基于火积的换热网络综合策略及应用研究

发布时间：2018-04-10 02:33

本文选题：换热网络综合　切入点：火积　出处：《青岛科技大学》2017年硕士论文

【摘要】：过程系统工程的一个重要的研究内容是换热网络综合,对高耗能的过程工业实现节约资源、提高能源的利用率具有重要意义。在换热网络综合方法中,夹点分析法可以确定换热网络的节能目标,得到与能量目标一致的最大热回收换热网络,但不能确定换热网络的热效率;熵分析法和?分析法虽然能计算换热网络的热效率,但是不能得到换热网络中的匹配关系。若能提出一种换热网络综合策略,以热效率为优化目标,指导换热网络的合成,实现能量最大回收利用,而且具有科学意义。从换热网络存在火积耗散量的不可逆性出发,首先讨论了基于火积的传热状态图,从而确定了温度-热流图,然后研究了冷、热物流及公用工程火积量、火积耗散量、火积回收量间的关系,并提出了基于火积的换热网络能量目标的确定方法。接着分析了基于火积的换热网络综合问题,提出了火积量守恒准则、火积耗散量最小准则、温差最小准则和热势能传递不可逆性准则的4个换热网络匹配准则。根据能量目标的确定方法和匹配准则得到了最高火积传热效率的换热网络,从而形成了完整的基于火积的换热网络综合策略。为了验证基于火积的换热网络综合策略的正确性,对柴油加氢装置和汽油吸附脱硫装置进行基于火积的换热网络节能研究。结果表明:柴油加氢装置需要8.543×106 kW·K的最小热公用工程火积量和7.428×106 kW·K的最小冷公用工程火积量,利用基于火积的换热网络综合策略,得到了与能量目标一致的最高火积传递效率换热网络,实现了节约热公用工程47.72%和冷公用工程41.19%,火积传递效率从69.77%提高到92.29%,投资回收期为0.71年;汽油吸附脱硫装置需要8.196×105kW·K的最小热公用工程火积量和5.506×105 kW·K的最小冷公用工程火积量,利用基于火积的换热网络综合策略,得到了与能量目标一致的最高火积传递效率换热网络,实现了节约热公用工程75.75%和冷公用工程71.60%,火积传递效率从77.63%提高到91.07%,投资回收期为0.38年。结果验证了基于火积的换热网络综合策略的正确性。并通过两个装置换热网络的节能研究,都得到了与能量目标一致的换热网络,又证明了该策略的通用性,可以提高实际工业化生产装置的节能效果,实现了能量的有效利用。
[Abstract]:One of the important research contents of process system engineering is the synthesis of heat exchanger network, the process of high energy consuming industry to economize resources, is of great significance to improve the utilization rate of energy. In the heat exchanger network synthesis method, pinch analysis method can determine the energy saving target of heat exchanger network, the maximum heat recovery and energy targets get the heat exchanger network, but can not determine the thermal efficiency of the heat exchanger network; entropy analysis method and analysis method? Although can calculate the thermal efficiency of the heat exchanger network, but can not be changed, relationship between the thermal network. If we can put forward a heat exchanger network synthesis strategy, taking thermal efficiency as the optimization goal, synthetic guidance the heat exchanger network, to achieve maximum recycling energy, but also has scientific significance. Starting from the irreversibility of heat exchanger network existence of entransy dissipation quantity, firstly discusses the state diagram based on entransy transfer, so as to determine the temperature and heat flow diagram, Then the cold heat, logistics and utilities fire volume, entransy dissipation quantity, relationship between the amount of fire product recovery, and proposes a method for determining the heat exchanger network energy target based on entransy. Then analyzes the synthesis problem of heat exchanger network fire product based on the entransy conservation standards, the amount of the minimum entransy dissipation criterion, and the criterion of minimum temperature difference between the heat energy transfer irreversibility criterion 4 heat exchanger network matching criterion. According to the energy method to determine the target and the matching principle, obtained the heat exchanger network maximum entransy heat transfer efficiency, thus forming a complete thermal network for comprehensive strategy based on entransy to. Verification of heat exchanger network synthesis strategy is correct based on entransy, diesel hydrogenation unit and gasoline adsorption desulfurization unit of energy-saving heat exchanger network based on entransy. The results show that most of diesel oil and small heat hydrogen device requires 8.543 x 106 kW - K Minimum cooling utilities utilities volume and fire fire 7.428 * 106 kW K volume, the use of comprehensive strategy for thermal network based on entransy, obtained the highest fire target product is consistent with the energy transfer efficiency of the heat exchanger network, can save the hot utilities and 47.72% cold utilities 41.19%, entransy transfer the efficiency is increased from 69.77% to 92.29%, the payback period is 0.71 years; the minimum cold utilities fire minimum heating utility gasoline adsorption desulfurization device requires 8.196 x 105kW K fire volume and 5.506 x 105 kW K volume, the use of comprehensive strategy for thermal network based on entransy, obtained the highest consistent fire the target product and energy transfer efficiency of the heat exchanger network, can save the hot utilities and 75.75% cold utilities 71.60%, entransy transfer efficiency increased from 77.63% to 91.07%, the payback period is 0.38 years. The results show the thermal network ensemble selection based on entransy transfer Through the energy conservation research of the two heat exchanger networks, we get the heat exchanger network which is consistent with the energy target, and prove the universality of the strategy. It can improve the energy saving effect of the actual industrial production device and achieve the effective utilization of energy.

【学位授予单位】：青岛科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TE965

【相似文献】