Electrically heated liquid nitrogen evaporator

Abstract

Electric heating liquid nitrogen evaporator relates to the technical field of liquid nitrogen equipment, including box, the inside of box is provided with liquid nitrogen straight pipe, nitrogen straight pipe and heating device;Among them, the one end of liquid nitrogen straight pipe is open, the other end is closed;The one end of nitrogen straight pipe is open, the other end is closed;Nitrogen straight pipe is arranged in parallel with liquid nitrogen straight pipe;Heating device includes at least one heating coil and multiple independent heating coils, one end of heating coil is communicated with liquid nitrogen straight pipe, the other end of heating coil is communicated with nitrogen straight pipe;Heating coil is arranged on the outside of heating coil, and at least two heating coils are arranged on each heating coil.The application can improve the thermal efficiency, reduce the volume, eliminate the safety hidden danger caused by open fire and fuel storage, and reduce the complexity of structure and maintenance cost.

Description

Technical Field

[0001] This utility model relates to the field of liquid nitrogen equipment technology, and in particular to an electrically heated liquid nitrogen evaporator. Background Technology

[0002] In oil and gas field development, liquid nitrogen pump trucks are key specialized equipment used to produce and inject high-pressure nitrogen gas. Their core component—the liquid nitrogen evaporator—is responsible for converting cryogenic liquid nitrogen into high-temperature, high-pressure nitrogen gas. This conversion not only provides stable power for downhole operations but also effectively prevents cavitation and cryogenic embrittlement risks caused by liquid nitrogen directly entering the pump body, ensuring the safe and efficient operation of the system. Currently, the mainstream liquid nitrogen evaporators mainly include two types: direct-fired and heat recovery types, which differ significantly in their structural principles and application characteristics.

[0003] Direct-fired liquid nitrogen evaporators use diesel fuel to generate high-temperature fuel gas, which is then blown by a fan onto the outer wall of the liquid nitrogen pipeline. The liquid nitrogen is vaporized through convective heat transfer between the air and the pipe wall. However, due to the low specific heat capacity and thermal conductivity of air, the overall heat transfer efficiency is relatively low. To meet the on-site requirements for nitrogen flow rate and pressure, these devices are often large and bulky, making them difficult to move and install, and resulting in high manufacturing costs and energy consumption. Furthermore, their continuous diesel fuel consumption poses certain safety risks and environmental pollution problems, indicating significant shortcomings in energy efficiency and economy.

[0004] In contrast, heat recovery liquid nitrogen evaporators employ energy recovery technology, indirectly heating liquid nitrogen by collecting waste heat generated from the vehicle's engine cooling and exhaust systems. This method avoids direct fuel combustion, making it safer and more environmentally friendly, and effectively utilizes waste heat, exhibiting excellent energy-saving characteristics. However, the equipment structure is more complex, requiring a higher degree of integration in the control system, and its performance is susceptible to changes in ambient temperature and operating conditions, which to some extent increases the technical threshold and maintenance costs. Utility Model Content

[0005] In view of this, the technical problem to be solved by this utility model is to provide an electrically heated liquid nitrogen evaporator that can improve thermal efficiency, reduce volume, eliminate safety hazards caused by open flame and fuel storage, and reduce structural complexity and maintenance costs.

[0006] To solve the above-mentioned technical problems, the technical solution of this utility model is as follows:

[0007] An electrically heated liquid nitrogen evaporator, comprising a housing, wherein the interior of the housing is provided with:

[0008] A liquid nitrogen straight tube, wherein one end of the liquid nitrogen straight tube is open and the other end is closed;

[0009] A nitrogen straight pipe, one end of which is open and the other end is closed, and the nitrogen straight pipe is arranged parallel to the liquid nitrogen straight pipe;

[0010] A heating device includes at least one heating coil and multiple independent heating coils. One end of the heating coil is connected to the liquid nitrogen straight pipe, and the other end of the heating coil is connected to the nitrogen straight pipe. The heating coils are disposed on the outside of the heating coil, and at least two heating coils are disposed on each heating coil.

[0011] Preferably, the heating coil is an S-shaped heating coil, which includes multiple heating sections, each of which is vertically upward and connected by an arc-shaped section between adjacent heating sections.

