Method for recovering heat energy of copper-clad plate factory

Abstract

The invention provides a method for recovering heat energy of a copper-clad plate factory, and belongs to the technical field of heat energy recovery. The countercurrent heat exchange is performed on the organic waste gas and the fresh air, so that the heat of the waste gas generated by the copper-clad plate glass fabric coating machine can be exchanged to the fresh air, the obtained hot air can be directly used as a heat source and can replace heat energy generated by conventional organic waste gas combustion, the organic waste gas does not need to be combusted, and the environment is protected. Pollution caused by combustion of organic waste gas is reduced; cooling waste gas generated by countercurrent heat exchange is absorbed, organic pollutants in organic waste gas can be removed, discharged tail gas has few pollutants, and the problem of environmental pollution caused by organic waste gas emission is solved; moreover, countercurrent heat exchange is utilized, the heat exchange efficiency is high, and heat in the organic waste gas can be fully recycled.

Description

Technical Field

[0001] The present invention relates to the technical field of heat energy recovery, and in particular to a method for heat energy recovery in a copper clad laminate factory. Background Art

[0002] During the production process of a copper clad laminate glass fiber cloth coater, a large amount of high-temperature organic waste gas is generated. The temperature of the high-temperature organic waste gas is about 150 °C. If this heat energy is directly dissipated into the air and cannot be well collected, it will cause waste of resources. Currently, the main method for treating high-temperature organic waste gas is to send it to an incinerator for incineration, and the heat generated by incineration is used to heat the heat transfer oil and reused for oven heating. However, since the heat energy generated by the combustion of the organic part of the organic waste gas is much greater than the heat energy required by the oven, the excess heat energy is dissipated and wasted, resulting in a great waste of energy and resources; moreover, a large amount of nitrogen oxides and the like generated by the combustion of the organic waste gas have an adverse impact on the environment.

[0003] Therefore, there is an urgent need to provide a method for heat energy recovery in a copper clad laminate factory with low pollution and high heat energy utilization rate. Summary of the Invention

[0004] The purpose of the present invention is to provide a method for heat energy recovery in a copper clad laminate factory with low pollution and high heat energy utilization rate.

[0005] In order to achieve the above-mentioned invention purpose, the present invention provides the following technical solutions:

[0006] The present invention provides a method for heat energy recovery in a copper clad laminate factory, including the following steps:

[0007] (1) Performing countercurrent heat exchange on the organic waste gas and fresh air to obtain cooled waste gas and hot air; the organic waste gas is the waste gas generated by a copper clad laminate glass fiber cloth coater;

[0008] (2) Performing absorption treatment on the cooled waste gas obtained in step (1) and then discharging it;

[0009] (3) Using the hot air obtained in step (1) as a heat source for application.

[0010] Preferably, in step (1), the temperature of the organic waste gas is 145 - 155 °C.

[0011] Preferably, in step (1), the temperature of the fresh air is 20 - 35 °C.

[0012] Preferably, in step (1), the ratio of the air volume of the organic waste gas to the air volume of the fresh air is (7000 - 8000) : (5500 - 6500).

[0013] Preferably, in step (1), the ratio of the air volume of the organic waste gas to the air volume of the fresh air is (7500 - 8000) : (6000 - 6500).

[0014] Preferably, the temperature of the cooled waste gas in step (1) is 50 - 60 °C.

[0015] Preferably, the temperature of the hot air in step (1) is 120 - 130 °C.

[0016] Preferably, the absorption treatment method in step (2) includes: adsorbing the cooled waste gas in an adsorbent and discharging the adsorbed tail gas.

[0017] Preferably, the adsorbent includes ethylene glycol diacetate, N-methylpyrrolidone, propylene glycol methyl ether, or dimethyl sulfoxide.

[0018] Preferably, the method applied in step (3) includes heating fresh air for a boiler.

