DE102010035900A1 - Method for selecting a heat source of a heat pump - Google Patents

Abstract

The invention relates to a method for providing a heat output to a consumer for heating a room or for preparing hot domestic water by means of an air heat pump with an air supply element, at least one air flow generator, an evaporator and a heat pump circuit, the air heat pump being connected to the air supply element. The air flow generator conveys air from the air supply element to the evaporator arranged in the air heat pump. The heat output provided by the air source heat pump is conducted to the consumer via the heat pump circuit. The air source heat pump has a performance figure (COP = Coefficient Of Performance) that is dependent on the air delivered, which corresponds to the quotient of the heat output (Qc) delivered to the consumer and the drive power (W) used to operate the air heat pump, whereby the drive power (W ) essentially consists of the electrical connection loads of a compressor and a throttle of the air heat pump, the air flow generator and control electronics. According to the invention, to increase the COP, a measuring and control unit selects between at least two different air sources and introduces air from the selected air source into the air supply element or connects the selected air source to the air supply element.

Description

The invention relates to a method for providing a heat output to a consumer for the heating of a room or preparation of domestic hot water by means of an air heat pump.

Domestic engineering systems for supplying a building with hot water or for controlling the temperature of buildings with and without heat pumps are well known from the prior art.

DE 39 03 665 C2 shows a decentralized room air conditioner with a refrigerant circuit. The air conditioner is attached to an exterior wall. A discharge pipe leads through an outside wall to the outside. The air conditioner also has a through the outer wall leading into the open air exhaust port and an intake manifold.

DE 10 2006 046 630 A1 describes a decentralized home technical unit, which is designed as a facade element. It is used for decentralized ventilation, heating or cooling of a room and has the building services for ventilation, heating, temperature control and optionally for hot water production. An external air heat pump enables not only ventilation but also heating or temperature control of the room. The temperature control is carried out by reversing the refrigeration cycle is operated.

According to one embodiment, the home automation unit includes an externally mounted solar module. If this is a photovoltaic module, this is intended to supply the power either directly to the home automation unit, z. B. to operate a fan or the electric motor of the heat pump compressor, or to the power grid. If a thermal solar collector is integrated or placed outside in the decentralized building services, the thermal energy is used to operate a service water storage tank or a heating system or air preheating.

Further describes DE 10 2006 046 630 A1 a countercurrent heat exchanger, which is the heat recovery from exhaust air flowing out of the room and transmits a portion of the humidity from the exhaust air flowing into the room supply air to allow automatic humidity control of the room.

A disadvantage of all building services systems that the heat pumps have a low efficiency, especially in the cool heating season. This leads to low annual operating figures, since the heat pump must be deactivated in the presence of particularly low temperatures, since otherwise more energy must be expended for the operation, as energy is available to a consumer.

It is an object of the invention to increase the efficiency of heat pumps and their annual work rate, it should be noted that the solution also offers economic benefits.

This is achieved with the features of claim 1 according to the invention. Advantageous developments can be found in the dependent claims.

The invention relates to a method for providing a heat output to a consumer for the heating of a room or preparation of domestic hot water by means of an air heat pump with an air supply element, at least one air flow generator, an evaporator and a heat pump circuit, wherein the air heat pump is connected to the air supply element. In this case, the air flow generator promotes air from the air supply element to the arranged in the air heat pump evaporator. The provided by the air heat pump heat output is passed through the heat pump cycle to the consumer. The air heat pump has a coefficient of performance dependent on the delivered air, which corresponds to the quotient of the heat output (Q _c ) delivered to the consumer and the drive power (W) used to operate the air heat pump, whereby the drive power ( W) essentially consists of the electrical connection performance of a compressor and a throttle of the air heat pump, the air flow generator and a control electronics. According to the invention, to increase the coefficient of performance, it is provided that a measuring and control unit selects between at least two different air sources and introduces air from the selected air source into the air supply element or connects the selected air source with the air supply element.

An advantage of such a configuration is that by increasing the coefficient of performance of the heat pump, the annual operating hours (annual work count) of the heat pump can be increased. This is due to the fact that the operation of the heat pump does not have to be set as soon as air from one source leads to such a low coefficient of performance that further operation no longer makes ecological and economic sense. Rather, according to the invention, the heat pump does not have to be deactivated until none of the air sources is suitable for maintaining or receiving the operation.

In addition, it is advantageous if the coefficient of performance can be increased by selecting the more suitable air source on average. Thus, the rising Efficiency, as the operating power to be used decreases and the heat output gained increases. Ultimately, the operating costs, the payback period of the heat pump costs and all additional costs are reduced. The heat pump may also have lower power for the same power requirement.

