#1 Vapor Compression Refrigeration Background

The Vapor Compression Refrigeration Cycle is nearly 200 years old, marked by crucial milestones and technological advancements.   In 1834, Jacob Perkins patented the vapor compression refrigeration cycle, laying the foundation for modern refrigeration systems.   Over the next few decades, inventors and engineers like Felix Carre and Alexander Twining further developed this technology, experimenting with refrigerants and system designs.   By the 1850s, commercial vapor compression refrigeration systems began to emerge, initially used for large-scale applications like ice making.   Over time, these systems became more efficient and practical, enabling their widespread adoption across industries.

In recent decades, many challenging applications and environmental concerns have driven advances in vapor compression refrigeration technology.   The search for more environmentally friendly refrigerants has led to the development of alternatives like ammonia and carbon dioxide.   Alongside this, improvements in compressor efficiency, compactness, performance, heat exchanger design, and control systems have continued to enhance the performance of these systems.   As a result,  in response to the market’s demand and technological advancement, the miniature yet maintained with high efficiency and high-performance compressors came out, and then the compact, lightweight, compressor cooling systems followed.

#Moir’s Compact, Vapor Compression Refrigeration Technology

Moir Cooling is committed to engineering, developing, and manufacturing compact, reliable vapor compression systems, and offering custom compact cooling solutions to meet the growing demands of many demanding applications in a wide variety of industries.   We provide the world’s smallest rotary compressors and have designed a series of mini cooling systems/ mobile refrigeration systems based on this technology.   These high capacity cooling systems are designed smaller than a shoe box / A4 paper that can be integrated inside the tight confiness of your device chassis.

Because of the ultra-compact size and high energy density features, now, our compact compressor cooling systems have been widely supplied to many industry-leading equipment manufacturers for applications ( such as medical aesthetic, electronic cooling, industrial lasers, transport food delivery, beverage cooling, portable air conditioners etc.)

Our in-house manufactured miniature compressors, it operates at variable-capacity and employs a high efficiency, high energy density brushless DC motor.   Combining with an advanced inverter drive controller,  it gives us a unique advantage when it comes to compact, lightweight, efficient, cutting-edge cooling systems.

Approached by the clients’ different requirements globally, we’ve developed air-cooled systems, liquid-chilled systems, and direct refrigerant systems.   Apart from our standard DC cooling units,  we offer tailor-made service.   If you need a high performance, high efficiency, rock-solid reliable, compact compressor cooling system, our team of experienced engineers will partner with you to customize a refrigeration system to meet your requirements and offer you a distinct market advantage.

# 3 Types Compact, Vapor Compression Refrigeration Systems

Having the right compressor cooling system in place is significantly crucial for elevating your device practice and keeping running effectively.   The water-cooled system ( or liquid circulating systems) is the most powerful, but an air-cooled approach is less resource-heavy.   Following the direct expansion systems is much smaller, lighter, and higher reliability.    Let’s take a look at the differences among them.

1) Air-Cooled Systems

An air conditioning system is great for almost any light-duty application.   They’re especially in areas where outdoor temperatures remain moderate throughout the year.   The air-cooled compressor cooling units use recirculated air in a sealed environment as the cooling mechanism.

MOIR’s micro air conditioners efficiently eliminate heat and humidity from the air, which is then circulated through the system to effectively cool the heat source.   These air cooling and circulating systems are particularly suitable for cooling extensive heat loads or multiple distributed loads, like electronic components, while minimizing any necessary modifications to the existing system.

2) Liquid-Chilled Systems

In contrast to traditional icy water chillers, the liquid chiller system operates as a compressor-driven circulating cooling system.   Leveraging a refrigeration cycle, it effectively extracts heat from various liquids.   This chilling system directs chilled coolant to a radiator or other heat exchangers.

A compressor chiller offers high heat transfer rates because the secondary coolant has a high thermal conductivity and specific heat. Water chiller systems can be quite compact because a pump circulates a coolant which offers high heat flux. Using a secondary coolant enables the size of heat exchangers to shrink, while thermal performance increases. A water-cooled chillers from compressor is perfect of cooling high heat flux components and in application where a solutin must be of rock-solid reliability. 

3) Direct Expansion Systems (DX Systems)

Direct expansion systems are known as direct refrigerant systems or refrigerant circulating systems.  With direct refrigerant cooling, refrigerant flows directly through the cold plate(evaporator) with the circulation being driven by the mini compressor.   They typically offer the highest heat transfer rates.

The DX System eliminates the need for a liquid recirculating pump, fluid reservoir, and associated tubing and connectors, sources of failures and leaks.  This method greatly minimizes the size and component count of system, and it is significantly simplified improving reliability with an MTBF>90,000 hours.

#4 Why Vapor Compression Cooling?

Derived from the same technology that keeps your home refrigerator chilled, vapor compression technology has been perfected over a century of technological advancements.  This active thermal cooling is an efficient and reliable cooling solution that utilizes the phase change of a refrigerant to effectively cool heat sources to temperatures below ambient conditions.

