联合太阳能沼气的冷热电供能系统的集成及经济性分析

冷热电联供是一种先进、高效的能源系统,目前在我国应用的主要问题是天然气成本高,导致系统经济性差。太阳能和沼气是非常清洁的可再生能源,在我国来源广泛且廉价。将冷热电联供系统与太阳能、沼气完美地结合起来,集成为联合太阳能沼气的冷热电供能系统。该系统较为合理的组合方式是采用太阳能沼气池作为燃料提供装置,采用微型燃气轮机、余热锅炉、溴化锂吸收式制冷机、蒸汽换热器等作为供电、供冷和供热机组,采用太阳能集热器、换热器等装置为沼气池加热,太阳能不足时采用尾气加热。该系统能够实现能量的梯级利用,提高一次能源利用率,达到综合用能的目的,同时可有效治理环境。以某酒店作为该系统的用户对象,分析其经济性并与常规模式进行对比。结果表明,该系统一次能源利用率为74.8%,而常规模式为62.3%;综合能源价格为0.3398元/(k W·h),而现阶段电网电价约为0.6元/(k W·h);环境与减排评价指标也具有明显优势。

Integration and Economic Efficiency of Combined Cooling Heating and Power Production System Based on Combined Use of Solar Energy and Biogas

Combined cooling,heating and power production is an advanced efficient energy system.The main obstacle to a wider use of this system in China is its poor economic efficiency due to high natural gas cost.Solar energy and biogas are very clean renewable energy sources and these resources are abundant and cheap in China.A combined cooling,heating and power production system can be well integrated with solar energy and biogas to form a system supplying cooling,heat and power based on solar energy and biogas.A good form of such system is using a solar biogas generating pit as the fuel-supplying unit and micro gas turbines,residual heat boilers,lithium bromide absorption refrigerators and steam heat exchangers as the pow-er,cooling and heating supply assembly,and using solar thermal collectors and heat exchangers to heat the biogas generating pit.When solar energy is insufficent,tail gas is used to heat the pit.Such system can achieve a gradient utilization of energy,raise the efficiency of primary energy,realize an integrated use of different energy sources and reduce environmental pollution.Using a hotel as the potential user of such system,this article analyzes the economic efficiency of using this system and compares such system with a conven-tional system.Analysis results show that such system ′ s primary energy efficiency is 74.8%,compared with a conventional system ′s efficiency of 62.3%.The composite price of energy used by such system is 0.3398 yuan per k W·h,while the current price of power from the grid is abot 0.6 yuan per k W·h.The system also has considerable advantages in environmental and emission reduction evaluation aspects.