kraftwerk - Mephisto BHKW G8

G8

Natural gasAsynchronous

Our pint-sized unit ensures a low primary energy factor in smaller buildings.

Technical data

Mephisto G8

TypeMephisto G8 A NGGeneratorAsynchronous generatorFuelNatural gas

Net output (adjustable)

Electric, net5,5 to 8 kWElectric, gross8,2 kWThermal16,5 to 20,9 kWGas20,9 to 28,3 kWHi

Net efficiency Electric

Electric, effective28,3 %Electric, ISO 304629,7 %Thermal, effective73,8 % (tReturn = 35 °C)Overall, effective102,1 % (tReturn = 35 °C)

General

Energy efficiency classA++Seasonal space heating energy efficiency 142 %CHP coefficient0,38Primary energy factor(fPE,WV as per DIN SPEC 4701-10/A1:2016-05) 0,42Primary energy saving29,78 % - The high-efficiency criterion specified in EU Directive 2012/27/EU for CHP systems is met.FuelNatural gas

Gas connection

Gas connection rating28,3 kWHi = 31,4 kWHSGas connection pressure20-100 mbarGas flow pressure≥ 10 mbarMating dimensionDN 20 (3/4“ male thread)

Heating connection

Heating circuit minimum pressure1,2 barPermitted operating pressuremax. 4,0 bar (pressures up to 6 bar on request)Flow temperaturemax. 90 °CReturn temperaturemax. 70 °CMating dimension1“ male threadDesign flow rate0,92 m³/hResidual head for net output6,3 mWSWith 40 K spread:Design flow rate: 0,46 m³/h
Residual head for net output: 7,3 mWS

Electrical connection

  • Pre-fuse NH00 35 A gL (gG) or SLS E-34A
  • Supply line H07RN-F 5 x 6 mm2, up to 40 m in length for installation types B to G

Plate heat exchanger

Soldered stainless steel compact heat exchanger for separating the heating system from the CHP engine water circuit

Pollutant emissions

Mephisto G8 comes 50% below the German regulation emission limit

Combustion intake air

Space-air-dependent operating mode

Flue gas connection

  • Flue gas conduit D80, fire resistance class B1 plastic pipe made of PP, permitted as a flue gas conduit for condensing heat generators with flue gas temperature up to 120 °C
  • Flue gas temperature limited to max. 90 °C on thermostat
  • Safety thermal cut-out set to 100 °C
  • Recommended flue gas counter-pressure: 500 Pa; maximum flue gas counter pressure 750 Pa
  • Flue gas flow rate: 36 m3/h i.N. in normal state is equivalent to 38,5 m3/h at TFlue gas = 80 °C
  • Maximum condensate quantity: 3,9 l/h

Flue gas heat exchanger

  • Thermodynamically optimised cast aluminium-silicon heat exchanger
  • Integrated catalytic converter

Utilisation of calorific value

  • The flue gas temperature is a maximum of 15 K above the corresponding return temperature
  • Calorific value used at a return temperature of about 55 °C and above

Engine

  • Toyota industrial gas engine
  • Model: 1 KS CHP
  • 3-cylinder Otto engine, water-cooled
  • Displacement: 953 cm³

Coupling

Maintenance-free, plug-in, flexible metal/plastic coupling to compensate for radial, axial and angular misalignment.

Generator

  • Four-pole asynchronous machine for parallel operation on the public grid
  • Manufacturer: Weier GmbH
  • Model: DGA-F-132/L4 water-cooled
  • 3 × 400 V, 50 Hz
  • Start-up current: about 40 A
  • Rated current: 14,8 A
  • cos φ: 0,78 (inductive)
  • Rated power: 8 kW
  • Rated speed: 1.564 min-1

Compensation

Due to the requirements in German code of practice VDE-AR-N 4105:2018-11, operating own generating systems without reactive power compensation is only permitted in exceptional cases. A cos cos φ of 0.95 is achieved with the standard fixed compensation.

Controller

  • Industrial computer with powerful MPC555 microcontroller, 32-bit power PC with FPU
  • Fully automatic operating control
  • Remote monitoring/operation via LAN or optional mobile data connection
  • Interfaces to higher-level DDC controls: digital and analogue inputs and outputs; optional CAN bus, RK512, Modbus, LON bus, Profibus DP, BACnet/IP, IEC 104, Profinet

Housing

  • Sturdy, easily removable, frameless full thermoacoustic enclosure
  • Machine unit on four Asonator steel springs
  • Optional base on two vibration dampers to isolate noise

Noise emissions

  • Mean sound pressure level at 1 m distance ≤ 47,5 dB (A) as per DIN 45635-11
  • Mean sound pressure level (standard equipment) at 1 m distance (10°) to chimney outlet ≤ 44,2 dB (A) as per DIN 45635-11

Third octave band spectra isolation can be provided on request

Dimensions

L × W × H in mm: 1.380 × 800 × 930 Without electrical enclosure.
Height with electrical enclosure: 1.580 mm

Required space

L × W × H in mm: 3.000 × 1.800 × 1.800, without sound insulation base. Height of sound insulation base: 250 mm.

Installation and base plans will be provided on request

Operating weight

530 kg

Delivery

  • Machine unit, self-supporting: 1.010 mm × 650 mm, 315 kg
  • Panelling with accessories on pallet: 1.200 mm x 800 mm, 260 kg

Product range

You will find all technical specifications for the supplied heat pumps and for our Mephisto combined heat and power units and the Direktor controller in the product range.

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Accessories & equipment features

In addition to the standard scope of supply, we also offer a wide range of accessories to adapt the Mephisto CHP unit to your individual needs. Here you will find an overview of standard equipment and added options.

More information

Contact

Do you have any questions about the heat pumps we offer or would you like to submit a request for project planning? Send us a message.

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