SE530407C2 - Control device - Google Patents

Description

25 30 530 40? the water in the water heater, the so-called the secondary water or domestic hot water, of the so-called primary water which is heated via the heat pump loop. Since the available water heating temperature available is limited by the temperature to which the heat pump is able to heat the primary water, there is a limitation on the temperature to which the secondary water can be heated.

When designing heat pumps, a number of criteria must therefore be taken into account. For example, hot water for baths and showers should be at least 40 ° C at the tap. Furthermore, there are, at least in Sweden, rules that say that the temperature in an accumulating water heater must be at least 50 ° C. In addition, to prevent overgrowth of legionella bacteria, all hot water should be heated to at least 60 ° C at regular intervals.

The heat pump can thus not heat the primary water to any high temperature, at least not in an economical way, which leads to limitations on how much the secondary water, the domestic hot water, can be heated by the primary water.

There is thus a need for a heat pump that can provide a larger amount of secondary water at a lower cost.

OBJECTS AND MOST IMPORTANT FEATURES OF THE INVENTION It is an object of the present invention to provide a control device which, in the case of a heat pump, can provide a larger amount of secondary water at a lower cost.

This object is achieved, according to a first aspect of the invention, with a control device according to claim 1, a method according to claim 13 and a heat pump according to claim 22 and a heating system according to claim 23, The control device according to the present invention, an evaporator and a 73633.doc; 2005-07-06 UI 10 15 20 25 30 530 407 condenser wherein a heat transfer medium heated by means of the evaporator and a compressor in a heat transfer circuit is arranged to provide heat to a main liquid flow via a first heat exchanger portion and a second heat exchanger portion, at least in a heating mode, diverting a partial flow from said main water flow for passage through the second heat exchanger portion. This has the advantage that the lower flow significantly changes the ratio between heat transfer surface and flow compared with known technology, which leads to the partial flow being able to be heated to a significantly higher temperature than before, and also to a significantly lower cost. The partial flood can then be used to heat secondary water to a significantly warmer temperature than before.

Said partial flow can be diverted after passage of the main liquid flow through the first heat exchanger portion. This has the advantage that the partial flow is already partially heated when it reaches the second heat exchanger portion.

The device may comprise means for directing heated partial flow through or adjacent to a water container for dissipating heat from the partial flow to water in the container at the passage of the partial river. This means that accumulated water with a high temperature at a low heating cost can be obtained.

The device may further comprise control means for regulating the share of the partial flow of the total flow. The regulatory body can e.g. consists of a controllable shunt valve or throttle valve.

This has the advantage that the flow of the partial flow can be regulated so that it is always ensured that the temperature of the flow that enters the top of the water tank does not fall below a certain temperature, e.g. 50 ° C. Furthermore, the water flows can be regulated at all times as needed, e.g. can in some cases hot »water production be prioritized, while in other cases heating 73 6330cc, 2005-0106 10 15 20 30 530 40? prioritized. The control is preferably controlled by means of the heat pump's control computer.

The return flow of the partial flow and the return flow of the hot water can be connected on the cold water side of the first heat exchanger section.

This has the advantage that accumulated energy in the heating system can be “borrowed” to temporarily increase hot water production.

The first heat exchanger portion may be substantially a condenser, and the second heat exchanger portion may be substantially a hot gas heat exchanger. This has the advantage that the hot hot gas can heat the partial flow to a very high temperature.

Brief description of the drawings Figure 1 generally shows a heat pump according to the prior art.

Figures 2a-e show different operating cases with associated enthalpy diagrams for an example heat pump according to the prior art.

Figures 3a and Bb show a heat pump according to an exemplary embodiment of the present invention.

Figure 4 shows an exemplary operating case according to the present invention.

Figure 5 shows another exemplary operating case according to the present invention.

Figure 6 shows an alternative embodiment of the present invention.

