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7. Application
7.1. Daily Consumption, Temperature and Quality of Hot Water
7.1.1, Daily consumption
No.
Type of building
unit
Max. daily consump tion per day (L)
Usage time(hour)
1
residence
With self-supply heating water and bath equipment
Daily per person

40~80
60~100
24
2
Villa
Daily per person
70~110
24
3
Students’ dormitory, training room, ordinary hotel, etc.
With public cloakroom
With public cloakroom and bathroom
With public cloakroom, bathroom and clothes-washing room
With separate toilet and clothes-washing room

Daily per person
Daily per person Daily per person

Daily per person

25~40
60~60
50~80

60~100
24 hours or fixed time
4
Guest room of hotel
Guest
Staff

Daily per bed
Daily per person

120~160
40~50
24
5
In-patient department of hospital
With public cloakroom
With public cloakroom and bathroom
With separate toilet and clothes-washing room
Medical workers
Out-patient department, dispensary
Sanatorium

Daily per bed
Daily per bed
Daily per bed

Daily per bed
Daily per bed

60~100
70~130
110~200
70~130
7~13
100~160

24

8
24
6
Geracomium
Daily per person
50~70
24
7
Kindergarten and baby farm
In residence
No

Daily per child
Daily per child

20~40
10~15

24
10
8
Public Bathhouse
Shower
Bath, tub
Sauna (bath and massage)

per person every time
Daily per person
Daily per person

40~60
60~80
70~100

12
9
Hairdressing, beauty parlor
Daily per person
10~15
12
10
Clothes-washing room
Per kg dry clothes
15~30
8
11
Dietetic place
Restaurant
Fast food, students’ and employees’ dinning room.
Taproom, coffee house, Kara okay room

One time per person


15~20
7~10
3~8

10~12
11
18
12
Office building
Daily per person
5~10
8
13
Gymnasium
Every time per person
15~25
12
14
Sports centre
Shower for athlete
Every time per person

25~35

4
15
Meeting room
Every time per seat
2~3
4






7.1.2?sanitary ware
No.
Type of sanitary ware
Once water consumption (L)
Hourly consumption (L)
Water temperature of use (?)
1
Residence, hotel and villa
Tub with shower apparatus
Tub without shower apparatus
Shower apparatus
Washbowl,


150
125
70~100
3
-

300
250
140~200
30
180

40
40
37~40
30
50
2
Rest house, group room, training centre.
With shower room
Without shower room
Washstand

70~100
-
3~5

210~300
450
50~80

37~40
37~40
30
3
Dietetic place
Washing pan or pool
Washbowl: for staff
For customer
Shower device

-
3
-
40

250
60
120
400

50
30
30
37~40
4
Kindergarten and baby farm
Bath tub:Kindergarten
Baby farm
Shower device:Kindergarten
Baby farm
Washstand
Washing pan or pool

100
30
30
15
15
-

400
120
180
90
25
180

35
35
35
35
30
50
5
Hospital, dispensary, sanatorium
Washing pan
Washbowl
Tub

-
-
125~150

15~25
300
250~300

35
50
40
6
Public Bathhouse
Tub
Shower device: With shower room
Without shower room
Washbowl

125
100~150
-
5

250
200~300
450~540
50~80

40
37~40
37~40
35
7
Office building, washbowl
-
50~100
35
8
Hairdressing, beauty parlor, washbowl
-
35
35
9
Laboratory
Washbowl
Lavabo

-
-

60
15~25

50
30
10
Theatre
Shower device
Washbowl foe actor (actress)

60
5

200~400
80

37~40
35
11
Sports centre
30
300
35
12
Living room of factory and enterprise
shower:Ordinary workshop
Dirty workshop
Wash pan: ordinary workshop
Dirty workshop

