{"id":22360,"date":"2026-01-20T11:22:06","date_gmt":"2026-01-20T10:22:06","guid":{"rendered":"https:\/\/mag.ebmpapst.com\/en\/?p=22360"},"modified":"2026-01-20T11:22:07","modified_gmt":"2026-01-20T10:22:07","slug":"companamic-scalable-compact-turbo-compressors-for-oil-free-gas-compression","status":"publish","type":"post","link":"https:\/\/mag.ebmpapst.com\/en\/industries\/refrigeration-ventilation\/companamic-scalable-compact-turbo-compressors-for-oil-free-gas-compression_22360\/","title":{"rendered":"Scal\u00adable, Compact Turbo Compres\u00adsors for Oil-Free Gas Compres\u00adsion"},"content":{"rendered":"\n

In terms of instal\u00adla\u00adtion space, low weight, high effi\u00adciency, and long service life, elec\u00adtri\u00adcally driven, gas-bearing turbo compres\u00adsors are one of the best solu\u00adtions for this. The newly devel\u00adoped oil-free CompaNamic turbo compres\u00adsors from ebm-papst in the motor power range from 10 kWe to approx. 55 kWe enable vari\u00adable delivery rates for different refrig\u00ader\u00adants and require signif\u00adi\u00adcantly less refrig\u00aderant thanks to an internal volume reduc\u00adtion of 90% (intro image). The 10 kWe vari\u00adants devel\u00adoped for R290 and R1234ze(E) are suit\u00adable for many areas of appli\u00adca\u00adtion. However, maximum gas purity through the elim\u00adi\u00adna\u00adtion of oil lubri\u00adca\u00adtion and a wide range of appli\u00adca\u00adtions required inno\u00adv\u00ada\u00adtive approaches to oil-free bearing tech\u00adnology, aero\u00addy\u00adnamics, motor design, and power elec\u00adtronics. New methods for the preci\u00adsion machining of compres\u00adsors and gas bear\u00adings were inte\u00adgrated for large-scale series produc\u00adtion planned for the end of 2028.<\/p>\n\n\n\n

The task of a compressor for heat pumps and refrig\u00ader\u00ada\u00adtion tech\u00adnology is to compress refrig\u00ader\u00adants as effi\u00adciently as possible over long periods of time with low oper\u00adating noise. Ideally, it should operate oil-free, keeping the system clean, increasing heat transfer effi\u00adciency, and elim\u00adi\u00adnating the need for auxil\u00adiary equip\u00adment such as oil sepa\u00adra\u00adtors, oil sumps, and the design complexity of oil return systems (Figure 1). Depending on the area of appli\u00adca\u00adtion, the compres\u00adsors and, above all, their bear\u00adings must operate with as little main\u00adte\u00adnance as possible for many years, both in contin\u00aduous oper\u00ada\u00adtion and in start-stop cycles. The end units should also be as small and light as possible, so that compact and dynamic PFAS-free compres\u00adsors are in demand, which can be installed in any posi\u00adtion without having to worry about oil return. While the drive and bear\u00adings can remain virtu\u00adally unchanged for a wide range of refrig\u00ader\u00adants, the aero\u00addy\u00adnamics some\u00adtimes must be adapted signif\u00adi\u00adcantly to the gas used. <\/p>\n\n\n\n

\n
<\/div>\n\n\n\n
Figure 1: Ideally, the compressor oper\u00adates oil-free, keeping the system clean, increasing heat transfer effi\u00adciency, and elim\u00adi\u00adnating the need for auxil\u00adiary equip\u00adment such as oil sepa\u00adra\u00adtors, oil sumps, and the design complexity asso\u00adci\u00adated with oil return systems. (Image | ebm-papst)<\/figcaption><\/figure>\n<\/div><\/div>\n\n\n\n

In prac\u00adtice, the devel\u00adopers were able to achieve this by using high-speed internal rotor motors enable the construc\u00adtion of very compact compres\u00adsors with 10 kWe at a diam\u00adeter of only 130 mm and a length of 300 mm, weighing only 6 kg. At the same time, an internal volume reduc\u00adtion to just 400 cc in the ebm-papst P3 compressor \u2013 compared to conven\u00adtional compres\u00adsors with approx. 5000 cc \u2013 has made it possible to dras\u00adti\u00adcally reduce the amount of refrig\u00aderant required. By elim\u00adi\u00adnating oil, heat transfer is improved due to the lack of surface wetting with lubri\u00adcant (oil including addi\u00adtives) in the heat exchangers, and pres\u00adsure losses are mini\u00admized. In addi\u00adtion, there is no oil cont\u00ada\u00adm\u00adi\u00adna\u00adtion and effi\u00adciency degra\u00adda\u00adtion of the heat exchangers due to oil over their service life. As only pure refrig\u00aderant is in circu\u00adla\u00adtion, oil main\u00adte\u00adnance and oil handling equip\u00adment are no longer neces\u00adsary. The perfectly balanced rotating parts result in vibra\u00adtion-free, quiet oper\u00ada\u00adtion. The sound power level is around 60 dB(A). To achieve this, advanced tech\u00adnical solu\u00adtions are required in many areas.<\/p>\n\n\n\n

