CN118189057A - A heating and cooling device for pipelines - Google Patents

Abstract

The invention belongs to the technical field of pipeline temperature and pressure reduction, and relates to a heat tracing temperature and pressure reduction device for a pipeline, which comprises: the heat exchange temperature reduction unit is communicated with a steam shunt pipe, the steam shunt pipe is suitable for guiding steam to the temperature of the temperature reduction water passing through the heat exchange temperature reduction unit, a steam return pipe is communicated between the temperature reduction pipe and the heat exchange temperature reduction unit, and the steam passing through the heat exchange temperature reduction unit returns to the temperature reduction pipe through the steam return pipe; the outlet shunt tube is communicated between the temperature reducing tube and the steam reflux tube, and the inlet shunt tube is communicated between the inlet tube and the steam shunt tube. The temperature of the temperature reduction water in the heat exchange temperature reduction unit is improved by utilizing the temperature of the input steam, so that the temperature of the temperature reduction water can be reasonably adjusted, the energy-saving effect can be achieved, and the input steam can be recovered; according to the actual conditions, two modes of high-pressure steam and reduced-pressure steam are utilized respectively, so that accurate and stable temperature and pressure control is realized, and the requirements of pipelines, equipment and processes are met.

Description

A heating and cooling device for pipelines

Technical Field

The present invention belongs to the technical field of pipeline temperature reduction and pressure reduction, and in particular, relates to a heating temperature reduction and pressure reduction device for a pipeline.

Background technique

Pipeline heating refers to a heat preservation measure taken to prevent the materials in pipelines, equipment or containers from solidifying or freezing in low temperature environments or to maintain process temperatures. The heating system usually provides heat to pipelines and containers through external heating to ensure that the internal medium is in suitable flow or storage conditions. Common heating methods include: electric heating, hot water heating/steam heating, hot air heating, industrial heating cables, etc. The cooling water in the cooling and pressure reduction device needs to be heated and then the cooling water is used to adjust the temperature.

In practical applications of temperature and pressure reduction devices, there are always certain fluctuations in steam pressure control. If the outlet set temperature is very close to the saturation temperature under the steam working pressure, when the pressure fluctuates, the set temperature may be lower than the saturation temperature of the steam, and part of the steam in the pipeline will condense into water droplets, resulting in steam-water two-phase flow.

And when the set temperature is very close to the saturation temperature under the steam working pressure, if the temperature of the injected cooling water is below 50℃, it will cause the temperature field in the steam pipe to be uneven, and the injected cooling water will be difficult to evaporate completely and will be suspended in the steam. These condensed water droplets or incompletely evaporated water droplets will adhere to the surface of the temperature sensor, causing the temperature sensor to collect the wrong temperature, causing large fluctuations in temperature control.

The cooling water temperature is a very critical parameter, which directly affects the cooling water volume and the rate at which the cooling water is converted from water to steam. When the cooling water temperature is higher, the water tension is smaller, and the closer to the saturation temperature, the easier it is to evaporate. In addition, when the cooling water is sprayed into the pipeline, the higher the temperature, the easier it is to atomize, and the smaller the droplets produced are, and small droplets evaporate faster than large droplets.

At this time, a heating, cooling and pressure reducing device for pipelines is needed. The diversion is used to allow the steam to pass through the heat exchanger to heat the cooling water, increase the cooling water temperature in the heat exchange cooling system, and maintain the cooling water temperature. The steam then flows back to the pipeline and the heated cooling water is sent to the nozzle. The high-temperature water enters the nozzle and is fully mixed with the steam and evaporates quickly, thereby improving the overall performance of the system.

Summary of the invention

The purpose of the present invention is to overcome the shortcomings of the above-mentioned prior art and to provide a cooling device capable of regulating water temperature by introducing a diversion flow to allow steam to pass through a heat exchanger, increase the temperature of cooling water in a heat exchange cooling system, and then the steam flows back to the pipeline.

