Device for recovering low-temperature evaporated gas

Abstract

The utility model provides a device for recycling low-temperature evaporated gas, which comprises a body and is characterized by comprising a high-pressure gas passage, a low-temperature evaporated gas passage, a gas flow sensing unit and a gas recycling unit, the gas flow sensing unit is composed of a heating mechanism, a pressure detection module, a flow detection module and a control valve. The gas recycling unit is composed of an injection unit and a compressor unit. A heating mechanism, a pressure sensor, a flow sensor and a compressor unit are sequentially arranged on the low-temperature evaporation gas passage; a control valve and an injection unit are sequentially arranged on the high-pressure gas passage; the pressure detection module is used for monitoring the low-temperature boil-off gas pressure of the low-temperature boil-off gas passage; the flow detection module is used for monitoring the low-temperature evaporation gas flow of the low-temperature evaporation gas passage; the compressor unit and the injection unit are used in cooperation to recycle low-temperature evaporation gas, flow distribution of the low-temperature evaporation gas is reasonably controlled through the adjusting valve, and the effect of reducing energy consumption is achieved.

Description

Technical Field

[0001] The utility model belongs to equipment for treating low-temperature boil-off gas, in particular to a device for recovering low-temperature boil-off gas. Background Art

[0002] At present, most of the low-temperature evaporative gas recovery adopts the traditional compressor recovery method. The low-temperature evaporative gas is pressurized by the compressor and then input into the downstream gas pipeline network. This method has problems such as incomplete recovery, high equipment cost, large occupied area, and high equipment energy consumption.

[0003] The combination of a compressor and an ejector is used to recover the low-temperature evaporated gas, which can recover the low-temperature evaporated gas in a more economical, more reasonable and easier way. Utility Model Content

[0004] In view of the difficulties in the prior art, the utility model provides a device and method for recovering low-temperature evaporated gas. The process flow of the device adopts a compressor recovery and an ejector combined recovery scheme. According to the flow change of the evaporated gas, the recovery route is flexibly selected. When the amount of evaporated gas is small, only the ejector is used for recovery. When the amount of evaporated gas is large, a combination of a compressor and an ejector is used to reduce the total investment of the device and achieve the advantages of energy saving, economy and easy operation.

[0005] In order to solve the existing technical problems, the utility model adopts the following technical solutions:

[0006] A device for recovering low-temperature boil-off gas, the device is composed of a body, a high-pressure gas passage, a low-temperature boil-off gas passage, a gas flow sensing unit and a gas recovery unit; the flow sensing unit is composed of a heating mechanism, a pressure detection module, a flow detection module and a control valve; the gas recovery unit is composed of an injection unit and a compressor unit; the low-temperature boil-off gas passage is provided with a heating mechanism, a pressure sensor, a flow sensor and a compressor unit in sequence; the high-pressure gas passage is provided with a control valve and an injection unit in sequence; the pressure detection module is used to monitor the low-temperature boil-off gas pressure of the low-temperature boil-off gas passage; the flow detection module is used to monitor the low-temperature boil-off gas flow of the low-temperature boil-off gas passage; wherein:

[0007] One output end of the flow monitoring module is connected to the compressor unit; the other output end is directly connected to the input end of the injection unit through a control valve; wherein:

[0008] When the low-temperature boil-off gas inputted by the low-temperature boil-off gas passage meets the ejector processing threshold, the flow monitoring module issues a command to adjust the opening of the control valve F101, and the boil-off gas is ejected by the high-pressure gas in the ejector and sent to the gas pipe network;

[0009] When the low-temperature evaporated gas input into the low-temperature evaporated gas passage exceeds the injector threshold, the flow detection module issues a full-start control valve command. At this time, the injector still cannot completely handle the evaporated gas when working at full load. The remaining evaporated gas will increase the pressure detection value. The pressure detection module issues a compressor start command. The compressor unit pressurizes the low-temperature evaporated gas input into the low-temperature evaporated gas passage and sends it into the gas pipeline network.

[0010] Beneficial Effects

[0011] 1. The utility model overcomes the existing technology of using only traditional compressors to compress and recover low-temperature evaporated gas. Instead, the utility model uses a compressor unit and an injection unit to recover low-temperature evaporated gas, and reasonably controls the flow distribution of low-temperature evaporated gas through a regulating valve to achieve the effect of reducing energy consumption;

[0012] 2. The utility model does not need to use a compressor of larger specifications. Even when the amount of low-temperature evaporated gas to be recovered is small, only the ejector is used instead of the compressor;

[0013] 3. The utility model reduces the maintenance workload and difficulty of low-temperature evaporated gas recovery and improves production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 The utility model is a schematic diagram of the structure of a device for recovering low-temperature evaporated gas. DETAILED DESCRIPTION

[0015] The following is combined with Figure 1 The utility model is described as follows:

[0016] like Figure 1 As shown, the utility model provides a device for recovering low-temperature boil-off gas, the device comprising a high-pressure gas passage 101, a low-temperature boil-off gas passage (201, 202), a gas flow sensing unit 200 and a gas recovery unit 300; the flow sensing unit 200 is composed of a heating mechanism E101, a pressure detection module PT, a flow detection module FT and a control valve F101; the gas recovery unit 300 is composed of an injection unit P101 and a compressor unit C101; the low-temperature boil-off gas passage (201, 202) is provided with a heating mechanism E101, a pressure detection module PT, a flow detection module FT and a compressor unit C101 in sequence; the high-pressure gas passage 101 is provided with a control valve F101 and an injection unit P101 in sequence; the pressure detection module is used to monitor the low-temperature boil-off gas pressure of the low-temperature boil-off gas passage; the flow detection module FT is used to monitor the low-temperature boil-off gas flow of the low-temperature boil-off gas passage; wherein:

[0017] One output end of the flow monitoring module FT is connected to the compressor unit C101; the other output end of the flow monitoring module FT is directly connected to the input end of the injection unit P101 through the control valve F101; wherein:

[0018] When the low-temperature boil-off gas inputted by the low-temperature boil-off gas passage meets the ejector processing threshold, the flow monitoring module FT issues a command to adjust the opening of the control valve F101, and the boil-off gas is ejected by the high-pressure gas in the ejector and sent to the gas network.

[0019] When the low-temperature evaporated gas input into the low-temperature evaporated gas passage exceeds the injector threshold, the flow detection module issues a full-start control valve command. At this time, the injector still cannot completely handle the evaporated gas when working at full load. The remaining evaporated gas will increase the pressure detection value. The pressure detection module issues a compressor start command. The compressor unit pressurizes the low-temperature evaporated gas input into the low-temperature evaporated gas passage and sends it into the gas pipeline network.

[0020] The specific generation process of this utility model:

[0021] The utility model has two operation modes according to the flow rate of low-temperature evaporation gas, using an ejector alone or a compressor and an ejector in combination to recover the low-temperature evaporation gas.

[0022] When the low-temperature evaporation gas flow rate is lower than or equal to the maximum working flow rate of the ejector P101, the ejector recovery system operation (stream 202) is performed, and the ejector is operated to pressurize and recover the low-temperature evaporation gas, which includes the following steps: the low-temperature evaporation gas is heated by the heating device E101, and enters the suction inlet of the ejector P101 through the stream 202, and the flow regulating valve F101 is opened to allow the driving fluid to flow into the power inlet of the ejector P101, and the low-temperature evaporation gas entering the ejector contacts and mixes with the driving fluid in the ejector P101, the evaporation gas in the ejector P101 is pressurized, and the gas in the ejector P101 is discharged from the ejector P101 outlet and transported to the gas network;

[0023] When the low-temperature evaporated gas flow rate is higher than the maximum working flow rate of the ejector P101, the compressor C101 and the ejector P101 operate simultaneously to pressurize and recover the evaporated gas, which includes the following steps: after the low-temperature evaporated gas is heated by the heating device E101, a part of the heated low-temperature evaporated gas enters the suction inlet of the ejector P101 through the stream 202, and the flow regulating valve F101 is opened to allow the driving fluid to flow into the power inlet of the ejector P101. The low-temperature evaporated gas entering the ejector contacts and mixes with the driving fluid in the ejector P101, and the evaporated gas in the ejector P101 is pressurized, and the gas in the ejector P101 is discharged from the outlet of the ejector P101; the other part of the evaporated gas increases its pressure in the stream 201, and the pressure detection module monitors and issues a command to automatically start the compressor C101. The compressor C101 pressurizes the evaporated gas and mixes it with the ejector outlet fluid stream 301 and inputs it into the gas network.

[0024] Although the utility model has been described above, the utility model is not limited to the above-mentioned specific embodiments. The above-mentioned specific embodiments are merely illustrative and not restrictive. Under the guidance of the utility model, ordinary technicians in this field can make many modifications without departing from the purpose of the utility model, which are all within the protection of the utility model.

Claims

1. A device for recovering low-temperature boil-off gas, characterized in that: The device comprises a high-pressure gas passage, a low-temperature evaporation gas passage, a gas flow sensing unit and a gas recovery unit; the gas flow sensing unit is composed of a heating mechanism, a pressure detection module, a flow detection module and a control valve; the gas recovery unit is composed of an injection unit and a compressor unit; the low-temperature evaporation gas passage is provided with a heating mechanism, a pressure sensor, a flow sensor and a compressor unit in sequence; the high-pressure gas passage is provided with a control valve and an injection unit in sequence; the pressure detection module is used to monitor the low-temperature evaporation gas pressure of the low-temperature evaporation gas passage; the flow detection module is used to monitor the low-temperature evaporation gas flow of the low-temperature evaporation gas passage; wherein: One output end of the flow detection module is connected to the compressor unit; the other output end is directly connected to the input end of the injection unit through a control valve; wherein: When the low-temperature boil-off gas inputted by the low-temperature boil-off gas passage meets the ejector processing threshold, the flow detection module issues an instruction to adjust the opening of the control valve, and the boil-off gas is ejected by the high-pressure gas in the ejector and sent to the gas pipe network; When the low-temperature evaporated gas input into the low-temperature evaporated gas passage exceeds the injector threshold, the flow detection module issues a full-start control valve command. At this time, the injector still cannot completely handle the evaporated gas when working at full load. The remaining evaporated gas will increase the pressure detection value. The pressure detection module issues a compressor start command. The compressor unit pressurizes the low-temperature evaporated gas input into the low-temperature evaporated gas passage and sends it into the gas pipeline network.

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