Natural gas station excess pressure cold energy utilization rewarming device

Abstract

The utility model discloses a natural gas station excess pressure cold energy utilization rewarming device which comprises a filter, a first-stage expansion generator, a heat exchanger A, a second-stage expansion generator, a heat exchanger B, an ice maker and a reheater. The first-stage expansion generator is connected with the heat exchanger A through a second connecting pipeline, the heat exchanger A is connected with the ice maker through a third connecting pipeline, the heat exchanger A is further connected with the recuperator through a ninth connecting pipeline, the filter is connected with the second-stage expansion generator through a fourth connecting pipeline, and the second-stage expansion generator is connected with the ice maker through a ninth connecting pipeline. And the secondary expansion generator is connected with the heat exchanger B through a fifth connecting pipeline. According to the device, the problem of waste of natural gas energy is solved, the energy is converted into electric energy and cold energy through a natural gas pipe network excess pressure recovery technology, gradient utilization of the energy is achieved, and the system efficiency and economic benefits are greatly improved.

Description

Technical Field

[0001] The utility model relates to the technical field of natural gas surplus pressure power generation cold energy recovery and rewarming, in particular to a natural gas station surplus pressure cold energy utilization and rewarming device. Background Art

[0002] It is a common method for natural gas to be transported from the gas source to downstream users through a high-pressure pipeline network after being reduced in pressure by a pressure regulating valve, but the pressure of pipeline transportation is relatively high. Directly using a pressure reducing valve to reduce the pressure, the temperature of the natural gas after the pressure reduction is low, and the pressure energy is wasted, causing safety hazards such as low-temperature icing and blockage of subsequent pipelines. Using the residual pressure of natural gas to generate electricity and recover cold energy, the reheating system can recover pressure energy to generate electricity and obtain cold energy, realize the cogeneration of cold and electricity, and improve energy utilization.

[0003] The patent with the authorization announcement number CN216043931U discloses a system for recovering and utilizing cold energy for natural gas pressure regulation, including: a filter, a heat exchanger, a shut-off valve, a regulating valve, an expander, a gearbox, and a generator. The high-pressure natural gas passes through the filter to remove impurities, and the heat exchanger reheats the cold flow natural gas to meet the requirements of the downstream pipeline; the gas expander regulates and reduces the pressure of the high-pressure natural gas to the required pressure, and converts the differential pressure in the pipeline network into mechanical energy for impeller rotation, and adjusts and reduces the speed through the gearbox, driving the generator to convert the mechanical energy into electrical energy, and the generator is connected to the power grid to generate electricity and go online; the low-temperature natural gas after power generation enters the cold energy recovery device for cold energy recovery; the cold flow of natural gas after cold energy recovery enters the reheater again to be reheated, and is transported downstream after meeting the standards.

[0004] However, this patent has defects: the pressure is directly reduced by a pressure reducing valve, and the temperature of the natural gas after the pressure reduction is low, resulting in pressure waste and causing safety hazards such as low-temperature icing and blockage of subsequent pipelines. For this purpose, a natural gas station surplus pressure cold energy utilization and rewarming device is provided. The device can realize the recovery and utilization of natural gas surplus pressure and perform cascade utilization of energy. The pressure energy is now converted into electrical energy and then the cold energy is recovered and utilized, thus realizing energy recovery and utilization compared with traditional pressure regulating devices. Utility Model Content

[0005] The purpose of the utility model is to provide a natural gas station waste pressure cold energy utilization rewarming device in view of the defects of the prior art, so as to solve the problems raised by the above-mentioned background technology.

[0006] To achieve the above-mentioned purpose, the utility model provides the following technical solutions: a natural gas station waste pressure cold energy utilization reheating device, comprising a filter, a primary expansion generator, a heat exchanger A, a secondary expansion generator, a heat exchanger B, an ice maker, and a reheater, wherein the filter is connected to the primary expansion generator through a first connecting pipe, the primary expansion generator is connected to the heat exchanger A through a second connecting pipe, the heat exchanger A is connected to the ice maker through a third connecting pipe, the heat exchanger A is also connected to the reheater through a ninth connecting pipe, the filter is connected to the secondary expansion generator through a fourth connecting pipe, the secondary expansion generator is connected to the heat exchanger B through a fifth connecting pipe, the heat exchanger B is connected to the ice maker through a sixth connecting pipe, and the filter is connected to the reheater through a seventh connecting pipe.