Since the air sources can be spatially separated from each other, this results in different flow resistance for the flow of the respective source air to the evaporator. If the power of the first flow generator is sufficient to produce a sufficient air flow, the air source is connected to the air supply element. In the event that certain air sources have higher flow resistances, additional air flow generators or the like may be used to assist and the air is then actively introduced from the source into the air supply element.

A simple implementation of the invention takes place in that the measuring and control unit, with the aid of temperature sensors, determines air temperatures of the different air sources and selects the air source which has the highest temperature and is also available. Thus, only one sensor per air source is required. Furthermore, it is advantageous that only the source with the highest temperature is selected. Complex calculations are therefore not necessary.

In order to further increase the coefficient of performance of the heat pump, it is provided in a development of the invention that the measuring and control unit determines an enthalpy content and an availability of air of the different air sources with the aid of temperature sensors and / or humidity sensors and / or pressure sensors. The enthalpy gives much better information about how much energy is present in the air of a source, as an exclusive temperature measurement, because humid air of a certain temperature has a higher enthalpy than dry air of the same temperature.

The prerequisite for this is an equal air pressure, because the higher the air pressure, the higher the enthalpy at the same temperature and the same humidity.

A particular advantage of the invention is that with the aid of the moisture sensors, the measuring and control unit can take into account when selecting the air source that different air sources may have different humidities, which have a significant influence on the coefficient of performance of the air heat pump. This will increase the figure of merit on an annual average and also increase the annual workload.

The same applies to the use of pressure sensors, whereby the measuring and control unit can take into account when selecting the air source that different air sources can have different pressures, which also have a significant influence on the coefficient of performance of the air source heat pump. This also increases the figure of merit on an annual average and can also increase the annual employment rate.

In order to use the determined enthalpy content to increase the coefficient of performance, an embodiment of the invention provides that the measuring and control unit selects the air source having the highest enthalpy content and is available or calculates the coefficient of performance for each air source and the one with the highest Select number of benefits.

This results in a significant increase in the coefficient of performance, in particular when the different air sources have greatly different atmospheric humidities, compared to an exclusive selection according to the temperature of the air of an air source. High differences in humidity, for example, can result from the fact that air is taken from a living space rather than from the environment.

Even by a source of air higher pressure benefits can arise. For example, slight differences in pressure may be present when air from the living space is forced into the environment for ventilation by a fan anyway. This is also conceivable with an extractor hood, in which additionally high air humidity could be present, just as with a bathroom ventilation. Larger pressures may be present, for example, in sources that are, for example, a large exhaust fan or an exhaust system. Exhaust gases from internal combustion engines often have high pressure.

In a particularly advantageous embodiment of the invention, the measuring and control unit takes into account in the selection of the air source the energy required for a supply of air from this. Due to different flow resistances for the air flow from an air source to the evaporator, it may be that the performance of the air flow generator must be adjusted, or other flow generators must be turned on. In particular, by taking account of this power for the air flow generator whose energy consumption increases at the same air flow rate and higher flow resistance of the supply from an air source, the average coefficient of performance of the heat pump can be further increased. Preferably, the air flow rate and the power consumption of the air flow generator is measured or values are stored.

The latter is advantageous because additional components for measuring the power consumption and the air flow rate are not required if only air sources are provided with non-changing flow resistance as air sources. When commissioning the heat pump, a simple reference measurement can then be made once, the results of which are stored in the measuring and control unit. To calculate the coefficient of performance, the required power for the air supply only has to be added to the drive power used to operate the air heat pump. The cost of such an embodiment of the invention are thus low and no power is required to perform the measurement, whereby a high efficiency is achieved.

A further advantage results from an embodiment of the method according to the invention in which measuring sensors for the air flow and the air flow generator power are used when air sources with changing flow resistances are provided as air sources. This can be the case, for example, with air sources, which are preceded by filters. In this way, the measuring and control unit can take into account that filters from different air sources can be affected to a varying extent by pollution and the power requirement for the air supply changes with increasing time. Furthermore, the flow resistance can be influenced, for example, by a wind direction. As a result, the measuring and control unit can precisely determine the coefficient of performance of the different air sources and select the best possible air source, which increases the annual average coefficient of performance of the heat pump and also increases the annual work rate. Also, the costs of the measurement implementation are limited and are poored by the higher average annual performance, so that the use of the measurement also has economic benefits.

