Sanyo Sequence of cooling operation DE, Sequence of heating operation DE, Super Absorption

ENVIRONMENTALLY FRIENDLY TECHNOLOGY

SUPER ABSORPTION

Sequence of cooling operation (DE)

Sequence of heating operation (DE)

Figure 27 illustrates the typical operating sequence of a SANYO DE di- rect-fired absorption chiller / heaters. The NE steam-fired unit does not include the time delays associated with the burner blower, gas valve and ignition functions.

With a chilled water setpoint of 6.7° C and with the chiller/heaters en- abled, the start signal will be energized as the leaving chilled water tem- perature rises to 7.7° C, 1.0° C above setpoint.

The burner initially completes a 36-seconds pre-purge operation that in- cludes gas valve and supply air damper modulation to full open to insure complete purging of the combustion chamber.

The No. 1 absorbent pump flow rate is changed during all stages of op- eration to insure quicker start-up and optimum performance at part load.

Figure 27. Typical combustion time chart (cooling operation)

Start signal

As the cooling load is satisfied with the chiller/heaters at minimum load, the unit will cycle off as the leaving chilled water temperature drops to 5.5° C, 1.5° C below setpoint.

When the microprocessor issues a stop signal, the generator heat source will shut off and the dilution cycle will start. The dilution cycle will last between 6 and 15 minutes depending on generator temperature. The dilution cycle will consist of stopping of the refrigerant pump, absorbent pump(s), and the cooling water pump in turn. The unit is capable of re- starting during the dilution cycle.

Stop signal

Figure 28 illustrates the typical operating sequence of a SANYO DE di- rect-fired absorption chiller/heaters in heating mode.

With a hot water setpoint of 55° C, the start signal will be energized as the leaving heating water temperature drops to 54° C, 1.0° C below setpoint. The burner initially completes a 36-second pre-purge operation that in- cludes gas valve and supply air damper modulation to full open to insure complete purging of the combustion chamber. The No. 1 absorbent pump flow rate is varied during all stages of operation to insure quicker start-up and optimum performance at part load. On chiller/heaters with two ab- sorbent pumps, the No. 2 pump remains off at all times during the heat- ing mode.

Figure 28. Typical combustion time chart (heating operation)

Start signal

As the heating load is satisfied with the chiller/heaters at minimum load, the unit will cycle off as the leaving heating water temperature rises to 57° C, 2° C above setpoint.

When the microprocessor receives a stop signal, the generator heat source will shut off and the dilution cycle will begin. The dilution cycle will last approximately 5 minutes depending on generator temperature. The dilution cycle consists of timed stopping of the No. 1 absorbent pump. The chiller/heaters is capable of restarting during the dilution cycle.

Stop signal

Chiller stop

	Pre-purge	4	2	8	2	Control	Post-purge
	36 sec.	sec.	sec.	sec.	sec.	area	12 sec.
Burner	ON
Blower	OFF
Gas control	Open
valve	Close
Ignition	ON
	OFF
Sol. valve	ON
Ignition gas	OFF
Sol. valve	ON
Main gas	OFF
No. 1 ABSO	ON
pump	OFF
No. 2 ABSO	ON
pump	OFF
Refrigerant	ON
pump	OFF

Approx. 5 min. Dilution cycle

Approx. 6 -- 15 min.

Chiller stop

	Pre-purge	4	2	8	2	Control	Post-purge
	36 sec.	sec.	sec.	sec.	sec.	area	12 sec.
Burner	ON
Blower	OFF
Gas control	Open
valve	Close
Ignition	ON
	OFF
Sol. valve	ON
Ignition gas	OFF
Sol. valve	ON
Main gas	OFF
No. 1 ABSO	ON
pump	OFF

Approx. 5 min.	Dilution cycle
	Approx. 5 min.

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