More than twenty years Hungarian experience in one pipe heating system renovation

Transcription

1 .. More than twenty years Hungarian experience in one pipe heating system renovation Tamas Szekely - BDM 1 Hydronic Balancing & Control

2 Obvious Demand of energy saving EPBD Usage of TRV (high capacity for one pipe, presetting for two pipe systems) Comfortable room temperature (Xp: 2K/1K) Hydraulic balancing? 2 Hydronic Balancing & Control

3 Consequences of bad hydronic balance Noise problems Insufficient capacity Bad comfort Long start up times Waste of energy 3 Hydronic Balancing & Control

4 Renovation of systems in Hungary Installation of thermostatic radiator valves and thermo heads Installation of riser controller manual automatic 4 Hydronic Balancing & Control

5 Few statistical data 643k district heated flats in 86 cities 52% are renovated (heating) 60% one pipe system 80% from top to down piping, rest P Few DHCs support the renovation only Additional ~ 400k flats with big central boiler station (>40 flat) No information about renovation % Few, small size Housing Associations >95% housing communities Potential still 1M TRV, 130T BV Usage of HCA is very popular Covers 65% of installation market 5 Hydronic Balancing & Control

6 Flats Number of district heated flats and renovation in Budapest only 60% are renovated Flats Renovated flats Cities 6 Hydronic Balancing & Control

7 Type of one pipe heating systems Without by-pass with by-pass on top with by-pass+valve/trv Typically 5, 10 and 16 floors buildings Distribution on top P type Combination of them Special applications handrail partition wall 7 Hydronic Balancing & Control

8 Directions of renovation Included with wall insulation and window exchange ~60% Conventional solution Install by-pass (if needed) + TRV, BV Often equipped with HCA Install new two pipe, to be replaced 1 pipe system (<3%) Too expensive, never pays back Separation from DH system (more often forbidden) Removing of boiler station and individual boiler installation per flat Renovation goes house to house Convince All housing comunities one by one 8 Hydronic Balancing & Control

9 Features of renovation projects Tender specifications are wrong does not contain DHW renovation In 15-20% only Budapest DH company made compulsory MB usage for 1 pipe It changed to AB 2 years ago Typically low quality solution Cheap products, manual balancing Danfoss put more focus on renovation in Not possible to replace RA-G due to high capacity (Danfoss replaced others) Automatic balancing more popular Partners are grateful for Danfoss experience 9 Hydronic Balancing & Control

10 Subordinated risers Improving saving potential

11 Do we concentrate enough on those risers? TRV in important rooms No TRVs in subordinated rooms Balancing in the bottom of important risers Manual balancing Automatic balancing Balancing of subordinated risers 11 Hydronic Balancing & Control

12 Typical problems TRV generally not used in staircases Often used candle riser for bathrooms Radiators are oversized mostly In both, one-pipe and two-pipe systems Manual balancing is used if at all Overflow and energy loss on subordinated risers during partial load 12 Hydronic Balancing & Control

13 Recommendation Automatic balancing...+ self-acting control... + electronic control 13 Hydronic Balancing & Control

14 Project execution Where from the money and how we can install

15 Financing Panel block flat rehabilitation program by government from 1995 Covers up to 50% of total value Due to limited source, slows down the process (52% of total till today) In 2010 the government subsidy cancelled and renovation stopped Financing restarted by municipalities in these years Normally covers up to 30% of total value but mostly for heating only Kecskemet 90%, the city almost ready Renovation is collapsing nowadays Lack of money (70% is too much for houses) Owner finance should started now 15 Hydronic Balancing & Control

16 Installation HCA companies are the biggest players (Techem 60-70% of total) 3-4 additional player on the market Operating Structures are specifying and handling the projects Without knowledge and experience Low quality design Danfoss preferred as problem solver Low manpower in plumbing sector (today) Few special solution for unique systems Yearly market ~1.000 flat today 16 Hydronic Balancing & Control

17 Collection of renovated buildings THT Condominium Households Yearly issue - till 2015 The top 100 renovation Different level of renovations Complete renovation Window exchange + heating renovation Detailed info about executed installation Saving result compensated by degree day method Includes useful information (advertisement) from suppliers 17 Hydronic Balancing & Control

18 Content of project sheet Location Picture about the building Labelling - rank development Size of investment/building Saving chart Source of money Installer name Technical parameters windows exchange heating renovation TRV Balancing Radiator exchange HCA Total saving 18 Hydronic Balancing & Control

19 Full renovation (included insulation) Location Picture about the building Labelling rank development Size of investment Saving chart Source of money Installer Technical parameters windows exchange heating renovation TRV Balancing Radiator exchange HCA Total saving 19 Hydronic Balancing & Control

20 ...one more example Location Picture about the building Labelling rank development Size of investment Saving chart Source of money Installer Technical parameters windows exchange heating renovation TRV Balancing Radiator exchange HCA Total saving 20 Hydronic Balancing & Control

21 Learning points Diameter diminution in front of radiator Noise Aluminum radiator as an amplifier Pipe fixation among floors Air bubbles de-aeration Filling method, heat up the water to reduce the solute oxygen from water Balancing valve Capacity of TRVs (bigger is better) Insulation of building and the flow temperature 16 floor buildings are critical, precise calculation is needed Stretching risers 21 Hydronic Balancing & Control

22 Learning point by-pass installation The critical radiator is the first one in the loop Wit by-pass installation we have lower emission in fist radiator a < 1; Let s presume 20% Result around 10-15% reduction We need to compensate it Increasing flow rate bigger pump Higher flow temperature hard to solve Most of the case the radiators are oversized, so not need special action... but must to check and precisely calculate! 22 Hydronic Balancing & Control

23 Case study from HU AB-QM saving potential

24 Case study (HU) Address: Nepfürdő u. 19 Number of floors: 10 Number of staircases: 6 Number of flats: 260 Heated space: m3 Number of radiators: 1040 Number of risers: 128 AB-QM installation only DN (26, 68, 34 pcs.) 25 Hydronic Balancing & Control

25 Case study (HU) 26 Hydronic Balancing & Control

26 Case study from PL AB-QM + CCR3 saving potential

27 Why shall we use CCR3 In partial load, we need significantly lower flow demand Lowering the return temperature with CCR3 despite water by-passing Penalty for too high return temperature (e.g. in Germany) heat loss on return pipeline, efficiency drop on co/trigeneration power station Saving on pumping (create variable flow in one pipe system) 28 Hydronic Balancing & Control

28 System design 29 Hydronic Balancing & Control

29 Components of electronic return temp. limit. CCR3 control electronic TWA-Z thermal actuator to AB-QM Temperature sensors 30 Hydronic Balancing & Control

30 Energy saving in whole hating season 31 Hydronic Balancing & Control

31 Test result of electronic control Long (period) test Setting of CCR3 Two parallel risers Decreasing outdoor (blue line), the flow temp (red line) increasing The return temperature (yellow and green) follow the trend of flow temperature 32 Hydronic Balancing & Control

32 Energy saving The energy saving calculation based on 24 days measurement The electronic control was established in two staircases Heating energy saving is 24% Pumping energy saving is 69% 33 Hydronic Balancing & Control

33 Energy saving Conclusion: Recommended investment, with acceptable expenditure we can realise significant energy and money saving in whole season long. The pay back time is favourable! To be taken into consideration we need to use hydronic balancing in any case the payback time become shorter!) 34 Hydronic Balancing & Control

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