PAREMPAA TEHOKKUUTTA ETSIMÄSSÄ

Esitys aiheesta: "PAREMPAA TEHOKKUUTTA ETSIMÄSSÄ"— Esityksen transkriptio:

1 PAREMPAA TEHOKKUUTTA ETSIMÄSSÄ
LIIKERAKENNUSTEN KATTILASOVELLUKSET SUUNNITTELIJASEMINAARI Trainer introduction Let me give you a brief introduction into boiler application problematice in relation with circulator pumps

2 JOTEN KOHTELE NIITÄ SITEN
„Jokainen kattila voi olla kondensoiva kattila“ JOKAINEN KATTILA ON YKSILÖLLINEN JOTEN KOHTELE NIITÄ SITEN Laske palaavan veden lämpötila alle 57°C ja vesi kondensoi jossain kattilan osassa EROJA ON PIILEVIEN LÄMPÖPOTENTIAALIEN HYÖDYNTÄMISESSÄ JA SAMANAIKAISESTI PITKÄ-IKÄISEN LAITOKSEN AIKAANSAAMINEN Boilers are basically nothing else but heat exchangers dealing with various media, temperatures, energy sources, energy kinds, made of various materials and meant to operate in predesigned way. However this general description may seem as all boilers are the same, there are vast differences between individual boiler applications as well as different operation conditions aiming to achieve maximal efficiency

3 GRUNDFOS-RATKAISUN EDUT
Before After HALUAISTKO: Optimoida kattila-asennuksesi Alentaa käyttökustannuksia Saada yksityiskohtaista tietoa laitoksen toiminnasta In this presentation I would like to present possibile solution allowing you to optimize your boiler installation, lower the operating costs and at te same time be able to monitor your systém extensively.

4 EI KONDENSOIVAT KATTILAT
GRUNDFOS-RATKAISU: EI KONDENSOIVAT KATTILAT Lets start with conventional boiler setup

5 Here is a illustration of larger example of conventional boiler.
GRUNDFOS COMMERCIAL BUILDINGS Here is a illustration of larger example of conventional boiler. I chose this example to illustrate that the problematics does not deal only with household installations, but bigger residential, commercial and industrial installations as well. At this scale energy savings and operation cost reduction will prove quite significant.

6 PERINTEISEN KATTILAN TOIMINNAN SEURAUKSIA
PERINTEINEN KATTILA 80oc 30oc PÄÄPUMPPU VESIPISAROITA (KONDENSAATIO) SAVUPIIPPU POLTIN PAKOKAASU LÄMPÖSHOKKEJA KORROOSIOTA This is a typical conventional boiler system setup. Boiler, chimney, supply and return piping together with main system pump installed in supply piping. Issue occuring within such installation is too low return temperature into the boiler. Considering the boiler dealing with water as the circulated liquid, and natural gas as the fuel, return temperature lower than approximately 57°C (hydro-carbon dew point) causes the flue gas to condensate, resulting in corrosion of boiler components. When the return temperature drops to the point where th differential temperature across supply and return pipes exceeds 30K, the effects of thermal shock appear.

7 KORROOSIO JOHTUU: Rikkipitoisten pakokaasujen kondensaatio
JOKA JOHTAA: Sedimentaatiota, ruosteen syntymistä Materiaalien eliniän lyhenemistä Corrosion is being caused by acidous flue gas condensation droplets coming into contact with untreated surface of boiler components. This results in incrustations and material degradation.

8 LÄMPÖSHOKKI JOHTUU: Kuuman veden paluusta kattilaan
Epäonnistuminen kattilan lämpötilan hitaassa nostamisessa sitä käynnistettäessä Säännöllinen syklittäinen käynti JOKA JOHTAA: Vuotaviin kattilaputkiin Valurautakattiloiden murtuneisiin osiin Together with corrosion, thermal shock may prove to be very destructive element. These two aspects go hand in hand and usually have same cause. The biggest challenge then is not just to make sure these two destructive forces do not occur during operation, but doing so while maintaining high system efficiency.

9 KATTILAN SEKOITUS PERINTEISELLÄ VAKIORATKAISULLA
PERINTEINEN KATTILA – SEKOITUSPUMPPURATKAISU TAVOITE Säätää paluuveden lämpötila kohteen tarpeisiin sopivaksi… KEINOT Kattilan sekoitus – meno- ja paluuputkien yhdistäminen, varustettuna pumpulla aikaansaa sekoituspiirin POLTIN Return water temperature has major impact on boiler operation, both conventional and condensing. There is number of ways to ensure the right temperature. One of the most common ones is using boiler shunt with shunt pump installed.

