Catalytic combustion heating system capable of controlling oxygen content

Abstract

The invention relates to a catalytic combustion heating system capable of controlling the oxygen content. The catalytic combustion heating system comprises a mixer, a heat exchanger, a heater and a catalytic combustor. An outlet of the mixer is communicated to a cold source inlet of the heat exchanger, a cold source outlet of the heat exchanger is communicated to an inlet of the catalytic combustor through the heater, an outlet of the catalytic combustor is communicated to a heat source inlet of the heat exchanger, and a heat source outlet of the heat exchanger is communicated to an inlet of the mixer; the catalytic combustor is provided with a heat conduction system. In order to overcome the defects in the prior art, the catalytic combustion heating system capable of controlling the oxygen content is provided, air is diluted by non-combustible gas, and the oxygen content in premixed gas is controlled by adjusting the flow of the non-combustible gas.

Description

Technical Field

[0001] The invention belongs to the technical field of chemical equipment, and in particular relates to a catalytic combustion heating system for controlling oxygen content. Background Art

[0002] Endothermic reactions require a continuous supply of external heat sources to achieve a stable reaction. Electric heating has a high operating cost in industrial applications, although electric heating can achieve better temperature control; in addition, the combustion system with an open flame heats the circulating heat transfer oil as a heat source, which has open flame safety distance restrictions, greatly increasing the equipment investment cost and safety hazards. Catalytic combustion reduces the equipment investment cost by lowering the ignition temperature and combustion temperature of the fuel. It has the advantages of energy saving, environmental protection, strong adaptability, and easy operation. Catalytic combustion exothermic direct heating endothermic reactions still face the problem of heat coupling. For example, a sharp increase in heat release leads to catalyst deactivation and a sharp increase in heat absorption leads to catalytic combustion flameout. Introducing heat transfer oil as an intermediate heat storage medium can solve this problem well.

[0003] However, most devices still use premixed gas as the inlet reactant of the catalytic burner. In order to reduce heat loss, the premixed gas is usually preheated and overheated before entering the reactor, which causes the fuel in the premixed gas to be within the explosion limit range in the air. Therefore, the oxygen content is controlled below 8%, so that the ratio of fuel and oxygen in the premixed gas is in the absolute safe zone of the explosion triangle, which is used to solve the safety hazards of the premixed gas in the system. In order to solve this problem, researchers in this field have proposed a catalytic combustion heating system that controls the oxygen content. Summary of the invention

[0004] The purpose of the present invention is to overcome the deficiencies in the prior art, solve or at least alleviate the potential safety hazard caused by the ratio of fuel and oxygen in the premixed gas of the catalytic combustion heating system being within the explosion range, and this problem can be well solved by controlling the oxygen content in the premixed gas. Specifically, a catalytic combustion heating system for controlling oxygen content is invented, so that the non-combustible gas dilutes the air, and the oxygen content in the premixed gas is controlled by adjusting the flow rate of the non-combustible gas.

[0005] The present invention is achieved through the following technical solutions:

[0006] A catalytic combustion heating system for controlling oxygen content, comprising a mixer, a heat exchanger, a heater and a catalytic burner;

[0007] The outlet of the mixer is connected to the cold source inlet of the heat exchanger, the cold source outlet of the heat exchanger is connected to the inlet of the catalytic burner through the heater, the outlet of the catalytic burner is connected to the hot source inlet of the heat exchanger, and the hot source outlet of the heat exchanger is connected to the inlet of the mixer;

[0008] The catalytic burner is provided with a heat conduction system, which includes a heat conduction cavity, an endothermic reactor and an oil pump arranged in the catalytic burner. Heat conduction oil flows in the heat conduction cavity of the catalytic burner, and the outlet of the heat conduction cavity of the catalytic burner is connected to the inlet of the heat conduction cavity of the catalytic burner through the oil pump and the endothermic reactor.

[0009] In order to further realize the present invention, the following technical solutions may be preferably selected:

[0010] Preferably, the inlet of the mixer includes an air inlet, a fuel inlet and an exhaust gas split inlet.

[0011] Preferably, the heat exchanger has a three-way pipe, one end of which is connected to the heat source outlet of the heat exchanger, one end is connected to the tail gas diversion inlet, and the other end is the tail gas diversion outlet.

[0012] Preferably, a section of the three-way pipe connected to the tail gas diversion inlet is provided with a throttle valve and a flow meter, and a section of the three-way valve close to the tail gas diversion outlet is provided with a throttle valve.