40
60
3
5

360~540
180~480
90~120
100~150

37~40
40
30
35
13
Body cleaner
10~15
120~180
30

7.1.3. Sanitary index of the life hot water quality
It should be conform to the current


7.1.4. Raw water treatment
The raw water solution of integrated hot water supply system should be confirmed according to comparison of many economic and technical factors such as e the quality, temperature, structure and requirement of heating device, etc.
(1) For washing room, if the daily consumption of washing room is more than 10m3 and the total hardness (calcium carbonate) of raw water is larger than 300mg/L, it should be soften. If the total hardness (calcium carbonate) of raw water range from 150 to 300mg/L, it is recommended to be soften.
(2) For other location, if the daily consumption of washing room is more than 10m3 and the total hardness (calcium carbonate) of raw water is larger than 300mg/L, it is recommended to be softened or stabilization treated. The range of total water hardness after softening should be within: 1) washing room, 50~100mg/L 2) other location: 75~150mg/L.
(3) Stabilization treatment should accord to the hardness, temperature, time of treating or effective span and work voltage hence to select physical treatment or chemical stabilizer treatment.
(4) If the system requires a high-degree of dissolved oxygen controlling, it is recommended to adopt oxygen eliminating measure.  

7.1.5. Calculating temperature of cold water.
The calculating temperature should be confirmed according to the mean temperature data of local coldest water.

7.1.6. Maximum outlet temperature and minimum temperature of water distribution.
They can be selected in the following table,
Water treating condition
The maximum outlet temperature of Boiler, heating water system or water heater
Minimum temperature of distribution
Unnecessary to soften the raw water, but raw water need to treat and had been treated.
75
50
Raw water need to treat but haven’t been treated.
60
50
Remark: when the supplying system just provide hot water for bath and washstand, not washing pan and pool, the distribution temperature should not be less than 40

7.1.7. Selection of tank capacity:
Residence, hotel, hospital (Out-patient department, dispensary)
(1) Supply hot water all day and night
      Peak-time water consumption (design hourly consumption)
Peak-time   34hours
Variation co efficiency K of peak-time
Style of building
Quantity of residence person for residence, hotel, quantity of beds for hospital
35
50
60
75
100
150
200
250
300
450
500
600
900
1000
Residence

6.58


5.12
4.49
4.13
3.38
3.7

3.28


2.86
Hotel


9.65


6.84


5.61
4.97

4.58
4.19

Hospital
7.62
4.55


3.54

2.93

2.6

2.23


1.95
Peak-time hourly consumption:
Qr= kQtotal /24           
Total consumption in peak time:
Qpeck =4Qr               
Suppose the peak period is 4 hours.
Available capacity of tank Q (Available capacity means the total capacity under the highest level)
Qavailable=Qpeck--4 Qunit                         
(2)Tank selection for part-time supply
h stands for supplying period and Qtotal means total water consumption.
Qtank=Qtotal --h Qunit,                  
Because of the heat-pump heating theory, when in low ambient temperature, the heating capacity will decrease. For the sake of supplying sufficient hot water, we recommend to set auxiliary electric heater. (It will automatically start when the ambient temperature is too low.)
For MGH-F35W/S it should match electric heater of 10KW.
For MGH-F17.5W/S(N2) it should match electric heater of 5KW.
7.2. Hydraulic Calculation

After selecting the main water pipe it is necessary to do the hydraulic calculation. If the resistance of waterside is more than the selected pump head, a larger pump should be replaced. Or choose the water pipe with larger diameter.
For the detailed calculating course please refer to the relevant technical book and standard.
The following is about the application of Hazen-Williams formula:
According to relevant water supply and sewerage design criterion, calculate the resistance by Hazen-Williams formula.
According to the national standard, the resistance loss is calculated as follows:
I=10.5C-1.85dj-4.87Q1.85
(Hazen-Williams formula)
In the formula, i —head loss of pipe per unit lengthm H2O/ m; Q —flow volumem3/s; dj —inner diameter, m; C —Hazen-Williams factor, seen in the following table
Condition
Type
New
Has been used for 25 years
Has been used for 50 years
PVC
150
150
140
Galvanized steel
150
130
100
Cast iron
130
110
90
Take cast iron pipe for example, according to the calculated velocity and resistance loss, select proper water pump and dia. of pipe.
Cast iron pipe