10 KATTILAN SEKOITUS PERINTEISELLÄ VAKIORATKAISULLA STANDARD SOLUTION
SEKOITUSPUMPUN ASENNUS Mitoitusesimerkki: Kattilan teho: kW Menoveden lämpötila: 80oc Paluuveden lämpötila: 30oc Min. kattilan paluunlämpötila: 60oc Systeemivirtaama: = 4,77 l/s 4,19*50 Kattilan virtaama: = 11,93 l/s 4,19*20 Sekoituspumppu: 11,93-4,77 = 7,16 l/s POLTIN 80oc PÄÄKIERTOPUMPPU PAKOKAASUT SAVUPIIPPU 30oc >57oc SEKOITUS- PUMPPU Standard solution In conventional boiler installation shunt pump runs hot water through the shunt in order to reach return water temperature higher than the flue gas dew point, tehrefore it poses as a mixing loop within a boiler circuit. Maintaining Tr above the dew point should prevent both corrosion and thermal shock since ∆T is kept within an acceptable range.

11 KATTILAN SEKOITUS DYNAAMINEN VAIHTOEHTO
SEKOITUSPUMPUN ASENNUS JA VIRITYS BURNER E T Lämpötilaohjattu kattilan sekoituspumppu Jonkinverran energiansäästöjä Dynaaminen käynti E-solution Nowadays common practice is to connect the pump to some kind of regulation, based on temperature settings, either internal or external. It can be both just a start/stop regulation based on temperature feedback or frequency converter based pump setpoint modulation, again according to recent demands.

12 KATTILAN SEKOITUS GRUNDFOSIN RATKAISULLA
; SEKOITUSPUMPPU Optimaalinen dynaaminen käyttö Vakio T käyttö Tset = 60°C Automaattinen pumpun käy/seis Raja-arvo ylitetty toiminto Tstop=65°C, Tstart= 60°C Monitorointi ja diagnostiikka Toimintahäiriön varoitus ∆T ≥ 30K 2 ulkoista lämpötila-anturia, Tf Tr Pääsy suureen käyttötietojen määrään pumpun kautta 80oC 30oC PÄÄKIERTOPUMPPU SAVUPIIPPU Tf Tr POLTIN PAKOKAASUT iSolution In Grundfos, we went further… The requirements to the function of the TPE2 pump are as follows: The main function is to keep the return pipe temperature tR constant at fixed value equal to 60 °C. If the return pipe temperature tR reaches 65 °C or above, the pump shall be stopped. When the temperature is reduced down to 60 °C, the pump shall be started again. The pump shall supervise the differential temperature across the boiler Δt = tF – tR and if the differential temperature exceeds 30 °C a warning shall be given. The warning shall be cancelled if the Δt < 28 °C

13 KONDENSOIVIEN KATTILOIDEN ASENNUS
GRUNDFOS RATKAISU: KONDENSOIVIEN KATTILOIDEN ASENNUS Now for the condensing boiler scenario

14 Kondensaatio mahdollistaa korkeamman hyötysuhteen
KONDENSSIKATTILAN TOIMINTAPERIAATE ILMA PUHALLIN KAASUVENTTIILI MAAKAASU LÄMMITYS MENO LÄMMITYS PALUU YLIJÄÄMÄKAASU KONDENSSIVEDEN VIEMÄRÖINTI Kondensaatio mahdollistaa korkeamman hyötysuhteen Erityiset käyttöolosuhteet ovat tarpeen: Paluuveden lämpötila Alempi T mahdollistaa alemman pakokaasun lämpötilan Paloaste (modulaatiopiste) Modulaarisen kattilan tehokas säätö A condensing boiler extracts additional heat from the waste gases by condensing this water vapour to liquid water, thus recovering its latent heat of vaporization. A typical increase of efficiency can be as much as 10-12%. While the effectiveness of the condensing process varies depending on the temperature of the water returning to the boiler, it is always at least as efficient as a non-condensing boiler. Condensing boiler also differs in an installation setup from a non-condensing ones. The main differences are represented by air intake, boiler surface material/coating, necessity of condensate drain system.

15 ESIMERKKI: ESTÁDIO DA LUZ, LISBON
Let us illustrate the condensing boiler issues on real life example, the football stadium in Lisbon Portugal.

16 USEITA KONDENSSIKATTILOITA ASENNETTUNA LISSABONIN STADIONILLE
KONDENSSIKATTILA MENOVESI - 82o C PALUUVESI - 68 o C A large number of condensating boilers were at the stadium in Lisboa. However, none of them vere running in condensing mode because the return temperature was too high.

17 OLETETTU SYSTEEMIKÄYRÄ SUUNNITELLUT TUOTTOARVOT
SUUNNITELTU SKENAARIO 100% NOSTOKORKEUS OLETETTU SYSTEEMIKÄYRÄ SUUNNITELLUT TUOTTOARVOT VIRTAAMA Now even though the design was sound and all the theoretical calculations and figures correct…

18 TODELLISET ARVOT …real life system showed different behaviour due to imperfections in systém construction and also perhaps designer adding „safety margins“ to his calculations.

