CN108072274A - A kind of high-efficiency heat-accumulating tubular heater system - Google Patents

Abstract

The invention discloses a high-efficiency regenerative tubular heating furnace system, relates to the technical field of tubular heating furnaces and energy saving and emission reduction, and is used to solve the problem of low thermal efficiency, short service life, poor stability and system investment of existing tubular heating furnaces. Advanced problem, the present invention includes tubular furnace body, burner, regenerator, four-way reversing valve, blower, induced draft fan, air distribution valve and flame detector etc. The left and right regenerators exchange heat with the corresponding regenerators respectively, raising the temperature of the combustion air to above 300°C, and the exhaust gas passes through the corresponding regenerators periodically, and the temperature gradually drops to 130°C after exchanging heat with the corresponding regenerators The left and right are exhausted by the induced draft fan, and the air and exhaust gas are periodically exchanged in the left and right double regenerators respectively to achieve high efficiency and stability of combustion. At the same time, the traditional convection section is omitted, and the exhaust gas temperature is reduced and the thermal efficiency is improved, making the comprehensive investment of the tube furnace the lowest. Save and prolong service life.

Description

A high-efficiency regenerative tubular heating furnace system

technical field

The invention discloses a high-efficiency regenerative tubular heating furnace system, relates to the technical field of tubular heating furnaces and energy saving and emission reduction, and specifically discloses a high-efficiency and stable two-way double-circuit regenerative tubular heating furnace.

Background technique

Tubular heating furnace is a process heating furnace widely used in petroleum refining, petrochemical and coal chemical industries. The flow medium of the heated material in the tube is gas or liquid, and they are all flammable and explosive substances. The operating conditions are harsh. At the same time, it operates continuously for a long period of time, and the heating method is directly exposed to fire. The exhaust gas temperature of the tubular heating furnace can be reduced to about 100°C to realize partial condensation of the acid-containing water vapor in the flue gas, and while recovering the low-temperature sensible heat of the flue gas, part of the latent heat of vaporization of the acid-containing water vapor can be recovered, further Improve the thermal efficiency of the heating furnace and save energy.

In the prior art, there are many documents about tubular heating furnaces. For example, the invention of application number 201520869189.8 discloses a high-efficiency tubular heating furnace with uniform heating, including a tubular furnace body. It is characterized in that the tubular furnace body is equipped with Combustion chamber and heat exchange chamber, one end of the tubular furnace body is the entrance of the combustion chamber connected with the combustion chamber, the other end of the tubular furnace body is the smoke outlet connected with the combustion chamber, and the tubular furnace body near the entrance of the combustion chamber A heated medium outlet is provided on the furnace body, and a heated medium inlet is provided on the tubular furnace body near the smoke exhaust port; the heat exchange chamber communicates with the heated medium inlet and the heated medium outlet; the combustion chamber includes a combustion chamber Combustion chamber and inner combustion chamber, the outer combustion chamber is sleeved on the inner wall of the tubular furnace body, the bottom of the inner combustion chamber and the outer combustion chamber communicate with each other, the top of the inner combustion chamber and the outer combustion chamber are connected to the exhaust The smoke port is connected; a heat exchange chamber for medium heating is formed between the inner combustion chamber and the outer combustion chamber; the inner wall of the outer combustion chamber is provided with a first spiral deflector, and the outer wall of the inner combustion chamber is A second helical baffle with a helical direction opposite to that of the first helical baffle is provided.

The invention patent with application number 201110459125.7 discloses a waste heat recovery system for tubular heating furnaces, which includes a blower, a pre-heater and an air pre-heater. The pre-heater is set at the inlet or outlet of the blower. The outlet of the preheater is connected to the inlet of the air preheater. After passing through the blower, the cold air enters the preheater, is heated by the preheater and then discharged, and finally enters the air preheater; the preheater is Finned tube heat exchanger or tube bundle heat exchanger; the heat source in the preheater is hot water or steam.

