CN201866787U - Heat transfer oil furnace waste heat high-efficiency recycle device with phase-change heat exchanger - Google Patents

Abstract

The utility model relates to a high-efficiency recovery device for waste heat of a heat-conducting oil furnace with a phase-change heat exchanger, which comprises a heat-conducting oil furnace and a flue. Contains an evaporator and a condenser, where the condenser is located outside the flue. A condenser of a phase change heat exchanger and an air preheater are arranged outside the flue. The condenser of the phase change heat exchanger adopts the indirect heat exchange method as the preferred heat transfer oil as the cooling medium. After the heat transfer oil is heated, it is sent to the heat transfer oil heater, and the heat transfer oil heated by the heat transfer oil heater enters the air preheater as the cooling medium. The heat source heats the air as the combustion air of the heat transfer oil furnace. The utility model can make the heat-conducting oil furnace operate economically and with high thermal efficiency, solve the problem of difficult waste heat recovery of the heat-conducting oil furnace, and achieve the purpose of saving energy and reducing consumption. The utility model can be used in combination with the existing waste heat recovery technology of the heat-conducting oil furnace.

Description

High-efficiency recovery device for heat transfer oil furnace waste heat with phase change heat exchanger

technical field

The invention relates to a high-efficiency recovery device for waste heat of a heat-conducting oil furnace, which belongs to the field of waste heat recovery of boiler flue gas.

Background technique

Heat-conducting oil furnace is a special boiler with organic heat carrier, heat-conducting oil as the medium. The boiler generates high-temperature heat-conducting oil through fuel combustion to provide heat for heat-consuming equipment that requires heat energy. After the boiler fuel is burned, the heat generated can reach 350 ° C ~ 450 ° C high temperature flue gas.

Most heat-conducting oil furnaces do not recover waste heat or only increase the air preheater to recover part of the waste heat of flue gas. Part of the process is equipped with a waste heat recovery device with a steam generator such as a heat tube boiler, such as ZL200420027889.4 provides a structural schematic diagram of a heat transfer oil furnace tail gas waste heat recovery device with a steam generator (as shown in Figure 1):

The labels in Figure 1 are: 1-furnace body, 2-flue, 3-steam generator, 31-steam generator shell, 32-steam generator drum, 33-steam generator heat transfer tube, 34- Steam generator tube plate, 4-air preheater, 41-air intake pipe of air preheater, 5-induced fan, 6-chimney.

This patented technology can reduce the exhaust gas temperature of the heat transfer oil furnace to 160°C and recover a certain amount of steam.

ZL200710046604.X provides a device process for boiler flue gas waste heat recovery. The main application field of this technology is power plant boilers. The structural schematic diagram of the embodiment of the technology is shown in Fig. 2 .

Explanation of reference signs of the embodiment: 1-automatic control device, 2-automatic control valve, 3-steam drum, 4-upper water pipe, 5-downstream pipe, 6-medium and low pressure evaporator, 7-coal economizer, 8-feed water pump, 9-air preheater, 10-flue, 11-lower section of phase-change heat exchanger, 12-wall temperature tester, 13-upper section of phase-change heat exchanger, 14-air duct, 15-drum safety valve, 16 - Drum level gauge.

Compared with ZL200420027889.4, this technology can reduce the exhaust gas temperature of the boiler to about 130°C and increase the thermal efficiency of the boiler by 1% to 2%.

However, if the unit using the heat-conducting oil furnace does not need the steam generated by the waste heat recovery process, the use of this type of technology is greatly limited, and only the air preheater can be added to recover part of the waste heat of the flue gas. The exhaust gas temperature of the boiler is usually 250 Above ℃, the overall thermal efficiency of the boiler is low and the energy waste is large. Does not meet energy saving requirements. If the exhaust gas temperature is reduced to about 130 °C, the thermal efficiency of the boiler can be increased by about 9%. Therefore, it is difficult to further rationally recycle the waste heat of the flue gas from the heat transfer oil furnace, reduce the exhaust gas temperature and improve the thermal efficiency, which has become a research hotspot in this field.