In order to solve the above technical problems, the present invention provides a heating and cooling and pressure reducing device for pipelines, comprising: an inlet pipe, a cooling pipe, a steam pressure reducing valve, a heat exchange cooling unit, a steam shunt pipe, a steam reflux pipe, an outlet shunt pipe, an inlet shunt pipe and a flow regulating valve, wherein the inlet pipe and the cooling pipe are respectively connected to the inlet and outlet of the steam pressure reducing valve, the cooling pipe is connected to the heat exchange cooling unit, and the heat exchange cooling unit is used to transport cooling water to the cooling pipe; the heat exchange cooling unit is connected to the steam shunt pipe, and the steam shunt pipe is suitable for guiding steam to the heat exchange cooling unit. The cooling unit is used to increase the temperature of the cooling water, and at the same time, the heat exchange cooling unit and the cooling water therein are subjected to heat treatment. The steam reflux pipe is connected between the cooling pipe and the heat exchange cooling unit, and the steam passing through the heat exchange cooling unit is refluxed to the cooling pipe through the steam reflux pipe; the outlet diversion pipe is connected between the cooling pipe and the steam reflux pipe, and the inlet diversion pipe is connected between the inlet pipe and the steam diversion pipe. The outlet diversion pipe, the inlet diversion pipe and the steam diversion pipe are connected through a three-way joint, and flow regulating valves are installed on the steam reflux pipe, the outlet diversion pipe and the inlet diversion pipe.

Preferably, it also includes: a steam check valve, and the outlet diverter pipe and the inlet diverter pipe are both provided with a steam check valve.

Preferably, the heat exchange cooling unit includes: a heat exchanger body connected to the steam diversion pipe and the steam return pipe, and a water pipe running through the heat exchanger body and the cooling pipe; an atomizing nozzle located in the cooling pipe is installed at the output end of the water pipe, and cooling water is sprayed into the cooling pipe by the atomizing nozzle; a cooling water thermometer is installed on the water pipe, and the cooling water thermometer is located between the heat exchanger body and the cooling pipe.

Preferably, it also includes: a pressure pump and a cooling water check valve. The water pipe has a spirally coiled winding portion. The winding portion on the water pipe is located in the heat exchanger body. The heat exchange area of the water pipe in the heat exchanger body is increased by the winding portion to ensure the heat exchange effect. The input end of the water pipe is installed with a pressure pump and a cooling water check valve. The pressure pump provides sufficient input pressure for the input cooling water, and the check valve prevents the input cooling water from flowing back.

Preferably, it also includes: an outlet pipe, a safety valve, a pressure gauge and a steam thermometer. The safety valve is installed on the cooling pipe; the outlet end of the cooling pipe is connected to the outlet pipe, and the outlet pipe is installed with a pressure gauge for measuring the pressure of the final discharged steam and a steam thermometer for measuring the temperature of the final discharged steam.

Preferably, it also includes: an inner through pipe, an inner through pipe is arranged inside the cooling pipe, the inner through pipe is installed on the inner bottom side of the cooling pipe through a mounting seat, the inner through hole of the inner through pipe is concentric with the cooling pipe, the atomizing nozzle is arranged inside the inner through pipe, and the inner through pipe replaces the cooling pipe to receive the cooling water sprayed by the atomizing nozzle.

Preferably, the inner hole of the inner tube is a structure that expands at both ends and narrows in the middle, the atomizing nozzle is arranged at the narrowed part of the inner tube, and the spray direction of the atomizing nozzle is away from the inlet end of the inner tube to prevent the input steam from affecting the atomizing nozzle, wherein the inlet end of the inner tube is facing the input direction of the steam.

Preferably, the end of the steam return pipe is bent in the temperature reduction pipe, and the bent end pipe opening of the steam return pipe corresponds to the inlet of the inner through hole of the inner through pipe.

Preferably, it also includes: a venturi tube, a venturi tube is provided in the cooling tube and is located between the outlet end of the cooling tube and the outlet end of the inner tube, the venturi tube and the cooling tube are sealed, a sealing ring is connected between the outer side of the venturi tube and the inner side of the cooling tube, the inlet section of the venturi tube surrounds the outlet end of the inner tube, and the length surrounded by the venturi tube is one quarter of the length of the inner tube.

Preferably, the safety valve is located between the outlet end of the desuperheating pipe and the outlet end of the venturi tube, and is suitable for maintaining the pressure of the steam that is ultimately required to be discharged.

The present invention overcomes the shortcomings of the prior art and can achieve the following beneficial effects:

1. The temperature of the cooling water in the heat exchange cooling unit can be increased by using the temperature of the input steam, which can reasonably adjust the temperature of the cooling water and achieve energy-saving effects. The input steam can also be recovered. According to the actual situation, high-pressure steam and reduced-pressure steam are used respectively to achieve precise and stable temperature and pressure control under limited installation conditions on site to meet the requirements of pipelines, equipment and processes.

