L-CNG加气站系统配置与运行能耗研究

发布时间：2018-02-25 00:13

本文关键词： L-CNG加气站系统配置运行能耗增压系统 NPSH 充装系统　出处：《山东建筑大学》2017年硕士论文　论文类型：学位论文

【摘要】：L-CNG加气站是以LNG为气源,利用低温高压泵加压至25MPa再经气化后向CNG车辆加气。由于近年来进口LNG逐渐体现出价格优势,加气站运营企业纷纷投资新建L-CNG加气站或是在原有LNG加气站基础上增设增压气化设施。L-CNG加气站在我国发展起步较晚,相关的研究并不完善。在L-CNG加气站运营中经常出现实际运行能耗往往高于预期能耗;选取的设备与加气能力不匹配造成的资源浪费或超负荷运行;以及L-CNG加气站内增压系统工艺设计不合理而导致的低温高压泵回气不畅、汽蚀、空车等现象。所以,对L-CNG加气站运行能耗以及系统配置进行系统分析,对站内工艺系统优化进行深入研究能够为L-CNG加气站的设计以及运行提供理论及技术支持,有利于加气站企业的节能运营。本文以L-CNG加气站系统配置和运行能耗为研究对象,阐述加气站的系统配置以及相关工艺;分析加气站运行过程中的能源消耗分布;研究加气站最大能耗单元增压系统的吸入性能;模拟加气站的充装过程以及供气模式。其具体工作如下:1.阐述L-CNG加气站内的系统配置及其相关工艺,并通过调研加气站的加气数据,得到加气站用气规律和加气时不均匀系数,在此基础下对站内的关键设备(LNG储罐、低温高压泵、高压气化器、CNG储气装置等)在不同用气量、不同建站条件下提出相应的选型方法。2.分析L-CNG加气站内运行过程中产生的能源消耗,界定加气站运行过程的能耗评价范围,选取产品单位产量综合能耗法为分析依据,将L-CNG加气站内各类能耗数量折算为标准煤进行比较和分析,得到运行过程中的能耗分布、各工艺的能源消耗方式及特点,并确定其主要能耗环节即站内增压系统。3.研究L-CNG加气站增压系统的吸入性能,利用不稳定流动伯努利方程理论分析低温高压泵正常吸入时的必要条件;利用更符合实际情况的低温高压泵NPSH(净正吸入压头)来阐释低温高压泵正常工作时所要满足的要求;并基于MATLAB软件对影响加气站增压系统NPSHa的各因素进行计算分析;基于MATLAB GUI实现增压系统NPSHa值分析平台的GUI设计,并模拟加气站增压系统的运行参数利用分析平台对增压系统进行评估,最后结合上述理论研究与分析对实际站点增压系统提出相应的改进思路。4.模拟L-CNG加气站的充装过程和供气模式,利用CNG车辆加气过程数学模型对储气瓶组车辆加气过程进行了模拟,得到气体利用率最大的储气瓶组高、中、低压配比,以及切换压差;通过对储气瓶组单一供气和储气瓶组和低温高压泵联合供气两种不同供气模式的工作时序的计算,分析出在L-CNG加气站特殊工艺前提下储气瓶组和低温高压泵联合供气是最优供气模式。
[Abstract]:The L-CNG filling station uses LNG as the gas source, uses low temperature and high pressure pump to pressurize to 25MPa and then vaporizes to CNG vehicle. Because in recent years the imported LNG gradually reflects the price advantage. Gas station operators have invested in the construction of new L-CNG gas filling stations or the addition of pressurized gasification facilities on the basis of the original LNG filling stations. The development of L-CNG gas filling stations has started relatively late in China. The related research is not perfect. In the operation of L-CNG gas station, the actual energy consumption is often higher than the expected energy consumption, and the selected equipment is not matched with the gas filling capacity, which results in the waste of resources or overload operation. And the phenomena of low temperature and high pressure pump backflow, cavitation and empty car caused by unreasonable process design of charging system in L-CNG filling station. Therefore, the energy consumption and system configuration of L-CNG filling station are analyzed systematically. The deep research on the optimization of the in-station process system can provide theoretical and technical support for the design and operation of L-CNG gas filling station, and be beneficial to the energy saving operation of the gas filling station enterprise. This paper takes the system configuration and operation energy consumption of the L-CNG gas station as the research object. The system configuration and related technology of the gas station are described, the distribution of energy consumption during the operation of the station is analyzed, and the suction performance of the booster system of the maximum energy consumption unit of the gas station is studied. Simulation of filling process and gas supply mode of filling station. The specific work is as follows: 1. The system configuration and related technology in L-CNG filling station are expounded, and by investigating the filling data of gas station, the gas law and uneven coefficient of gas filling station are obtained. On this basis, for the key equipment in the station, such as LNG storage tank, low temperature and high pressure pump, high pressure gasifier CNG gas storage unit, etc. 2. The energy consumption generated in the operation of L-CNG gas station is analyzed, the energy consumption evaluation range of the operation process of the gas station is defined, and the comprehensive energy consumption method of product unit output is selected as the basis for the analysis. The energy consumption distribution in the operation process, the energy consumption mode and the characteristics of each process are obtained by comparing and analyzing the amount of energy consumed in L-CNG gas station converted into standard coal. And determine its main energy consumption link, I. e., the in-station booster system .3.Study on the suction performance of the L-CNG charging system, and analyze the necessary conditions for the normal suction of the low-temperature high-pressure pump by using the unsteady flow Bernoulli equation theory. Using NPSHs (net positive suction head), which is more suitable to the actual situation, to explain the requirements of the cryogenic high pressure pump in normal operation, and to calculate and analyze the factors that affect the NPSHa of charging system of gas station based on MATLAB software. Based on MATLAB GUI, the GUI design of the NPSHa value analysis platform of the supercharging system is realized, and the operation parameters of the turbocharging system are simulated to evaluate the supercharging system by using the analysis platform. Finally, based on the above theoretical research and analysis, the author puts forward the corresponding improvement ideas for the actual station pressurization system. 4. Simulating the filling process and the gas supply mode of the L-CNG filling station. By using the mathematical model of CNG vehicle filling process, the gas filling process of gas cylinder group was simulated, and the high, medium and low pressure ratio and the switching pressure difference of gas cylinder group with the largest gas utilization ratio were obtained. Based on the calculation of the working time of two different gas supply modes, the single gas supply and the gas storage cylinder combined with the low temperature and high pressure pump, the working time series of the single gas supply and the gas storage cylinder combined with the low temperature and high pressure pump are calculated. On the premise of special technology of L-CNG gas filling station, the optimal gas supply mode is the combination of gas tank set and low temperature and high pressure pump.
【学位授予单位】：山东建筑大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TE974

【相似文献】