Contents of the invention

The purpose of the present invention is to solve the shortcomings of the above-mentioned prior art, realize the efficient recovery of waste heat from the heat conduction oil furnace flue gas, and achieve the purpose of saving energy and reducing consumption.

Heat conduction oil furnace waste heat efficient recovery device with phase change heat exchanger, including heat conduction oil furnace 1, flue 9 and equipment outside the flue, heat conduction oil furnace 1 includes heating source 2, heating source 2 can use coal, oil or gas as fuel. A heat transfer oil heater 10 and a phase-change heat exchanger 11 are sequentially provided in the flue 9, and the phase-change heat exchanger 11 includes an evaporator 11-1 and a condenser 11-2, wherein the condenser 11-2 is located outside the flue. The working medium of the evaporator 11-1 is water. A condenser 11 - 2 of a phase change heat exchanger 11 and an air preheater 16 are arranged outside the flue 9 . The condensing section of the phase change heat exchanger 11 adopts the indirect heat exchange method and uses heat transfer oil or air as the cooling medium. As the preferred choice of heat transfer oil as the cooling medium, the heat transfer oil is heated and sent to the heat transfer oil heater 10. 10. The heat-conducting oil heated by 10 enters the air preheater 16 as a heat source to heat air, and the hot air 18 heated by the air 17 is sent into the heat-conducting oil furnace 1 as combustion-supporting air.

The heat transfer oil circulation loop at the high temperature end of the present invention is as follows: the heat transfer oil enters the heat transfer oil furnace 1 after being pressurized by the heat oil pump 7 to absorb the heat generated by combustion, and then enters the heat transfer oil after passing through the heat using equipment 3, the oil-gas separator 5, and the filter 6. The oil pump is connected through the pipeline system to form a closed loop.

The heat transfer oil circulation circuit at the low temperature end of the present invention is as follows: the heat transfer oil is pressurized by the heat transfer oil pump 12 at the low temperature end, enters the phase change heat exchanger condenser 11-2 to absorb heat, and passes through the heat transfer oil heater 10, the air preheater 16, The oil-gas separator 15 and the filter 14 then enter the low-temperature end heat oil pump 12 and are connected through a pipeline system to form a closed loop.

A flue gas discharge temperature control device 13 is provided, and the control device 13 controls the phase change heat exchanger condenser 11- 2, the opening of the bypass regulating valve and other means can reduce the exhaust gas temperature at the flue outlet to only higher than the acid dew point temperature of the flue gas on the evaporator wall of the phase change heat exchanger 11, under the premise of avoiding condensation , to achieve the purpose of maximizing the use of flue gas waste heat, so that the heat transfer oil furnace can operate economically and with high thermal efficiency, and achieve the purpose of saving energy and reducing consumption.

This device uses the waste heat of high-temperature flue gas from the heat-conducting oil furnace as the heat source of the heat-conducting oil heater 10 and the phase-change heat exchanger 11, and the heat-conducting oil with a higher temperature is used to heat the air 17, and the generated hot air 18 is fed into the heat-conducting oil Furnace 1, increase the inlet air temperature and reduce fuel consumption.

The invention can be used in combination with the existing waste heat recovery technology of the heat conduction oil furnace.

The heat recovered by the heat conduction oil in the present invention is used to heat air by taking an air preheater as an example, and can also be used to heat other fluids that need to be properly heated, such as producing steam.

Description of drawings

Fig. 1 is the structure schematic diagram of the tail gas waste heat recovery device of the heat-conducting oil furnace with steam generator in the prior art;

Fig. 2 is the device flow chart of recovery of boiler flue gas waste heat of prior art;

Fig. 3 is a structural schematic diagram of the method and device for efficient recovery of waste heat from a heat-conducting oil furnace with a phase-change heat exchanger according to the present invention.