Dia.
Flow
Velocity
Resistance


mm
L/S
m/s
mm/m

100
5.00
0.65
9.02

125
20.00
1.66
39.24

150
25.00
1.43
24.25

200
30.00
0.96
8.30

250
80.00
1.64
17.14

300
80.00
1.14
7.03

350
140.00
1.46
9.33

400
200.00
1.60
9.41

450
230.00
1.45
6.86

500
400.00
2.05
11.43

600
500.00
1.77
7.10

700
600.00
1.56
4.69

800
800.00
1.60
4.17

900
1000.00
1.58
3.55

1000
1100.00
1.40
2.53


























Remarks:
When the dia. ranges DN15~20 the velocity should be limited to 1.0m/s
When the dia. ranges DN25~40 the velocity should be limited to 1.2m/s
When the dia. ranges DN50~70 the velocity should be limited to 1.5m/s
When the dia. equal or over DN80 the velocity should be limited to 1.8m/s, or else the figure is italic.









7.3. Sample Project:

7.3.1, Main introduction
 (1) Present status and specification
 Supply hot water for a three star hotel. According to the data supplied by first party, there’re 168 sets of guest rooms and peak number of people is 250. Location city is Foshan in Guangdong province, PRC.
This project should think about the connection of water heating device, water storage, and electric control system and power supply pipe and between them.
(2) Weather data
According to the statistics data of latest 40 years by Chinese National Meteorological Centre, the meteorological data of Foshan is as follows: outdoor design temperature is 33.5, annual average water temperature is 20, and average water temperature in the three months of winter is 16.

7.3.2. Design standard
The project should conform to the national water supply and sewerage work and design standard. Also it should base on the local meteorological data.

7.3.3. Parameter design basis
The design parameters should base on relevant technical manual as well as the requirements, such as water temperature, supplying period, local climate, habits and custom, etc. Hence to confirm the water volume of central hot water supplying system. 

7.3.4. Water consumption calculation 
For quest room, the hot water consumption is about 120~160L daily per person. Considering the affluence of heat source, we choose 120L daily per person as index. So the total consumption is 250*120L=30000L per day. For this project the water demand is about 30ton per day (temp. is 60)
Hence the required quantity of heat is: Quantity of heat (Kcal)=specific heat of water (Kcal/Kg·)*temperature difference ()*daily consumption (Kg)
Q =1*(60-20)*30000=1200000(Kcal)

7.3.5. Select the main unit
(1) According to the calculated result and actual situation, we choose the model MGH-F35W/S, maximum power input is 9.0kw, heating capacity is 35kw, rated hot water output is 660~1200L/H (because of the change of outdoor temperature, the output will have some change. Under the worst condition it can insure to produce hot water 660L/H and average output is 850L/H, for more details, PLS refer to the technical manual of the Air-source Heat-Pump Heating Water System.)
(2) Quantity of units’ calculation. The design requires the system operate for less than 14h under standard work condition and operate for less than 18h when under worst condition. Suppose the average daily working time is 14 hours, 1200000÷(35860×14)=2.8(units), hence we choose 3 units.

7.3.6. Select the tank
The total daily consumption is 30000L; simultaneous usage factor of guest room is about 0.6.
Peak-time   34hours
(1) Peak-time hourly consumption:
Qr= kQtotal /24
Qr= 5.530 /24=6.875 ton
(2) Total consumption in peak time
Qpeck =4Qr     (Suppose the peak period is 4 hours.)
Qpeck =46.875=27.5 ton
(3) Available capacity of tank Q (Available capacity means the total capacity under the highest level)
Qavailable=Qpeck--4 Qunit
Qavailable=27.54(3*0.85)=17.3 ton
     (4) It is recommended to select tank of 18 ton capacity.
     (5) Other (just recommendation, not standard)
        a. Inner structure: stainless steel board
        b. Insulated layer: foamed polyurethane.
        c. Outside protective layer: stainless steel  
        d. Holder for tank: groove steel or double-T steel.
      Remark: the placement of tank should consider the load of architecture.