[0012] Preferably, the heating coil is disposed on the outside of the heating part, and each heating coil is independently connected to an external power source.

[0013] Preferably, the heating coil is an electromagnetic coil with a spiral structure wound on the heating part.

[0014] Preferably, a liquid nitrogen temperature sensor is provided at the open end of the liquid nitrogen straight pipe; a nitrogen temperature sensor is provided at the open end of the nitrogen straight pipe.

[0015] Preferably, a coil temperature sensor is provided on the outside of each heating coil.

[0016] Preferably, the housing includes a left housing and a right housing, both having an L-shaped structure and interlocking with each other;

[0017] The liquid nitrogen straight pipe, the nitrogen gas straight pipe, and the heating device are all installed on the left box.

[0018] Preferably, a fixing plate is installed at the bottom of the left box.

[0019] Preferably, a control device is installed on the side wall of the left housing, and the control device is electrically connected to the heating coil.

[0020] After adopting the above technical solution, the beneficial effects of this utility model are:

[0021] The electrically heated liquid nitrogen evaporator of this application includes a housing, inside which are arranged a liquid nitrogen straight pipe, a nitrogen gas straight pipe, and a heating device; wherein, both the liquid nitrogen straight pipe and the nitrogen gas straight pipe are open at one end and closed at the other end; the heating device includes at least one heating coil and multiple independent heating coils, one end of the heating coil is connected to the liquid nitrogen straight pipe, and the other end of the heating coil is connected to the nitrogen gas straight pipe; the heating coils are arranged on the outside of the heating coil, and each heating coil is provided with at least two heating coils.

[0022] Liquid nitrogen enters from the open end of a liquid nitrogen straight pipe and is distributed to one or more heating coils. During its flow through the heating coils, multiple independently controlled heating coils on the outside generate heat, segmentally heating the coils. This causes the liquid nitrogen flowing inside to absorb heat, rapidly rise in temperature, and completely vaporize into nitrogen gas. The generated high-pressure nitrogen gas then flows into a nitrogen gas straight pipe parallel to the liquid nitrogen straight pipe and is finally stably output from its open end, providing power for downhole operations. In this application, by incorporating heating coils, the heating area of ​​the liquid nitrogen is increased, improving vaporization efficiency and energy utilization. Simultaneously, in conjunction with the heating coils, the structure is compact and the volume is reduced, overcoming the bulky and heavy problems of traditional evaporators. During operation, there is no diesel combustion stage, eliminating the safety hazards associated with open flames and fuel storage, fundamentally preventing related safety risks and pollutant emissions. It also effectively prevents cavitation and low-temperature embrittlement, significantly enhancing system safety. Attached Figure Description

[0023] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0024] Figure 1 This is a schematic diagram of the internal structure of the electrically heated liquid nitrogen evaporator according to an embodiment of the present invention;

[0025] Figure 2 yes Figure 1 A schematic diagram of the structure of the liquid nitrogen straight pipe, nitrogen gas straight pipe, heating coil, and heating coil;

[0026] Figure 3 yes Figure 1 A structural diagram from another direction;

[0027] Figure 4 yes Figure 1 A structural diagram after the right housing is assembled;

[0028] In the picture:

[0029] 1. Box body; 11. Left box body; 12. Right box body; 13. Fixing plate;

[0030] 2. Liquid nitrogen straight tube; 21. Liquid nitrogen temperature sensor;

[0031] 3. Nitrogen straight pipe; 31. Nitrogen temperature sensor;

[0032] 4. Heating device; 41. Heating coil; 411. Heating section; 412. Arc-shaped section; 42. Heating coil; 421. Coil temperature sensor;

[0033] 5. Control device. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model.

[0035] like Figures 1 to 4 As shown, this utility model includes a housing 1, inside which are arranged a liquid nitrogen straight pipe 2, a nitrogen gas straight pipe 3, and a heating device 4. The liquid nitrogen straight pipe 2 is open at one end and closed at the other, with the open end used to connect to an external liquid nitrogen input device. The nitrogen gas straight pipe 3 is open at one end and closed at the other, and is arranged parallel to the liquid nitrogen straight pipe 2. This parallel arrangement is for a reasonable layout and compact structure. The open end of the nitrogen gas straight pipe 3 is used to output nitrogen gas.