2. The temperature of the cooling water after cooling treatment is measured by the cooling water thermometer, so as to facilitate the use of high-pressure steam and reduced-pressure steam according to the actual needs; the pressure in the cooling pipe is maintained within the set pressure range through the safety valve to ensure the safety of the cooling device.

3. Through the design of the inner through pipe and the Venturi tube, the cooling water is prevented from directly contacting the cooling pipe, which causes excessive temperature fluctuations and excessive alternating stress and damage, thereby improving the safety and reliability of the cooling and pressure reduction system. In addition, the atomization effect of the cooling water can be improved by utilizing the phenomenon of increased speed and reduced pressure.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of an assembly of the present invention.

FIG. 2 is a front view of the present invention.

FIG. 3 is a partial schematic diagram of the present invention.

FIG. 4 is a schematic diagram of the heat exchanger body and the water pipe of the present invention.

FIG5 is a full cross-sectional schematic diagram of the temperature reduction tube of the present invention.

FIG. 6 is a full cross-sectional schematic diagram of the inner tube and the venturi tube of the present invention.

FIG. 7 is an enlarged view of point A in FIG. 6 of the present invention.

FIG. 8 is a table showing the basic physical properties of water on the saturation line in the Heat Transfer Handbook of the Ministry of Chemical Industry.

The markings in the accompanying drawings provided by the present invention are: 101-inlet pipe, 102-cooling pipe, 103-outlet pipe, 1031-pressure gauge, 1032-steam thermometer, 2-steam pressure reducing valve, 3-safety valve, 4-heat exchange cooling unit, 41-heat exchanger body, 42-water pipe, 420-winding part, 421-atomizing nozzle, 422-pressure pump, 423-cooling water check valve, 424-cooling water thermometer, 431-steam diverter pipe, 432-steam reflux pipe, 44-outlet diverter pipe, 45-inlet diverter pipe, 46-steam check valve, 47-flow regulating valve, 51-internal pipe, 52-Venturi tube.

Detailed ways

In the description of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they should not be understood as limitations on the present invention.

In addition, the terms "first", "second" and "third" are used for descriptive purposes only and should not be understood as indicating or implying relative importance. The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. It should be noted that the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

Embodiment 1: A heating and cooling device for a pipeline, as shown in FIGS. 1 to 3, comprises: an inlet pipe 101, a cooling pipe 102, a steam pressure reducing valve 2, a heat exchange cooling unit 4, a steam diverter pipe 431, a steam reflux pipe 432, an outlet diverter pipe 44, an inlet diverter pipe 45 and a flow regulating valve 47, wherein the inlet pipe 101 and the cooling pipe 102 are respectively connected to the inlet and outlet of the steam pressure reducing valve 2, and the input steam enters the cooling pipe 102 after being reduced in pressure by the steam pressure reducing valve 2 through the inlet pipe 101, and the cooling pipe 102 is connected to the heat exchange cooling unit 4, and the heat exchange cooling unit 4 is used to transport cooling water to the cooling pipe 102, and the transported cooling water will mix with the steam flowing in the cooling pipe 102, thereby realizing the cooling and pressure reduction of the steam; the heat exchange cooling unit 4 is connected to the steam diverter pipe 4 31, the steam diversion pipe 431 is suitable for guiding the above-mentioned input steam to pass through the heat exchange cooling unit 4 to increase the temperature of the cooling water. According to the nature of water and the principle of heat exchange, the temperature of the cooling water in the heat exchange cooling unit 4 is increased by using the temperature of the input steam, the thermodynamic properties of the cooling water are improved, and the following aspects are affected: surface tension, droplet size distribution, potential heat of atomization, atomization rate, which is beneficial to the atomization of the cooling water. At the same time, the input steam will also heat the heat exchange cooling unit 4 and the cooling water therein to prevent the cooling water in the heat exchange cooling unit 4 from solidifying or freezing in a low temperature environment or to maintain the temperature of the heat exchange cooling unit 4, thereby ensuring the insulation effect of the cooling water. The steam reflux pipe 432 is connected between the cooling pipe 102 and the heat exchange cooling unit 4. The steam of the heat exchange cooling unit 4 flows back to the cooling pipe 102 through the steam return pipe 432. The used steam is recovered and the recovered steam is cooled due to heat exchange, so that the recovered steam can also achieve the cooling function, reducing the need for cooling water and achieving energy saving effect. The outlet branch pipe 44 is connected between the cooling pipe 102 and the steam return pipe 432, and the inlet branch pipe 45 is connected between the inlet pipe 101 and the steam branch pipe 431. The outlet branch pipe 44, the inlet branch pipe 45 and the steam branch pipe 431 are connected through a three-way joint. If the input steam flows from the inlet branch pipe 45 into the steam branch pipe 431 and is then used in the heat exchange cooling unit 4, the thermal enthalpy of the high-pressure steam is higher at this time, and the heat can be transferred to the cooling water before the pressure is reduced. Maximize the use of the thermal energy of steam; if the input steam flows from the outlet diversion pipe 44 into the steam diversion pipe 431 and is then used in the heat exchange cooling unit 4, the steam flow and pressure after decompression are stable, and the heat exchange process can be controlled relatively accurately. The steam return pipe 432, the outlet diversion pipe 44 and the inlet diversion pipe 45 are all equipped with a flow regulating valve 47. The flow regulating valve 47 is controlled to adjust the flow of steam in the pipeline, thereby controlling the residence time of the flow in the steam return pipe 432 and the flow rate of the steam in the outlet diversion pipe 44 and the inlet diversion pipe 45. The two methods of high-pressure steam and reduced-pressure steam can be used respectively according to actual conditions to achieve precise and stable temperature and pressure control under limited installation conditions on site, meeting pipeline, equipment and process requirements.