[0019] The present invention provides a method for heat energy recovery in a copper clad laminate factory, which includes the following steps: performing countercurrent heat exchange on organic waste gas and fresh air to obtain cooled waste gas and hot air; the organic waste gas is the waste gas generated by a copper clad laminate glass fiber cloth coater; discharging the cooled waste gas after absorption treatment; and applying the hot air as a heat source. The present invention adopts countercurrent heat exchange of organic waste gas and fresh air, which can transfer the heat of the waste gas generated by the copper clad laminate glass fiber cloth coater to the fresh air, and the obtained hot air can be directly used as a heat source, which can replace the heat energy generated by the combustion of conventional organic waste gas, without burning the organic waste gas, reducing the pollution generated by the combustion of organic waste gas; the present invention performs absorption treatment on the cooled waste gas generated by countercurrent heat exchange, which can remove organic pollutants in the organic waste gas, making the discharged tail gas have fewer pollutants, and solving the environmental pollution problem caused by the emission of organic waste gas; moreover, the present invention uses countercurrent heat exchange with high heat exchange efficiency, which can fully recover the heat in the organic waste gas. The results of the examples show that the heat exchange efficiency of the method provided by the present invention is 81%, which can significantly improve the energy utilization efficiency of the production process and reduce the thermal pollution and organic waste gas pollution to the environment. Detailed Embodiments

[0020] The present invention provides a method for heat energy recovery in a copper clad laminate factory, which includes the following steps:

[0021] (1) Performing countercurrent heat exchange on organic waste gas and fresh air to obtain cooled waste gas and hot air; the organic waste gas is the waste gas generated by a copper clad laminate glass fiber cloth coater;

[0022] (2) Discharging the cooled waste gas obtained in step (1) after absorption treatment;

[0023] (3) Applying the hot air obtained in step (1) as a heat source.

[0024] The present invention performs countercurrent heat exchange between organic waste gas and fresh air to obtain cooled waste gas and hot air.

[0025] In the present invention, the organic waste gas is the waste gas generated by a copper clad laminate fiberglass cloth coater. The present invention has no special limitation on the specific composition and type of the waste gas generated by the copper clad laminate fiberglass cloth coater, and any waste gas generated by the copper clad laminate fiberglass cloth coater that can be collected by those skilled in the art can be used.

[0026] In the present invention, the temperature of the organic waste gas is preferably 145 - 155°C, more preferably 150 - 155°C. The organic waste gas used in the present invention is the waste gas generated by a copper clad laminate fiberglass cloth coater, and its temperature is within the above range, having a relatively high temperature, and the recovered heat can be used for heating, improving the utilization efficiency of heat.

[0027] In the present invention, the fresh air is preferably air, and the temperature of the fresh air is preferably 20 - 35°C, more preferably 25 - 30°C. Using air at the above temperature as fresh air in the present invention to obtain hot air by means of a heat exchanger is environmentally friendly.

[0028] In the present invention, the air volume ratio of the organic waste gas to the fresh air is preferably (7000 - 8000) : (5500 - 6500), more preferably (7500 - 8000) : (6000 - 6500). Controlling the air volume ratio of the organic waste gas to the fresh air within the above range in the present invention can fully transfer the heat of the organic waste gas to the fresh air.

[0029] In the present invention, the device for countercurrent heat exchange is preferably a gas-gas heat exchanger. The present invention has no special limitation on the model of the gas-gas heat exchanger. Using a conventional gas-gas heat exchanger can ensure that the air volumes of the organic waste gas and the fresh air are within the above range. Through countercurrent heat exchange in the present invention, the heat exchange efficiency can be improved, enabling the heat of the organic waste gas to be fully transferred to the fresh air to obtain high-temperature hot air. In the embodiments of the present invention, the model of the gas-gas heat exchanger can be a shell and tube heat exchanger or a plate heat exchanger.