In the figure, 1—heat conduction oil furnace, 2—heating source, 3—heating equipment, 4—high expansion tank, 5—oil and gas separator, 6—filter, 7—thermal oil pump, 8—low oil storage tank, 9— Flue, 10—heat transfer oil heater, 11—phase change heat exchanger, 11-1—phase change heat exchanger evaporator, 11—2 phase change heat exchanger condenser, 12—low temperature end heat oil pump, 13— Control device, 14-filter, 15-oil-gas separator, 16-air preheater, 17-air, 18-hot air.

Detailed ways

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

Accompanying drawing 3 is the embodiment of the waste heat efficient recovery device of heat conduction oil furnace with phase change heat exchanger, heat conduction oil furnace 1 and flue 9 and equipment outside the flue, heat conduction oil furnace 1 includes heating source 2, and heating source 2 can adopt coal , oil or gas as fuel. A heat transfer oil heater 10 and a phase-change heat exchanger 11 are sequentially provided in the flue 9, and the phase-change heat exchanger 11 includes an evaporator 11-1 and a condenser 11-2, wherein the condenser 11-2 is located outside the flue. The working medium of the evaporator 11-1 is water. A condenser of a phase change heat exchanger 11 and an air preheater are arranged outside the flue 9 . The condenser of the phase change heat exchanger 11 adopts an indirect heat exchange method and uses heat transfer oil or air as a cooling medium. As a preferred choice, heat transfer oil is used as a cooling medium, and the heat transfer oil is heated and sent to the heat transfer oil heater 10. 10. The heat-conducting oil heated by 10 enters the air preheater 16 as a heat source to heat air, and the hot air 18 heated by the air 17 is sent into the heat-conducting oil furnace 1 as combustion-supporting air.

The heat transfer oil circulation loop at the high temperature end is as follows: the heat transfer oil enters the heat transfer oil furnace 1 after being pressurized by the heat transfer oil pump 7 to absorb the heat generated by combustion, and then enters the heat transfer oil pump through the heat using equipment 3, oil and gas separator 5, and filter 6. The road system is connected to form a closed loop.

The heat transfer oil circulation loop at the low temperature end is as follows: the heat transfer oil is pressurized by the heat oil pump 12 at the low temperature end, enters the phase change heat exchanger condenser 11-2 to absorb heat, and then passes through the heat transfer oil heater 10, the air preheater 16, and the oil-gas separator 15. After the filter 14 enters the low-temperature end heat oil pump 12, it is connected through a pipeline system to form a closed loop.

A flue gas discharge temperature control device 13 is provided, and the control device 13 controls the phase change heat exchanger condenser 11- 2, the opening of the bypass regulating valve and other means can reduce the exhaust gas temperature at the flue outlet to only higher than the acid dew point temperature of the flue gas on the wall surface of the evaporation section of the phase change heat exchanger 11.

Although the present invention has been disclosed above with preferred embodiments, they are not intended to limit the present invention, and any skilled person can make various changes or modifications without departing from the spirit and scope of the present invention. Belong to the protection scope of the present invention. For example, the flow process of the phase-change heat exchanger of the present invention is also applicable to industrial pit furnaces. Therefore, the protection scope of the present invention should be defined by the claims of the present application.

