which is connected to the exhaust gas outlet of the glass melting furnace. An exhaust gas outlet is provided at the other end of the economizer.

[0010] The hot water heat exchanger includes an inlet pipe, one end of which is fixed to an inlet manifold, and several heat exchange tubes are fixedly installed on the inlet manifold. The other ends of the several heat exchange tubes are jointly fixed to a drain manifold, and a drain pipe is fixedly installed on the drain manifold.

[0011] Furthermore, the exhaust gas inlet is located at the top of the economizer, and the exhaust gas inlet has a funnel-shaped structure.

[0012] Furthermore, the exhaust port is located at the bottom of the economizer, and a valve is installed at the exhaust port.

[0013] Furthermore, the inlet pipe and the outlet pipe are arranged in parallel, and the inlet manifold and the outlet manifold are arranged in parallel.

[0014] Furthermore, the heat exchange tube consists of three straight pipe sections and four U-shaped bends, with the four U-shaped bends and three straight pipe sections distributed alternately in sequence, and each straight pipe section is fixed with a heat-conducting copper sheet.

[0015] Furthermore, the number of heat exchange tubes installed in the same hot water heat exchanger shall not be less than eight.

[0016] Furthermore, the air duct is inclined downwards, and a blower is installed at the inlet of the air duct.

[0017] 3. Beneficial effects

[0018] Compared with existing technologies, the advantages of this utility model are:

[0019] This solution introduces low-temperature exhaust gas into the economizer and uses a blower in conjunction with a gas guide pipe to agitate the low-temperature exhaust gas in the economizer, allowing the low-temperature exhaust gas to fully contact the hot water heat exchanger, thereby improving the waste heat exchange efficiency to a greater extent, increasing the waste heat recovery rate of the low-temperature exhaust gas, and enhancing the effect of waste heat recovery and reuse. Attached Figure Description

[0020] Figure 1 This is a plan view of the waste heat recovery and reuse device for low-temperature exhaust gas from a glass melting furnace in this utility model. Figure 1 ;

[0021] Figure 2 This is a plan view of the waste heat recovery and reuse device for low-temperature exhaust gas from a glass melting furnace in this utility model. Figure 2 ;

[0022] Figure 3 This is a plan view of the waste heat recovery and reuse device for low-temperature exhaust gas from a glass melting furnace in this utility model. Figure 3 ;

[0023] Figure 4 This is a three-dimensional structural diagram of the hot water heat exchanger in this utility model.

[0024] Explanation of the labels in the diagram:

[0025] 1. Steel structure support;

[0026] 2. Economizer; 201. Exhaust gas inlet; 202. Exhaust gas outlet;

[0027] 3. Hot water heat exchanger; 301. Inlet pipe; 302. Inlet manifold;

[0028] 303, heat exchange tube; 3031, straight pipe section; 3032, U-shaped bend; 3033, thermally conductive copper fin;

[0029] 304. Drainage manifold; 305. Drainage pipe;

[0030] 4. Air delivery tube. Detailed Implementation

[0031] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present utility model without creative effort are within the protection scope of the present utility model.

[0032] Example 1:

[0033] Please see Figure 1 - Figure 4 A device for recovering and reusing waste heat from low-temperature exhaust gas of a glass melting furnace includes a steel structure support 1, an economizer 2 fixedly installed inside the steel structure support 1, several hot water heat exchangers 3 fixedly installed inside the economizer 2, a gas guide pipe 4 fixedly installed on the side of the economizer 2, an exhaust gas inlet 201 provided at one end of the economizer 2, the exhaust gas inlet 201 being connected to the exhaust gas outlet of the glass melting furnace, and an exhaust gas outlet 202 provided at the other end of the economizer 2.

[0034] The hot water heat exchanger 3 includes an inlet pipe 301, an inlet manifold 302 fixed at one end of the inlet pipe 301, a plurality of heat exchange tubes 303 fixedly installed on the inlet manifold 302, a drain manifold 304 fixedly installed at the other end of the plurality of heat exchange tubes 303, and a drain pipe 305 fixedly installed on the drain manifold 304.

[0035] See Figure 1 , Figure 2 , Figure 3 Specifically, the exhaust gas inlet 201 is located at the top of the economizer 2, and the exhaust gas inlet 201 has a funnel-shaped structure.

[0036] This facilitates the smooth introduction of low-temperature exhaust gas through the exhaust gas inlet 201.