As shown in FIG. 3 , it also includes: a steam check valve 46 . The outlet diverter pipe 44 and the inlet diverter pipe 45 are both provided with a steam check valve 46 . The steam check valve is used to prevent the steam entering the outlet diverter pipe 44 and the inlet diverter pipe 45 from flowing back.

As shown in FIGS. 2 to 4 , the heat exchange cooling unit 4 includes: a heat exchanger body 41 connected to a steam shunt pipe 431 and a steam return pipe 432, and a water pipe 42 running through the heat exchanger body 41 and the cooling pipe 102; the steam flows through the heat exchanger body 41, thereby performing a heat treatment on the heat exchanger body 41 and the water pipe 42 therein, thereby heating the cooling water and maintaining a certain temperature; an atomizing spray nozzle located in the cooling pipe 102 is installed at the output end of the water pipe 42. Head 421, the atomizing nozzle 421 sprays cooling water into the cooling pipe 102, so that the heated cooling water is atomized and mixed with the steam in the cooling pipe 102 to reduce the temperature. A cooling water thermometer 424 is installed on the water pipe 42, and the cooling water thermometer 424 is located between the heat exchanger body 41 and the cooling pipe 102. The cooling water thermometer 424 measures the temperature of the cooling water after the cooling treatment, so as to facilitate the use of high-pressure steam and reduced-pressure steam according to actual needs.

As shown in Figure 3, it also includes: a pressure pump 422 and a cooling water check valve 423. The water pipe 42 has a spirally wound winding portion 420. The winding portion 420 on the water pipe 42 is located in the heat exchanger body 41. The heat exchange area of the water pipe 42 in the heat exchanger body 41 is increased by the winding portion 420 to ensure the heat exchange effect. The input end of the water pipe 42 is installed with a pressure pump 422 and a cooling water check valve 423. The pressure pump 422 provides sufficient input pressure for the input cooling water, and the check valve prevents the input cooling water from flowing back.

As shown in FIG2 , it also includes: an outlet pipe 103, a safety valve 3, a pressure gauge 1031 and a steam thermometer 1032. The safety valve 3 is installed on the cooling pipe 102, and the pressure in the cooling pipe 102 is maintained within a set pressure range through the safety valve 3 to ensure the safety of the cooling device; the outlet end of the cooling pipe 102 is connected to the outlet pipe 103, and the outlet pipe 103 is installed with a pressure gauge 1031 for measuring the pressure of the final discharged steam and a steam thermometer 1032 for measuring the temperature of the final discharged steam.