[0013] Preferably, an oxygen content detector is provided at the outlet of the mixer. Preferably, the oil pumps are two arranged in parallel, one of which is a standby pump, and the standby pump is provided with a stop valve.

[0014] Preferably, the heat transfer system further comprises a high-level tank, and the high-level tank is used to replenish and store heat transfer oil.

[0015] Through the above technical solution, the beneficial effects of the present invention are:

[0016] In the catalytic combustion heating system with controlled oxygen content, the oxygen content of the premixed gas is controlled by the combustion exhaust gas diversion ratio, and the oxygen content of the premixed gas is controlled within 8%, which is within the absolute safety zone of the explosion triangle.

[0017] In the catalytic combustion heating system with controlled oxygen content, the premixed gas is heated by the catalytic combustion exhaust gas through the heat exchanger and then superheated in the heater, thereby reducing the heat loss of the catalytic combustion. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the structure of the present invention;

[0019] Figure 2 is a flow chart of the present invention;

[0020] Figure 3 It is the hydrogen explosion limit diagram of the present invention;

[0021] Among them: 1. mixer; 1-1. air inlet; 1-2. fuel inlet; 1-3. catalytic combustion exhaust gas diversion inlet; 2. heat exchanger; 3. heater; 4. oil pump; 4-1. standby pump; 5. stop valve; 6. catalytic burner; 7. endothermic reactor; 8. high-level tank; 9. flow meter; 10. throttle valve; 11. endothermic reactor material inlet; 12. endothermic reactor material outlet; 13. catalytic combustion exhaust gas diversion outlet; 14. oxygen content detector. DETAILED DESCRIPTION

[0022] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0023] The following will be combined with the drawings in the embodiments of the invention to clearly and completely describe the technical solutions in the embodiments of the invention. Obviously, the described embodiments are only part of the embodiments of the invention, not all of the embodiments. Based on the embodiments of the invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the invention.

[0024] Embodiment 1:

[0025] like Figure 1-Figure 3 As shown, a catalytic combustion heating system for controlling oxygen content includes a mixer 1, a heat exchanger 2, a heater 3 and a catalytic burner 6;

[0026] The outlet of the mixer 1 is connected to the cold source inlet of the heat exchanger 2, the cold source outlet of the heat exchanger 2 is connected to the inlet of the catalytic burner 6 through the heater 3, the outlet of the catalytic burner 6 is connected to the heat source inlet of the heat exchanger 2, and the heat source outlet of the heat exchanger 2 is connected to the inlet of the mixer 1;

[0027] The catalytic burner 6 is provided with a heat conduction system, which includes a heat conduction cavity, an endothermic reactor 7 and an oil pump 4 arranged in the catalytic burner 6. Heat conduction oil flows in the heat conduction cavity of the catalytic burner 6, and the outlet of the heat conduction cavity of the catalytic burner 6 is connected to the inlet of the heat conduction cavity of the catalytic burner 6 through the oil pump 4 and the endothermic reactor 7.

[0028] The inlet of the mixer 1 includes an air inlet 1-1, a fuel inlet 1-2 and an exhaust gas split inlet.

[0029] The heat exchanger 2 has a three-way pipe, one end of which is connected to the heat source outlet of the heat exchanger 2, one end is connected to the tail gas diversion inlet, and the other end is the tail gas diversion outlet.

[0030] A section of the three-way pipe connected to the exhaust gas diversion inlet is provided with a throttle valve 10 and a flow meter 9, and a section of the three-way valve close to the exhaust gas diversion outlet is provided with a throttle valve 10. The flow meter 9 and the throttle valve 10 are used to control the diversion ratio of the combustion exhaust gas, and then control the oxygen content of the premixed gas. The flow meter 9 includes but is not limited to a rotor flow meter 9, a vortex flow meter 9, etc.

[0031] An oxygen content detector 14 is provided at the outlet of the mixer 1 . The oxygen content detector 14 is signal-connected to the throttle valve 10 and the flow meter 9 . The oxygen content in the premixed gas is monitored in real time by the oxygen content detector 14 .

[0032] There are two oil pumps 4 arranged in parallel, one of which is a standby pump 4 - 1 , and the standby pump 4 - 1 is provided with a stop valve 5 .

[0033] The heat transfer system further comprises a high-level tank 8, which is used for replenishing and storing heat transfer oil.

