System and method for gasifying lng in distributed energy station

Abstract

The invention relates to a system and a method for gasifying LNG for distributed energy station. The system comprises a gasifying device, a gas turbine, a waste heat boiler, a steam turbine and a condenser, wherein the gas delivery port of the gasifying device is connected with the gas inlet of the gas turbine, the smoke discharge port of the gas turbine is connected with the waste heat boiler, the steam discharge port of the waste heat boiler is connected with the steam inlet of the steam turbine, the steam discharge port of the steam turbine is connected with the steam inlet of the condenser, the condensation water outlet of the condenser is connected with the condensation water inlet of the waste heat boiler, the water inlet of the condenser is connected with a water supply pipe, the water outlet of the condenser is connected with a water return pipe, the water return pipe is divided into two paths, one path is connected with the water inlet of the gasifying device, the other path is connected with an impounding reservoir, the impounding reservoir communicates with the atmosphere, and the water outlet of the gasifying device is connected with the water supply pipe. The system and the method not only have the advantages of being high in energy utilization rate and good in power plant economical efficiency, and can avoid the problem that combustible gas is brought into a steam circulation thermodynamic system and reduce personal safety risk.

Description

technical field [0001] The invention relates to LNG gasification technology, in particular to a system and method for gasifying LNG at a distributed energy station. Background technique [0002] Distributed energy is a comprehensive energy utilization system distributed at the user end, pursuing energy cascade utilization to achieve higher energy utilization efficiency. The distributed energy system whose prime mover is a small gas turbine generally uses natural gas as fuel. In some distributed energy stations with unstable pipeline gas sources, an additional LNG (liquefied natural gas) gasification station is often set up to ensure that the pipeline gas cannot meet the requirements. During the normal operation of the unit, the LNG is transported by tank trucks. After gasification and pressure regulation of the LNG in the gasification station, the natural gas is delivered to the prime mover through pipelines. LNG gasification heat absorption generally adopts air-temperature...

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Problems solved by technology

The heat source of the water-bath gasifier comes from the hot water provided by the water heater. LNG gasification requires the water heater to consume an additional part of natural gas, and the gas consumption increases. Due to the combustion in the small combustion furnace, the combustion control is uneven and passes through the middle The medium hot water provides the heat required for LNG gasification, the energy utilization efficiency is low, and high-temperature flue gas is emitted to the atmosphere, which is not conducive to reducing pollutant emissions, and natural gas is operated and controlled in multiple branches, which is not conducive to combustible gases Leakage monitoring, there are high safety risks such as gas leakage and deflagration

[0003] Or generally, natural gas is used to generate power through a gas turbine, and the waste heat from the exhaust gas heats the steam into the steam turbine to generate power. A part of the steam with high calorific value is extracted in the middle of the steam turbine, leading to the LNG gasification system, and using high-grade steam through the gasifier The latent heat of vaporization gasifies LNG, the steam temperature is high, it belongs to the pressure pipeline, and the gasifier is also a pressure vessel. The safety requirements of these equipment and pipelines are high, which increases the cost of the gasification equipment; in addition, the steam is cooled and condensed into water. For higher-quality working fluid, the condensed water is re-boosted and discharged into the thermal system of the steam cycle. Due to the risk of pipe breakage in the gasifier, natural gas may escape into the steam and condensed water system, and the leaked natural gas will be carried away immediately. Into the pipelines and equipment of the thermal system, there are potential safety hazards of re-leakage and deflagration

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