Advantageously, the measuring and control unit takes into account a power which is provided in any case, for example by activation of the extractor hood, the bath ventilation or living room ventilation, not for calculating the coefficient of performance. In this way, the measuring and control unit selects the air source, which actually leads to the highest possible annual output.

A further improvement of the invention can be achieved in that the measuring and control unit simultaneously introduces air from different air sources into the air supply element or simultaneously connects the different air sources with the air supply element, preferably in such a way that the coefficient of performance is maximized. In particular, this may be useful if an air source is available only to a limited extent, so that the heat pump can not be operated alone with her. This allows the air source with the higher temperature to switch on the air source at the next lower temperature. It is also possible for the air source with the higher enthalpy content to connect the air source with the next lower enthalpy content or the air source with a higher coefficient of performance to the air source with the next lowest coefficient of performance. This leads, for example, to an increase in the coefficient of performance of the heat pump, if only a small amount of very hot and humid air from an extractor hood is available, which must be mixed with another air source in order to be used at all. It is important to ensure that the air source with the highest temperature or enthalpy or coefficient of performance is 100% fed into the air supply element and the next lower air source introduces the remaining required air. Here, too, it is possible to observe how high the energy for the air supply of the individual sources is.

One version of the invention provides that a first air source is outside air from the earth's atmosphere. This is the market's most widely used air source for a heat pump. An advantage of this air source is that it is always available without restrictions.

Another version of the invention provides that a second air source is exhaust air from the room. This is particularly advantageous because living rooms must be ventilated regularly anyway. In a ventilation by opening the window, a significant heat output is lost. However, if the air is used as an air source for the heat pump, a large part of the heat output can be used to obtain new heat output. Particular advantages result from the fact that extractor hoods and bathroom vents are connected to the air supply element. These air sources have a high short-term power potential in connection with the heat pump that can be used with the inventive solution.

Another possibility is to direct the exhaust air before entering the air supply element through a heat exchanger, where it gives off energy to fresh air flowing into the room or to service or to heating water. For the selection of the air source, accordingly, the measurement of temperature, humidity and pressure of this air source between the heat exchanger and evaporator is carried out.

Particular advantages of the invention will become apparent from the fact that a third air source is an air collector, the outside air preheated by sunlight in a continuous process and in particular a facade collector. In this way, the energy of the sun is used ecologically by warming the air of this air source before it is fed to the heat pump. By using an air collector operation of the heat pump can be ensured, especially at low outdoor temperatures. As a result, the total operating time of the heat pump is significantly increased in a year of operation, because heat output is needed especially at low outdoor temperatures and the heat pump is therefore primarily in this time in operation. Furthermore, the performance is significantly increased even if outside air is available, but by a preheating of the air, a significantly higher coefficient of performance can be achieved.

According to the invention it can be provided that the measuring and control unit can direct air from the third air source directly into the room. If outside air in an air collector, for example, heated above the living room temperature, a ventilation of the living space can be made without this cools. In this way, the ventilation time can be performed automatically when the lowest heat loss is expected.

In one embodiment of the invention, the measuring and control unit for connecting the selected air source with the air supply element controls at least a first valve or a first flap. These can have a closed and open position, or be infinitely adjustable. The advantage here is that the adjustment can be done automatically via actuators, for which still only a small power is required.

Of course, the invention can be used not only in living rooms, but at all locations of air heat pumps. For example, in buildings, houses and halls. Especially in industrial buildings can also be advantageous to use of exhaust gases as an air source.

The drawings illustrate embodiments of the invention and show in the figures:

1 An air heat pump with one air supply element, two air sources and a measuring and control unit

2 An air heat pump with an air supply element, two air sources with sensors and a measuring and control unit

3 An air heat pump having an air supply element, an outside air air source, and an air collector air source

4 An air heat pump having an air supply element, an outdoor air source, an air collector air source and an exhaust air source

5 An air heat pump having an air supply element, an outside air air source, an air collector air source and an exhaust air source with a heat exchanger

1 shows an air heat pump 1 with an air flow generator 3 , an evaporator 4 and a heat pump cycle 5 with a consumer 6 in a room 50 , Both evaporator 4 as well as air flow generator 3 are in an outlet opening of the air heat pump 1 arranged. The air heat pump 1 is input side with an air supply element 2 flow-connected. This in turn is with a first air source 21 fluidly connected, provided a measuring and control unit 10 a first flap 15 not moved to a closed position and with a second air source 22 flow-connected, provided the measuring and control unit 10 a second flap 16 not moved to a closed position.

