Low-temperature nitrogen recycling device
By designing a low-temperature nitrogen recycling device, the problem of the low-temperature nitrogen discharged from the reactor being unable to be utilized was solved, the recycling and energy recovery of nitrogen were realized, the enterprise cost was reduced, and the energy-saving and consumption-reduction requirements of the modern energy system were met.
Patent Information
- Application Number
- CN202422446877.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Priority Date
- 2024-09-30
- Filing Date
- 2024-10-10
- Publication Date
- 2025-09-12
- Estimated Expiration
- 2034-10-10
AI Technical Summary
In the prior art, the low-temperature nitrogen discharged after the reactor is cooled with liquid nitrogen cannot be directly utilized, resulting in energy waste.
A low-temperature nitrogen recycling device was designed, which included a low-temperature nitrogen input end, a liquid nitrogen output end, a main heat exchanger, a nitrogen boosting and cooling device, and a gas-liquid separator. The low-temperature nitrogen was recycled and utilized through the boosting, cooling, and separation processes.
It realizes the recycling of low-temperature nitrogen, improves the nitrogen utilization rate, reduces the operating costs of the enterprise, and meets the energy-saving and consumption-reduction requirements of the modern energy system.
Smart Images
Figure CN223332020U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the field of nitrogen application and relates to a low-temperature nitrogen circulation utilization device, in particular to a low-temperature nitrogen circulation utilization device for a reaction kettle or a reactor. Background Art
[0002] According to China's energy development and modern energy system plan, accelerating the construction of a modern energy system is an inherent requirement for ensuring national energy security and striving to achieve carbon peak and carbon neutrality as scheduled. It is also an important support for promoting high-quality economic and social development. With the development of refined energy, energy conservation and consumption reduction have penetrated into all walks of life. Taking the reactor as an example, the reactor uses liquid nitrogen as a cold source to cool the equipment and medium. Pressurized liquid nitrogen enters the reactor and exchanges heat with the cooled medium. The liquid nitrogen absorbs heat and vaporizes, eventually turning into low-temperature nitrogen and exiting the reactor. Because this part of nitrogen cannot be directly used, it is eventually discharged into the atmosphere, resulting in a huge waste of energy. Utility Model Content
[0003] In order to solve the above technical problems existing in the background technology, the utility model provides a low-temperature nitrogen recycling device that saves energy and reduces consumption.
[0004] In order to achieve the above purpose, the utility model adopts the following technical solutions:
[0005] A low-temperature nitrogen recycling device, characterized in that: the low-temperature nitrogen recycling device includes a low-temperature nitrogen input end, a liquid nitrogen output end, a main heat exchanger E1, a nitrogen boosting and cooling device, and a gas-liquid separator NV; the low-temperature nitrogen input end is connected to the nitrogen boosting and cooling device through the main heat exchanger E1; the high-pressure nitrogen output by the nitrogen boosting and cooling device is connected to the liquid nitrogen output end through the gas-liquid separator NV after heat exchange with the main heat exchanger E1.
[0006] Preferably, the nitrogen boost cooling equipment used in the present invention includes a booster B, the low-temperature nitrogen input end is connected to the booster B through the main heat exchanger E1, and the high-pressure nitrogen output by the booster B is connected to the liquid nitrogen output end through the gas-liquid separator NV after heat exchange with the main heat exchanger E1.
[0007] Preferably, the nitrogen boost cooling device used in the present invention further includes a cooler WE; the high-pressure nitrogen output by the booster B is cooled by the cooler WE and then exchanges heat with the main heat exchanger E1.
[0008] Preferably, the nitrogen boost cooling device used in the present invention further includes a first feedback pipeline; the cooler WE is connected to the booster B via the first feedback pipeline; and a first regulating valve is provided on the first feedback pipeline.
[0009] Preferably, the nitrogen boost cooling equipment used in the present invention also includes a turbine expander ET; the high-pressure nitrogen output after the booster B and heat exchange with the main heat exchanger E1 is divided into a large air flow branch and a small air flow branch; the high-pressure nitrogen in the large air flow branch is connected to the booster B after passing through the turbine expander ET and heat exchange with the main heat exchanger E1; the high-pressure nitrogen in the small air flow branch is connected to the liquid nitrogen output end through the gas-liquid separator NV.
[0010] Preferably, the turbine expander ET used in the present invention is connected to the booster B and drives the booster B to work.
[0011] Preferably, the low-temperature nitrogen recycling device adopted in the present invention further includes a second feedback pipeline; the top of the gas-liquid separator NV is connected to the atmospheric flow branch passing through the turbine expander ET through the second feedback pipeline.
