1. Refrigeration Equipment Planning

Based on the determination of refrigeration cycle methods and planning work parameters, and considering the user's refrigeration capacity requirements and operational conditions, we analyze and calculate the methods and capacities of each component in the refrigeration equipment. For vapor compression refrigeration units, first, we determine the type and number of compressors; taking into account various compressor types (such as reciprocating, centrifugal, screw, scroll, and rolling piston), their refrigeration capacity ranges, operating functions, initial investment, vibration and noise levels, and safety factors, we select an appropriate type. Generally, using multiple compressors in the same system, especially in high-capacity refrigeration systems, is beneficial for energy scheduling during partial load operation, which can save energy consumption. Secondly, we design the heat exchanger structure and size (mainly including condensers and evaporators), considering both high heat transfer efficiency and factors such as initial investment, equipment arrangement, and operational maintenance. For instance, increasing the heat transfer area can reduce operating costs, but also increases material consumption and initial investment.

Again, select the type of energy-saving equipment (float valves, thermal expansion valves, electronic expansion valves, capillary tubes, etc.) based on the flow scheduling characteristics of the equipment to ensure excellent matching with the refrigeration system. In some cases, the selection of equipment type is already determined at the outset of the planning phase. For refrigerator manufacturers, the type of product produced is determined by the decision-making level based on market conditions and the company's own production technology. However, from a general perspective of refrigeration equipment design, this part of the work is indispensable.

2. Refrigeration Equipment Control Measures Planning

During internships, due to changes in external conditions, thermal loads and equipment operating parameters are continuously and irregularly modified. It is necessary to promptly and accurately schedule all refrigeration equipment to ensure they operate safely, stably, and economically. With the development of technology, various automated devices are now used in refrigeration systems. According to different levels of automation, they can be roughly categorized as:

① Manually controlled collaborative safety maintenance equipment.

② Some Automatic Control: On the basis of completing safety maintenance, the automatic control of the liquid pump circuit and evaporator circuit has been added, which can improve scheduling accuracy, stabilize the cooling temperature strategy, and save energy consumption. Now, the use of some control applications for cold storage is increasing domestically, and mature planning and management experience has been summed up.

③ Semi-Automatic Control: Primarily manifests in the automatic start/stop of the compressor and energy scheduling, with some control elements excluded.

④ Full Automatic Control: In addition to semi-automatic control, it also encompasses auxiliary equipment operation and automatic control of factors like humidity, such as automatic oiling, automatic oil draining, automatic air release, and automatic scheduling of condenser cooling water volume.

⑤ Effective Operating Condition Scheduling and Control: The controlled parameters are not fixed values but are adjusted according to the changes in practical working conditions, making judgments on various conditions based on the input program. The system selects the most energy-efficient operating condition from a predefined set for control, ensuring the system operates optimally. This control method requires a deeper understanding of refrigeration equipment operations, establishing a reasonable mathematical model, and developing an excellent control strategy to advance the control and energy-saving capabilities of refrigeration equipment to a higher level.

As the level of automatic control advances, the precision of control increases, leading to improved quality of refrigeration products and a reduction in equipment energy consumption. Concurrently, this also effectively reduces the labor intensity of operators, prevents accidents, and ensures the personal safety of staff. However, the initial investment for the equipment will increase, and maintenance and repair will also become more complex. Therefore, when choosing control methods, do not blindly pursue the degree of automatic control but consider aspects such as energy-saving, economy, operation, and maintenance holistically.