DE202016007060U1 - Mechanical / de-energized pump for fresh water station - Google Patents

Abstract

Mechanical / electroless pump for a fresh water station, characterized in that it works purely mechanically.

Description

Introduction to the problem area:

For domestic hot water heating in households, the temperature in hot water storage tanks should be as low as necessary from a technical point of view. Thus, the radiation losses are lower and the hot water generator has a higher efficiency (keyword condensing boiler).

Because of the danger of Legionella the boiler must be operated with at least 60 ° C in order to avoid the disease germs.

• – Hohe Rücklauftemperatur zum Warmwassererzeuger → wenig/kein Brennwertnutzen
• – Aufgrund hoher Temperatur im Boiler → Anfälligkeit gegen Kalk, damit immer schlechter werdender Wirkungsgrad des internen Wärmetauschers.
• – Hohe Bereitschaftsverluste → schlechte Effizienz
• – Hoher Platzbedarf für den Boiler

The disadvantages of a boiler are thus:

• - High return temperature to the hot water generator → low / no calorific value
• - Due to high temperature in the boiler → susceptibility to lime, thus deteriorating efficiency of the internal heat exchanger.
• - High standby losses → poor efficiency
• - High space requirement for the boiler

Current state of the art:

For these reasons, so-called fresh water stations have been developed. With these fairly compact systems, the cold fresh water DIRECTLY is heated as needed in a continuous process. In addition, the temperatures of the heated water are lower (max 50 ° C).

The function is as follows:
From a buffer tank in which only lime-free heating water is located, the hot water is pumped through a plate heat exchanger by means of an electrically driven pump. This warms the process water, which also passes through the plate heat exchanger. The speed of the pump is controlled by electronics and a flow sensor located on the cold service water side.

• – Sehr niedrige Rücklauftemperatur zum Puffer → voller Brennwertnutzen des Warmwassererzeugers. Außerdem verringern sich die Brennerstarts, da mehr Energie aus dem Puffer gezogen werden kann!
• – Keine Bereitschaftsverluste → Brauchwasser wird bei Bedarf erzeugt.
• – Weniger Platzbedarf
• – Aufgrund niedriger Temperatur → wenig Kalkausfall

With the right attitude you have several advantages:

• - Very low return temperature to the buffer → full calorific value of the hot water generator. In addition, the burner starts to lower as more energy can be pulled out of the buffer!
• - No standby losses → service water is generated as required.
• - Less space required
• - Due to low temperature → little lime failure

• – Mehr Bedarf an Technik/Elektronik
• – Bei Stromausfall (auch kurz) steht SOFORT kein warmes Wasser mehr zur Verfügung!

Unfortunately, this system also has its drawbacks, and that's exactly where my invention comes in:

• - More need for technology / electronics
• - In case of power failure (also short) IMMEDIATELY no hot water is available!

By my invention, the pump should be replaced by a mechanical / currentless variant. My solution principle is as follows:
Since the cold water connection on the house almost always has too high a water pressure, it makes sense to use this previously unused differential pressure to drive a hydraulic motor. This motor drives a pump which circulates the hot water from the buffer tank through the plate heat exchanger.

The advantages of this mechanical pump:

If more hot water is needed in the house, the engine and thus the pump runs faster and vice versa. An electronic control can be omitted completely with correct dimensioning! Likewise, the purely mechanical pump works even in case of power failure. Due to the very simple structure, omission of sensors and control electronics and a cheap production and ease of maintenance is expected.

Detailed description of the invention:

P

= Antriebsleistung (kw)

Δp

= Differenzdruck (bar)

Q

= Volumenstrom (dm³/min)

nges

= gesamter Wirkungsgrad (kleiner 1)

In drawing 1 you can see the exact functioning of the complete system:
The cold water from the supply network flows to point 1 into the input of the hydraulic motor (eg vane motor). Due to the flow of water, which arises when hot water is required by turning the tap, the hydraulic motor (point 12 ) to turn. The power of the hydraulic motor (point 12 ) is from the flow rate and the pressure difference, which is between point 1 and point 2 arises, easy to calculate with the following formula. P = (Δp · Q · nges) / 600

P

= Drive power (kw)

Ap

= Differential pressure (bar)

Q

= Flow rate (dm ³ / min)

nges

= overall efficiency (less than 1)

According to this formula, at Δp = 1 bar, Q = 20 dm ³ , nges = 0.85, a drive power of 28.3 watts, which is easily sufficient for a pump.

After the still cold fresh water has passed the hydraulic motor (point 2 ), it flows into the inlet of the plate heat exchanger (point 3 ). In the plate heat exchanger (point 14 ) It is heated in countercurrent principle and comes at the point 4 out of the plate heat exchanger out again. Thus, the now hot service water is ready for use (point 5 ).

That was the freshwater circuit. Now to the heating water cycle:
Due to the mechanical coupling (shaft, magnet, etc.) of the hydraulic motor (point 12 ) with the pump (point 13 ), this also begins to turn when you turn on the hot water tap. Thus, hot heating water from the buffer (point 6 ), into the inlet of the plate heat exchanger (point 7 ) sucked. In this, the energy is withdrawn from the heating water countercurrent principle and comes strongly cooled to point 8th out of the plate heat exchanger again. It continues to the inlet of the pump (point 9 ), is accelerated by this and by the output of the pump (point 10 ) to the lower part of the buffer (point 11 ). Thus, this cycle is closed

LIST OF REFERENCE NUMBERS

1

Input hydraulic motor, fresh water

2

Output hydraulic motor, fresh water

3

Input plate heat exchanger cold, fresh water

4

Output plate heat exchanger warm, fresh water

5

Connection to the domestic hot water network (service water)

6

Buffer tank heating water, top connection (flow to the plate heat exchanger hot)

7

Input plate heat exchanger, heating water hot

8th

Output plate heat exchanger, heating water cold

9

Pump inlet, heating water, suction side

10

Pump output, heating water, pressure side

11

Buffer tank heating water, connection below (return cold from the plate heat exchanger)

12

hydraulic motor

13

pump

14

Plate heat exchanger

15

buffer memory

Claims (5)

Mechanical / electroless pump for a fresh water station, characterized in that it works purely mechanically. Pump according to claim 1, characterized in that it requires no supply of electricity for the function. Pump according to claim 1 and 2, characterized in that it is driven by the energy of the fresh water network. Pump according to claim 1, 2 and 3, characterized in that the regulation of the flow rate for the heating water in the plate heat exchanger works purely mechanically and without sensors. Pump according to claim 1, 2, 3 and 4, characterized in that there is a mechanical coupling between service water and heating water circuit.

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