Water Waste Reduction in Solar Heating System

By:Ayas kanta Mohapatra

Guide:Prof. Vidya Pratap

Prof. Seena Biju

Background

• Hot water is stored in solar tank and then flows through pipelines

• However, the water loses heat if not used for a longer time

• So we have to waste the cold water till we get hot water

• This objective of this project is to reduce the amount of water wasted in this way.

Assumptions

• Only prototypes have been explained• Major amount of water is wasted in the morning• All the water present in the pipes in the morning are wasted• The volume of the pipe is equal to the water wasted in the

morning• Four (35m*45m*25m) building has been considered

Limitations• Confidential data has been removed• Only prototypes have been explained

Water Wastage

Diameter of Pipe 0.025 meter

Total Length of all pipes in a single building 1080 meter

Volume of pipes in a single building 0.530357143 cubic meter

Total No. of buildings 4 numbers

Total volume of pipes 2.121428571 cubic meter

Monthly waste 63.64285714 KL

560.4220286 Gallon

Amount of water wasted = more than 63KL per month

Current Pipeline Design

Alternative – 1

• Direct water recirculation through an additional pump

Cost AnalysisAlternatives Equipments Specification Unit Cost Requirement Cost

Alternative 1

Centrifugal Pump1 HP, 5m Head, 1500 rpm 6500 1 6500

Timer 320 1 320

Cable 3 core, 2.5 sqmm 30 10 300

RCCB 2 Pole, 10A 1700 1 1700

Ball Valve 1 "(25 mm) 211 1 211

CPVC Pipe 1 "(25 mm) * 16' 463 34.85 16135.55

CPVC Tee 1 "(25 mm) 38 24 912

CPVC Elbow 1 "(25 mm) 30 5 150

Union 1 "(25 mm) 95 2 190

Labour

Total 26418.55

Alternative – 1

• Pros– Economic– Automatic system – Independent system

• Cons– More electricity consumption– Cavitation problem may occur– NPSH issue may be there

Alternative – 2

• Water Recirculating System using an external pump

Cost AnalysisAlternatives Equipments Specification Unit Cost Requirement Cost

Alternative 2

Centrifugal Pump

5 HP, 40m Head, 3000 rpm, FR= 150.876 gallon/ minute 14000 1 14000

Timer 320 1 320RCCB 2 Pole, 10A 1700 1 1700Cable 3 core, 2.5 sqmm 30 20 600Ball Valve 1 "(25 mm) 211 2 422CPVC Pipe 1 "(25 mm) * 16' 463 34.85 16135.55CPVC Tee 1 "(25 mm) 38 24 912CPVC Elbow 1 "(25 mm) 30 7 210Union 1 "(25 mm) 95 2 190Concrete tank 2m*2m*2m 10000 10000Labour * Total 44489.55*

Alternative – 2

• Pros– Independent system– Semi-automatic system (with level sensor)– Can be helpful during maintenance of tank

• Cons– Expensive• Concrete tank• Pipeline layout• Pump

Alternative – 3

• Water Recirculating System using the existing pump

Cost AnalysisAlternatives Equipments Specification Unit Cost Requirement Cost

Alternative 3

NRV 1 "(25 mm) 300 1 300

Ball Valve 1 "(25 mm) 211 2 422

CPVC Pipe 1 "(25 mm) * 16' 463 34.85 16135.55

CPVC Tee 1 "(25 mm) 38 24 912

CPVC Elbow 1 "(25 mm) 30 5 150

Union 1 "(25 mm) 95 2 190

Concrete tank 2m*2m*2m 10000 10000

Labour *

Total 18109.55*

Alternative – 3

• Pros

– No additional pump required

– Can be helpful during maintenance of tank

• Cons

– Expensive

• Concrete tank

• Pipeline layout

Alternative – 4

• By insulating the hot water pipes

Cost Analysis

Alternatives Equipments Specification Unit Cost Requirement Cost

Alternative 4

K Flex Sheets

Part No.- 6RX038028, 1" nesting (square feet pricing) 350 100.10427 35036.49

Labour *

Total

35036.49*

Alternative – 4

• Pros

– Economic

• Cons

– Less efficiency

Suggestion

• Alternative 1

– To avoid higher instant investment

– Less labor cost

– Automatic system

– Independent system