19 TODELLINEN TOIMINTAPISTE TODELLINEN SYSTEEMIKÄYRÄ
TODELLISTEN PAINEHÄVIÖIDEN MÄÄRITTÄMINEN ON VAIKEAA, JOTEN TODELLINEN SYSTEEMIKÄYRÄ VOI OLLA ERILAINEN 100% NOSTOKORKEUS PUMPPUKÄYRÄ TODELLINEN TOIMINTAPISTE TODELLINEN SYSTEEMIKÄYRÄ VIRTAAMA All in all this resulted in the system pressure drop being much lower than expected. The duty point therefore moved according to the new systém curve to the area of higher flow and lower pressure drop and caused excess flow in the system.

20 TASAPAINOTTAMATON VIRTAAMA
KONDENSSIKATTILA– TASAPAINOTTAMATTOMAN JÄRJESTELMÄN SEURAUKSET SUUNNITTELUARVOT Menoveden lämpötila 80 o C Paluuveden lämpötila 50 o C ΔT: 30 o C Φ = 1050 kW Q = Φ = 1050 kW = 8,35 l/s 4,19*ΔT ,19* 30 o C TASAPAINOTTAMATON VIRTAAMA Menoveden lämpötila 80 o C Tasapainottamaton virtaama Q = 13,9 l/s ΔT = Φ = 1050 kW = 18 o C 4,19*Q 4,19*13,9 l/s Paluuveden lämpötila: o C = 62 o C The impact of excess flow (50m3/h instead of 30m3/h) is such that the return temperature has rised to 62°C instead of calculated 50°C

21 PALUUVEDEN LÄMPÖTILA °C
EPÄTASAPAINON VAIKUTUS HYÖTYSUHTEESEEN BOILER EFFICIENCY AT VAROUS TEMPERATURES AND FIRING RATES PALOASTEET 100% 98% 96% 94% 92% 90% 88% 86% 84% 4% HYÖTYSUHDE 50% HYÖTYSUHDE 100% HYÖTYSUHDE 50 oC Alhainen hyötysuhde arvolla Tr = 62°C 62oC 20 25 30 35 40 45 50 55 60 65 PALUUVEDEN LÄMPÖTILA °C Source: Lochinvar/Facility Excecutive This scenario caused the boiler to operate with much lower efficiency that presumed.

22 VAKIORATKAISUT SEKOITUSPIIRIRATKAISU
MEKAANINEN VIRTAAMAN RAJOITTAMINEN Now there are few possibilities of how to sort out such situation: Diverting loop solution Such a solution requires a bypass installed between return and supply piping with diverting valve install in return piping. External controller based on information from a temperature sensor between a diverting valve and the boiler, the valve would control the amount of return water flowing back to the boiler and thus allowing for lower volume of return water being returned. Such solution though is very demanding on components, third party control etc… Mechanical flow limitation solution Mechanical throttling valve installed beyond the main pump limits the flow into the system to the design volume, allowing for the water to transfer right amount of energy so the return temperature would be as designed. This solution however increases differential pressure in the system (constant curve operation) and does not respond to dynamic behaviour of the system.

23 FLOWLIMIT-TOIMINNON HYÖDYNTÄMINEN JÄRJESTELMÄSSÄ
FLOWLIMIT AKTIVOITU HEAD FLOWLIMIT AKTIVOITU PUMPPUKÄYRÄ FLOW 8,35 l/s 13,9 l/s VIRTAAMA This is an illustration of how the duty point would change with the machanical throttling valve solution. The duty point would follow the constant curve and move to the point of designed flow. However it does not take into account, that it is now dealing with different systém curve. By introducing flow limit into the solution the duty point, maintaining the required maximum flow moves „down“. That means that the pump decreases its speed so, that it maintains the required flow, follows the real system curve, and since according to the affinity equation the energy consumption changes with n3 (pumps speed cubed) the energy saving s of such solution will be significant on the pump, plus of course as of now the system is able to reach correct return temperature, thus allowing for condensation, therefore the overal efficiency and energy consumption will improve very much.

24 FLOWLIMIT-TOIMINNON HYÖDYNTÄMINEN JÄRJESTELMÄSSÄ
80oC 57oC MAHDOLLINEN VAROITUS MIKÄLI ESIM. 57°C YLITTYY And how have we affected the system? Basically we have not touched it…for the Customer this is also a benefit – without interfering with the system, changing or adding any components or controls we managed to gain better efficiency and operational cost reduction of the installation. Furthermore Grundfos pumps allow for more functionalities, like for instance monitoring the return temperature and giving out a warning if it reaches set limit etc…

25 70 o C menoveden lämpötila
FLOWLIMIT MAHDOLLISTAA JÄRJESTELMÄN OPTIMOINNIN 70 o C menoveden lämpötila Lämpötilaero, Δt 10 o C 20 o C 30 o C Paluuveden lämpötila, tR 60 o C 50 o C 40 o C Kattilan hyötysuhde, η 87,5% 94,5% 96% Kaasun kulutus, V 158.7 m3/h 147.0 m3/h 144.7 m3/h INDEX 111 INDEX 102 INDEX 100 And such monitoring can prove useful in adjusting the operation to gain even more savings and optimizing the operation – for instance by finding the ideal return temperature for the optimal operation.

26 KIITOKSET MIELENKIINNOSTA !