[0036] The heating device 4 includes at least one heating coil 41 and multiple independent heating coils 42. One end of the heating coil 41 is connected to the liquid nitrogen straight pipe 2, and the other end of the heating coil 41 is connected to the nitrogen straight pipe 3. The heating coils 42 are disposed on the outside of the heating coil 41, and at least two heating coils 42 are disposed on each heating coil 41.

[0037] Liquid nitrogen enters from the open end of the liquid nitrogen straight pipe 2 and is distributed to one or more heating coils 41. During the flow through the heating coils 41, multiple independently controlled heating coils 42 on the outside generate heat, segmentally heating the heating coils 41. This causes the liquid nitrogen flowing inside to absorb heat, rapidly rise in temperature, and completely vaporize into nitrogen gas. The generated high-pressure nitrogen gas then flows into a nitrogen straight pipe 3, which is parallel to the liquid nitrogen straight pipe 2, and is finally stably output from its open end, providing power for downhole operations. In this application, by setting up heating coils 41, the heating area of ​​the liquid nitrogen is increased, improving vaporization efficiency and energy utilization. Simultaneously, in conjunction with the heating coils 42, the structure is compact and the volume is reduced, overcoming the problem of traditional bulky and heavy evaporators. During operation, there is no diesel combustion stage, eliminating the safety hazards caused by open flames and fuel storage, fundamentally eliminating related safety risks and pollutant emissions. It also effectively prevents cavitation and low-temperature embrittlement, significantly enhancing system safety.

[0038] In this application, the heating coil 41 is an S-shaped heating coil 41, which includes multiple heating sections 411, which are vertically upward-facing, and adjacent heating sections 411 are connected by an arc-shaped section 412. By setting it to an S-shaped structure and a meandering path, the flow path and heating time of liquid nitrogen are greatly extended, allowing the liquid nitrogen to fully and uniformly absorb heat. The vertically upward-facing heating sections 411 cleverly utilize gravity and the characteristics of gas-liquid two-phase flow. The nitrogen bubbles generated by heat absorption at the bottom rise naturally under the action of buoyancy. This process not only violently disturbs the fluid inside the tube and breaks the boundary layer, thereby enhancing heat transfer, but also effectively propels the fluid forward by the rising motion of the bubbles, enhancing the flow self-driving force and improving vaporization efficiency and stability. The arc-shaped section 412 ensures a smooth transition of the flow channel, effectively reducing flow resistance and local pressure loss. The overall structure maximizes the heat exchange area within a limited space, combining high efficiency, stability, and compactness.

[0039] Preferably, the heating coil 42 is disposed on the outside of the heating part 411, and each heating coil 42 is independently connected to an external power source; wherein, the heating coil 42 is an electromagnetic coil with a spiral structure wound on the heating part 411.

[0040] Each independently powered heating coil 42 enables precise segmented temperature control at each stage of the liquid nitrogen vaporization process, ensuring uniform heating and complete conversion of the liquid nitrogen. Utilizing electromagnetic induction heating achieves highly efficient heat transfer, significantly improving energy utilization. The independently controlled design not only enhances system reliability, ensuring that a single coil failure does not affect overall operation, but also facilitates maintenance. Simultaneously, the non-contact heating method fundamentally eliminates the risk of electrical contact, effectively guaranteeing the equipment's safe operation in flammable and explosive environments. The overall design, through precise temperature control, efficient heat transfer, and high reliability, collectively ensures the efficiency, stability, and safety of the liquid nitrogen to nitrogen gas conversion process.

[0041] A liquid nitrogen temperature sensor 21 is installed at the open end of the liquid nitrogen straight pipe 2; a nitrogen temperature sensor 31 is installed at the open end of the nitrogen straight pipe 3; and a coil temperature sensor 421 is installed on the outside of each heating coil 42.