As shown in Figures 5 to 7, it also includes: an inner tube 51. The inner tube 51 is arranged in the cooling tube 102. The inner tube 51 is installed on the inner bottom side of the cooling tube 102 through a mounting seat. The inner hole of the inner tube 51 is concentric with the cooling tube 102. The atomizing nozzle 421 is arranged inside the inner tube 51. The inner tube 51 replaces the cooling tube 102 to receive the cooling water sprayed by the atomizing nozzle 421, so as to avoid the cooling water being directly sprayed onto the cooling tube 102, and prevent the cooling tube 102 from being subjected to both the heat of the steam and the cooling of the cooling water, thereby reducing the alternating stress that the cooling tube 102 needs to withstand and improving the safety and reliability of the cooling and pressure reduction system.

As shown in Figure 7, the inner hole of the inner tube 51 is a structure that expands at both ends and narrows in the middle. The atomizing nozzle 421 is arranged at the narrowed part of the inner tube 51, and the spray direction of the atomizing nozzle 421 is facing away from the inlet end of the inner tube 51 to prevent the input steam from affecting the atomizing nozzle 421. The inlet end of the inner tube 51 is facing the input direction of the steam, and the speed of the fluid passing through the narrowed part of the inner tube 51 is increased and the pressure is reduced. Therefore, when the input steam passes through, it will have an adsorption effect on the surrounding area, and the cooling water sprayed by the atomizing nozzle 421 will be adsorbed, thereby improving the atomization effect of the cooling water and allowing it to be fully mixed with the steam.

As shown in Figure 6, the end of the steam return pipe 432 is bent in the cooling pipe 102, and the bent end of the steam return pipe 432 corresponds to the inner hole inlet of the inner pipe 51. The utilized steam passing through the heat exchange cooling unit 4 will directly flow back to the inner pipe 51 in the cooling pipe 102 through the steam return pipe 432, so that the steam can further exchange heat with the cooling water sprayed in the inner pipe 51, and at the same time help stabilize the cooling process and avoid excessive temperature fluctuations.

As shown in Figures 5 and 6, it also includes: a venturi tube 52. The cooling tube 102 is provided with a venturi tube 52 located between the outlet end of the cooling tube 102 and the outlet end of the inner tube 51. The venturi tube 52 and the cooling tube 102 are sealed. A sealing ring is connected between the outer side of the venturi tube 52 and the inner side of the cooling tube 102. The inlet section of the venturi tube 52 surrounds the outlet end of the inner tube 51. The length surrounded by the venturi tube 52 is one quarter of the length of the inner tube 51. The steam in the cooling tube 102 that enters the inner tube 51 and the steam that does not enter the inner tube 51 will eventually be mixed in the venturi tube 52. On the basis of the aforementioned function of the inner tube 51, the consistency of the steam pressure and temperature that needs to be discharged in the end is guaranteed.

As shown in FIG. 6 , the safety valve 3 is located between the outlet end of the temperature reduction pipe 102 and the outlet end of the venturi tube 52 . The safety valve 3 arranged at this position is suitable for maintaining the pressure of the steam that needs to be discharged in the end.

As shown in Figure 8, it can be seen from the table that as the water temperature increases, the thermal enthalpy of water increases, the kinematic viscosity decreases, the dynamic viscosity decreases significantly, and the expansion coefficient increases. Therefore, based on the properties of water, increasing the temperature of the cooling water can achieve rapid evaporation after cooling and reduce the hydrophobic effect.

Obviously, the embodiments described above are only part of the embodiments of the present invention, rather than all of the embodiments. They only express the preferred implementation modes of the present invention, and the description is relatively specific and detailed, but it cannot be understood as limiting the patent scope of the present invention.

It should be pointed out that, for ordinary technicians in this field, several modifications, increases and decreases in quantity, improvements and substitutions can be made without departing from the concept of the present invention. Therefore, based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative work are within the scope of protection of the present invention.

Claims (10)

1. A heat tracing temperature and pressure reducing device for a pipeline comprises:

a steam pressure reducing valve (2);

An inlet pipe (101) and a temperature reducing pipe (102) which are respectively communicated with an inlet and an outlet of the steam pressure reducing valve (2);

an exchange temperature reduction unit (4) connected with the temperature reduction pipe (102), wherein the heat exchange temperature reduction unit (4) is used for conveying temperature reduction water;

It is characterized in that the method also comprises the following steps:

Switching on a steam shunt pipe (431) of the heat exchange and temperature reduction unit (4), wherein the steam shunt pipe (431) is suitable for guiding steam to pass through the heat exchange and temperature reduction unit (4) to raise the temperature of the temperature reduction water, and carrying out heat tracing treatment on the heat exchange and temperature reduction unit (4) and the temperature reduction water therein;

