RDZ UMHPI, Руководство пользователя

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UMHPI
Industrial inverter air/water heat pumps with axial fans
22
The cycle described above is represented on the pressure-enthalpy diagram, at the side of the diagram where represented the
point 2 the conditions of the gas at the end of compression with suction always carried out under the conditions of point 1 but
without vapor injection.
It is therefore evident that the main effects of the injection are the ones to increase the liquid sub-cooling from the temperature 3
to that of point 4 equal to about 10 - 15°C and decreasing the superheating at the exhaust from point 2' to point 2 (approximately
15 - 30°C). Please see the paragraph 11.8 for changing the parameters.
2’
In the following section for to be consistent with the manuals the below definitions are adopted:
VEIV = Vapor injection electronic valve
VEE = main expansion electronic valve
SSH = superheating in suction
DSH = superheating at exhaust
SSH I° = overheating at inactive injection
SSH II°= overheating at active injection
Here in below are described the algorithms used in the vapor injection control and/or double set of superheating. The
management is enabled if you have all the necessary resources.
In particular it is necessary that the parameter
v22 (step number of the vapor injection valve) is set not to be 0. The expansion
valve for the vapor injection located on the expansion module I/O number 1.
The fact that
v22 is different from 0 enables automatically the presence of the first expansion module I/O.
7.16.1 Main circuit VEE, Double control
1) Sensor for calculation of primary circuit superheat calculation
If the parameter v22 is set to be 0, the injection will be disabled.
2) SSH system
SSH system is currently implemented and that is always used
For superheat calculation are used:
−
Suction pressure sensor
−
Suction temperature sensor
It’s necessary to have mounted these two sensors.
3) DSH calculation
The two below sensors are used for evaluating the superheat at DSH exhaust:
−
Exhaust pressure sensor
−
Exhaust temperature sensor
7.16.2 Injection electronic valve VEIV
1) Sensors for superheat calculation for the vapor injection
Management of VEIV (Vapor injection electronic valve) requires the acquisition of the following values:
−
A temperature sensor (T1) positioned between the injection of the compressor and vapor injection heat exchanger.
−
A pressure transducer, positioned between the injection of the compressor and vapor injection heat exchanger for
getting the saturation temperature T2 of the refrigerant that is corresponding to the detected pressure.
Note: The T2 is different from the one obtained for VEE management, and then is neither the one of exhaust nor the one
of suction of the compressor. Necessary condition for having the vapor injection function active furthermore, the T1 and
T2 sensors should be mounted and configured.
2) Electronic valve control with vapor injection circuit
In the case of multi-inverter compressors and if are present the in addition to VEE, also the VEIV, the management of the
valves must be as follows.
The management of the VEE proceeds with the SSH adjustment until the fulfillment of one of the following conditions
depending on the mode of operation:
Heat pump operation
(Eq.1) T air < T air set ( v09 ) Chiller operation
(Eq.2) T air > T air set ( v10 ) Heat pump operation