The air flow generator 3 is operated such that a negative pressure in an interior of the air heat pump 1 and the air supply element 2 is present. The measuring and control unit 10 make a decision about which of the air sources with the air supply element 2 should be connected and controls the first flap 15 and the second flap 16 at. Unless the first flap 15 is not in a closed position, flows due to the negative pressure in the air supply element 2 Air from the first air source 21 into the air supply element 2 , from there to the interior of the air source heat pump 1 and then to the evaporator 4 , Unless the second flap 16 is not in a closed position, flows due to the negative pressure in the air supply element 2 Air from the second air source 22 into the air supply element 2 , from there to the interior of the air source heat pump 1 and then to the evaporator 4 ,

The air is at the evaporator 4 a part of their energy and leaves the heat pump 1 then through the exit opening. The result of the evaporator 4 The heat output gained is via the heat pump cycle 5 to the consumer 6 directed. This will make the room 50 heated.

In 2 becomes an air heat pump 1 with an air flow generator 3 shown with an air supply element 2 fluidly connected. This in turn is with a first air source 21 fluidly connected, provided a measuring and control unit 10 a first flap 15 not moved to a closed position and with a second air source 22 fluidly connected, provided a measuring and control unit 10 a second flap 16 not moved to a closed position. The measuring and control unit 10 is with a temperature sensor 11 , a humidity sensor 12 and a pressure sensor 17 the first air source 21 and a temperature sensor 11 , a humidity sensor 12 and a pressure sensor 17 the second air source 22 connected. In addition, the measuring and control unit 10 also with the air flow generator 3 connected.

By measuring the temperature, humidity and pressure, the measuring and control unit calculates 10 the enthalpy of the first air source 21 and the second air source 22 , Based on the result, the measuring and control unit meets 10 a decision on which of the air sources with the air supply element 2 to be connected.

Advantageously, however, a coefficient of performance of the air heat pump 1 calculated. In this calculation can also be the power for the air flow generator 3 flow in, that of the measuring and control unit 10 can be measured.

Provided the enthalpy of the first air source 21 higher than that of the second air source 22 controls the measuring and control unit 10 the first flap 15 such that it is moved to an open position and the second flap 16 such that it is moved to a closed position. However, if the enthalpy of the second air source 22 higher than that of the first air source 21 controls the measuring and control unit 10 the first flap 15 such that it is moved to a closed position and the second flap 16 such that it is moved to an open position.

In the event that air from the air source with the flap in the open position is insufficiently available, the flap, which is in the closed position, is opened so far that enough air is supplied to the heat pump. It is noted that the air from the air source with fully open flap still fully into the air supply element 2 is introduced and air from the other air source only the remaining air requirement of the heat pump 1 provides.

In 3 is an air heat pump 1 represented, the input side with an air supply element 2 connected is. This in turn is connected to two air sources, with a first air source 21 Outside air and a third air source 23 an air collector 24 is. The first air source 21 can with the help of a first valve 13 with the air supply element 2 get connected. If this is in an open position, almost exclusively outside air flows into the air supply element 2 , as the air flow resistance of the air collector 24 is significantly higher. Is the first valve located? 12 however, in a closed position, outside air initially flows through the air collector 24 and then to the air supply element 2 , In this way, the outside air can be preheated.

According to 4 is an air heat pump 1 on the input side with an air supply element 2 connected. This in turn is connected to three air sources, with a first air source 21 Outside air, a second air source 22 Exhaust air and a third air source 23 an air collector 24 is. The first air source 21 can with the help of a first flap 15 with the air supply element 2 be connected and the second air source 22 with the help of a second flap 16 , The air flow resistance of the air collector 24 is significantly higher than that of the other air sources, whereby air from this only flows into the air supply element when the first flap 15 and the second flap 16 are closed.

Not shown is that the exhaust air from the second air source 22 also in the air collector 24 could be initiated. However, this is possible and useful, provided that this is the coefficient of performance of the air heat pump 1 is increased. For this purpose, a channel and a further flap would advantageously be provided, which are designed such that the exhaust air in a position of the flap to the air supply element 2 and in another to the air collector 24 ,

In a further embodiment of the invention shows 5 an air heat pump 1 with an evaporator 4 that with an air supply element 2 connected is. This in turn is connected to three air sources, with a first air source 21 Outside air, a second air source 22 Exhaust air and a third air source 23 an air collector 24 is. The first air source 21 can with the help of a first flap 15 with the air supply element 2 be connected and the second air source 22 with the help of a second flap 16 , The air flow resistance of the air collector 24 is significantly higher than that of the other air sources, whereby air from this only flows into the air supply element when the first flap 15 and second flap 16 are closed.