The process involves a compressor that pumps the refrigerant from an evaporator, where it absorbs heat, to a condenser, where it releases that heat to the surrounding air.  During this cycle, the refrigerant undergoes a phase change, transforming from a liquid to a vapor in the evaporator and back to a liquid in the condenser.  This phase change, along with the pumping action of the compressor, enables the process to operate with high efficiency.

Vapor compression refrigeration systems are notable for their ability to produce more cooling than the amount of power consumed.  This efficiency, coupled with the use of appropriate refrigerants, compressors, and heat exchangers, allows vapor compression refrigeration to be used in a wide range of applications, from household refrigerators to medical devices, life science research tools, laboratory equipment, high-tech lasers, military communications, and even electric vehicle charge cables.

Small-scale vapor compression refrigeration refers to systems with lower cooling capacity than those provided by conventional units, and its purpose is to provide localized cooling at a certain place, system, space, or body demanding cooling.

Moir is always committed to focusing on compact, energy-efficient cooling solutions with environmentally compatible refrigerants used, which adhere to all international regulations for the reduction of ozone-depleting and global warming substances.  Our step and mission on this will never stop.

#5 How Vapor Compression Refrigeration Works?

The key refrigeration components of a vapor compression system are the compressor, condenser, expansion valve (or capillary), and evaporator.  Refrigeration circulation is a process that uses physical phase change and heat transfer.   Below is a brief overview of the cycle:

Compression: The compressor is the heart of the cooling system, powering the refrigeration circulation.  Moir engineered and manufactured a miniature rotary compressor that efficiently generates a significant capacity within a small volume.  It draws in low-pressure, low-temperature refrigerant vapor and compresses it, raising its pressure and temperature.

Condensation: The compressed refrigerant vapor enters the condenser, where it releases heat to the surrounding environment and condenses into a liquid.

Expansion: The liquid refrigerant flows through the capillary, where its pressure and temperature drop, turning it into a low-pressure, low-temperature liquid-vapor mixture.

Evaporation: The refrigerant enters the evaporator, where it absorbs heat from the surrounding environment, evaporating into a vapor.  This process cools the space inside the evaporator.

Completion of the Cycle: The refrigerant vapor is then drawn back into the mini compressor, completing the cycle.

#6 Vapor Compression vs Thermoelectric Cooling

Vapor compression technology is widely utilized in cooling buildings and data centers due to its unparalleled efficiency and performance.  It stands as the most effective cooling method currently available, offering a remarkable ratio of cooling power to energy consumption.  Depending on the operational settings, a standard vapor compression refrigeration system can generate cooling power that is double the amount of energy it utilizes.  This level of efficiency far surpasses any other cooling technology.

The most common alternative technology is the thermoelectric-based Peltier device, which falls short in comparison.  These devices require at least twice the amount of power they provide in cooling, or four times more power than a vapor compression system operating under similar conditions.

In terms of maximum thermodynamic efficiency, vapor compression systems boast a Carnot efficiency of up to 80%, while achieving a commercially viable efficiency of 60%.  Conversely, thermoelectric systems have a maximum Carnot efficiency of only 35% and a commercially attained efficiency of approximately 15%, which is just a quarter of the efficiency achieved by vapor compression systems.

#7  Choosing the Right Miniature Vapor Compression System

The miniaturization of components and complete refrigeration systems represents a new era in the development of vapor compression refrigeration systems.  They are producing smaller, lighter, wearable, or portable systems that maintain high efficiency, performance and reliability.

However, as mentioned above, there are 3 types of vapor compression refrigeration systems( Air Circulating System, Liquid Circulating System, and Refrigerant Circulating System).  How to choose the right compact vapor cooling system for your application to boost their cooling performance while maintaining productivity and equipment longevity can be challenging.  A proper compact cooling system must be of the right size and performance to deliver the required level of cooling while remaining efficient.

When comparing miniature vapor cooling options, be mindful that the cost of operating the compressor is merely one consideration.  Additionally, take into account the amount of space you possess and the feasibility of effortlessly connecting your system to a water source.  This is imperative if you intend to opt for an open design, as it necessitates a reliable connection to running water.

Before introducing a new compact cooling system from a micro compressor, it’s crucial to address any underlying issues that have previously caused overheating problems.  Electrical wiring damage, overload operation, and other factors can all contribute to overheating.  If these are not properly resolved, your new vapor cooling unit may still be prone to early failure, even though a robust cooling system may temporarily extend its lifespan.

Also, it’s important to note that the size of the cooling system can become a limiting factor in determining the compressor’s capacity and the level of demand it can efficiently handle.  To obtain personalized advice on precise system sizing, it’s recommended to consult experts in miniature compressor cooling engineering.

To get the optimal small-scale vapor compression refrigeration solution for your small thermal application, contact MOIR at info@moircooling.com now.