[0007] As a preferred technical solution of the present utility model, an inlet cut-off valve A is installed on the first connecting pipeline.

[0008] As a preferred technical solution of the present utility model, an inlet cut-off valve B is installed on the fourth connecting pipeline.

[0009] As a preferred technical solution of the utility model, a bypass cut-off valve and a bypass pressure regulating valve are installed on the seventh connecting pipeline.

[0010] As a preferred technical solution of the present utility model, the heat exchanger B is connected to the reheater through an eighth connecting pipe.

[0011] As a preferred technical solution of the present utility model, the eighth connecting pipe is respectively connected to the seventh connecting pipe and the ninth connecting pipe.

[0012] As a preferred technical solution of the present utility model, the first connecting pipe is respectively connected to the seventh connecting pipe and the fourth connecting pipe.

[0013] As a preferred technical solution of the utility model, the filter is connected to a natural gas inlet pipeline, and the reheater is connected to a natural gas outlet pipeline.

[0014] Compared with the prior art, the beneficial effects of the utility model are: this application aims to solve the problem of natural gas energy waste, and through the natural gas pipeline network residual pressure recovery technology, its energy is converted into electrical energy and cold energy, realizing the cascade utilization of energy, greatly improving the system efficiency and economic benefits.

[0015] After throttling and expansion, high-pressure natural gas is depressurized, but at the same time it is reduced to a relatively low temperature. The existing method is to release this part of cold energy directly, and it is also necessary to consume gas to heat it through water bath heaters and other equipment, which wastes energy. The utility model recovers this part of cold energy and realizes the reheating of natural gas without energy consumption, which reduces energy consumption and investment, reduces pollution emissions, saves resources, and meets the temperature requirements of the downstream pipeline network to prevent ice blockage and other situations. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a structural schematic diagram of the utility model.

[0017] In the figure: 1. filter; 2. inlet shut-off valve A; 3. first-stage expansion generator; 4. heat exchanger A; 5. inlet shut-off valve B; 6. second-stage expansion generator; 7. heat exchanger B; 8. bypass shut-off valve; 9. bypass pressure regulating valve; 10. ice maker; 11. reheater. DETAILED DESCRIPTION

[0018] The preferred embodiments of the present invention are described in detail below in conjunction with the accompanying drawings so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making a clearer and more definite definition of the protection scope of the present invention.

[0019] Example: See Figure 1 The utility model provides a technical solution: a natural gas station waste pressure cold energy utilization reheating device, including a filter 1, a primary expansion generator 3, a heat exchanger A4, a secondary expansion generator 6, a heat exchanger B7, an ice maker 10, and a recuperator 11. The filter 1 is connected to the primary expansion generator 3 through a first connecting pipe, the primary expansion generator 3 is connected to the heat exchanger A4 through a second connecting pipe, the heat exchanger A4 is connected to the ice maker 10 through a third connecting pipe, the heat exchanger A4 is also connected to the recuperator 11 through a ninth connecting pipe, the filter 1 is connected to the secondary expansion generator 6 through a fourth connecting pipe, the secondary expansion generator 6 is connected to the heat exchanger B7 through a fifth connecting pipe, the heat exchanger B7 is connected to the ice maker 10 through a sixth connecting pipe, and the filter 1 is connected to the recuperator 11 through a seventh connecting pipe.

[0020] An inlet cut-off valve A2 is installed on the first connecting pipeline.

[0021] An inlet shut-off valve B5 is installed on the fourth connecting pipeline.

[0022] A bypass cut-off valve 8 and a bypass pressure regulating valve 9 are installed on the seventh connecting pipeline.

[0023] The heat exchanger B7 is connected to the reheater 11 through an eighth connecting pipe.

[0024] The eighth connecting pipeline is respectively connected to the seventh connecting pipeline and the ninth connecting pipeline.

[0025] The first connecting pipe is communicated with the seventh connecting pipe and the fourth connecting pipe respectively.

[0026] The filter 1 is connected to a natural gas inlet pipeline, and the reheater 11 is connected to a natural gas outlet pipeline.

