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.”