While the core concept of the refrigeration circuit has remained constant over time, portable chillers now have a range of comparatively modern features to optimise water flow to the process and ensure precise temperature regulation. Scroll compressors, tube-in-tube evaporators, and autotuning are only a few of the “bells and whistles” that aid process management or reduce maintenance headaches. These standard or optional features, along with tried-and-true features like hot-gas bypass and nonferrous construction, all contribute to the process’s optimum performance.
Size Pumps Correctly
It’s vital not to skimp on pump size when it comes to portable chillers. Pumps for portable chillers typically vary in size from 1/3 to 1 1/2 horsepower, but correct pump sizing is determined by the cooling specifications of the mould. Internal pressure drop in chillers is usually five to seven psi, which must be factored into pump sizing. One way to reduce the impact of pressure drop is to use two pumps, one for circulating water through the evaporator and the other for sending water out to the process. If there is an exceptionally high flow demand, dual-pump systems, which are more common in larger chillers (25-ton range), could be warranted on smaller devices.
A Choice of Heat Exchangers
In portable chillers, alternatives to the traditional shell-in-tube evaporators can reduce pressure drop, improve heat transfer, and reduce the chiller’s footprint. The tube-in-tube evaporator, for example, has a large orifice (5/8- to 7/8-in.) that lowers pressure drop to less than two psi on average. The evaporator’s copper surfaces prevent corrosion and scale build-up, which can limit chiller performance.
Brazed-plate evaporators, which are made up of a series of thin plates stacked side by side to form passages that alternately hold water and refrigerant, are another choice. This architecture is said to have high heat-transfer rates and is highly resistant to freeze-ups. Since brazed-plate evaporators are so thin, portable chillers can be made with smaller footprints. They are also rust-resistant due to their stainless-steel structure.
Compressor Efficiency is the Key
On chillers up to ten tons, most manufacturers use hermetic (reciprocating) compressors, whereas larger units use semi-hermetic forms. Scroll compressors, an up-and-coming replacement for small chillers, are being sold by many manufacturers as a somewhat more expensive choice. Scroll compressors are said to be more reliable, have fewer moving parts, and are less prone to mechanical failure than regular compressors. Scroll varieties are also said to be more resistant to “slugging” of liquid refrigerant.
Compressors can have an anti-cycle timer as a safety mechanism that stops the compressor from restarting for around two and a half minutes after it has cycled off. The time lag prevents overheating of the engine windings.
Capacity Control Devices
Hot-gas bypass and cylinder unloading are two methods widely used to minimise the chiller’s capability under low-load situations. By enabling some of the refrigerants to skip the condenser and go straight to the evaporator, hot-gas bypass creates an artificial load on the chiller. This lowers the evaporator’s power, resulting in less cooling. Most suppliers sell hot-gas bypass as a standard or optional feature. Since it reduces constant starting and stopping, hot-gas bypass reduces compressor wear and tear. It also aids in temperature regulation accuracy by keeping the water temperature within a narrower window.
Cylinder unloading, the other capacity-control process, is commonly used for semi-hermetic compressors. Cylinder unloading on a four-cylinder compressor can stop two cylinders when the load is low and restart them as the load increases. Since cylinder unloading produces rapid capacity fluctuations rather than a curve, temperature regulation is less precise. Cylinder unloading, on the other hand, does result in some energy savings.
Are you going on a picnic? Having a portable chiller with you would help you to chill your beverages without using electricity. You suggest you can’t drink wine in public. That’s cool since the majority of these chillers will still chill pop. It also has a feature on the digital settings to ensure that the pop is cooled to the perfect temperature.
Only a note that these aren’t intended to keep drinks cold for long periods; they’re just meant to keep things chilled and drinkable. It’s a perfect addition to an ice chest on a camping trip or picnic, and if you can’t keep any of your drinks cold and you only need a fast fix, these are for you. Just put in a can of pop and go; it just takes a minute.