[0027] Working principle: A natural gas station residual pressure cold energy utilization and reheating device, comprising a filter 1, a primary expansion generator 3, a heat exchanger A4, a secondary expansion generator 6, a heat exchanger B7, an ice maker 10 and a reheater 11. The high-pressure natural gas passes through the filter 1 to remove impurities, and then opens the inlet shut-off valve A2 and the inlet shut-off valve B5, and flows into the gas expansion machine (primary expansion generator 3 and secondary expansion generator 6) in parallel, reducing the pressure of the high-pressure natural gas to the required pressure, and converting the differential pressure in the pipeline network into mechanical energy through the rotation of the impeller of the primary expansion generator 3, and the speed is adjusted and reduced through the gearbox to drive the generator to convert the mechanical energy into electrical energy. The generator is connected to the power grid for power generation and access to the grid; the low-temperature natural gas after power generation enters the heat exchanger (heat exchanger A4 and heat exchanger B7) cold energy recovery device for cold energy recovery; after heat exchange, it returns to the ice maker 10, and provides cold capacity for ice making in the ice maker 10; the natural gas after the initial temperature increase is merged into the reheater 11 to be reheated, and is transported downstream after reaching the standard. Compared with traditional voltage regulating devices, it realizes energy recovery and utilization, greatly improving economic benefits.

[0028] When the pressure difference residual pressure power generation device fails, the expander inlet cut-off valve A2 and the inlet cut-off valve B5 are closed urgently, and the bypass cut-off valve 8 connected in parallel with the residual pressure power generation device is quickly opened to allow the natural gas to pass through the bypass and pass through the pressure reducing valve 9 to reduce it to the pressure required by the downstream users, and then enter the reheater 11 to increase the temperature, ensuring stable operating pressure and ensuring that downstream users can smoothly and uninterruptedly receive natural gas.

[0029] The above embodiments only express the implementation methods of the utility model, and the description is relatively specific and detailed, but it cannot be understood as limiting the scope of the utility model patent. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the utility model, which all belong to the protection scope of the utility model.

Claims

1. A natural gas station waste pressure cold energy utilization and reheating device, comprising a filter (1), a primary expansion generator (3), a heat exchanger A (4), a secondary expansion generator (6), a heat exchanger B (7), an ice maker (10), and a reheater (11), characterized in that: The filter (1) is connected to a primary expansion generator (3) via a first connecting pipe, the primary expansion generator (3) is connected to a heat exchanger A (4) via a second connecting pipe, the heat exchanger A (4) is connected to an ice maker (10) via a third connecting pipe, the heat exchanger A (4) is also connected to a recuperator (11) via a ninth connecting pipe, the filter (1) is connected to a secondary expansion generator (6) via a fourth connecting pipe, the secondary expansion generator (6) is connected to a heat exchanger B (7) via a fifth connecting pipe, the heat exchanger B (7) is connected to the ice maker (10) via a sixth connecting pipe, and the filter (1) is connected to the recuperator (11) via a seventh connecting pipe.

2. A natural gas station waste pressure cold energy utilization and rewarming device according to claim 1, characterized in that: An inlet shut-off valve A (2) is installed on the first connecting pipeline.

3. A natural gas station waste pressure cold energy utilization and rewarming device according to claim 1, characterized in that: An inlet shut-off valve B (5) is installed on the fourth connecting pipeline.

4. A natural gas station waste pressure cold energy utilization and rewarming device according to claim 1, characterized in that: The seventh connecting pipeline is installed with a bypass cut-off valve (8) and a bypass pressure regulating valve (9).

5. A natural gas station waste pressure cold energy utilization and rewarming device according to claim 1, characterized in that: The heat exchanger B (7) is connected to the reheater (11) via an eighth connecting pipe.

6. A natural gas station waste pressure cold energy utilization and rewarming device according to claim 5, characterized in that: The eighth connecting pipe is communicated with the seventh connecting pipe and the ninth connecting pipe respectively.

7. A natural gas station waste pressure cold energy utilization and rewarming device according to claim 1, characterized in that: The first connecting pipe is communicated with the seventh connecting pipe and the fourth connecting pipe respectively.

8. A natural gas station waste pressure cold energy utilization and rewarming device according to claim 1, characterized in that: The filter (1) is connected to a natural gas inlet pipeline, and the reheater (11) is connected to a natural gas outlet pipeline.

Images