ZETA Hot Water boilers
ZETA Hot Water boilers
A ZETA hot water system offers great flexibility. The system is adaptable for use in combination with alternative energy sources such as biomass, heat pumps, etc. Combined operation with oil is already common, the actual method of heating varying with the price and availability of the different energy sources.
ZETA electric hot water boilers may be used either directly on-line or in combination with an accumulator. The particular configuration depends on the heating requirement during the day and the local energy situation (for instance, the availability of cheap electricity at certain periods).
Operation
The current from the phase electrodes flows directly through the water, which is heated in the process. The current is a function of the active surface area of the electrodes and the water conductivity. The active area of the electrodes can be infinitely varied by operating the control screens, thus enabling output to be controlled between a minimum load of 10-20 % (depending on boiler size and voltage) and 100 %.
Design
The ZETA hot water boiler, type ZVPI, is equipped with an electrode system, consisting of three-phase electrodes, one neutral point electrode and three control screens.
As shown in the drawing below, the phase electrodes (2) are firmly mounted in insulated bushings, which are fixed in glands at the bottom of the boiler.
The neutral point electrode (3), surrounding the phase electrodes comprises three cylindrical tubes, which are firmly mounted in the boiler body.
The three control screens (4) are mounted on a common yoke and attached to the to the control motor by means of a control rod. The screens can be traversed along the phase electrodes, thereby controlling the boiler output.
Boilers with a maximum output of 24 MW can be connected to a grid with an insulated neutral point since the boiler itself has a high-resistance insulated neutral point. The boiler shell (pressure vessel) is mounted on insulators, while the activating mechanism is similarly protected. Outlet and inlet pipes are galvanic ally insulated from the boiler shell by means of insulating tubes in lengths designed to provide a total resistance to earth of 1.5 or 2.5 kohm at 10 kV.
Boilers with an output exceeding 24 MW are designed with a directly earthed neutral point.
Dimensions
| DIMENSIONS | ||||||
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| TYPE ZVPI/ZHPI | A (mm) |
B (mm) |
C (mm) |
D (mm) |
TRANSPORT WEIGHT (tons) |
FOUNDATION WEIGHT (tons) |
| 1600 | 4150 | 2650 | 2150 | 100 | 1.7 | 7.0 |
| 1806 | 4300 | 3500 | 2330 | 150 | 2.2 | 10 |
| 1808 | 4600 | 3500 | 2330 | 150 | 2.5 | 10 |
| 2010 | 5400 | 3800 | 2530 | 200 | 3.0 | 13.5 |
| 2020 | 6500 | 5200 | 3900 | 250 | 4.5 | 18 |
| 2500 | 7200 | 5200 | 3900 | 300 | 6.0 | 25 |
| 2800 | 7900 | 5200 | 3900 | 300 | 9.0 | 30 |
| 23000 | 6500 | 6600 | 4000 | 200 | 9.5 | 33 |
| 23200 | 6700 | 6600 | 4000 | 250 | 10.0 | 35 |
| 24200 | 6700 | 7600 | 5000 | 300 | 15.0 | 60 |
Hot Water Boilers - technical specification
| VOLTAGE | 6 kV | 10 kV | 15 kV | |
| TYPE | ZVPI/ZHPI ZVP/ZHP |
OUTPUT MW | MW | MW |
| 1600 | 0,5-2,4 | 1-4 | - | |
| 1800 | 3,6-4,8 | 6-8 | - | |
| 2000 | 6,0-12,0 | 10-20 | - | |
| 2500 | 15 | 24 | - | |
| 2800 | 24 | 40 | - | |
| 23000 | 10 | |||
| 23200 | 16 | |||
| 24200 | 20-32 | |||
| ZVPI/ZVP | ZHPI/ZHP | |||
| Design temperature primary side | 130°C | 160°C | ||
| Design pressure primary side | 5 Bar | 10 Bar | ||
| Operating temperature primary side | 120°C | 145°C | ||
| Operating temperature secondary side | 110°C | 120°C | ||
| ZVPIZHPI – BOILERTYPE WITH HIGH RESISTANCE INSULATED NEUTRAL POINT. ZVP/ZHP – BOILER TYPE WITH DIRECTLY EARTHED NEUTRAL POINT. BOILERS TO SPECIFICATIONS OTHER THAN STANDARD CAN ALSO SUPPLIED. |
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