Knowledge K5 - 0002 Energy Savings with BELIMO Characteristic

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					                                                    Knowledge                                                                             K5 - 0002

                                                   Energy Savings with BELIMO Characteristic Control Valves (CCV)
Task
HVAC systems run in standby mode for a con-
siderable number of operating hours, without
requiring any energy (especially during the
transitional period between winter and spring).
The energy generators (boiler and chiller) are
in operation and the control valves for the air
heaters/air coolers are closed. The leakage
amounts are small, depending on the valve
size and valve design. Viewed over the entire
year, this hardly noticeable energy loss results
in a considerable sum of money.
The annual energy loss depends on various
factors:
– Leakage rate of the valve (LR),
– Valve authority (PV),
– a-value (heat transfer),
– Power of the heat exchanger (Q) and
– Number of standby operating hours.
Examples
Air cooler with 100 kW power and throttling cir-
cuit on the valve side. The supply is 6°C, the
return is 12°C and the setpoint value is 22°C.
This yields an a-value of 0.23. The valve was
designed with a valve authority (PV) of 0.5.
The air cooler is in no-load operation (valve      Calculation basis
closed) for 2000 hours a year. The energy loss
with a conventional globe valve can be up to                      Q [kWh/year] = Q0       Q [Heat exchanger]       Operating hours per year
                                                                                      *                        *
627 kWh/year (with a leakage rate of 0.05% of
the kvs-value). In practice, the valve authority
                                                                     1                                   1
PV will be lower, i.e. the energy loss increases          Q0 =                            V0 =                                   a = f * VL – RL
                                                                     1 – V0                        1 + PV(LR2 – 1)                        VL – t
with PV 0.3 to 809 kWh/year.                                      1+
                                                                       V0
Air heater with 100 kW power and mixing cir-
cuit on the valve side. The supply is 55°C,         Q0 Dissipated energy [ – ]        V0 Leakage volume [ – ]             a    a-value                [–]
                                                                                      PV Valve authority [ – ]            VL   Supply temperature     [°C]
the return 40°C and the setpoint value 22°C.
                                                                                      LR Leakage rate    [–]              RL   Return temperature     [°C]
This yields an a-value of 0.43. With a valve                                                                              t    Setpoint               [°C]
authority (PV) of 0.5 and 2000 hours per year                                                                             f    Factor = 1 or 0.6
in no-load operation, the energy loss is around
310 kWh/year.
                                                   Energy savings diagram
Solution                                           Q [kWh/Jahr]
BELIMO has developed the characteristic con-
                                                   1400
trol valve (CCV) and the pressure-indepen-
dent control valve from the proven shut-off ball
valve. In the closed position, the valve shuts     1200
air-bubble tight with a closing pressure of 14
bar. Regardless of the valve authority and the
a-value of the system, no energy is lost from      1000
the medium over the control path.                                       Air cooler (e.g. 100 kW)
Payback                                             800

The energy costs are approximately
0.03 €/kWh for heating and 0.06 €/kWh for          600
cooling.
Using a BELIMO control ball valve with DN40                                                   Air heater (e.g. 100 kW)
for an air cooler saves around370 € in energy      400
                                                                                                          LR < 0.05% PV = 0.3
costs over ten years, i.e. the payback period is
three years.                                       200
                                                                                                          LR < 0.05% PV = 0.5
                                                                                                          LR = 0%    PV = 0.3
                                                      0                                                                               a-value [ – ]
                                                           0.1                0.3            0.5               0.7              0.9




www.belimo.com                                                                                                                                               1
    K5 - 0002                                           Energy Savings with BELIMO Characteristic Control Valves (CCV)

Product overview

               Standard      Spring return                                                 Actuator types
                     X                           TRD    TR                  LR..A
 Actuators




                                    X                                          LF
                     X                                                                          NR
                     X                                                                                       SR..A
                                    X                                                                                         ARF
             Valve types   2-way        3-way    DN10   DN15   DN15     DN20        DN25       DN32         DN32 *     DN40         DN50     DN65       DN80
                           Female
             R2..K         thread                
                                        Female
             R3..K                      thread   
                           Female
             R2..          thread                                                                                            
                                        Female
             R3..                       thread                                                                               
                           Female
             R2..P                                                                                                             
 Valves




                           thread
                           Female
             R4..K         thread                
                                        Female
             R5..K                      thread   
                            Male
             R4..          thread                                                                                            
                                         Male
             R5..                       thread                                                                               
                           Flange
             R6..R          PN6                                                                                                                 
                                        Flange
             R7..R                       PN6                                                                                  
* in housing DN40


Experience
The BELIMO characteristic control valve was
successfully launched on the market in 1999
and has proven its worth over several heating
and cooling periods in the meantime.
As of today, over one million BELIMO charac-
teristic control valves are in use throughout the
world and demonstrate their robustness and
reliability on a daily basis.




                                                                                                            Illustrations:
                                                                                                            Midfield Zurich, heat recovery (left), BELIMO
                                                                                                            “Longus” building, air conditioning (above),
                                                                                                            Aquilana insurance Baden, heating (page 1).
                                                                                                            All three displayed systems were put into operation
                                                                                                            during the first quarter of 2000.
                                                                                                                                                                  Knowledge K5-0002 • en • v1.2 • 04.2006 • Subject to modifications




Key words:
energy savings, shut-off device, characterisitic
control valve, control ball valve



For more detailed information, please contact your BELIMO representative:




2                                                                                                                                           www.belimo.com

				
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