[0012] Preferably, the low-temperature nitrogen recycling device adopted in the present invention also includes a circulating nitrogen compressor NC2 and a second motor; the second motor is connected to the circulating nitrogen compressor NC2 and drives the circulating nitrogen compressor NC2 to work; the low-temperature nitrogen input end is connected to the booster B through the main heat exchanger E1 and the circulating nitrogen compressor NC2.
[0013] Preferably, the low-temperature nitrogen recycling device used in the present invention also includes a raw nitrogen compressor NC1 and a first motor; the first motor is connected to the raw nitrogen compressor NC1 and drives the raw nitrogen compressor NC1 to work; the low-temperature nitrogen input end is connected to the booster B through the main heat exchanger E1, the raw nitrogen compressor NC1 and the circulating nitrogen compressor NC2.
[0014] Preferably, the low-temperature nitrogen recycling device used in the present invention further includes a second regulating valve arranged between the bottom of the gas-liquid separator NV and the liquid nitrogen output end.
[0015] The advantages of the utility model are:
[0016] The present invention provides a low-temperature nitrogen recycling device, comprising a low-temperature nitrogen input, a liquid nitrogen output, a main heat exchanger E1, a nitrogen booster cooling device, and a gas-liquid separator NV. The low-temperature nitrogen input is connected to the nitrogen booster cooling device via the main heat exchanger E1. The high-pressure nitrogen output by the nitrogen booster cooling device exchanges heat with the main heat exchanger E1 and is then connected to the liquid nitrogen output via the gas-liquid separator NV. The present invention recycles low-temperature nitrogen discharged from a reactor, etc., ensuring both nitrogen recycling and the energy contained in the low-temperature nitrogen. This significantly increases nitrogen utilization, reduces enterprise operating costs, and makes the entire system more energy-efficient and rational, thereby achieving the goal of energy conservation and consumption reduction. This fully complies with the relevant requirements of China's energy development and modern energy system planning. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Figure 1 This is a schematic structural diagram of the low-temperature nitrogen recycling device provided by the utility model;
[0018] Figure 2 This is a schematic structural diagram of a preferred low-temperature nitrogen recycling device provided by the present invention;
[0019] in:
[0020] NC1-raw nitrogen compressor; NC2-circulating nitrogen compressor; B-booster; ET-turbine expander; WE-cooler; E1-main heat exchanger; NV-gas-liquid separator; F1-reactor; M-motor. DETAILED DESCRIPTION
[0021] The utility model provides a low-temperature nitrogen recycling device, comprising a low-temperature nitrogen input, a liquid nitrogen output, a main heat exchanger E1, a nitrogen pressurizing and cooling device, and a gas-liquid separator NV. The low-temperature nitrogen input is connected to the nitrogen pressurizing and cooling device via the main heat exchanger E1. The high-pressure nitrogen output from the nitrogen pressurizing and cooling device exchanges heat with the main heat exchanger E1, and then is connected to the liquid nitrogen output via the gas-liquid separator NV. The low-temperature nitrogen input can be connected from a reaction kettle or reactor, and the liquid nitrogen output can be directly connected to the reaction kettle or reactor, forming a complete nitrogen utilization cycle through the reaction kettle or reactor.
[0022] The nitrogen boosting and cooling equipment employed in this invention includes a booster B. The low-temperature nitrogen input is connected to booster B via a main heat exchanger E1. The high-pressure nitrogen output from booster B, after heat exchange with the main heat exchanger E1, is connected to the liquid nitrogen output via a gas-liquid separator NV. The nitrogen input to booster B is pressurized by booster B, and can be cooled through natural pipelines for subsequent or further use. Of course, booster B can also be driven by other drive devices.
[0023] In order to quickly cool the pressurized high-pressure nitrogen, the nitrogen pressurization cooling device provided by the present invention further includes a cooler WE; the high-pressure nitrogen output by the supercharger B is cooled by the cooler WE and then exchanges heat with the main heat exchanger E1.
[0024] The nitrogen boost cooling device further includes a first feedback pipeline; the cooler WE is connected to the booster B via the first feedback pipeline; and a first regulating valve is provided on the first feedback pipeline.
