How to increase efficiency of hot water systems Effective prevention from Legionella bacteria for hospitals, hotels and residential building

Transcription

1 How to increase efficiency of hot water systems Effective prevention from Legionella bacteria for hospitals, hotels and residential building

2 Disadvantages of non balanced DHW systems Too high temperature Required temperature Insufficient temperature Insufficient temperature 2

3 Manual balancing is not a solution Disadvantages: Needs measuring/balancing Difficult to size/calculate Static, so no reaction to variable loads 3

4 Typical risks in DHW systems To low Temperature: Risk of Legionella growth To high Temperature: Waste of energy due to bigger heat loses and over pumping Unfair energy cost allocation (based on water mettering) Shorter lifetime of installation: corrosion, lime,.. Long hot water waiting time Waste of water Risk of shin burn 4

5 Legionella contamination risk in DHW systems Legionella Facts Natural aerobic bacteria that are natural inhabitants in water in all environments Grows in standing water between 25-46ºC Dangerous when inhaled with aerosols (air-borne particles) Causes pneumonia-like symptoms and, sometimes, death Those at risk People 50 years or older, current or former smokers, those with a weak immune system, or those with lung disease Prevention Chemical methods (chlorination, ozoning. Both influence negative on the water quality and corrosion) Physical methods (thermal disinfection, ultraviolet light) Treatment Course of antibiotics as administered by your doctor High temperatures is by far the easiest and most reliable way to disinfect the system (65ºC kills all in ~10 minutes) 5

6 Legionella cases in EU Top legionella cases in y Legionella issues in LT (y.2017) France Germany Italy Netherlands Spain 6

7 Bacteriological decontamination The optimal temperature for growth is 36 0 C+/- 1 0 C The time of regeneration of cells at this temperature is 6-8 hours At temperatures above 46 0 C the bacteria is killed off The time of pasteurization process depend on temperature : for 48 C takes 30 hours for 50 C takes 7 hours for 58 C takes 20 minutes for 70 C takes only 2 minutes!!! Apart from water temperature other factors influencing the growth of Legionella are the presence of: biofilm, food supply, water properties and the presence of tougher organism, such as amoebae. 7

8 What is the right temperature of hot water? Only proper control and regulation of hot water can simultaneously meet all requirements: 42 C - to ensure comfort on min temperature? C - to reduce the risk of Legionella infection? 45 C - to reduce the risk of scalding to minimum? 50 C - to reduce lime and corrosion problems? Instant access to tap water at the desired temperature C For efficient pasteurization instalation must be exposed to superheat only for short/efficient time. 8

9 Danfoss MTCV Solution Thermal balancing secures a constant temperature irrespective of changing operating condition MTCV reduces circulation flow to minimum Plug & Play MTCV WB animation 9

10 Complete Solution for Electronic Dissinfection = MTCV-C MTCV-A Adapter for TWA-A PT1000 temp. sensor TWA-A NC T-modul for PT Upgrade to disinfection function can be done under the water pressure any time when valve is operating! CCR2+ electronic dissinfection controller & temperature register 10

11 Kv ( l/h) How it works? 2000 MTCV setting 50 C Basic (MTCV-A) Disinfection (MTCV-C) Circulation water temperature ( C) MTCV-A (thermal balancing) Simply return flow temperature limiter No dissifection function Valve is closed at water temperature 5 C above the set MTCV-C (dissinfection) is upgrated A version version plus additional features: Electronically disinfection function (via bypass flow for providing higher working temp.) driven by CCR2 controller 11

12 CCR2+ - Complete Solution for Electronic Dissinfection Advance control & safety Registration & Monitoring of disinfection process realization (T, t). Optimization of the disinfection process by selecting the temperature and time of disinfection Full control of the disinfection process - even for a single section Alarm output Energy & Time savings Shorter disinfection time for the entire system Lower pump head for dissinfection Reducing the Risk of sludge and corrosion of zinc Flexibility CCR2+ master up to 20 risers. System can be expanded with CCR+ Slave unit (aditional 16 risers) Independent or Dependent control (integration with other water treatment systems/automatic solutions) Integration with BMS (RS485 RTU or IP Modbus) Connectivity TPC/IP web server and (WI-FI) for remote access to data and settings Ergonomics interface Flexibility towards customer IT 12

13 MTCV performance proven in running application Case I Case II Case III 34% energy saving after MTCV instalation 25% energy saving after MTCV instalation 26% energy saving after MTCV instalation 13

14 Pilot project Frederica, DK Electronic disinfection case study Starting point/problem MF house with 46 flats 19 risers, non balanced circ. No Disinfection Legionella contamination The project Instalation of MTCV-C 2pcs of CCR2s Disinfection was done automatically once a week Process started AM 3: min long procedure Comfort temp 50 C Disinfection temp. 66 C 6 min disinfection for each risers Goal To compare Legionella contamination before and after instalation of Danfoss MTCV-C. 14

15 Pilot project Frederica, DK Application before installation of Danfoss thermal disinfection valves. T 1 =55 0 C T 2 =55 0 C T 19 =42 0 C +17x exceeding values t s =57 0 C MBV 120 l/h MBV 120 l/h MBV 120 l/h 15

16 T 1 =50 0 C T 2 =50 0 C T 19 =50 0 C Pilot project Frederica, DK Application after installation of Danfoss thermal disinfection valves. t s =57 0 C 30 l/h 40 l/h 100 l/h 16

17 Pilot project Frederica, DK Bacteria analyses Before installation of Danfoss thermal disinfection valves. Sample No. Water installation All bacteria Legionella bacteria Danish limit values All Legionella bacteria Content per litre Content per litre Max. content per litre Exceeding values * 1 Cold tap water None * 2 Hot tap water % ** 3 Hot return tap water % * Apartment ** Boiler room After installation of Danfoss thermal disinfection valves. Sample No. VS Water installation All bacteria Legionella bacteria Danish limit values All Legionella bacteria Content per litre Content per litre Max. content per litre Exceeding values * 1 Cold tap water None * 2 Hot tap water None ** 3 Hot return tap water None * Apartment ** Boiler room 17

18 Pilot project Zabrze, PL Monitoring of electronic disinfection proces Starting point/problem 5 stories MF house, 7 riser Non balanced circ. Big heat loses in instalation No Disinfection Legionella risk The project Instalation of MTCV-C 1pcs of CCR2s Disinfection was done automatically once a week CCR2 connected to ECL Risers: DN15: 1,2 DN20 3,4,5, min long procedure Comfort temp 50 C Disinfection temp. 70 C 6 min disinfection for each risers Goal To monitor electronic disinfection proces after instalation of Danfoss MTCV-C. 18

19 Pilot project Zabrze, PL Installation setup of Danfoss thermal disinfection valves. R1 R2 R3 R4 R5 R6 R7 19

20 Pilot project Zabrze, PL Temperature in risers during disinfections process Temperatury na zaworach MTCV z dnia (t dis =70 o C, t cwu =82 o C, III bieg pompy) T dis =70 0 C riser riser riser riser riser riser riser :22:00 00:36:15 00:50:18 01:04:34 01:18:55 01:33:02 01:46:59 02:01:12 02:15:23 02:29:27 02:43:28 PION 1 PION 2 PION 3 PION 4 PION 5 PION 6 PION 7 20