7.3.7. Drawing of the project
7.3.8. Comparison with Diesel Oil Boiler:
HEATING MODE
Diesel Oil Boiler
Midea air source Water Heating System
Energy resource
Diesel Oil
Electricity
Combustion value
10200 kcal/kg
860 kcal/h
Efficiency
75%
420%
Daily water consumption
30.0 ton60
Average temperature increase
2060
Quantity of heat absorbing
30.0T×60-20×1000kcal/T=120,000,000 kcal
Daily fuel consumption
156.9kg
332.2kwh
Unit price of fuel
4.3CNY/kg
1.0CNY/kwh
Daily operation cost
564.8CNY
332.2CNY
Annual operation cost
206152CNY
121253CNY
Danger
Medium
No harm to people
Noise
Noisy
A little
Pollution
Medium
No harm to environment
Comparison
Large floor area, special room for boiler, pay for the worker, fee of annual inspection, etc.
Small floor area, outdoor installed and auto control.
Remark: The comparison based on the energy price in China:
Commercial Electricity=0.13USD/kW h,
Diesel oil=0.52USD/L, LPG=1.23USD/cbm (the exchange rate in Sep. 2006 is 1 CNY = 0.125 USD)
Comparing with Diesel Oil Boiler, Heat Water Heat Pump System has the advantages of high efficiency, low expense, safe, environment protecting, low maintenance expense, etc. It can save the operation cost by about 50% per year.



7.3.9. Comparison with solar water heater
Feature of solar energy
heating water system
Feature of air resource heating pump heating water system
1. No operation cost when in sunny days, but during other days it should use auxiliary electric heater completely. Take Guangdong Province as example, as the weather data shows, there is sunlight in 240 days of one year. But in the other 125 days the energy consumption of electric heater is equal to 562 days (125*4.5=562, COP of heating water system is 4.5) consumption of heat pump water heating system.
1. The annual operation cost of heating water system is lower than solar.
The cost is about 75% of solar energy heating water unit, also it is auto control system.
2. The water quality is not good. For the solar water heater it adopts copper-aluminum composite material, bad secondary pollution.
2. Good water quality. It adopts stainless steel heat exchanger, conforming to the food-grade sanitary condition. 
3. Large floor area. On average the heat I square meter absorb can heating about 60L water daily. Hence if the demand is 19.6 ton it need heat absorbing board 326 square meters.
3. Small floor area. To produce 19.6 ton hot water it just needs one unit which floor area is only 4 square meters.
4. Large investment cost. The power of auxiliary electric heater is 10 times than heat pump water heating system.  
4. Power input of one unit is less than 10kw.
5. Sunlight in winter is always bad but good in summer. The actual situation is: hot water demand in summer is less in winter; further the required temperature is higher.
5. it can be set the outlet temperature according to the demand of different seasons. Much more energy-saving.

7.3.10Installation
No.
Accessories
Function
1
Filter
Filtrate the dust or impurity of heat-exchanger
2
Check valve
anti-water hammering, protect the pump
3
Hydraulic pressure gauge
Debugging and maintenance
4
Soft connection
Decrease vibration
5
Main unit
Supply caloric to heat the water
6
Insulated tank
Storage hot water
7
Blow down valve
Eliminate the dirty water after washing the tank
8
Water pump
Supply the water of tank to the terminal of whole system. Force certain pressure and circulate the cold water to be reheated.

9
Pressure switch
Confirm according the resistance of worst cycle and demand pressure of user hence control the ON/OFF of pump.

10
Temperature switch
Could be set according to the customer demand. Default is conducting when temp. lower than 35 and disconnecting if temp. over 42. To control ON/OFF of water pump and electromagnetic valve

11
Electromagnetic valve

Controlled by temperature switch

12
Ball valve

For maintenance


7.3.11Construction introduction
1) Dimension of tank: confirm the diameter and height of tank(according to the bearing ability of floor)
2) Diameter of water pipe: confirm the diameter and variable-diameter according to the flow volume and velocity
3) Water pump: confirm the pump head and flow
4) Thickness of insulated layer: confirm the thickness of insulated layer according to the material, heat loss.
5) Elbow: confirm according to the drawing supplied by party A
6) Supporter for tank: confirm the shape and size
7) Drawing: Such as water system and piping collocation
7.3.12Present operation status
Since the completion of project and Up to now, it is still in a good working order. Party A also gives a high opinion of this project and Midea heating water system for the reliable quality and economical performance.
Hướng dẫn các tính chọn và thiết kế máy Heating water Midea Reviewed by Máy làm mát - Máy lọc nước Daikio on 08:19 Rating: 5

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