[0034] The catalytic burner 6 is filled with a catalyst for catalytic combustion, and the endothermic reactor 7 is filled with a catalyst for endothermic reaction.

[0035] The fuel, air and oxygen content control flow enter the mixer 1 through the fuel inlet 1-2, the air inlet 1-1 and the catalytic combustion exhaust gas diversion inlet 1-3, and form a premixed gas in the mixer 1. The premixed gas passes through the heat exchanger 2 and the heater 3 and reacts in the catalytic burner 6. The catalytic burner 6 releases heat to form high-temperature heat transfer oil, which is used to heat the endothermic reactor 7.

[0036] Fuels include but are not limited to methane, hydrogen, methanol, carbon monoxide, VOC, etc.

[0037] The catalytic burner 6 and the endothermic reactor 7 are of a shell and tube structure. The heat transfer oil is heated in the heat transfer cavity of the catalytic burner 6 . The high-temperature heat transfer oil enters the endothermic reactor 7 to provide heat for the endothermic reaction in the endothermic reactor 7 . The heat transfer oil circulates through the oil pump 4 .

[0038] Embodiment 2:

[0039] The fuel feed includes hydrogen, carbon monoxide and carbon dioxide, with flow rates of 5kmol / h, 1kmol / h and 5kmol / h respectively; the air includes oxygen and nitrogen, with flow rates of 4kmol / h and 16kmol / h respectively. In addition, the temperature difference between the heat source outlet and the cold source inlet of the heat exchanger 2 is set to 40K, the temperature of the heater 3 and the catalytic burner 6 are both 260℃, and the pressure is 1bar. The combustion exhaust gas diversion rate is controlled according to the throttle valve 10 and the flow meter 9.

[0040] The following is the change in oxygen content in the premixed gas that can be achieved by controlling the combustion exhaust fraction:

[0041]

[0042]

[0043] Finally, it should be noted that the above are only preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments, or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A catalytic combustion heating system for controlling oxygen content, characterized in that: It comprises a mixer (1), a heat exchanger (2), a heater (3) and a catalytic burner (6); The outlet of the mixer (1) is connected to the cold source inlet of the heat exchanger (2), the cold source outlet of the heat exchanger (2) is connected to the inlet of the catalytic burner (6) through the heater (3), the outlet of the catalytic burner (6) is connected to the heat source inlet of the heat exchanger (2), and the heat source outlet of the heat exchanger (2) is connected to the inlet of the mixer (1); The catalytic burner (6) is provided with a heat conduction system, which comprises a heat conduction cavity arranged in the catalytic burner (6), an endothermic reactor (7) and an oil pump (4); heat conduction oil flows in the heat conduction cavity of the catalytic burner (6); and the outlet of the heat conduction cavity of the catalytic burner (6) is connected to the inlet of the heat conduction cavity of the catalytic burner (6) through the oil pump (4) and the endothermic reactor (7).

2. A catalytic combustion heating system for controlling oxygen content according to claim 1, characterized in that: The inlet of the mixer (1) comprises an air inlet (1-1), a fuel inlet (1-2) and an exhaust gas split inlet.

3. A catalytic combustion heating system for controlling oxygen content according to claim 2, characterized in that: The heat exchanger (2) has a three-way pipe, one end of which is connected to the heat source outlet of the heat exchanger (2), one end of which is connected to the tail gas diversion inlet, and the other end of which is the tail gas diversion outlet.

4. A catalytic combustion heating system for controlling oxygen content according to claim 3, characterized in that: A section of the three-way pipe connected to the tail gas diversion inlet is provided with a throttle valve (10) and a flow meter (9), and a section of the three-way valve close to the tail gas diversion outlet is provided with a throttle valve (10).

5. A catalytic combustion heating system for controlling oxygen content according to claim 4, characterized in that: An oxygen content detector (14) is provided at the outlet of the mixer (1), and the oxygen content detector (14) is signal-connected to the throttle valve (10) and the flow meter (9).

6. A catalytic combustion heating system for controlling oxygen content according to claim 1, characterized in that: The oil pumps (4) are two arranged in parallel, one of which is a standby pump (4-1), and the standby pump (4-1) is provided with a stop valve (5).

7. A catalytic combustion heating system for controlling oxygen content according to claim 1, characterized in that: The heat transfer system further comprises a high-level tank (8), and the high-level tank (8) is used to replenish and store heat transfer oil.

Images