Build Daily

August 12, 2017 18:06

Heat pumps with their own hands

mankind since ancient times «accustomed» to use the available natural energy that simply burned for heat or for conversion into other forms of energy.They learned how people use and the hidden potential of water flows - started of watermills and reached the powerful hydroelectric power stations.However, what it seemed quite sufficient still hundred years ago, today it can not meet the needs of a growing world population.

Heat pumps with their own hands

Heat pumps with their hands

Firstly, natural « storage » still not bottomless, and energy production becomes more and more difficult every year, moving into remote areas or even offshore.Secondly, the burning of natural raw materials is always associated with emissions of combustion gases into the atmosphere that the current huge volumes such emissions have put the planet on the brink of ecological disaster.Hydroelectric energy is not enough, and disruption of the hydrological balance of rivers and attracts a lot of negative consequences.Nuclear power, which

once was regarded as "a panacea", after a number of resonance man-made disasters cause a lot of questions, and in many regions of the world NPP construction is simply forbidden by law.

However, there are other, virtually inexhaustible sources of energy, which have been widely used recently.Modern technology has allowed very effectively used to produce electricity or heat, wind, sunlight, ocean tides and etc .One from alternative sources is the thermal energy of the earth's interior, reservoirs , atmosphere.It is the use of such sources based heat pump.Similar equipment for us until still included in the category of "exotic novelties", and at the same time in this manner is fired its housing very many people in Europe - for example, in Switzerland or Scandinavia the number of homes with similar systems exceeded50%.Gradually begins this kind of practice and the production of heat in the Russian expanses, while prices for the acquisition of high-tech equipment set is look very frightening.But, as always, are the master enthusiasts who display their creative abilities and collect heat pumps with their own hands.

publication is aimed at to ensure that the reader can get a closer look and a basic principle of the heat pump unit and learn about the advantages and disadvantages of quiet.In addition, you will learn about successful experience of creating their own operating systems.

The principle of operation of the heat pump

Article Contents

  • 1 Principle of operation of the heat pump
  • 2 low potential energy sources
    • 2.1 A. The use of thermal energy of ground
    • 2.2 B. thermal energy from wells
    • 2.3 B. use of water bodies as sources of heat
    • 2.4 G. heat from the air intake
    • 2.5 Video: useful information on the theory and practice of using heat pumps
  • 3 General advantages and disadvantages of heat pumps
  • 4 can we collect a heat pump with your hands?
    • 4.1 Video: making the heat pump using the ready-made heat exchangers
    • 4.2 Video: how to master develops his own generated heat pump

Not all of this thought, but all around us - a lot of heat sources that "working "round the clock.For example - even in the most severe cold temperature under the ice of a frozen reservoir all well remains positive.The same pattern and with the recess in the thickness of the soil - below the limits of its freezing temperature is almost always stable and is approximately equal to the average, typical for this region.Considerable heat potential carries in itself and the air.

The approximate table of the temperature distribution in the soil column

approximate table of the temperature distribution in the soil column

Perhaps someone will confuse all, it would seem, the low temperature of the water, soil or air.Yes, they are low-grade energy sources, but the main "trump card» - stability, and advanced technology, based on the laws of thermal physics, allow even a small difference in converting the required heat.And, you see, when it's cold in the winter is 20 degrees below freezing and the ground is 5 ÷ 7 degrees, this amplitude difference - already very decorous.

It is this continuity of property receipt of low potential energy inherent in the heat pump circuit.In fact, this unit is a device that "pumps" and "concerts" heat is taken from the inexhaustible source.

can draw some analogy to all friends refrigerator.The products that are placed therein for cooling and storing and entering the air chamber when the door opening - also have a not too high temperature.But if you touch the heat exchange lattice condenser on the rear wall of the refrigerator, it is either very warm, or even hot.

The prototype of the heat pump - familiar to all refrigerator condenser grille which is hot .

The prototype of the heat pump - familiar to all refrigerator condenser grille which is hot.

So why not use this principle to heat the coolant? course fridge analogy is not direct - there is no stable external heat source, and at most is wasted energy.But in the case of a heat pump source can be found (to organize), and then it will turn out "refrigerator vice versa » - main focus of the unit is just to heat.

By what principle of a heat pump work?

It is a system of three circuits with circulating them coolants.

Schematic diagram of the heat pump is included in the home heating system

Schematic diagram of the heat pump is included in the heating

  • home system in the body of the heat pump ( poses . 1) are arranged two heat exchangers ( poses . 4 and 8), the compressor ( pos. 7), the refrigerant circuit ( poses . 5), regulation and control devices.
  • first circuit ( pos. 1) with its own circulation pump ( poses . 2) posted ( immersed ) in the low-grade heat source (on their device will be discussed below).Receiving thermal energy from an external uninterruptible source (shown broad pink arrow), heated a few degrees (normally using probes or collectors in the ground or in water - up to 4 ÷ 6 ° C ), circulating the coolant fallsin exchanger-evaporator (pos. 4).Here is the primary heat transfer obtained from the outside.
  • The refrigerant used in the inner loop of the pump (pos. 5), has a very low boiling point.Usually there is used one of the modern, environmentally friendly CFC , or carbon dioxide (in fact - the liquefied carbon dioxide).At the entrance to the evaporator (. Pos 6) it fits in a liquid state under reduced pressure - it provides an adjustable throttle (pos. 10).The special shape of the inlet capillary type and shape of the evaporator contribute virtually instantaneous transition of the refrigerant in a gaseous state.According to the laws of physics, it is always accompanied by the evaporation of quenching and absorption of ambient heat.Since this portion of the inner loop is located in a first heat exchanger circuit selects the Freon heat from the coolant while cooling it (broad orange arrow). Chilled coolant continues to circulate and re-gaining thermal energy from an external source.
  • refrigerant in the gaseous state, transferring transfers heat to it, enters the compressor (pos. 7), where under the influence of compression its temperature rises sharply .Further, it falls into the following heat exchanger (pos. 8) which is a condenser and the third tube of the heat pump circuit.(Pos. 11).
  • Here comes completely opposite process - the refrigerant condenses turning into a liquid state, while giving its heat to the heat carrier of the third circuit.Further, in the liquid state at high pressure passes through the reactor where the pressure is reduced, and the cycle of the physical transformations of the aggregate state of the refrigerant is repeated again and again.
  • now moves to the third circuit (pos. 11) of the heat pump.Him through the heat exchanger (pos. 8) betrayed thermal energy from the heated refrigerant compression (wide red arrow).This circuit has its own circulation pump (pos. 12) that provides for movement of coolant heating pipes.However, a much wiser use still accumulating and carefully insulated buffer container (pos. 13), which will be transferred to accumulate heat.Stockpiling of heat energy is consumed even for the needs of heating and hot water, spending gradually, as needed.This measure allows the safe side in case of a power outage or use more cheaper night rate electricity required to operate the heat pump.
Increase the efficiency of heating will heat the battery