However, although the existing tubular heating furnaces add some pre-heaters and heat exchangers in the utilization of exhaust waste heat or set up a turbulent flow heat exchange chamber and a heat exchange chamber between the combustion chamber and the heat exchange chamber, they all For indirect heat exchange, the heat exchange area is limited, the pipeline is easy to scale, and the heat energy utilization rate is not high. The regenerative tubular heating furnace uses the regenerator to absorb the waste heat of the exhaust gas to directly heat the combustion air, direct heating, and adopts two-way double-circuit Regenerator, stable combustion, high utilization rate of heat energy, small footprint per unit load tube furnace, low comprehensive investment and long service life.

Contents of the invention

Under the condition of ensuring stable combustion, the present invention maximizes the utilization rate of heat energy of the tubular heating furnace, and provides a high-efficiency regenerative tubular heating furnace, which can change the waste heat of tail gas from indirect heat exchange to direct heat exchange. The heat exchange tube or heat exchange chamber is changed to a regenerator, and a two-way double-circuit regenerator is adopted. The periodic heat exchange between the combustion air and the exhaust gas is realized in the regenerator through the control system, and the waste heat of the exhaust gas is fully utilized.

In order to solve the problems of the technologies described above, the technical scheme that the present invention takes is:

A high-efficiency regenerative tubular heating furnace system includes a tubular furnace body, a burner, a regenerator, a four-way reversing valve, a blower, an induced draft fan, an air distribution valve, and a flame detector. The combustion-supporting air required by the combustion of the type heating furnace system and the exhaust gas produced are respectively exchanged periodically in the two-way double-circuit regenerator to realize heat exchange, that is, the left and right directions, and each direction is a double-circuit regenerator to realize a separate Exchange; the combustion-supporting air on the left is periodically blown into the regenerator on the left by the exhaust gas heat exchange through the blower, so that the temperature of the combustion-supporting air rises from room temperature to above 300 ° C, and the exhaust gas on the left passes through the induced draft fan periodically from the other to the left. In the regenerator where the combustion air cools down, the temperature of the exhaust gas is gradually reduced to about 130°C and discharged; the combustion air on the right is periodically blown into the regenerator on the right by the blower, so that the temperature of the combustion air rises from room temperature to Above 300°C, the exhaust gas on the right is periodically discharged from another regenerator on the right which is cooled by the combustion air through the induced draft fan, and the temperature of the exhaust gas gradually drops to about 130°C; The heat chamber undergoes a certain period of reversing operation, repeated cycles, to achieve energy-saving effects; the gas is not exchanged, and the exchange time of the combustion-supporting air and exhaust gas in the left and right regenerators is staggered, so that the combustion system is stable; the burner adopts the diffusion combustion method, and the air Gas and gas are sprayed into the furnace separately to avoid tempering, increase the range of combustion adjustment, and use the difference in air and gas flow rates to increase the mixing speed of air and gas to ensure the completeness of combustion; remote control automatically starts or stops related equipment according to the process sequence; set up related safety Interlocking to ensure the safe operation of the tube heating furnace system.

The combustion-supporting air and exhaust gas are periodically exchanged in the regenerators on the left and right sides respectively, and both pass through the four-way reversing valve, which is automatically controlled by the set program, that is, the control program automatically controls the time interval of the periodic exchange and the sequence of each valve switch. order.

The combustion-supporting air and exhaust gas are exchanged at different times in the left and right regenerators, that is, the time for changing the combustion-supporting air and exhaust gas in and out of the left and right regenerators is different, so as to reduce the fluctuation of the combustion system, and when one side fails, it does not affect the other side. run.

The gas is not exchanged, that is, the gas does not pass through the regenerator, but directly enters the burner, so that the combustion is stable.

The regenerator adopts a mullite ceramic regenerator with strong heat storage capacity. The exhaust gas and combustion-supporting air directly enter the regenerator and directly contact with the regenerator. The heat is transferred to the regenerator mainly through heat conduction and heat radiation. The heat chamber and the regenerator transfer heat to the combustion air. Because the regenerator is equipped with an anti-blocking hole pattern, it can prevent blockage and be easy to clean. It is equipped with an anti-blocking layer and anti-sticking paint.