[0030] The present invention has no special limitation on the operation method of the countercurrent heat exchange. It is only necessary to transport the organic waste gas and the fresh air to the countercurrent heat exchange device in a countercurrent manner. In the embodiments of the present invention, the operation method of the countercurrent heat exchange can be: collecting and transporting the organic waste gas through a pipeline by an induced draft fan to the hot side of the countercurrent heat exchange device, and transporting the fresh air into the cold side of the countercurrent heat exchange device; the hot side and the cold side of the countercurrent heat exchange device can enable the organic waste gas and the fresh air to achieve countercurrent heat exchange.

[0031] In the present invention, the temperature of the cooled waste gas is preferably 50 - 60°C, more preferably 55 - 60°C.

[0032] In the present invention, the temperature of the hot air is preferably 120-130 °C, more preferably 125-130 °C. By performing countercurrent heat exchange between the organic waste gas and fresh air, the present invention can reduce the temperature of the organic waste gas at 145-155 °C to 50-60 °C, and increase the temperature of the fresh air at 20-35 °C to 120-130 °C, achieving the recovery of the heat of the organic waste gas.

[0033] After obtaining the cooled waste gas, the present invention performs absorption treatment on the cooled waste gas and then discharges it.

[0034] In the present invention, the method of the absorption treatment preferably includes: adsorbing the cooled waste gas in an adsorbent and discharging the adsorbed tail gas.

[0035] The present invention has no special limitation on the operation method of the adsorption. It is only necessary to introduce the cooled waste gas into the adsorbent.

[0036] In the present invention, the adsorbent preferably includes ethylene glycol diacetate, N-methylpyrrolidone, propylene glycol methyl ether or dimethyl sulfoxide, more preferably ethylene glycol diacetate, N-methylpyrrolidone or propylene glycol methyl ether. Through the above adsorbent, the present invention can adsorb the organic gas in the cooled waste gas, making the tail gas meet the emission standard. In the present invention, the emission standard preferably conforms to the environmental protection standard GB16297-1996.

[0037] In the present invention, when the adsorbed tail gas does not meet the standard, the present invention preferably reintroduces the unqualified tail gas into the adsorbent for adsorption until the tail gas meets the standard and then discharges it.

[0038] After obtaining the hot air, the present invention uses the hot air as a heat source.

[0039] In the present invention, the method of the application preferably includes heating fresh air for a boiler. By using the recovered heat to heat the fresh air for the boiler, the present invention can reduce the thermal energy required to heat the cold air.

[0040] The method provided by the present invention can recover the heat of the organic waste gas, exchange it into high-temperature hot air, and the high-temperature hot air can supply heat without further combustion, reducing the pollution problem caused by direct combustion of the organic waste gas; after the heat of the organic waste gas is exchanged into fresh air, although the heat in the obtained cooled waste gas is relatively low, it still contains organic pollutants. By performing absorption treatment on the cooled waste gas and then discharging it, the pollution of the organic pollutants to the environment can be reduced.

[0041] The technical solutions in the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the scope of protection of the present invention.

[0042] Embodiment 1

[0043] A method for heat energy recovery in a copper clad laminate factory, the steps are as follows:

[0044] (1) The waste gas generated by the copper clad laminate fiberglass cloth coater is collected by an induced draft fan through a pipeline and transported to the hot side of the gas-gas heat exchanger. Fresh air is input from the outside to the cold side of the gas-gas heat exchanger, and then countercurrent heat exchange is carried out to obtain cooled waste gas and hot air;

[0045] Among them, the air volume of the organic waste gas is 8000 m 3 / h, and the temperature of the organic waste gas is 150 °C; the air volume of the fresh air is 6500 m 3 / h, and the temperature of the fresh air is 35 °C; the temperature of the cooled waste gas is 55 °C, and the temperature of the hot air is 130 °C;

[0046] (2) The cooled waste gas obtained in step (1) is introduced into ethylene glycol diacetate for adsorption, so that the tail gas meets the environmental protection standard GB16297-1996 and is discharged into the atmosphere;

