NH3/CO2 Cascade Refrigeration System
1. NH3/CO2: The Principle of Cascade Refrigeration System
The NH3/CO2 cascade refrigeration system comprises two distinct stages: high temperature and low temperature. In the high-temperature stage, NH3 (ammonia) serves as the refrigerant, while CO2 (carbon dioxide) is utilized in the low-temperature stage. The system operates by evaporating NH3 in the high-temperature stage to condense CO2 refrigerant gas from the low-temperature stage. A unique condensation evaporator bridges these two stages, functioning dually as the condenser for the low-temperature stage and the evaporator for the high-temperature stage.
The heat load is efficiently transferred to the CO2 refrigerant via the end evaporator. The heat absorbed by the CO2 refrigerant is then conveyed to the high-temperature NH3 refrigerant through the condensing evaporator. Subsequently, the high-temperature NH3 refrigerant transfers the heat to the high-temperature condenser, releasing it into the environment through a cooling medium. The condensed CO2 then flows into the CO2 reservoir and passes through a dryer filter and throttle valve into the CO2 gas-liquid separator. Driven by a CO2 circulation pump, the liquid CO2 reaches the CO2 evaporator. Post-evaporation, the two-phase CO2 returns to the gas-liquid separator, where the gaseous CO2 is compressed by the compressor and directed back into the condensing evaporator. This cycle perpetuates the cascade refrigeration process seamlessly.
In the NH3/CO2 cascade refrigeration system, the high and low-temperature stages operate as independent refrigeration systems, each utilizing a single refrigerant. The equipment layout mirrors this bifurcation: the high-temperature NH3 system includes a refrigeration compressor, condenser, liquid storage, gas-liquid separator, and throttling device, while the low-temperature CO2 system features a CO2 compressor, condensing evaporator, reservoir, gas-liquid separator, filter dryer, pump, throttling device, evaporator, and expansion vessel.
The The CO2 gas-liquid separator is integral to maintaining system efficiency, separating CO2 gas droplets from the evaporator to prevent compressor wet stroke. It stabilizes the liquid level during pump operation and stores liquid from the end equipment and pipelines when the pump is inactive. In non-operational periods, the separator functions as a CO2 reservoir, holding the system's liquid CO2 volume. An auxiliary evaporator atop the gas-liquid separator prevents excessive CO2 pressure post-shutdown. In the NH3/CO2 cascade system, the condensing evaporator serves a dual role as an NH3-side evaporator and a CO2-side condenser, where compound liquid evaporates and absorbs heat within the tube, while CO2 gas condenses into a liquid in the shell.
2. Advantages of NH3/CO2 Cascade Refrigeration System
(1) Reduced NH3 Risk Factors:
(1.(1)) The NH3/CO2 cascade system significantly lowers the condensing pressure of the NH3 refrigerant charge to about one-tenth of traditional ammonia systems.
(1.(2)) NH3 is confined to the machine room and equipment room, akin to a 'tiger in a cage,' supervised by skilled personnel.
(1.(3)) Optimal use of NH3's excellent heat transfer properties in high-temperature regions to cool CO2.
(2) CO2 serves as the refrigerant in personnel-intensive areas, such as single-freezing machines and warehouses, ensuring safety for both personnel and property.
024dc247
Compressor type |
Piston, screw |
Condensor |
enough condenser heat exchanger surface |
Fan type |
Axial fan:High degree of protection, large Air flow, low noise |
Unit kinds |
Open type, box type, side discharge type |
Cooled type |
Air cooled |
Refrigeration type |
R717;R507;R22;CO2 |
Copper tube connector |
fitting reducer |
Place to assemble |
Indoor/out door(concrete construction building/steel
construction building). |
Voltage |
220V/50HZ, 220V/60HZ, 380V/50HZ etc |
Controller |
Automatic electric controller, PLC |
Warranty |
1 Year |
Case material |
The galvanized sheet is coated with plastic powdered painted |
Quality Assurance |
2.6Mpa leak-proof stress test |
Package |
Plywood box and pallet |
Qingdao Bingyan Refrigeration Equipment Co., Ltd. Founded in 2011 and nestled in the picturesque coastal city of Qingdao, Qingdao Bingyan Refrigeration Equipment Co., Ltd. is a pioneering high-tech enterprise. We specialize in the integration of industrial and commercial freezing, cold storage solutions, and cutting-edge refrigeration systems. Our expertise spans research, development, design, manufacturing, and sales.
Since our inception, we have been steadfastly guided by our commitment to 'science and technology' and fortified by 'management' excellence. Our mission is to meet market demands and provide unparalleled customer service, delivering comprehensive and innovative refrigeration system solutions, products, and services.
With over ten national technology patents to our name, Qingdao Bingyan is dedicated to the perpetual advancement of high-efficiency, energy-saving, and environmentally friendly refrigeration systems. Our product portfolio includes high-efficiency refrigeration units, energy-saving barrel pumps, and smart PLC program control boxes, reflecting our commitment to technological innovation.
Our services extend to the custom design and equipment solutions for a variety of applications, including food quick-freezing storage, cold storage for food, ultra-low temperature cold storage, pharmaceutical storage, air-conditioned storage for fruits and vegetables, workshop air conditioning, quick-freezing, freeze-drying, and thawing devices.
BINGYAN IS DEDICATED TO DELIVERING SCIENTIFICALLY SOUND AND INNOVATIVE REFRIGERATION SOLUTIONS, COUPLED WITH EXEMPLARY ENGINEERING AND UNMATCHED AFTER-SALES SERVICES.
Bingyan offers a full spectrum of services, encompassing sales, design, construction, and after-sales support.
1. Our sales department excels at discerning and capturing customer needs, ensuring their intentions are clearly conveyed and maintaining seamless, constant communication.
2. Our design department delivers expert engineering advice, crafting bespoke and dependable refrigeration plans tailored to each customer's specific requirements.
3. Our engineering department meticulously manages every construction phase, striving for excellence and delivering high-caliber projects.
4. Our after-sales department is perpetually prepared and poised to guarantee our customers' success.

Q:What's your advantage?
A: A: Our expert designers tailor cooling solutions to your specific needs, ensuring the selection of the ideal refrigeration equipment. This meticulous approach guarantees maximum cooling efficiency, energy conservation, and significant power savings.
Q: How strong is your company?
A: Established in 2011, our company boasts a highly skilled cold storage design team, an efficient installation crew, and seasoned after-sales maintenance staff. We offer comprehensive services including cold storage design, installation guidance, and ongoing maintenance support.
Q:Where are you? Can I visit you?
A: Absolutely! We warmly welcome you to visit our factory at your convenience.
Q:How about the delivery time?
A: Your order will be ready for delivery within 60 days after we confirm your requirements.
Q:What kind of payment does your company support?
A: Typically, we require a 30% down payment via T/T after confirming the Proforma Invoice (PI), with the remaining balance payable post-inspection and pre-shipment. We accept telegraphic transfer and sight letters of credit.
Q: When can I get the price?
A: We usually provide a quotation within 24 hours of receiving your inquiry.
Q: Which shipping way can you provide?
A: We offer flexible shipping options including sea freight, air transport, and express delivery.