Dual Flow Cold Room Ammonia Evaporator

Dual Flow Cold Room Ammonia Evaporator

Key structural design

Dual-flow evaporation coil:

Main flow (Primary Flow): bear the main refrigeration load, liquid ammonia enters from one end of the coil, and evaporates along the single or multiple paths, which is suitable for cooling down the main area of the cold storage.

Secondary Flow: For local hot spots (such as porch, cargo-intensive areas) or special needs (such as rapid cooling) of the cold storage, set up independent branch coils, which can adjust the flow rate individually.

Shunt device:

Adopting liquid-splitting head or Electronic Expansion Valve (EEV), liquid ammonia is proportionally distributed to the main and auxiliary flow to ensure even flow in each branch.

Air circulation system:

Equipped with double fans or adjustable-speed fans, the main process corresponds to the main fan (to maintain the regular air speed), and the auxiliary process corresponds to the auxiliary fan (to increase the air speed to strengthen the local heat exchange).

Working Principle

Main-stream refrigeration:

Liquid ammonia is evaporated through the coil of the main process, absorbing the heat of the air in the cold storage, and the cold air is circulated to the main area of the storage through the main fan to maintain the set temperature (e.g. - 18℃~0℃).

Auxiliary process compensation:

When there is uneven temperature in the cold storage (e.g. hot air influx caused by opening the door) or when rapid cooling is required, the auxiliary process is opened, the liquid ammonia flow is increased, and the auxiliary fan is forced to exchange heat at a higher air speed to quickly eliminate the local temperature rise.

Dynamic regulation:

Real-time monitoring of the temperature in different areas of the warehouse through temperature sensors, the control system automatically adjusts the ammonia flow rate of the main and auxiliary processes and the fan speed, realizing “on-demand cooling supply”.

Application Scenario

Multi-temperature zone cold storage:

The same cold storage is divided into refrigerated area (0~5℃) and frozen area (below -18℃), the main process is responsible for the frozen area, and the auxiliary process adapts to the demand of the refrigerated area by adjusting the flow rate.

High-turnover cold storage:

Frequent entry and exit of logistics cold storage leads to temperature fluctuation, and the auxiliary process can quickly cope with the heat load introduced by opening the door and reduce the loss of cold volume.

Precision storage cold storage:

Pharmaceutical cold storages, biological sample storages, etc. require high temperature accuracy (±0.5℃), and the dual-flow design can dynamically adjust to meet the stringent standards.

Modified cold storage:

On the basis of the original single-flow system, additional auxiliary processes can be installed to improve performance without large-scale replacement of equipment (e.g. energy-saving renovation of old cold storage).