基于食品冷冻质量的冷库热湿环境多目标控制与系统能耗协同优化研究

In recent years, with the improvement of living standards, people have an increasing dependency on frozen foods, which leads to the rapid development of frozen food industry. In the current production of frozen foods, freezing time is commonly used as the single constraint of freezing quality, combined with the fixed room temperature in operation of cold storage. This operation mode generally leads to more energy consumption and the uncertainty of frozen food quality. This topic mainly focuses on food freezing in cold storage. With the combination of theoretical analysis, experimental test and numerical simulation, the influencing mechanism of freezing process and freezing quality are studied. Multiple quality control indexes of frozen food quality are established. Then the regulative mechanism of food freezing is revealed. On the basis of research on the non-uniform characteristics of air distribution in cold storage, a multi-scale model of air distribution in cold storage and food freezing is established to reveal the regulative mechanism of thermal and humidity environment of cold storage with multiple targets. The energy transfer and utilization efficiency in the coupling system of cold storage are clarified. By introducing the theory of collaborative optimization, the collaborative optimization model of freezing quality and energy consumption is developed, as well as a dynamic operation mode of cold storage, which satisfies not only the quality constraints of frozen food but also the energy-saving purpose. The establishment of energy-saving operation system of cold storage based on frozen food quality has important scientific implications for the improvement of existing operation mode of cold storage and the development of new processes of food freezing.

近年来随着人民生活水平的提高，人们对冷冻食品的依赖程度越来越高，这使得食品冷冻行业和冷库建设得到了快速的发展。在现有的冷库生产方式中，通常使用冻结时间作为食品冷冻质量的单一约束条件，并采用固定库温的冷库运行方式，这往往导致系统能耗高、食品冷冻质量无法保证等问题。本课题以冷库内食品冷冻过程作为研究对象，利用理论分析、实验测试和数值模拟相结合的手段，对冷库内食品冷冻过程与冷冻质量影响机制进行研究，建立食品冷冻质量多个评价指标。在冷库内热湿环境非均匀分布特性研究的基础上，建立冷库热湿环境与食品冷冻的多尺度模型，揭示基于食品冷冻质量的冷库热湿环境多目标控制机理。明确冷库耦合系统中的能量转移关系与利用效率，引入协同优化理论，建立食品冷冻质量与制冷系统能耗协同优化模型，寻求既满足食品冷冻质量又达到节能目的冷库动态运行方式，构建基于食品冻结质量的冷库节能运行体系。

食品冷冻通过降低食品温度来抑制食品内部酶和微生物的作用，从而达到长期贮藏的目的，是目前最有效的遏制食品腐坏的保存方法之一。近年来，随着人民生活水平的提高和快递物流行业的快速发展，作为冷链物流的核心节点的冷库行业得到快速发展。然而，食品冷冻过程的质量控制缺乏基础的理论研究，这给进一步保障冷冻质量、优化系统能耗带来了障碍。本项目采用理论、实验和数学仿真相结合的方法，研究了食品冷冻过程和冷冻质量的影响机制，分析食品冷冻质量与多个评价指标的内在关系，建立了食品冷冻质量评价指标；在研究食品冷冻中热力学和流体力学的基础上，建立食品冷冻过程热质传递数学模型，确定了食品冷冻质量的调控机理；开展和完善了冷库热湿环境非均匀分布特性及调控机理研究，以食品冷冻质量指标作为冷库热湿环境的控制目标，揭示了基于食品冷冻质量的冷库内热湿环境的多目标控制机理；以食品冷冻质量评价指标作为冷库运行约束条件，进行了食品冷冻质量与制冷系统能耗的协同优化研究，寻求既满足食品冷冻质量要求又达到节能目的的系统运行方式，为冷库节能优化的研究和食品冷冻工艺的制定提供重要的理论基础和技术基础，对于改进传统冷库运行方式和发展食品冷冻新工艺都具有重要的科学意义。