[0037] Specifically, the exhaust port 202 is located at the bottom of the economizer 2, and the exhaust port 202 is equipped with a valve.

[0038] A temperature sensor can be installed on the valve. The exhaust gas is allowed to pass only when the temperature sensor detects that the exhaust gas temperature is lower than the set value, so that the residual heat in the low-temperature exhaust gas can be effectively absorbed.

[0039] At the same time, by utilizing the principle that hot air rises and cold air falls, it is convenient for hot air to stay in the economizer 2, while cold air is discharged through the exhaust port 202.

[0040] See Figure 1 , Figure 4 Specifically, the inlet pipe 301 and the outlet pipe 305 are arranged in parallel, and the inlet manifold 302 and the outlet manifold 304 are arranged in parallel.

[0041] Specifically, the heat exchange tube 303 consists of three straight pipe sections 3031 and four U-shaped bends 3032. The four U-shaped bends 3032 and the three straight pipe sections 3031 are distributed alternately in sequence, and each straight pipe section 3031 is fixed with a heat-conducting copper sheet 3033.

[0042] Specifically, in the same hot water heat exchanger 3, the number of heat exchange tubes 303 installed is not less than eight.

[0043] This allows for the formation of more looped pipes, significantly increasing the contact area between the hot water heat exchanger 3 and the low-temperature exhaust gas. Combined with the excellent thermal conductivity of the thermally conductive copper sheet 3033, this enhances the efficiency and effectiveness of heat exchange.

[0044] See Figure 1 , Figure 2 , Figure 3 Specifically, the air duct 4 is inclined downwards, and a blower is installed at the inlet of the air duct 4.

[0045] By using a blower, gas is blown into the economizer 2 through the gas pipe 4, disturbing the low-temperature exhaust gas and increasing the contact frequency between the low-temperature exhaust gas and the hot water heat exchanger 3, thereby enhancing the heat exchange effect.

[0046] Working principle:

[0047] Low-temperature exhaust gas is introduced into economizer 2 from exhaust gas inlet 201. A blower and gas guide pipe 4 are used to disturb the low-temperature exhaust gas in economizer 2, so that the low-temperature exhaust gas can fully contact the heat exchange tube 303 in hot water heat exchanger 3 for waste heat recovery and heat exchange.

[0048] During the waste heat recovery and heat exchange process, cold water enters from the inlet pipe 301 and is split at the inlet manifold 302. The split cold water passes through different heat exchange pipes 303, absorbs heat from the outside of the heat exchange pipes 303, increases the temperature of the cold water, and forms hot water. The hot water is finally collected at the drain manifold 304 and discharged from the drain pipe 305.

[0049] In this way, the waste heat in the low-temperature exhaust gas can be converted into the heat of hot water for heating.

[0050] Example 2

[0051] Based on the above embodiment 1, further description will be made.

[0052] Specifically, in the entire waste heat recovery process of the flue gas, the flue gas flow rate is 14×104 Nm3 / h, the average winter temperature is ~155℃, and all the waste heat is used for heating. The flue gas temperature drops to about 90℃, with a heat capacity of about 3.5MW. The heating water consumption is about 150t / h. Based on a normal heating load of 50W of heat per square meter, it can provide heating for about 70,000 square meters. The remaining 68,000 square meters of heating area requires about 4.9t / h of steam to supplement (calculated based on 420℃ superheated steam being cooled to hot water below 190℃, with a heat capacity of about 3.4MW). This scheme not only saves steam consumption but also creates benefits for the enterprise.

[0053] The summary table of heating area is as follows:

[0054]

[0055] When calculating the temperature, the circulating water pump flow rate is: 1#-100*2 units + 80*1 unit; 2#-100*2 units m3 / h, and the head is 48m.

[0056] Among them, the data in serial number 1 above is the heat load value per unit heating area converted from the existing heating capacity and heating area, and the rest is the sum of the heating areas that can be achieved by calculating the heat load value per unit heating area.