Improve heating efficiency will help heat the battery

If you are installing a buffer storage tank, then to it already supplied the heating circuit ( poses . 14) with its own circulation pump ( poses . 15), providing a coolant moving throughpipe system ( poses . 16).As already mentioned, it can be a second circuit that provides hot water for domestic use.

heat pump can not work without power - it is required for the operation of the compressor (wide green arrow), and circulating pumps in external circuits also consume electricity.However, as we are assured developers and manufacturers of heat pumps, the electricity consumption is not comparable to that obtained « volume » thermal energy.Thus, with proper assembly and optimal operating conditions, often being talking about 300 percent more efficiency, that is, when one elapsed kilowatts of electricity a heat pump can provide "on-mountain" 4 kilowatts of heat energy.

In fact, a similar statement about the efficiency of several incorrect.The laws of physics has not been canceled, and an efficiency higher than 100% - same utopia as « perpetummobile » - perpetual motion.It in this case goes on the rational use of electricity in order to "transfer" and the transformation of energy coming from an external source of inexhaustible.It is appropriate to use the concept of COP (from the English «coefficient of performance» ) that in the Russian language, often called the "heat conversion efficiency."In this case, indeed, may obtain the value greater than one :

CO P = Q n / A , where:

CO P - Prevalence nt etc. eobrazovaniya heat;

Q n - the amount of heat energy produced by the consumer;

A - work performed by the compressor installation.

The scheme of distribution of energy flows

scheme of distribution of energy flows

There still one nuance about which often simply forget - specific energy consumption for the normal functioning of the pump requires not only the compressor and circulation pumps but in external circuits.Power consumption at them, of course, is much smaller, but, nevertheless , it can also be taken into account, and this often for marketing purposes is simply not done.

The resulting total amount of heat energy can be spent:

For what purposes can be used by energy obtained by the heat pump ?

For what purposes energy can be used, obtained by the heat pump?

1 - the optimal solution - a system warm water sexes.As a rule, heat pumps provide « rise » temperature to about 50 ÷ 60 ° With - is enough for floor heating.

2 - hot water at home.Usually hot water systems temperature at this level and is supported by - about 45 ÷ 55 ° C .

3 - but for conventional radiators such heating is insufficient.Exit - to increase the number of sections or the use of special low-temperature radiators.Help to solve the problem and the type of convection heaters.

4 - one of the major advantages of heat pumps - the ability to switch them to "reverse" mode.In the summer, this unit can perform air-conditioning function - taking away the heat from the premises and transferring it into the ground or water body .

Sources of low potential energy

What are the sources of low-potential energy capable of using heat pumps?In this role can act rocks, soil at different depths, water from natural reservoirs , wells or underground aquifers, atmospheric air or warm air stream withdrawn from buildings or industrial processcomplexes.

A. The use of thermal energy soil

As already mentioned, below the level of soil freezing characteristic this region, the ground temperature is stable throughout the year.This is used to operate the heat pump on a "ground - water ».

Принципиальная схема отбора энергии "грунт - вода"

principal energy extraction circuit "ground - water»

to create such a system is preparing special surface thermal field, which removes the top layer of soil to a depth of about 1,2 ÷ 1, 5 meters.The contours are placed, made of plastic or metal pipes with a diameter typically 40 mm.Efficiency removal of thermal energy depends on local climatic conditions and the total length of generated contour.

Roughly, for an average strip of Russia, it is possible to operate the following relationships:

  • dry sandy soils - 10 watts of power with one meter of pipe.
  • dry clay soils - 20 W / m.
  • wet clay soils - 25 W / m.
  • clay rocks with high location ground water - 35 W / m.

Despite the seeming simplicity of the heat, the way is not always the best solution.The fact is that it implies a very significant volumes excavation.What looks simple on the scheme - is much more difficult in practical performance.Judge for yourself - in order to "remove" from the underground circuit, even a 10 kV reflux eplovoy energy on clay soils need about 400 meters of pipe.If even take into account a mandatory rule that there must be an interval of not less than 1 , 2 meters, it will be necessary for laying an area of ​​4 hundred (20 × 20 meters) between the turns of the circuit.

Field tab for removing heat from the ground - very large-scale and time-consuming task

field tab for removing heat from the ground - very large-scale and time-consuming task

Firstly, not everyone has the opportunity to allocate a territory.Second, completely excluded any construction in this area, since the probability of damage to the circuit.And third - the selection of heat from the ground, especially in poorly conducted calculations, can not pass without leaving a trace.