Effi­ciency and reli­ab­il­ity at the heart of indi­vidual series pro­duc­tion

Oilon Oy has developed a family of heat pumps which can be set up for a client’s spe­cific envir­on­ment through a set of options. The firm is really now offer­ing the mass cus­tom­isa­tion of heat pumps.

Industry and energy pro­vi­sion need heat pumps. However, tem­per­at­ure levels, energy require­ments and other cir­cum­stances vary a lot and require equip­ment adjus­ted to the situ­ation. At the same time the equip­ment must be highly effi­cient, easily con­trol­lable and suited for high tem­per­at­ures. Moreover the heating system design­ers need tools for easily and quickly select­ing the exact solu­tion.

From cooling system con­tractor to heat pump man­u­fac­turer

“Everything started from Scan­cool Oy, which was a tra­di­tional con­tractor in the cooling busi­ness,” says Juha Aaltola, Doctor of energy tech­no­logy, and product devel­op­ment dir­ector of Oilon Oy. “A large cus­tomer in the food­stuff industry con­sidered the pos­sib­il­ity of util­ising waste water heat and the com­pleted project was so suc­cess­ful that a decision was made to start a com­pletely new busi­ness area. At that time in 2008 I joined the company to start and manage the heat pump busi­ness as a busi­ness dir­ector.”

“At that time indus­trial heat pumps didn’t exist but a couple of years later there were plenty of them. We were the pion­eers of the busi­ness. Sitra (the Finnish Innov­a­tion Fund) and the venture capital investor Wedeco Oy were already involved in the busi­ness and then in 2011 Oilon acquired the whole company. The rest is now history.”

Refri­ger­ants are a com­prom­ise of many prop­er­ties

In a heat pump a com­pressor pumps gaseous refri­ger­ant into a con­denser where it con­dens­ates to liquid and releases thermal energy. From the con­denser the liquid moves via an expan­sion valve to an evap­or­ator, evap­or­ates to gas, recov­ers energy and con­tin­ues its way to the com­pressor.

By util­ising the phase change it is pos­sible to move quite large amounts of energy with a rel­at­ively small mass flow of the refri­ger­ant. The cir­cu­la­tion between con­denser and evap­or­ator is con­tinu­ous and the basics of the tech­no­logy famil­iar to all pro­fes­sion­als in the area.

“Ther­mo­dy­namic prop­er­ties of refri­ger­ants are highly vari­able,” says Aaltola. “With a good refri­ger­ant one can produce a lot of cold and heat with a small mass and volume flow and in a way that rel­at­ively little power is needed in the com­pressor.”

“The reverse side is that such sub­stances may cause ozone deploy­ment or climate change. Some sub­stances are flam­mable and others pois­on­ous. Since the 1930s, CFCs, such as Freon, started to become common. The ODP effect (Ozone Deploy­ment Poten­tial) was, however, very high and use of those sub­stances started to be restric­ted from the end of the 1980s. After that HFC sub­stances became common. Their ODP value was zero but GWP value (Global Warming Poten­tial) very high. An altern­at­ive has always been natural refri­ger­ants that have lim­it­a­tions because of a.o. tox­icity, flam­mab­il­ity or require­ments of high pres­sure.”

During the last few years one of the most import­ant focuses of product devel­op­ment at Oilon has been new envir­on­ment­ally friendly refri­ger­ants and the tech­no­logy con­nec­ted with them. One of the new refri­ger­ants used by Oilon is, for instance, R1234ze, which is non-​toxic, it doesn’t harm the ozone layer and the GWP value is one.

Many new refri­ger­ants also have a low con­dens­ing pres­sure, and by using the right tech­no­logy it is pos­sible to produce higher tem­per­at­ures than pre­vi­ously. Accord­ing to Aaltola, since last year Oilon has achieved a tem­per­at­ure level of 140 degrees cen­ti­grade (°C) while 100°C is com­mon­place.

High effi­ciency requires the right design

“In many indus­trial heat pumps on the market the start­ing point has not been a heat pump but, for instance, cooling water,” con­tin­ues Aaltola. “With us the start­ing point of design and everything we do is always heating and as high quality and ver­sat­ile a heat pump as pos­sible.”

“In cooling devices the pres­sure dif­fer­ence between the warm and cold side is typ­ic­ally lower and also in other ways the targets of design are dif­fer­ent to a heat pump.”

“The effi­ciency of a heat pump, COP (Coef­fi­cient Of Per­form­ance) is highly depend­ent on the tem­per­at­ure dif­fer­ence it pro­duces,” explains Aaltola. “Less elec­tric power is needed when tem­per­at­ure dif­fer­ence is smaller. We utilise this char­ac­ter­istic in many cases by con­nect­ing two or more pumps in series, so each unit pro­duces a much smaller tem­per­at­ure dif­fer­ence. This kind of imple­ment­a­tions, however, requires ver­sat­ile products, advanced auto­ma­tion and at the design stage a highly developed selec­tion tool such as the Oilon Selec­tion Tool.”

