Industrial Cooling Water Chiller: Analysis of Cooling Cycle Principles and Core Components

Basic Principles of the Cooling Cycle

The core principle of the cooling cycle is the directional transfer of heat—absorbing heat from the area that needs cooling and releasing it into the external environment. Specifically, this is achieved by circulating a refrigerant within a closed system to transfer heat.

This process relies on the coordinated operation of four key components: the compressor, condenser, throttling device, and evaporator.

As a key supporting technology for modern industrial production, industrial cooling water chillers are widely used in modern industrial fields such as food processing, chemical synthesis, and biopharmaceuticals. They ensure the stability of production processes, enhance product quality, and improve energy efficiency.

Figure 1: Industrial Cooling Cycle

Core Components Analysis

I. Compressor

The compressor is the heart of the cooling system, responsible for compressing and heating gaseous refrigerant to increase its density. To achieve effective cooling, the temperature of the refrigerant must be higher than that of the cooling medium in the condenser (such as air or water) to release heat. At the same time, the compressor drives the circulation of the refrigerant within the closed system. Common types of compressors used in industrial cooling include screw, piston, centrifugal, and scroll types, with scroll and screw compressors being the most prevalent. Screw compressors are suitable for large-scale chemical, processing, and water-cooled air conditioning applications.

Figure 2: Semi-hermetic screw compressor

II. Condenser

The condenser is the key component that cools and condenses high-temperature, high-pressure refrigerant vapor into a liquid state by exchanging heat with a cooling medium (such as air or water), removing heat from the refrigerant.

(1) Finned Condenser

The finned condenser uses fans to force air to flow over the condenser coils, dissipating the heat from the refrigerant into the surrounding environment. It has a simple structure, low water consumption, and is suitable for outdoor use, especially in locations where water is scarce.

Figure 3: Finned Condenser

(2) Shell and Tube Condenser

The shell and tube condenser uses water as the cooling medium. The refrigerant flows inside the condenser tubes, and heat is transferred through the tube walls to the cooling water. Compared to air-cooled condensers, water-cooled condensers are more efficient in high-temperature environments, achieving lower condensing temperatures and thereby enhancing the overall performance of the cooling system.

Figure 4: Shell and tube condenser

III. Evaporator

The evaporator is a core component of the cooling system, where liquid refrigerant absorbs heat and evaporates, accomplishing the actual cooling task. Ruidong Group, as a professional HVAC design and manufacturing company, provides high-quality condensers and evaporators under its own brand, equipped with well-known brand compressors. From raw material control to product manufacturing, the company strictly ensures the quality of the units to meet the needs of various industrial cooling environments.

Figure 5: Heat exchanger inventory

Figure 6: Shell and tube condenser/evaporator production line

IV. Expansion Valve Overview

The expansion valve is a key component in the refrigeration cycle. Its main functions are to regulate the refrigerant flow rate to meet the "boiling" demand of the evaporator and to reduce the refrigerant pressure to facilitate the transition between the high-pressure side (compressor and condenser) and the low-pressure side (evaporator).

(1) Thermal Expansion Valve

The thermal expansion valve, commonly used in industrial refrigeration, automatically adjusts the refrigerant flow by detecting temperature and pressure changes in the evaporator via a sensing bulb to maintain superheat. Proper installation and calibration can prevent abnormal refrigerant flow.

(2) Electronic Expansion Valve

The electronic expansion valve monitors system parameters through sensors and controllers, and precisely controls the refrigerant flow based on real-time data. It is suitable for applications with significant load variations but requires a stable power supply and regular maintenance of electronic components.

Regardless of the type of expansion valve chosen, the core objective is to ensure effective refrigerant expansion and heat absorption in the evaporator while maintaining stable system operation. Ruidong Group can recommend the most suitable throttling device based on specific needs and system characteristics, and provide technical support and maintenance suggestions.

Other important components

I. Refrigerants

Refrigerants are the media for heat transfer in refrigeration systems. They circulate between liquid and gaseous states with changes in temperature and pressure, absorbing and releasing heat to achieve cooling. Ruidong Group commonly uses refrigerants such as R22, R134A, R410A, and R407C, which are safer and more environmentally friendly.

II. Pressure Control

Pressure sensors and controllers are installed in the refrigeration system to monitor pressure levels. They help prevent overpressure, which can cause equipment damage or safety risks. Pressure control also ensures that the refrigerant operates within the optimal pressure range, enhancing system performance and efficiency.

III. Safety Control

Safety control devices, such as high-pressure switches, low-pressure switches, overload protectors, and power protectors, are designed to protect the system and operators from potential hazards.

IV. Automation and Monitoring

Control programs use Siemens programming software, which allows flexible parameter adjustments based on actual operating conditions to achieve optimal control logic. This ensures efficient and energy-saving operation of the unit. The microcomputer controllers and electrical components are all from well-known brands, capable of stable operation in ambient temperatures ranging from -15°C to 55°C. They feature comprehensive automatic control functions and are equipped with RS-232/RS-485 interfaces for remote control.

The basic working principle of the refrigeration cycle is the same, but the selection, installation, and maintenance of components in industrial process refrigeration systems are crucial for system performance. Optimizing compressors, condensers, evaporators, expansion valves, and control systems can improve efficiency, reduce energy consumption, and ensure quality and safety.

Industrial chillers are widely used in industries such as power generation, marine, food and beverage, petrochemical, oil and gas, data processing, and district cooling. With the increasing demand for refrigeration in industrial applications, customized systems that meet strict standards are becoming the trend. These systems require careful design and implementation.

Ruidong Group offers comprehensive HVAC services, designing efficient, energy-saving, and environmentally friendly refrigeration systems for various industries. Contact us for more information.

Figure 7: Industrial Chiller and Commercial Air Conditioner Series