[0057] Specifically, the technical performance indicators for low-temperature exhaust gas waste heat recovery operations are shown in the table below:

[0058] Serial Number name unit hot water heat exchanger 1 exhaust gas flow rate Nm3 / h 140000 2 exhaust gas inlet temperature ℃ 155 3 Final flue gas temperature ℃ 90 4 Return water temperature ℃ 50 5 water supply temperature ℃ 70 6 Rated water supply flow t / h ～150 7 Water supply quality softened water 8 Total heat exchange area M2 1722 9 Water supply pressure MPa ≥0.4 10 heat exchange base tube Material ND

[0059] Specifically, the investment budget for the low-temperature exhaust gas waste heat recovery project is as follows:

[0060] Heating revenue (total heat capacity 3.5MW, lower heating value of standard coal: 8140W / kg, equivalent to 0.43 tons / hour of standard coal, coal price calculated at 800 yuan / ton, 180 heating days per year): 0.43×24×180×800=1.486 million yuan)

[0061] Annual fixed asset depreciation (based on equipment valued at 1.6 million yuan with a depreciation period of 5 years; and civil engineering valued at 400,000 yuan with a depreciation period of 15 years): 1.6 million / 1.13 / 5 + 400,000 / 1.09 / 15 = 307,000 yuan

[0062] Annual increase in benefits: approximately 148.6 - 30.7 = 117.9 million yuan

[0063] Payback period (planned investment of 2 million yuan): 200 / 117.9≈1.69 years, which is two heating seasons.

[0064] In summary, when the low-temperature exhaust gas waste heat recovery and reuse device for glass melting furnaces is in use, the waste heat generated by the flue gas from the glass production line can be turned into a valuable resource. The hot water produced by the waste heat can be used for winter heating. After the device is built and put into operation, it can save up to 3,510 tons of standard coal per year (based on 330 days of operation per year) and reduce CO2 emissions by 9,477 tons per year, demonstrating the practicality and economic value of the low-temperature exhaust gas waste heat recovery and reuse device for glass melting furnaces.

[0065] The above description is merely a preferred embodiment of this utility model; however, the protection scope of this utility model is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the technical scope disclosed in this utility model, based on the technical solution and its improved concept, should be included within the protection scope of this utility model.

Claims

1. A low-temperature tail gas waste heat recovery and recycling device for a glass melting furnace, comprising a steel structure support (1), characterized in that: An economizer (2) is fixedly installed inside the steel structure support (1). Several hot water heat exchangers (3) are fixed inside the economizer (2). A gas guide pipe (4) is fixedly installed on the side of the economizer (2). A tail gas inlet (201) is provided at one end of the economizer (2), which is connected to the tail gas outlet of the glass melting furnace. A tail gas discharge outlet (202) is provided at the other end of the economizer (2). The hot water heat exchanger (3) includes an inlet pipe (301), one end of which is fixed to an inlet manifold (302), and several heat exchange tubes (303) are fixedly installed on the inlet manifold (302). The other ends of the several heat exchange tubes (303) are jointly fixed to a drain manifold (304), and a drain pipe (305) is fixedly installed on the drain manifold (304).

2. The device for recovering and reusing waste heat from low-temperature tail gas of a glass melting furnace according to claim 1, characterized in that: The exhaust gas inlet (201) is located at the top of the economizer (2), and the exhaust gas inlet (201) has a funnel-shaped structure.

3. The device for recovering and reusing waste heat from low-temperature tail gas of a glass melting furnace according to claim 1, characterized in that: The exhaust port (202) is located at the bottom of the economizer (2), and the exhaust port (202) is equipped with a valve.

4. The device for recovering and reusing waste heat from low-temperature tail gas of a glass melting furnace according to claim 1, characterized in that: The inlet pipe (301) and the outlet pipe (305) are arranged in parallel, and the inlet manifold (302) and the outlet manifold (304) are arranged in parallel.

5. The device for recovering and reusing waste heat from low-temperature tail gas of a glass melting furnace according to claim 1, characterized in that: The heat exchange tube (303) consists of three straight pipe sections (3031) and four U-shaped bends (3032). The four U-shaped bends (3032) and the three straight pipe sections (3031) are distributed in sequence at intervals. Each straight pipe section (3031) is fixed with a heat-conducting copper sheet (3033).

6. The device for recovering and reusing waste heat from low-temperature tail gas of a glass melting furnace according to claim 1, characterized in that: In the same hot water heat exchanger (3), the number of heat exchange tubes (303) installed shall not be less than eight.

7. The device for recovering and reusing waste heat from low-temperature tail gas of a glass melting furnace according to claim 1, characterized in that: The air duct (4) is inclined downward, and a blower is installed at the opening of the air duct (4).

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