[0025] The nitrogen boosting and cooling equipment provided by the present invention also includes a turbine expander ET. The high-pressure nitrogen output from the booster B and after heat exchange with the main heat exchanger E1 is divided into a large flow branch and a small flow branch. The high-pressure nitrogen in the large flow branch passes through the turbine expander ET and heat exchange with the main heat exchanger E1 before being connected to the booster B. The high-pressure nitrogen in the small flow branch passes through a gas-liquid separator NV and is connected to the liquid nitrogen output port. The turbine expander ET is connected to the booster B and drives the booster B. The low-temperature nitrogen recycling device also includes a second feedback line. The top of the gas-liquid separator NV is connected to the atmospheric flow branch passing through the turbine expander ET via the second feedback line. Through the structural arrangement of the turbine expander ET, the main heat exchanger E1, and the booster B, the present invention partially liquefies the low-temperature nitrogen, achieving both nitrogen recycling and recovery of the energy contained in the low-temperature nitrogen, thereby achieving energy conservation and consumption reduction.
[0026] The low-temperature nitrogen recycling device also includes a circulating nitrogen compressor NC2 and a second motor; the second motor is connected to and drives the circulating nitrogen compressor NC2; the low-temperature nitrogen input is connected to booster compressor B through the main heat exchanger E1 and the circulating nitrogen compressor NC2. The low-temperature nitrogen recycling device also includes a raw nitrogen compressor NC1 and a first motor; the first motor is connected to and drives the raw nitrogen compressor NC1; the low-temperature nitrogen input is connected to booster compressor B through the main heat exchanger E1, the raw nitrogen compressor NC1, and the circulating nitrogen compressor NC2.
[0027] The low-temperature nitrogen recycling device further includes a second regulating valve arranged between the bottom of the gas-liquid separator NV and the liquid nitrogen output end.
[0028] The technical solution provided by the present invention is described in detail below with reference to the accompanying drawings: Figure 1 After the liquid nitrogen passes through the reactor F1 and exchanges heat with the cooled medium, it enters the main heat exchanger E1 of the liquefied cold box in the form of low-temperature nitrogen. It is reheated to room temperature by the positive flow nitrogen and then sent out of the liquefied cold box. It merges with the nitrogen reheated and exiting the liquefied cold box after the expander, enters the circulating nitrogen compressor NC2 for pressurization, and then enters the booster B driven by the turbine expander ET for boosting. It is cooled by the cooler WE and then enters the main heat exchanger E1: a large part of the nitrogen is extracted from the appropriate position of the main heat exchanger E1 and enters the turbine expander ET. After expansion, it returns to the main heat exchanger E1 and enters the circulating nitrogen compressor NC2 after reheating; a small part of the nitrogen is liquefied by the main heat exchanger E1 and throttled to enter the gas-liquid separator NV, and the liquid nitrogen is discharged from the bottom of the gas-liquid separator NV. The low-temperature nitrogen recycling device with this structure can be used if the pressure of the nitrogen discharged from the reaction kettle or reactor is above 0.35MPa, or if the flow rate of the nitrogen discharged from the reaction kettle or reactor is between 400Nm³ / h and 2000Nm³ / h.
[0029] Also, see Figure 2 This is a preferred embodiment of the low-temperature nitrogen recycling device provided by the present invention. In this structure, its specific operating mode is as follows: After passing through reactor F1 and exchanging heat with the cooling medium, liquid nitrogen enters the main heat exchanger E1 of the liquefied cold box as low-temperature nitrogen gas. It is reheated to room temperature by the forward nitrogen flow and then enters the raw nitrogen compressor NC1. The nitrogen compressed by the raw nitrogen compressor NC1 merges with the nitrogen reheated by the expander and exiting the liquefied cold box. It enters the circulating nitrogen compressor NC2 for further pressurization. It then enters the booster B driven by the turbine expander ET for boosting. After cooling in the cooler WE, it enters the main heat exchanger E1. This nitrogen is mainly divided into two parts. A large part of the nitrogen is extracted from the appropriate position of the main heat exchanger E1 and enters the turbine expander ET. After expansion, it returns to the main heat exchanger E1 and enters the circulating nitrogen compressor NC2 after reheating. A small part of the nitrogen is liquefied by the main heat exchanger E1 and throttled to enter the gas-liquid separator NV. The liquid nitrogen is discharged from the bottom of the gas-liquid separator NV. The low-temperature nitrogen recycling device with this structure can be used if the pressure of the nitrogen discharged from the reaction kettle or reactor is between 0.02MPa and 0.35MPa, or the flow rate of the nitrogen discharged from the reaction kettle or reactor is between 2000Nm³ / h and 4000Nm³ / h.
[0030] In actual use, specific analysis can be conducted based on actual production needs or in combination with actual conditions in order to select a more reasonable, low-energy, and highly economical process form.