A steam return pipe (432) connected between the temperature reducing pipe (102) and the heat exchange temperature reducing unit (4), wherein the steam passing through the heat exchange temperature reducing unit (4) returns to the temperature reducing pipe (102) through the steam return pipe (432);

An outlet shunt tube (44) communicated between the temperature reducing tube (102) and the steam return tube (432) and an inlet shunt tube (45) communicated between the inlet tube (101) and the steam shunt tube (431);

the steam return pipe (432), the outlet shunt pipe (44) and the inlet shunt pipe (45) are provided with flow regulating valves (47).

2. The heat trace, temperature and pressure reducing device for a pipeline according to claim 1, further comprising:

The steam check valve (46) is arranged on the outlet shunt pipe (44) and the inlet shunt pipe (45).

3. A heat trace, temperature and pressure reducing apparatus for pipelines according to claim 1, characterized in that the heat exchange and temperature reducing unit (4) comprises:

a heat exchanger body (41) for communicating the steam shunt pipe (431) with the steam return pipe (432), and a water pipe (42) penetrating through the heat exchanger body (41) and the temperature reducing pipe (102);

The output end of the water delivery pipe (42) is provided with an atomization nozzle (421) positioned in the temperature reduction pipe (102), and the atomization nozzle (421) sprays the temperature reduction water into the temperature reduction pipe (102);

A desuperheater thermometer (424) mounted on the water pipe (42), the desuperheater thermometer (424) being located between the heat exchanger body (41) and the desuperheater tube (102).

4. A heat trace, temperature and pressure reducing apparatus for a pipeline according to claim 3, further comprising:

A pressure pump (422) and a temperature-reducing water check valve (423), wherein the input end of the water delivery pipe (42) is provided with the pressure pump (422) and the temperature-reducing water check valve (423);

the water pipe (42) has a spirally wound serpentine portion (420), and the serpentine portion (420) on the water pipe (42) is located within the heat exchanger body (41).

5. A heat trace, temperature and pressure reducing apparatus for a pipeline according to claim 3, further comprising:

A safety valve (3) mounted on the temperature reducing pipe (102);

An outlet pipe (103) connected to the outlet end of the temperature reducing pipe (102), wherein a pressure gauge (1031) for measuring the pressure of the finally discharged steam and a steam thermometer (1032) for measuring the temperature of the finally discharged steam are mounted on the outlet pipe (103).

6. A heat trace, temperature and pressure reducing apparatus for a pipeline according to claim 3, further comprising:

An inner through pipe (51) arranged in the temperature reducing pipe (102), wherein an inner through hole of the inner through pipe (51) is concentric with the temperature reducing pipe (102);

The atomizing nozzle (421) on the water pipe (42) is arranged in the inner through pipe (51), and the inner through pipe (51) replaces the temperature reducing pipe (102) to receive the temperature reducing water sprayed by the atomizing nozzle (421).

7. The heat trace thermal and pressure reducing apparatus for a pipeline according to claim 6, wherein;

the inner through hole of the inner through pipe (51) is of a structure with two ends expanding and middle narrowing, the atomizing nozzle (421) is arranged at the narrowing position of the inner through pipe (51), and the spraying direction of the atomizing nozzle (421) is back to the inlet end of the inner through pipe (51).

8. A heat trace, temperature and pressure reducing apparatus for pipelines according to claim 6, characterized in that the ends of the steam return pipes (432) are bent in the temperature reducing pipe (102), and the bent end mouths of the steam return pipes (432) correspond to the inlets of the inner through holes of the inner through pipes (51).

9. The heat trace, temperature and pressure reducing apparatus for a pipeline according to claim 8, further comprising:

The venturi tube (52), the venturi tube (52) located between outlet end of the temperature reducing tube (102) and outlet end of the inner tube (51) is arranged in the temperature reducing tube (102), and sealing treatment is carried out between the venturi tube (52) and the temperature reducing tube (102); the inlet section of the venturi tube (52) surrounds the outlet end of the inner tube (51).

10. The heat trace thermal and pressure reducing apparatus for a pipeline according to claim 9, wherein;

a relief valve (3) is located between the outlet end of the desuperheater tube (102) and the outlet end of the venturi tube (52), adapted to maintaining the pressure of the final desired exhaust steam.