[0047] (3) The hot air obtained in step (1) is transported to the gas boiler of the process equipment that needs heating to provide the required heat energy;

[0048] Calculation of the heat exchange efficiency of this embodiment:

[0049] Specific heat capacity of organic waste gas: C p = 1.005 kJ / kg·C (air);

[0050] Density of organic waste gas: ρ = 1.2 kg / m 3 ;

[0051] Specific heat capacity of fresh air: C p = 1.005 kJ / kg·C (air);

[0052] Density of fresh air: ρ = 1.2 kg / m 3 ;

[0053] 1. Calculation of waste gas mass flow:

[0054] m˙waste gas = ρ × air volume of waste gas

[0055] waste gas = 1.2 kg / m 3 × 8000 m3 / h = 9600 kg / h;

[0056] 2. Fresh air mass flow rate calculation:

[0057] ṁfresh air = ρ × fresh air volume flow rate;

[0058] ṁfresh air = 1.2 kg / m 3 × 6500 m 3 / h = 7800 kg / h;

[0059] 3. Exhaust gas heat exchange quantity calculation:

[0060] Qexhaust gas = ṁexhaust gas × C p × ΔTexhaust gas

[0061] ΔTexhaust gas = 150 °C - 55 °C = 95 °C

[0062] Qexhaust gas = 9600 kg / h × 1.005 kJ / kg·°C × 95 °C = 919,680 kJ / h;

[0063] 4. Fresh air heat exchange quantity calculation:

[0064] Qfresh air = ṁfresh air × C p × ΔTfresh air

[0065] ΔTfresh air = 130 °C - 35 °C = 95 °C

[0066] Qfresh air = 7800 kg / h × 1.005 kJ / kg·°C × 95 °C = 744,435 kJ / h

[0067] 5. Heat exchanger efficiency calculation:

[0068] The calculation formula for the heat exchanger efficiency η is:

[0069] η = Qfresh air / Qexhaust gas

[0070] η = 744,435 kJ / h / 919,680 kJ / h ≈ 0.81

[0071] From this calculation, the efficiency of the heat exchanger is approximately 81%.

[0072] Example 2

[0073] A method for heat energy recovery in a copper clad laminate factory, the steps are:

[0074] (1) Collect the exhaust gas generated by the copper clad laminate fiberglass cloth coater through a pipeline by an induced draft fan and transport it to the hot side of the air-air heat exchanger, input fresh air from the outside to the cold side of the air-air heat exchanger, and then conduct countercurrent heat exchange to obtain cooled exhaust gas and hot air;

[0075] Among them, the air volume of the organic waste gas is 7000 m 3 / h, and the temperature of the organic waste gas is 145 °C; the air volume of the fresh air is 5500 m 3 / h, and the temperature of the fresh air is 30 °C; the temperature of the cooled waste gas is 55 °C, and the temperature of the hot air is 120 °C;

[0076] (2) Pass the cooled waste gas obtained in the step (1) into ethylene glycol diacetate for adsorption, so that the tail gas reaches the national environmental protection standard GB16297-1996 and is discharged into the atmosphere;

[0077] (3) Transport the hot air obtained in the step (1) to the gas boiler of the process equipment that needs to be heated to provide the required heat energy;

[0078] Calculation of the heat exchange efficiency of this embodiment:

[0079] Specific heat capacity of organic waste gas: C p = 1.005 kJ / kg·°C (air);

[0080] Density of organic waste gas: ρ = 1.2 kg / m 3 ;

[0081] Specific heat capacity of fresh air: C p = 1.005 kJ / kg·°C (air);

[0082] Density of fresh air: ρ = 1.2 kg / m 3 ;

[0083] 1. Calculation of the waste gas mass flow rate:

[0084] ṁwaste gas = ρ × air volume of waste gas

[0085] ṁwaste gas = 1.2 kg / m 3 × 8000 m 3 / h = 9600 kg / h;

[0086] 2. Calculation of the fresh air mass flow rate:

[0087] ṁfresh air = ρ × air volume of fresh air;

[0088] ṁfresh air = 1.2 kg / m 3 × 6500 m 3 / h = 7800 kg / h;

[0089] 3. Calculation of the waste gas heat exchange amount:

[0090] Qwaste gas = ṁwaste gas × C p × ΔTwaste gas;

[0091] ΔTwaste gas = 145 °C - 55 °C = 90 °C;

[0092] Q exhaust gas = 9600 kg / h × 1.005 kJ / kg·°C × 90 °C = 868320 kJ / h;

[0093] 4. Calculation of fresh air heat exchange quantity:

[0094] Q fresh air = ṁ fresh air × C p × ΔT fresh air

[0095] ΔT fresh air = 120 °C - 30 °C = 90 °C

[0096] Q fresh air = 7800 kg / h × 1.005 kJ / kg·°C × 90 °C = 705510 kJ / h

[0097] 5. Calculation of heat exchanger efficiency:

[0098] The calculation formula for the heat exchanger efficiency η is:

[0099] η = Q fresh air / Q exhaust gas

[0100] η = 705510 kJ / h / 868320 kJ / h ≈ 0.81

[0101] From this calculation, the efficiency of the heat exchanger is approximately 81%.

[0102] It can be seen from the results of the embodiments that the method provided by the present invention can effectively recover the waste heat of the waste gas of the copper clad laminate fiberglass cloth coater and use it to heat fresh air, achieving the expected heating effect and energy saving goal. Calculations show that the heat exchange efficiency of the heat exchanger is 81 - 99%, the system runs reliably, can significantly improve the energy utilization efficiency of the production process, and reduce the thermal pollution to the environment.

[0103] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A method for heat recovery in a copper clad laminate plant, comprising the following steps: (1) performing countercurrent heat exchange on organic waste gas and fresh air to obtain cooling waste gas and hot air; the organic waste gas is waste gas generated by a copper-clad laminate glass fiber cloth coating machine; (2) absorbing and treating the cooling waste gas obtained in step (1) and then discharging it; (3) Using the hot air obtained in step (1) as a heat source.

2. The method for heat recovery in a copper clad laminate plant according to claim 1, characterized in that: The temperature of the organic waste gas in step (1) is 145-155°C.

3. The method for heat recovery in a copper clad laminate plant according to claim 1, characterized in that: The temperature of the fresh air in step (1) is 20-35°C.

4. The method for heat recovery in a copper clad laminate plant according to claim 1, characterized in that: In the step (1), the ratio of the air volume of the organic waste gas to the fresh air is (7000-8000): (5500-6500).

5. The method for heat recovery in a copper clad laminate plant according to claim 1, characterized in that: In the step (1), the ratio of the air volume of the organic waste gas to the fresh air is (7500-8000): (6000-6500).

6. The method for heat recovery in a copper clad laminate plant according to claim 1, characterized in that: The temperature of the cooling exhaust gas in step (1) is 50-60°C.

7. The method for heat recovery in a copper clad laminate plant according to claim 1, characterized in that: The temperature of the hot air in step (1) is 120-130°C.

8. The method for heat recovery in a copper clad laminate plant according to claim 1, characterized in that: The absorption treatment method in step (2) comprises: adsorbing the cooled exhaust gas in an adsorbent and discharging the adsorbed exhaust gas.

9. The method for heat recovery in a copper clad laminate plant according to claim 8, characterized in that: The adsorbent includes ethylene glycol diacetate, N-methylpyrrolidone, propylene glycol methyl ether or dimethyl sulfoxide.

10. The method for heat recovery in a copper clad laminate plant according to claim 8, characterized in that: The method used in step (3) includes heating fresh air for boilers.