The burner of the regenerative tubular heating furnace adopts the diffusion combustion method, and the air and gas are sprayed into the furnace respectively, which can avoid tempering and increase the range of combustion adjustment; it is designed with high gas flow rate and low air flow rate, so that it can be used The difference in flow velocity increases the mixing velocity of air and gas to ensure the completeness of combustion.

The blower, induced draft fan, four-way reversing valve and flame detector are remotely controlled and monitored and automatically started or stopped according to the process sequence, so that the combustion-supporting air and exhaust gas are periodically reversed in the left and right regenerators, and controlled by the control program Adjust and control the relevant parameters such as temperature, flow and pressure of the tube heating furnace.

The regenerative tubular heating furnace is equipped with large fire and small fire flame detection signals to monitor the flame situation, and the safety of the system is ensured through relevant safety interlocking devices.

The traditional tubular furnace and the high-efficiency regenerative tubular heating furnace can be switched for use, and even if the regenerator breaks down, the furnace body itself can produce normally.

Compared with the prior art, the present invention has the following beneficial effects:

The high-efficiency regenerative tubular heating furnace has high reversing efficiency and strong heat storage and heat exchange capacity, which can greatly improve energy utilization. After heat exchange, the exhaust gas temperature is 250°C to 300°C lower than that of traditional tubular furnace exhaust gas, which is lower than that of metal The exhaust gas temperature of the heat exchange furnace is 120°C to 200°C lower.

The regenerator has a long service life and low cost. The regenerator does not have the problems of being oxidized, scaling and reducing the heat transfer efficiency. Metal heat exchangers generally have the above problems after 3 months of use, and they basically disappear after 3 years. Nothing works anymore.

The high-efficiency regenerative tubular heating furnace reduces the convection section, the conduction section, and also reduces the air heat exchanger, steam evaporator, corresponding piping, electric control and other facilities. Under the same load condition, the energy saving can reach more than 30%. System investment is reduced by 30%.

The high-efficiency regenerative tubular heating furnace has stable combustion. During the exchange process, the two-way double-circuit passes through the regenerator, and the gas does not switch, and once a failure occurs on one side, it will not affect production.

The high-efficiency regenerative tubular heating furnace has a high level of automation. Through program control, automatic exchange and automatic adjustment of related parameters are realized, which is safe and reliable.

Description of drawings

Figure 1 is a schematic diagram of the workflow related to the invention.

Marks in the figure: 1-tube furnace body, 2-chimney, 3-high temperature four-way reversing valve, 4-regenerator, 5-burner, 6-small fire detector, 7-high fire detector, 8- Low temperature four-way reversing valve, 9-air distribution valve, 10-induced fan, 11-blower, 12-gas inlet.

Detailed ways

The technical solutions in the present invention will be further described below in conjunction with the accompanying drawings and embodiments.

