Refrigeration Heat Exchangers

Alfa Laval’s ACH line of brazed plate heat exchangers are specialized models developed to work in air conditioning, refrigeration, chiller and heat pump applications. They feature efficient heat transfer with a small footprint, and are commonly used as evaporators, condensers, and economizers. Media within the units follow counter-current flow patterns, with single-pass configurations resulting in all connections being located on a single side of the unit for simple installation. Additional applications include acting as sub-coolers for liquid refrigerants via well water, desuperheaters to re-use excess heat and improve downstream efficiency, and intermediate units in absorption cycles (to pre-heat diluted solution or pre-cool concentrated solution). In the case of sub-coolers and desuperheaters, the port configuration is flexible assuming refrigerant flow rates and system pressure drops are adequate.

The CBH line is a subset of Alfa Laval’s widely-used CB line of copper brazed plate heat exchangers specifically aimed at refrigeration applications using standard sweat connections and pressure ratings up to 700 psi (48 bar). Like the ACH line, these models use 316 SS plates and are optimized for refrigeration and heat pump applications including cold storage rooms, process cooling, HVAC and comfort cooling ice rinks, and food & beverage refrigeration. Due to their robust design and high thermal efficiency, CBH units are used with virtually every service side fluid seen in th refrigeration industry. In constrast to the ACH line, CBH units are mainly used as condensers and feature symmetrical connection arrangements. For more information on available models by application, please refer to the tables below.

The AXP line of brazed plate heat exchangers from Alfa Laval builds upon the standard CBH and ACH platform of gasket-free design to create units that handle extreme pressure — up to 140 bar (2030 psi) depending on the model. These models are specifically engineered for subcritical and transcritical applications using CO2 as the refrigerant, and can support other fluids that require operation at extreme pressures. In refrigeration applications, AXP heat exchangers are suitable for heat recovery, condensing and sub-cooling to gas cooling, suction gas heating, hot water heat pump applications, supermarket chiller installations, and commercial air conditioning systems. Low-GWP refrigerants, such as CO2, are highly sensitive to maldistribution — the DynaStatic design of the AXP line promotes flexible distribution with a breakthrough production method, allowing you to fully tailor the placement, size, and number of inlets to optimize distribution within your system.
When working with transcritical systems, which routinely exceed 100 bar (1450 psi), it is crucial to design for sustained periods of high pressure, as well as stresses from rapid temperature and pressure spikes. The PressureSecure design of the AXP line supports high-temperature and high-pressure operation using thinner plates to translate to lower energy consumption and refrigerant charge over the lifespan of the unit. At the same time, the AXP is reinforced with robust tightening bolts and carbon steel external frames to withstand sustained pressure fluctuations throughout its design service life.

For specialized applications, the AXP is offered in a 100% stainless-steel fusion-bonded variant: the AXP AN. This line is similarly suited to extreme-pressure applications and features AlfaFusion stainless-steel filler material to seal and hold the plates together at the contact points for optimal pressure resistance and heat transfer efficiency. For more information on the AXP AN please click here.

Alfa Laval’s line of semi-welded gasketed plate-and-frame heat exchangers are a style of gasketed plate-and-frame heat exchanger that has welded ports on one side with alternating laser welds and gaskets for situations where gaskets are suitable for one but not both process media. This design makes them compatible with liquids and gases that are at high pressures or otherwise materially incompatible with common gasket materials. These units feature Alfa Laval’s RefTight™ system which uses a laser weld on the outside of the gasket groove, guaranteeing a lifetime seal between welded channels. Semi-welded units are suitable for refrigeration and heat pump applications facilitating condensing or evaporating with a number of primary refrigerants such as ammonia and carbon dioxide. Primary applications include use as: flooded evaporators, DX evaporators, liquid-cooled condensers, desuperheaters, economizers, oil coolers, and as part of cascade systems. Depending on the model, these units can handle refrigeration loads from between 28 and 3400 refrigeration tons (100 – 12,000 kW) at temperatures between -45°C to 250°C (-49°F to 392°F) and pressures from below vacuum to 900 psig (63 barg) on the welded side. Options for plate material include stainless steel (304 SS, 316 SS, Alloy 254) or titanium, and with various pressing depths and chevron patterns available, there is a configuration available for virtually every possible application in the industrial and commercial refrigeration sectors. Please refer to the table below for a comparison of the pressure and temperature capabilities of each model in the line.