[0031] Taking a reactor with a nitrogen flow rate of 2000Nm³ / h, a nitrogen discharge pressure of 0.1MPa, and a nitrogen discharge temperature of -150℃ as an example, the liquid nitrogen used in the original device was all purchased from outside; by matching the device described in this project, the 2000Nm³ / h (2.5t / h) nitrogen can be liquefied for recycling; if the liquid nitrogen is calculated at 500 yuan / ton, the cost of purchasing liquid nitrogen can be saved by about 10 million yuan per year (calculated based on 8000h), the liquid nitrogen consumption per ton of the device is about 508kW, and the unit price of electricity is calculated at 0.65 yuan / kWh, then the electricity bill is about 6.604 million yuan, and a total of about 3.396 million yuan can be saved each year.
Claims
1. A low-temperature nitrogen recycling device, characterized in that: The low-temperature nitrogen recycling device comprises a low-temperature nitrogen input end, a liquid nitrogen output end, a main heat exchanger (E1), a nitrogen pressurizing and cooling device, and a gas-liquid separator (NV); the low-temperature nitrogen input end is connected to the nitrogen pressurizing and cooling device through the main heat exchanger (E1); the high-pressure nitrogen output by the nitrogen pressurizing and cooling device exchanges heat with the main heat exchanger (E1) and is then connected to the liquid nitrogen output end through the gas-liquid separator (NV).
2. The low-temperature nitrogen recycling device according to claim 1, characterized in that: The nitrogen boost cooling equipment includes a booster (B), the low-temperature nitrogen input end is connected to the booster (B) through a main heat exchanger (E1), and the high-pressure nitrogen output from the booster (B) is connected to the liquid nitrogen output end through a gas-liquid separator (NV) after heat exchange with the main heat exchanger (E1).
3. The low-temperature nitrogen recycling device according to claim 2, characterized in that: The nitrogen boost cooling device further comprises a cooler (WE); the high-pressure nitrogen outputted by the booster (B) is cooled by the cooler (WE) and then exchanges heat with the main heat exchanger (E1).
4. The low-temperature nitrogen recycling device according to claim 3, characterized in that: The nitrogen boost cooling device further comprises a first feedback pipeline; the cooler (WE) is connected to the booster (B) via the first feedback pipeline; and a first regulating valve is provided on the first feedback pipeline.
5. The low-temperature nitrogen recycling device according to claim 2, 3 or 4, characterized in that: The nitrogen boost cooling device further includes a turbine expander (ET); the high-pressure nitrogen output after passing through the booster (B) and exchanging heat with the main heat exchanger (E1) is divided into a large flow branch and a small flow branch; the high-pressure nitrogen in the large flow branch is connected to the booster (B) after passing through the turbine expander (ET) and exchanging heat with the main heat exchanger (E1); the high-pressure nitrogen in the small flow branch is connected to the liquid nitrogen output end through the gas-liquid separator (NV).
6. The low-temperature nitrogen recycling device according to claim 5, characterized in that: The turbine expander (ET) is connected to the booster (B) and drives the booster (B) to work.
7. The low-temperature nitrogen recycling device according to claim 6, characterized in that: The low-temperature nitrogen recycling device also includes a second feedback pipeline; the top of the gas-liquid separator (NV) is connected to the atmospheric flow branch passing through the turbine expander (ET) through the second feedback pipeline.
8. The low-temperature nitrogen recycling device according to claim 7, characterized in that: The low-temperature nitrogen recycling device also includes a circulating nitrogen compressor (NC2) and a second motor; the second motor is connected to the circulating nitrogen compressor (NC2) and drives the circulating nitrogen compressor (NC2) to operate; the low-temperature nitrogen input end is connected to the booster (B) through the main heat exchanger (E1) and the circulating nitrogen compressor (NC2).
9. The low-temperature nitrogen recycling device according to claim 8, characterized in that: The low-temperature nitrogen recycling device also includes a raw nitrogen compressor (NC1) and a first motor; the first motor is connected to the raw nitrogen compressor (NC1) and drives the raw nitrogen compressor (NC1) to operate; the low-temperature nitrogen input end is connected to the booster (B) through the main heat exchanger (E1), the raw nitrogen compressor (NC1) and the circulating nitrogen compressor (NC2).
10. The low-temperature nitrogen recycling device according to claim 9, characterized in that: The low-temperature nitrogen recycling device further includes a second regulating valve arranged between the bottom of the gas-liquid separator (NV) and the liquid nitrogen output end.