Compressed natural gas discharging device and adjustment and control method

Abstract

The invention discloses a compressed natural gas discharging device and an adjustment and control method. The compressed natural gas discharging device is mainly composed of gas discharging columns, a vacuum heating furnace, a pressure adjusting device, a PLC automatic control system and the like. According to the technical scheme, incoming gas of tank trucks is metered through the discharging columns and then enters the heating furnace; when the pressure of the incoming gas is high, natural gas is directly discharged through a high-pressure adjusting pipeline; when the pressure of the incoming gas is low, the procedure is automatically switched, and the natural gas enters a low-pressure adjusting pipeline and is decompressed to the allowed inlet pressure of a compressor and then pressurized and discharged; the pressure and the temperature of the pressure-adjusted natural gas are monitored in real time through the PLC automatic control system, and after a judgment is made according to the hydrate generation condition, the power and the gas discharging speed of the heating furnace are adjusted in real time; and the compressor is automatically started and stopped and the conversion control over the gas discharging procedure of a single tank truck or the multiple tank trucks is achieved. The compressed natural gas discharging device is suitable for recycling and discharging operation of marginal natural gas such as scattered natural gas, shale gas and oil field associated gas, the automation degree is high, hydrate are prevented and treated, and meanwhile the purposes that gas discharging efficiency is improved, and the tank truck residual gas volume, the device heating energy consumption and operation risks are reduced are achieved.

Description

technical field [0001] The invention relates to a gas unloading device for safely and efficiently discharging marginal natural gas such as scattered natural gas, shale gas, and oilfield associated gas recovered by CNG tankers into natural gas gathering stations, export stations, etc., specifically relates to a A compressed natural gas unloading device and an adjustment control method belong to the field of natural gas gathering and transportation engineering. Background technique [0002] During the exploration and development of conventional natural gas fields and unconventional natural gas fields such as shale gas, due to the need to drill wells and evaluation wells, some scattered and remote single wells with low production and far away from gas gathering stations will inevitably be produced. In addition, during the development of oilfields, some oilfield associated gas will be produced from crude oil, the main component of which is also CH 4 , but the yield is low. Due...

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Problems solved by technology

The existing CNG unloading devices generally use water jacket heating furnace or electric heating to prevent and control hydrates, but the existing devices have the following deficiencies: 1) There is generally only one outlet pipeline for degassing and pressure regulation, and there is no suction booster. The reciprocating compressor used for compression leads to the high pressure and large amount of residual gas that cannot be discharged by the CNG tanker, which reduces the effective transportation capacity of the tanker and increases the transportation cost; 2) The degree of automation is low, and it is impossible to monitor the natural gas after heating Temperature and evaluate the risk of hydrate formation in the process pipeline. The heating furnace often uses a constant heating power to heat the natural gas, which cannot be adjusted in real time according to the actual needs of the process, resulting in high energy consumption of the heater and increasing the operation risk of the device

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