Design of Heat Exchange System of Sand Core Drying Furnace

Heat exchange system is a circulatory drying system on sand core drying furnace. However, there are some shortcomings in the heat exchange system of sand core drying furnace in the current industrial field. For example, the temperature in the drying process is not stable enough, and the optimal temperature control parameters are difficult to choose. In this study, a proportional regulating heat exchange system is designed. The system adopts SIMATIC 1200 programmable logic controller as controller, motor-driven control valve as actuator and back propagation neural network proportion integral differential control algorithm. After sand core drying test, the results revealed that the proportional regulating heat exchange system can realize automatic control of sand core drying temperature and output the optimal combination of heat exchange system control parameters. Compared to the previous heat exchange system, it has better drying temperature control stability.

Smart Heating and Cooling Heat Pump System by Standing Column Well and Cross-Mixing Balancing Well Heat Exchangers

Standing column well (SCW) geothermal heat exchanger permits a bleeding discharge of less than 20% in the event of a maximum load, which is an inappropriate method of using underground water. In this study, the existing operational method of two adjacent SCW geothermal heat exchangers, each with a single well, was modified. This technology aims to improve the coefficient of performance (COP) of the geothermal system by fundamentally preventing underground water discharge and maintaining a constant temperature of the underground heat exchanger. To curb the bleed water discharge, two balancing wells of cross-mixing methods were employed. The result of the cooling and heating operations with the existing SCW heat exchange system and the balancing well cross-combined heat exchange system showed that the measured COP increases by 23% and 12% during the cooling and heating operations, respectively. When operating with a balanced well cross-mixed heat exchange system, the initial temperature of the underground was constant with a small standard deviation of 0.08–0.12 °C.

Evaluation of Irreversibility and Optimal Organization of an Integrated Multi-Stream Heat Exchange System

This work proposes a structure synthesis and surface distribution algorithm in a heat exchange system for the case when all heat capacity rates and inlet temperatures of the hot streams are constant, while cold streams also have outlet temperatures set. The algorithm includes the possibility of changing the phase state of the contacting streams. The synthesis is based on minimization of dissipation for a given total heat load in the form of minimum total contact surface area, which again correlates with the cost of the heat exchange system. The proposed algorithm can be considered to follow a thermodynamic rationale and as development of pinch analysis.