Aero\u00addy\u00adnamics is the key element<\/h2>\n\n\n\n

The compressor size is deter\u00admined by the different require\u00adments of the heating or cooling tech\u00adnology used. A compressor power of 10 kWe for the refrig\u00ader\u00adants R290 and R1234ze(E) marks the start of the product port\u00adfolio. This is partic\u00adu\u00adlarly suit\u00adable for larger build\u00adings or indus\u00adtrial appli\u00adca\u00adtions. In order to effi\u00adciently cover the different require\u00adments resulting from the enve\u00adlope of pres\u00adsure ratio and mass flow, the entire range of design options for the wheel and blade geom\u00adetry must be utilized. The SCOP (Seasonal Coef\u00adfi\u00adcient of Perfor\u00admance) points from different appli\u00adca\u00adtions are used for this purpose. In addi\u00adtion, espe\u00adcially with small impeller diam\u00ade\u00adters, it is crucial to reduce the blade gap losses that occur to a tech\u00adni\u00adcally feasible minimum. This ensures highly effi\u00adcient aero\u00addy\u00adnamics. <\/p>\n\n\n\n

The enve\u00adlope (Figures 2 and 3) describes the oper\u00adating limits. The X-axis repre\u00adsents the evap\u00ado\u00adra\u00adtion temper\u00ada\u00adture, and the Y-axis repre\u00adsents the conden\u00adsa\u00adtion temper\u00ada\u00adture. The MidLift and High\u00adLift vari\u00adants require higher pres\u00adsure ratios and there\u00adfore 2-stage solu\u00adtions. A single-stage solu\u00adtion is suffi\u00adcient for the LowLift version. After simu\u00adla\u00adtion, the char\u00adac\u00adter\u00adistic maps were also measured, veri\u00adfied, and opti\u00admized in ebm-papst\u2019s own new, state-of-the-art compressor test facility. The company\u2019s core busi\u00adness in fans also provides access to a high-perfor\u00admance envi\u00adron\u00admental testing center. Here, the compres\u00adsors are subjected to long-term testing.<\/p>\n\n\n\n

Bearing tech\u00adnology<\/h2>\n\n\n\n

The high perfor\u00admance and dynamics of the units in rela\u00adtion to their size require a sophis\u00adti\u00adcated bearing system. The table (Figure 4) shows the differ\u00adences between high-speed bearing tech\u00adnolo\u00adgies, with a focus on radial bear\u00adings. Inex\u00adpen\u00adsive plain and ball bear\u00adings have a short service life at high speeds and can also cont\u00ada\u00adm\u00adi\u00adnate the gas with oil or grease. Magnetic and gas bear\u00adings, on the other hand, operate with virtu\u00adally no wear. However, magnetic bear\u00adings are still very expen\u00adsive, so gas bear\u00adings are a good compro\u00admise. Aero\u00addy\u00adnamic rigid gas bear\u00adings in partic\u00adular enable precise posi\u00adtioning of the shaft compared to film bear\u00adings, allowing a minimum blade gap between the blades and volute to be set during oper\u00ada\u00adtion for a partic\u00adu\u00adlarly effi\u00adcient flow machine. During oper\u00ada\u00adtion, the shaft floats on a cushion of compressed working gas. Lubri\u00adcants and coolants are not required, and possible cont\u00ada\u00adm\u00adi\u00adna\u00adtion by addi\u00adtional substances is avoided. The refrig\u00ader\u00adants remain absolutely pure. A suit\u00adable choice of mate\u00adrials and hard coating of the bearing surfaces ensures virtu\u00adally wear-free start-up and rotor run-out. ebm-papst compres\u00adsors are designed for a service life of approx. 150,000 hours and more than one million start-stop cycles.<\/p>\n\n\n

\n
<\/div>

Figure 2: Compressor enve\u00adlope for R290. (Image | ebm-papst)<\/p><\/div>\n

<\/div>

Figure 3: Compressor enve\u00adlope for R1234ze(E). (Image | ebm-papst)<\/p><\/div>\n<\/div>\n\n\n

Effi\u00adcient motor with compact dimen\u00adsions<\/h2>\n\n\n\n

Motor power is defined as the product of torque and speed, which is why high power can be achieved at high speeds even with a compact elec\u00adtric motor. Despite their low torque, the compact, high-speed internal rotor motors deliver 10 kWe at approx. 160,000 rpm, and larger versions will deliver up to 55 kWe at approx. 60,000 rpm. However, high-speed drives require precisely matched geom\u00adetry of the stator and perma\u00adnent magnet rotor, as other\u00adwise there will be signif\u00adi\u00adcant iron, copper, and rotor losses, which are further increased by frequency-related effects. Higher volt\u00adages allow smaller copper cross-sections, but place increased demands on the winding insu\u00adla\u00adtion. Various cooling concepts have been devel\u00adoped to dissi\u00adpate the waste heat gener\u00adated. The same applies to the power elec\u00adtronics.<\/p>\n\n\n\n

Power elec\u00adtronics for high-speed motors<\/h2>\n\n\n\n

The power elec\u00adtronics must be adapted to the oper\u00adating condi\u00adtions. In compres\u00adsors, they can utilize the wide range of supply volt\u00adages and allow for good power scaling thanks to the modular design of the output stages. The usual mains volt\u00adages are approx. 320V to 480V 3-phase AC. The high speed of the internal rotor motors requires currents with frequen\u00adcies of up to over 100 kHz for control in pulse width or pulse ampli\u00adtude modu\u00adla\u00adtion, which the power output stages must provide reli\u00adably. All compo\u00adnents must achieve the highest possible effi\u00adciency of more than 97% even at partial load, and the applic\u00adable stan\u00addards and user spec\u00adi\u00adfi\u00adca\u00adtions, e.g., for harmonics, must be complied with.<\/p>\n\n\n\n

\n
<\/div>\n\n\n\n