Claims (9)

1. A heat transfer oil furnace waste heat efficient recovery device with a phase change heat exchanger, including a heat transfer oil furnace (1) and a flue (9), characterized in that: the heat transfer oil furnace (1) includes a heating source (2), a heating source (2) Coal, oil or gas is used as fuel, and a heat conduction oil heater (10) and a phase-change heat exchanger (11) are arranged in the flue (9) in sequence, and the phase-change heat exchanger 11 includes an evaporator (11- 1) and the condenser (11-2), wherein the condenser (11-2) is located outside the flue (9), and the condenser (11-2) is used as one of the heat sources of the heat transfer oil circulation circuit at the low temperature end; After the heat transfer oil heated by the condenser (11-2) is heated by the heat transfer oil heater (10), the preheated air entering the air preheater (16) is sent to the heat transfer oil furnace (1) as combustion air. 2. The high-efficiency recovery device for heat transfer oil furnace waste heat with a phase change heat exchanger according to claim 1, characterized in that: the heat transfer oil circulation circuit at the low temperature end means that the heat transfer oil is added by the heat transfer oil pump (12) at the low temperature end After being compressed, it enters the phase-change heat exchanger condenser (11-2) to absorb heat, and then passes through the heat conduction oil heater (10), air preheater (16), oil-gas separator (15), and filter (14). The hot oil pump (12) entering the low temperature end is connected through a pipeline system to form a closed loop. 3. The high-efficiency recovery device for heat transfer oil furnace waste heat with a phase change heat exchanger according to claim 2, characterized in that it also includes a heat transfer oil circulation loop at the high temperature end, that is, after the heat transfer oil is pressurized by the thermal oil pump (7) After entering the heat-conducting oil furnace (1) to absorb the heat generated by combustion, it passes through the heat-using equipment (3), oil-gas separator (5), filter (6) and then enters the heat oil pump (7) to form a closed-circuit cycle through the connection of the pipeline system . 4. The high-efficiency recovery device for heat transfer oil furnace waste heat with a phase-change heat exchanger according to any one of claims 1 to 3, characterized in that: the phase-change heat exchanger condenser (11-2) includes a shell and At least one heat exchange tube passing through the casing, the inlet end and the outlet end of the casing are respectively connected with the outlet of the low temperature end heat oil pump (12) and the heat transfer oil heater (10) of the heat transfer oil circulation loop at the low temperature end. 5. The high-efficiency recovery device for heat transfer oil furnace waste heat with a phase change heat exchanger according to any one of claims 1 to 3, characterized in that: the heat transfer oil heater (10) has at least one heat exchange tube, said The inlet end and the outlet end of the heat transfer tube of the heat transfer oil heater (10) are respectively connected with the heat transfer oil outlet of the phase change heat exchanger condenser (11-2) and the organic heat carrier inlet of the air preheater (16). 6. The high-efficiency recovery device for heat transfer oil furnace waste heat with a phase change heat exchanger according to any one of claims 1 to 3, characterized in that: the air preheater (16) and the heat transfer oil adopt an indirect heat exchange method, The inlet end and the outlet end of the casing are respectively connected with the outlet of the heat transfer oil heater (10) and the heat transfer oil inlet of the oil-gas separator (15). 7. The high-efficiency recovery device for heat-conducting oil furnace waste heat with a phase-change heat exchanger according to any one of claims 1 to 3, characterized in that it is provided with a control device (13) for exhaust gas temperature, and the control device (13) is based on The wall temperature of the evaporator (11-1) of the phase-change heat exchanger (11-1) can control the opening degree of the bypass regulating valve of the condenser (11-2) of the phase-change heat exchanger to make the exhaust gas temperature at the flue outlet Reduce to only higher than the flue gas acid dew point temperature of the evaporation section wall of the phase change heat exchanger (11). 8. The high-efficiency recovery device for heat transfer oil furnace waste heat with a phase change heat exchanger according to any one of claims 1 to 3, characterized in that: the heat exchange tubes of the heat transfer oil heater (10) can be arranged tubes, Finned tubes, serpentine tubes or spiral grooved tubes. 9. The high-efficiency recovery device for heat transfer oil furnace waste heat with phase change heat exchanger according to any one of claims 1 to 3, characterized in that: the heat transfer oil circulation circuit is provided with a low-level oil storage tank (8) and a high-level expansion tank (4) Auxiliary equipment.

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