In conjunction with the accompanying drawings, the present invention provides a high-efficiency regenerative tubular heating furnace system, including 1-tube furnace body, 2-chimney, 3-high temperature four-way reversing valve, 4-regenerator, 5-burner, 6-small fire detector, 7-high fire detector, 8-low temperature four-way reversing valve, 9-air distribution valve, 10-induced fan, 11-blower, 12-gas inlet; the tubular heating furnace system burns through the gas It is mixed with combustion-supporting air at the burner 5, and the heated medium is heated in the tube furnace body 1, and the exhaust gas generated is passed through the chimney 2 through the high-temperature four-way reversing valve 3, through the regenerator 4 and the low-temperature four-way reversing valve 8 Exhausted by the induced draft fan 11, the combustion-supporting air passes through the blower 11 through the low-temperature four-way reversing valve 8 to the regenerator 4 and enters the burner 5 through the high-temperature four-way reversing valve 3, and the gas directly enters the burner through the gas inlet 12 and mixes with air Post-combustion: the combustion-supporting air and the exhaust gas are respectively passed through the high-temperature four-way reversing valve 3 and the low-temperature four-way reversing valve 8 in the two-way double-circuit regenerator, and are controlled by the control system to exchange periodically to realize heat exchange, that is, the left and right two Each direction is a double-circuit regenerator, which realizes separate exchange; the combustion air on the left is periodically blown into a regenerator on the left through the blower 11, which has been heat-exchanged by the exhaust gas, so that the temperature of the combustion air rises from the room temperature. When the temperature reaches above 300°C, the exhaust gas on the left is periodically discharged from another regenerator on the left through the induced draft fan 10, and the temperature of the exhaust gas is gradually reduced to about 130°C; the combustion air on the right is periodically blown into the right one by the blower 11 The regenerator after exhaust gas heat exchange raises the temperature of the combustion-supporting air from room temperature to above 300°C, and the exhaust gas on the right passes through the induced draft fan 10 periodically from the other regenerator on the right that is cooled by the combustion-supporting air, and the temperature of the exhaust gas gradually drops to Discharge at about 130°C; the gas is not exchanged, and the exchange time of the combustion-supporting air and exhaust gas in the left and right regenerators is staggered, that is, the left regenerator is exchanged for a period of time, and the right regenerator is exchanged again, and the right regenerator is exchanged for a period of time After that, the left side is exchanged again, and the burner burns stably. Air distribution valve 9 is responsible for the distribution of combustion-supporting air and exhaust gas volume on both sides. The small fire detector 6 monitors the small fire signal, and the large fire detector 7 monitors the large fire signal, forming a safety interlock with the gas shut-off valve and other equipment.

The burner 5 adopts the diffusion combustion method, and the air and gas are sprayed into the furnace separately, which can avoid tempering, increase the range of combustion adjustment, and use the difference in air and gas flow rates to increase the mixing speed of air and gas to ensure complete combustion.

Remote control of blower 11, induced draft fan 10, low-temperature four-way reversing valve 8 and high-temperature four-way reversing valve 3, etc., and automatically start or stop according to the process sequence setting program; air distribution valve 9 controls the combustion air and gas volume of the left and right circuits The distribution of the two sides is adjusted through the valve opening; the system realizes the automatic chain control of the whole set of equipment through the temperature, pressure, flow and flame detector signal collection; the four-way reversing valve fails, there is no normal switch, the program automatically cuts off the gas , the blower continues to blow, and when the fault cannot be eliminated in a short time, it is switched to single-valve group operation, which can ensure the normal use of the tube furnace.

If the exhaust gas temperature is too high and the regenerator temperature is abnormal, the reversing time or the gas volume will be adjusted automatically, the blower and induced draft fan signal feedback will be interrupted, and the program will automatically cut off the gas. When the main gas pressure is too low, the system will automatically alarm and cut off the main gas; In the event of blower failure or electrical failure, the gas is shut off.

The tail gas of the regenerative tubular heating furnace of the present invention directly enters the regenerator, directly contacts with the regenerator, and transfers heat to the regenerator mainly through heat conduction and heat radiation, so that the regenerator absorbs heat and the temperature of the regenerator As the exhaust gas temperature rises, the temperature of the exhaust gas decreases; the combustion air also directly enters the regenerator, directly contacts with the regenerator, and directly absorbs the heat of the regenerator through heat conduction and heat radiation, the temperature of the regenerator decreases, and the temperature of the combustion air rises. high.

The utility model adopts a mullite ceramic regenerator with strong heat storage capacity and anti-blocking hole type, which has long service life, low cost, and resistance to shock and heat; the regenerator does not have oxidation and scaling to reduce heat exchange efficiency Reduce the problem; the regenerator is equipped with heat preservation function, with heat-resistant steel lining inside; it is equipped with anti-displacement function (high temperature heat-resistant steel).

The invention has its own platform and stairs, which is convenient for operation and maintenance; the fire door, explosion-proof door and various instrumentation equipment of the tubular furnace have special maintenance platforms, which are simple and easy to operate; the heat insulation layer of the furnace body is mainly used. Stone casting material and aluminum silicate fiber felt, which can withstand the temperature of 1300 ℃; the coil support uses 1100 ℃ heat-resistant steel castings, which can stably support the coil without accidents.

The above description is only an embodiment of the present invention, and is not intended to limit the present invention. It should be pointed out that any changes, substitutions or improvements that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention are all Should be covered within the protection scope of the present invention.

