Sanyo DE Speedy digital PID control, Saving energy with the inverter, Purge system

ENVIRONMENTALLY FRIENDLY TECHNOLOGY

Speedy digital PID control

The introduction of new digital PID control to the E-model stabilizes the chilled/hot water temperature with high accuracy than the previous C model. It quickly responds to the load fluctuation and supplies stable

chilled/hot water temperature. It is suitable for air-conditioning intelligent buildings which require sophisticated control.

SUPER ABSORPTION

Optimum dilution cycle period can be shortened substantially according to microprocessor monitoring

This results in the appropriate dilution cycle operating hours.

Graph 6. Dilution cycle (DE)

Control of high temperature generator by solution level control

With the new control system, solution flow rate is precisely controlled so	getic effect of absorbent pump inverter control. This enables the supply
that the solution level of the high temperature generator is maintained at	of a more stable temperature for chilled/hot water compared to conven-
a certain level.	tional models.
Frequency of maneuvering has been substantially reduced with the syner-

Graph 4. Operating result by speedy PID control (gas-fired)

			Continuous operation of E model absorbent pump
Absorbent	ON
pump	OFF
	16				Conventional pump			E model
					ON-OFF(3 times)			Conventional
Temperature	12		Chilled water inlet temperature			Load change
(° C)
								E model
Temperature	8		Chilled water outlet temperature
setting 7° C
	4							Conventional
			Load factor 80%			Load factor 40%
	0
	0	5	10	15	20	25	30	35	40
					Time(minutes)

Saving energy with the inverter

Balancing the load and flow rate with the absorbent pump’s inverter con- trol enables efficient and energy saving operation. As a result, it saves the input energy and electric power consumption, running cost by 5%

compared to none-inverter control.

Graph 5. Running cost curve Table 4. Test condition

Operation	ON
signal	OFF
Chiller /	ON
heater	OFF
Cooling water	ON
pump	OFF
Chilled / hot	ON
water pump	OFF

	1 min	T 1	1 min	T 2
Stop signal				Chiller stop

T1: Count the time until generator temperature goes down to 120° C (About 4 to 20 minutes)

T2: Decide the time by generator temperature. (About 5 to 10 minutes)

Note :

1)Dilution time in cooling operation is minimum 6 minutes to maximum 15 minutes.

2)Dilution time in heating operation is 5 minutes.

Unit proper and hot water pump stop in 5 minutes after stop signal is lit.

3)Stop the air conditioning system after complete stop of chiller.

Purge system

The high performance purge system maintains the required operating pressure, preserves the chiller performance characteristics, minimizes chiller maintenance as one purge time operation per season in case there are four(4) seasons.

Steam valve opening control

Graph 7. Start up chart (NE)

ex.

	100
ratio(%)	80
			Non-inverter
			control
	60
consumption
	40
					E model
Fuel
	20
	0	20	40	60	80	100

Cooling load factor(%)

1.Chilled water outlet temperature 7° C constant

2.Cooling water inlet temperature

Load factor(%)	Temperature(° C)
100	32
50	27
30	25

		Variable(5-30minutes)								15minutes
										30minutes
												140
					Steam consumption							120
Temperature (° C)													Consumption ratio (%)	control opening ratio (%)
												100
	40						Steam control valve
												80
							opening ratio
	30
						Cooling water inlet temperature						60
	20
						Chilled water inlet temperature						40	Steam	Steam
	10											20
Setting
						Chilled water outlet temperature
7° C	0
	0		5	7 8		15	20	25	30	35	40
				10

Open angle of steam control valve at starting is controlled by means of the three steps, resulting that the excessive amount of steam and also the consumed time to reach the desired level became less than the previous model.

Of course, by means of adjusting the open speed of steam control valve at the second step and the third, it is possible to set up to the most suitable condition met to the site aux- iliary equipment.

Time(minutes)

8 9