“At the begin­ning we used spread sheets of our own for design­ing heat pump machinery and com­plete systems but they were dif­fi­cult to use. Then we started build­ing a Java-​based com­pre­hens­ive program that takes into con­sid­er­a­tion everything that is needed. I can claim that we are the first firm which has developed a user-​friendly cal­cu­la­tion program for dimen­sion­ing indus­trial heat pump systems in this scale. With the Oilon Selec­tion Tool it is pos­sible to choose many innov­at­ive tech­no­lo­gies that improve COP or other char­ac­ter­ist­ics, such as series con­nec­tion, sub­cool­ing, eco­nom­iser, various refri­ger­ants, inverter power control, partial load sim­u­la­tions etc.”

Reli­ab­il­ity requires a tested entirety

Indus­trial heat pumps are a strongly devel­op­ing busi­ness. Oilon has developed its busi­ness into a mass cus­tom­ised series pro­duc­tion, where tested basic equip­ment is fur­nished with tested options and the result is a com­pletely tested system that fulfils the exact needs of the cus­tomer.

“Ten years ago we designed the systems, man­u­fac­tured the pumps and installed the system at the cus­tomer’s place,” says Aaltola. “Now we con­cen­trate on man­u­fac­tur­ing excel­lent equip­ment and deliv­ery with com­pre­hens­ive con­nec­tion instruc­tions.”

“A large number of com­pet­it­ors sell heat pumps that are designed to operate only under certain con­di­tions. However, the oper­at­ing con­di­tions of indus­trial heat pumps are often very vari­able. Depend­ing on the con­di­tions and imple­ment­a­tion, the same device may produce, for example, a power of 100 kilo­watts (kW) or 600 kW. It is not pos­sible to replace for instance the heat exchanger in such heat pumps with a more suit­able one, so the oper­a­tion under dif­fer­ent con­di­tions is not optimal.”

“On the other hand, many of our com­pet­it­ors design their heat pumps indi­vidu­ally for each loc­a­tion, so the result is always a new kind of indi­vidual, a pro­to­type in a way, that has not been tested in advance. Con­trol­lab­il­ity, oper­at­ing area and optimal effi­ciency are results of metic­u­lous testing. If the devices are not tested stand­ard products, there is a high risk that some­thing in the com­plete system doesn’t meet expect­a­tions.”

All altern­at­ives in a PDM system

Accord­ing to Aaltola the start­ing point at Oilon is always a certain stand­ard product and the oper­a­tion of the product is adjus­ted through the choice of refri­ger­ant, con­denser, sub­cool­ing, eco­nom­iser and vapor­iser together with control options. The final result con­sists of tested sub solu­tions and the com­plete system oper­ates the best pos­sible way in the cir­cum­stances it is designed for.

Com­pre­hens­ive product data man­age­ment is ele­ment­ary for effect­ive and eco­nom­ical man­u­fac­tur­ing. Oilon’s PDM system (Product Data Man­age­ment) includes all altern­at­ives and options. A 3D model of the product is also made in the system for pre­par­a­tion to man­u­fac­ture.

Man­u­fac­tur­ing takes place accord­ing to ‘Lean’ prin­ciples and each device goes through eight man­u­fac­tur­ing stages. The man­u­fac­tur­ing process is what creates the quality and the whole work­flow is developed with an aim for high quality. Each stage includes certain inspec­tions and the device is not moved to the next stage until the inspec­tions are made and doc­u­mented. In the final test each heat pump is tested in cir­cum­stances that are equal to the cus­tomer’s oper­at­ing envir­on­ment.

Global mon­it­or­ing and IoT lead the devel­op­ment

Most of the heat pumps from Oilon are con­nec­ted in a data network and send data of their oper­a­tion to the cloud. The system very quickly gives inform­a­tion if there is a problem in the oper­a­tion of the equip­ment. The system has been in oper­a­tion for five years and it is con­tinu­ously being developed further.

It is often pos­sible to remote service the devices thanks to a wealth of his­tor­ical inform­a­tion. Accord­ing to Aaltola it is pos­sible for the tech­ni­cian to estim­ate with the inform­a­tion from the system what tools and spare parts will be needed for a service visit – and if any visit is needed at all.

The cus­tom­ers can have reports that detail the system’s util­isa­tion rate, energy pro­duc­tion and money savings. Arti­fi­cial intel­li­gence under con­tinu­ous devel­op­ment iden­ti­fies the per­form­ance of the equip­ment and helps its optim­isa­tion, while data mining based on big data helps to anti­cip­ate even­tual prob­lems.

Innov­at­ive and open-​minded devel­op­ment

“The devel­op­ment of an expan­sion valve is just one small example of the results of our pro­gress,” says Aaltola. “It is an intel­li­gent device based on anti­cip­at­ing adjust­ing and includes both a phys­ical device and a program algorithm. It is a good example of how com­pet­ent and open-​minded our R&D people are. Not many – but extremely good people. Our high-​performance devel­op­ment is based on them.”