Claims (9)

1. A high-efficiency regenerative tubular heating furnace system comprises a tubular furnace body, a burner, a regenerator, a four-way reversing valve, a blower, an induced draft fan, an air distribution valve and a flame detector, and is characterized in that the tube The combustion-supporting air required by the combustion of the type heating furnace device and the tail gas generated are periodically exchanged in the double-circuit double regenerator to realize heat exchange, and the combustion-supporting air is periodically blown into the left and right regenerators after heat exchange by the exhaust gas through the blower. , so that the temperature of the combustion-supporting air rises from room temperature to above 300°C; the exhaust gas passes through the induced draft fan periodically from the left and right corresponding to the regenerator cooled by the combustion-supporting air, and the temperature of the exhaust gas gradually drops to about 130°C and is discharged, the combustion-supporting air and exhaust gas Two-way double-circuit entry and exit are respectively realized, and the left and right regenerators are controlled by the program through the four-way reversing valve to realize periodic exchange respectively. The gas does not switch, which reduces combustion fluctuations, improves thermal efficiency, prolongs the service life of the tube furnace and reduces comprehensive investment. 2. A high-efficiency regenerative tubular heating furnace system according to claim 1, characterized in that the working process is a periodic and repetitive process, that is, the combustion-supporting air is respectively in the left regenerator and the right regenerator. Periodically and repeatedly through the four-way reversing valve, it exchanges heat with the left regenerator and the right regenerator respectively and then enters the burner after heating up. The exhaust gas is periodically and repeatedly in the left regenerator and right regenerator respectively. Reversed through the four-way reversing valve, respectively exchange heat with the other regenerator on the left and the other regenerator on the right to cool down, and then discharge it through the chimney by the induced draft fan. Controlled by the control program, the exhaust gas temperature is reduced, which is beneficial to extend tube furnace life. 3. A high-efficiency regenerative tubular heating furnace system according to claim 1, characterized in that: left and right double circuits and double regenerators are used, that is, one of the two regenerators on the left enters combustion-supporting air and one exits exhaust gas, There are two regenerators on the right, one for combustion-supporting air and one for exhaust gas, the left and right exchanges independently without affecting each other, and the exchange time between the left and right is staggered to ensure stable combustion. 4. A high-efficiency regenerative tubular heating furnace system according to claim 1, characterized in that: only the air and exhaust gas are periodically exchanged and exchanged heat in the regenerator, and the gas directly enters the gas burning process without exchange and heat exchange. Mouth, avoid burning waves. 5. A high-efficiency regenerative tubular heating furnace system according to claim 1, characterized in that: the tail gas and combustion air directly enter the regenerator, and directly contact with the regenerator, mainly through heat conduction and heat radiation The heat is transferred to the regenerator, and the regenerator transfers the heat to the combustion air. The tube furnace saves the traditional convection section and reduces the equipment investment of the tube furnace. 6. A high-efficiency regenerative tubular heating furnace system according to claim 1, characterized in that: the gas burner is used, and the diffusion combustion method is used. Air and gas are injected into the furnace respectively, which can avoid tempering and increase combustion. Adjustment range: high gas flow rate and low air flow rate design are adopted, so that the difference in flow rate can be used to increase the mixing speed of air and gas to ensure the completeness of combustion. 7. A high-efficiency regenerative tubular heating furnace system according to claim 1, characterized in that: it adopts two-way double regenerators, which can realize the simultaneous use of two-way regenerators, and can also be used in one direction. , and the other side can be used normally without affecting normal production. 8. A high-efficiency regenerative tubular heating furnace system according to claim 1, characterized in that: fire detection and control signals for large fire and small fire are set, and related safety interlocks are set, and the gas will be automatically cut off in abnormal situations. 9. A high-efficiency regenerative tubular heating furnace system according to claim 1, characterized in that: remote control of blower, induced draft fan, low-temperature four-way valve, high-temperature four-way valve, flue valve and natural ventilation valve according to the process Sequential automatic start or stop, high automatic level, easy to operate.