[0042] By installing temperature sensors at the inlet of the liquid nitrogen straight pipe 2, the outlet of the nitrogen straight pipe 3, and each independent heating coil 42, precise monitoring and intelligent control of the entire liquid nitrogen vaporization process are achieved. The liquid nitrogen temperature sensor 21 monitors the initial liquid nitrogen state in real time, the nitrogen gas temperature sensor 31 ensures the output gas fully reaches the preset temperature requirement, and the coil temperature sensor 421 on each heating coil 42 directly monitors the operating status of each heating section. This multi-point monitoring system provides precise data support for the closed-loop control of the system, ensuring not only the stable and efficient vaporization process and preventing incomplete vaporization or localized overheating, but also quickly identifying and adjusting the power when individual coils malfunction, thereby significantly improving the overall system's reliability, safety, and energy utilization efficiency.

[0043] The housing 1 includes a left housing 11 and a right housing 12, both L-shaped and interlocking. The liquid nitrogen straight pipe 2, the nitrogen straight pipe 3, and the heating device 4 are all mounted on the left housing 11. A fixing plate 13 is installed at the bottom of the left housing 11 for easy installation and fixation. A control device 5 is installed on the side wall of the left housing 11, and the control device 5 is electrically connected to the heating coil 42.

[0044] The enclosure 1 adopts an interlocking design, integrating the liquid nitrogen straight pipe 2, nitrogen straight pipe 3, and heating device 4 into the left enclosure 11. Together with the bottom fixing plate 13 and the side wall control device 5, it forms a highly integrated, easy-to-install, and easy-to-maintain modular unit. The L-shaped split structure makes equipment assembly and internal maintenance more convenient; the concentration of all core components in the left enclosure 11, along with the fixing plate 13, ensures overall structural stability and ease of installation; the control device 5 is directly installed on the side wall and electrically connected to the heating coil 42, achieving centralized management of power and control, shortening wiring distance, and improving system response speed and maintenance convenience. This design significantly enhances the overall integrity, reliability, and engineering applicability of the equipment.

[0045] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. An electrically heated liquid nitrogen evaporator, characterized in that, Includes a housing, the interior of which is provided with: A liquid nitrogen straight tube, wherein one end of the liquid nitrogen straight tube is open and the other end is closed; A nitrogen straight pipe, one end of which is open and the other end is closed, and the nitrogen straight pipe is arranged parallel to the liquid nitrogen straight pipe; A heating device includes at least one heating coil and multiple independent heating coils. One end of the heating coil is connected to the liquid nitrogen straight pipe, and the other end of the heating coil is connected to the nitrogen straight pipe. The heating coils are disposed on the outside of the heating coil, and at least two heating coils are disposed on each heating coil.

2. The electrically heated liquid nitrogen evaporator as described in claim 1, characterized in that, The heating coil is an S-shaped heating coil, which includes multiple heating sections. The heating sections are arranged vertically upwards, and an arc-shaped section connects adjacent heating sections.

3. The electrically heated liquid nitrogen evaporator as described in claim 2, characterized in that, The heating coils are located on the outside of the heating part, and each heating coil is independently connected to an external power source.

4. The electrically heated liquid nitrogen evaporator as described in claim 3, characterized in that, The heating coil is an electromagnetic coil with a spiral structure wound around the heating part.

5. The electrically heated liquid nitrogen evaporator as described in claim 1, characterized in that, A liquid nitrogen temperature sensor is installed at the open end of the liquid nitrogen straight pipe; a nitrogen temperature sensor is installed at the open end of the nitrogen straight pipe.

6. The electrically heated liquid nitrogen evaporator as described in claim 1, characterized in that, A coil temperature sensor is provided on the outside of each of the heating coils.

7. The electrically heated liquid nitrogen evaporator as described in claim 1, characterized in that, The enclosure includes a left enclosure and a right enclosure, both of which are L-shaped and interlocked with each other; The liquid nitrogen straight pipe, the nitrogen gas straight pipe, and the heating device are all installed on the left box.

8. The electrically heated liquid nitrogen evaporator as described in claim 7, characterized in that, A fixing plate is installed at the bottom of the left box.

9. The electrically heated liquid nitrogen evaporator as described in claim 7, characterized in that, A control device is installed on the side wall of the left housing, and the control device is electrically connected to the heating coil.

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