Page 314 - Теория кавитации

Figure 2 - Photo-illustration of a made vortex tube (from plexiglass), used as part of VHG.

Pump installation:
One of the main components of the developed experimental VHG is a centrifugal pump (CP). The choice
of CP and its technical characteristics, of course, have been optimized taking into account the preliminary
theoretical calculations of the main parameters of VHG. Since the only consumer of energy (electricity) is the
CP, then the value of the power consumption of the CP plays a crucial role at designing and evaluating the
efficiency of the VHG (in particular, determining the efficiency and energy conversion coefficient - ECC).
Therefore, the choice of pumping equipment is a main step, on which both the technological parameters
and the performance of the projected installation of the air handling unit will depend. When choosing a pump
type, three groups of criteria can be distinguished:
 technological and design requirements;
 nature of the pumped medium;
 basic design parameters.
°
As practice shows, for example, to obtain thermal energy with t = 50 C-60 C in VHG, a pump with a
°
pressure of up to H = 100 m is required.
Within the framework of this project, a CP from Grundfos was selected to generate a vortex flow. Figure
3 shows the appearance of the CP used.
The following are the main characteristics of the Grundfos NS Basic used in the construction of this VHG:
 standard single phase motor
 overheating protection
 low noise
 liquid temperature range: from 10 to 35°C
 ambient temperature range: 0 to 40°C
 voltage, 220 V
 protection class (IEC 34-5) IP 68
 insulation class (IEC 85) F
 power, 3.7 watts.
The full technological scheme developed by VHG and includes a source of low-grade heat, made in the
form of a vortex tube with a centrifugal pump, a separating heat exchanger, supplying and discharging the
circuits of the heat source with shut-off and non-return valves, a circulation pump, thermometers and pressure
gauges for measuring the temperature and pressure of the supplied water in the network, heat pump, heat supply
system with heating devices, control valves and measuring devices.

Figure 3 - Exterior view of the Grundfos NS Basic 5-60 pumping unit (Denmark)

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