Uporaba PID-regulatorja za nastavitev temperature

ZAKRAJŠEK, DEJAN (avtor), Smole, Franc (mentor)

Kavni aparat Rancilio Silvia V3 spada med cenejše profesionalne kavne aparate. Zato lahko predvidevamo, da ima nekaj slabosti. Kavni aparat za regulacijo ne uporablja nobene elektronike. Uporablja enostavno regulacijo temperature vode z bimetalnimi termostati. Termostat kontrolira temperaturo majhnega, 3 decilitrskega medeninastega bojlerja. Nudi pa glavne lastnosti, ki jih dober kavni aparat potrebuje. Elektromagnetni ventil, nastavljiv OPV-ventil, profesionalna komercialna glava in 58-milimetrska standardna ročica. Temperaturno regulacijo ima izvedeno z dvema termostatoma ter enim varnostnim termostatom proti pregretju. Termostati niso natančni oz. povzročajo precejšnje nihanje temperature vode. Nikoli se pri pripravi oz. kuhanju kave ne ve, ali je temperatura v želenem območju. Delo zajema uporabo PID-regulatorja za temperaturno regulacijo. Uporablja se ga na več področjih, večinoma v industrijski tehniki. V svoji nalogi sem ga uporabil na kavnem aparatu Rancilio Silvia. Glavni razlog uporabe PID-regulatorjev je slaba regulacija, ki se uporablja na določenem produktu. Temperaturna regulacija je izvedena z bimetalnim termostatom, ki ima veliko odstopanje oz. velik ΔT. Takšna zvrst regulacije je še posebej moteča pri višjih temperaturah oz. hitrih spremembah le-te. Termostati povzročajo velika temperaturna nihanja oz. oscilacije. Pri manj preciznih sistemih, kot je npr. sobna regulacija prostora, termostat zadostuje oz. dobro služi svojemu namenu. Pri kavnih aparatih, kjer se temperatura lahko zelo hitro spreminja, pa je PID-regulacija zelo zaželena oz. skoraj nujna. Rancilio Silvia ima termostat pritrjen na vrh bojlerja, ki je narejen iz medenine. Medenina se s temperaturo vode spreminja oz. segreva in ohlaja z zakasnitvijo, in sicer glede na temperaturo vode v bojlerju. Zakasnitev termostatu povzroča še dodaten ΔT. Bimetalni termostat, ki ga uporablja kavni aparat Rancilio Silvia, ima fiksno vrednost 100 ºC. PID-regulator pa omogoča, da se temperatura lahko nastavi po želji, in sicer v območju natančnosti do 1 ºC z zelo odzivno in natančno regulacijo.

• Jezik: Slovenski jezik
• Ključne besede: PID-regulator N2006P, kavni aparat Rancilio Silvia, termostat, SSR-rele, termoelement, merilni instrument, temperaturna regulacija, regulator, parametri PID-regulatorja
• Vrsta gradiva: Diplomsko delo
• Organizacija: FE - Fakulteta za elektrotehniko
• Leto izida: 2016
• PID: 20.500.12556/RUL-82774
• Datum objave v RUL: 23.05.2016

Sekundarni jezik

• Jezik: Angleški jezik
• Naslov: Usage of PID-controller for temperature regulation

Izvleček

Rancilio Silvia V3 is a mid-range coffee machine, therefore it has some disadvantages. For regulation it does not use any electronics. It uses a bimetallic thermostat for simple water temperature regulation. The thermostat controls a temperature of a single small 3 dcl brass boiler. The coffee machine has all the main features that a quality coffee machine needs: electromagnetic valve, adjustable OPV valve, professional group head, professional 58 mm porta filter. Rancilio Silvia V3 coffee machine has temperature controlled with three thermostats: thermostat for brewing temperature, thermostat for steam temperature, and one safety thermostat against overheating. The thermostats are not accurate and cause considerable water temperature instability. In the preparation or brewing coffee, one can never know whether the temperature is in the desired range. The thesis encompasses the usage of PID controller for temperature regulation. It is used in many fields, mostly in industrial engineering. In this thesis, the PID controller is used on Rancilio Silvia V3 coffee machine. The main reason for using PID controllers is insufficiency of the existing regulation on certain products. The temperature is regulated with the bimetallic thermostat which has a large deviation of ΔT. This kind of regulation is especially problematic with higher temperatures or fast temperature changes. The thermostats cause major temperature changes or oscillations. But the thermostat is sufficient with the less precise systems e.g. room regulators. The temperature in coffee machine is constantly changing; therefore the PID controller is necessary or almost essential. Rancilio Silvia V3 has its thermostat on the top of the brass boiler. The brass changes its temperature (heating and cooling) with delay regarding the water temperature in boiler. The delay causes an extra ΔT to the thermostat. The bimetallic thermostat used in Rancilio Silvia V3 has fixed value of 100 ºC. But due to the PID controller the temperature can be set within the range of 1ºC and enables very responsive and accurate regulation.

• Ključne besede: PID-regulator N2006P, kavni aparat Rancilio Silvia, termostat, SSR-rele, termoelement, merilni instrument, temperaturna regulacija, regulator, parametri PID-regulatorja