Furthermore, outside air flows through a channel through a wall into a room 50 , In this channel is a heat exchanger 25 intended. On the opposite side of the heat exchanger 25 the exhaust air flows out of the room 50 to the air supply element 2 , provided the second flap 16 in an open position. In this case, heat is transferred from the exhaust air to the incoming outside air through the heat exchanger. This is possible less heat when ventilating the room 50 lost. However, this also reduces the temperature and the enthalpy of the exhaust air, so that a measurement of the temperature, the humidity and the pressure between the heat exchanger 25 and the evaporator 4 should be done.

LIST OF REFERENCE NUMBERS

1

air source heat pump

2

Air supply element

3

Airflow generator

4

Evaporator

5

Heat pump cycle

6

consumer

10

Measuring and control unit

11

temperature sensors

12

humidity sensors

13

first valve

14

second valve

15

first flap

16

second flap

17

pressure sensor

21

first air source

22

second air source

23

third air source

24

air collector

25

heat exchangers

50

room

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 3903665 C2 [0003]
• DE 102006046630 A1 [0004, 0006]

Claims (12)

Method for providing a heat output to a consumer ( 6 ) for the heating of a room ( 50 ) or preparation of domestic hot water by means of an air heat pump ( 1 ) with an air supply element ( 2 ), at least one air flow generator ( 3 ), an evaporator ( 4 ) and a heat pump cycle ( 5 ), wherein the air heat pump ( 1 ) with the air supply element ( 2 ), the air flow generator ( 3 ) Air from the air supply element ( 2 ) to that in the air heat pump ( 1 ) arranged evaporator ( 4 ), from the air heat pump ( 1 ) provided heat output through the heat pump cycle ( 5 ) to the consumer ( 6 ) and the air heat pump ( 1 ) has a Coefficient Of Performance (COP) dependent on the delivered air, which is equal to the quotient from the consumer ( 6 ) heat output (Q _c ) and the operation of the air heat pump ( 1 ), wherein the drive power (W) substantially from the electrical connection performance of a compressor and a throttle of the air heat pump ( 1 ), the air flow generator ( 3 ) and a control electronics, characterized in that to increase the coefficient of performance, a measuring and control unit ( 10 ) is selected between at least two different air sources and air from the selected air source into the air supply element ( 2 ) or the selected air source with the air supply element ( 2 ) connects. A method according to claim 1, characterized in that the measuring and control unit ( 10 ) with the aid of temperature sensors ( 11 ) Determines air temperatures and air availability of the different air sources, and selects the air source that has the highest temperature and is available. Method according to one of claims 1 or 2, characterized in that the measuring and control unit ( 10 ) with the aid of temperature sensors ( 11 ) and / or humidity sensors ( 12 ) and / or pressure sensors ( 17 ) determines an enthalpy content and availability of air from the different air sources. A method according to claim 3, characterized in that the measuring and control unit ( 10 ) selects the source of air that has the highest enthalpy content and is available or calculates the coefficient of performance for each air source and selects the one with the highest coefficient of performance. Method according to one of the preceding claims, characterized in that the measuring and control unit ( 10 ) takes into account, in the selection of the air source, the energy demand for supplying air therefrom, in particular by considering the power for the air flow generator ( 3 ) whose energy consumption increases at the same air throughput and higher flow resistance of the supply from an air source, wherein preferably the air flow rate and the power consumption of the air flow generator ( 3 ) or values are stored. Method according to one of the preceding claims, characterized in that the measuring and control unit ( 10 ) Air from different air sources simultaneously into the air supply element ( 2 ) or the different air sources simultaneously with the air supply element ( 2 ), preferably such that the coefficient of performance is maximized. Method according to one of the preceding claims, characterized in that a first air source ( 21 ) Is outside air from the earth's atmosphere. Method according to one of the preceding claims, characterized in that a second air source ( 22 ) Exhaust air from the room ( 50 ). A method according to claim 8, characterized in that the exhaust air before entering the air supply element ( 2 ) through a heat exchanger ( 25 ) and energy in the room ( 50 ) emits flowing fresh air or to service or heating water. Method according to one of the preceding claims, characterized in that a third air source ( 23 ) an air collector ( 24 ) is, the outside air preheated by sunlight in a continuous process and in particular is a facade collector. Method according to claim 10, characterized in that the measuring and control unit ( 10 ) Air from the third air source ( 23 ) directly in the room ( 50 ). Method according to one of the preceding claims, characterized in that the measuring and control unit ( 10 ) for connecting the selected air source with the air supply element ( 2 ) at least one first valve ( 13 ) or a first flap ( 15 ).

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