Cooling, heating and HEX control in sequence

File: Heat HEX Cool.doc

Last edition: 4 of March 2003

Author: Mikael Krantz

History: 96-02-13/MK First released version.

96-10-03/MK Updated to Menta 1.20

97-09-02/MK Updated to Menta 3.0
Block for calculating signal for sequence calculation added.

98-09-03/mk Unit corrected.

98-12-30/MK New filename

2003-03-04/MK Updated to Menta 4.0

Description

Cooling, heating and HEX control in sequence, with separate P-band and I-times. If the flag for "Normal Control" is true, the main controller is activated, in other cases, the controller is set to closed valves and maximum HEX. The HEX can, however, be set to minimum be the "HEX min" flag. If the "Heating allowed" flag is false, the heating valve is forced to closed position. If the "Cooling allowed" flag is false, the cooling valve is forced to closed position. If the "HEX min" flag is true, the HEX is forced to min position, if the "HEX max" flag is true, the HEX is forced to max position.

Inputs

(Real) SP supply temperature, �C

(Real) Supply temperature, �C

(Binary) Normal control

(Binary) Heating allowed flag

(Binary) Cooling case flag

(Binary) HEX Min flag

(Binary) HEX max flag

Outputs

(Real) Cooling control signal 0 - 100%

(Real) HEX control signal 0 - 100%

(Real) Heat control signal 0 - 100%

Parameters

(Real) CoolingPBand 25 �C

(Real) CoolingITime 4 minutes

(Real) HEXPBand 25 �C

(Real) HEXITime 4 minutes

(Real) HeatingPBand 25 �C

(Real) HeatingITime 4 minutes

Public signals

(Real) Cooling

(Real) CoolingITime

(Real) CoolingPBand

(Real) HEX

(Real) HEXITime

(Real) HEXPBand

(Real) Heating

(Real) HeatingITime

(Real) HeatingPBand

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