Detailed Description of Preferred Embodiments Fig. 1 shows a prior art heat pump 10 installed in a property such as a villa, and schematically a radiator system 15. The heat pump 10 is provided with a control computer 12, which controls and monitors various functions in the heat pump. Examples of such functions can be setting 736331íoc: 2005-07-06 10 15 20 25 30 530 40? and / or monitoring of working temperatures for the heat pump's compressor, indoor and outdoor temperatures, setting of heating curve, control of room temperature depending on time of day or in case of holiday absence, etc. Further examples will be given below. A user can communicate with the control computer 12 via a display and keypad (not shown) arranged on the heat pump 10. The heat pump 10 further comprises a heat pump circuit and a water tank 11 with an inlet 13 in the lower part of the tank for supply of water to be heated and an outlet 14 in the upper part of the tank for discharge of heated water.

The heat pump circuit comprises a circulating heat transfer medium where mostly liquid heat transfer medium 21 absorbs heat from a heat source such as a rock heat loop 22, in which a coolant such as glycol water with a temperature of approx. ~ 5 ° - + 5 ° is circulated using a circulation pump in a water-filled borehole. When the liquid heat transfer medium 21 absorbs heat, it evaporates in an evaporator 23.

The evaporation temperature can e.g. be -7 °. The gaseous heat transfer medium is then compressed by means of a compressor 24 to a higher pressure, which due to the smaller volume of the gas means that the temperature of the gas is raised. The compressed, hot gas (hot gas) then gives off its heat via a condenser 25 and a second cooler 26 its heat to the so-called the primary water, or the radiator water 27, at the same time as the gas is condensed into liquid. The subcooling means that additional heat can be recovered and thus provides a more economical heat pump, while ensuring that no gas bubbles remain in the heat transfer medium when it reaches the expansion valve 28, via which the pressure of the liquid heat transfer medium is greatly lowered. absorbs heat from the geothermal heat loop 22. Instead of 7363 3 A106: 2005-07-06 10 15 20 30 530 40? the heating loop absorbs heat from rocks, it can absorb its heat from soil, air and / or water. The figure also shows an immersion heater 29, which is only used in cases where additional heat supplementation is required, e.g. very cold days, and a gear valve l6 for switching between hot water production and heat production. Furthermore, a circulation pump 17 is shown for circulating the primary water.

The primary water heated by the heat pump circuit is then used alternately to heat domestic hot water and the property's radiator and / or floor heating system. The efficiency of the heat pump is controlled by the condensing temperature of the heat transfer medium, the lower the temperature, ie. the lower the pressure, the condensation is started at, the higher the efficiency. When heating the primary water to e.g. 35 ° with a 10kW heat pump, the heat pump's so-called coefficient of performance (COP), ie. the ratio between output power and applied power, be 5, at 50 ° it can be 3.4 and at 60 ° it can be 2.5.

The heat pump can thus not heat the primary water to any high temperature, at least not in an economical way, which leads to limitations on how much the secondary water, the domestic hot water, can be heated by the primary water.

This is exemplified by Figures 2a-2e. Fig. 2a shows the system in Fig. 1 with temperatures for an imaginary operating case where the property is heated by an underfloor heating system, and heating / circulation of radiator water in the underfloor heating system according to the arrow-provided loop is in progress. As can be seen in the figure, the radiator water has a return temperature of 25 ° C when it is introduced at A into the subcooler 26. When passing through subcooler 26 and condenser 25, the radiator water heats to 35 °, while the temperature of the heat transfer medium is lowered from 66 ° C when entering the condenser to 28 ° C after passage through sub- 73633.doc; 2005-07-06 10 15 20 25 30 530 407 the cooler. Fig. 2b shows the corresponding enthalpy diagram, and as can be read in the figure, in this operating case a CO 2 value (Pm heat exchangers, ie cooling of the hot gas from 66 ° C to 39 ° C takes place without condensation, and only when the gas temperature reaches 39 ° C does the condensation begin.

Fig. 2c shows the same system, but with temperatures for an imaginary operating case where instead of hot water in the water tank II is heated. As can be seen in the figure, in this case the primary water has a return temperature of 47 ° C when it is introduced at A into the subcooler 26. Upon passage through the subcooler 26 and the condenser 25, the primary water is heated to 60 °, while the temperature of the heat transfer medium is lowered from 110 ° C when entering the condenser to 50 ° C after passage through the subcooler. Fig. 2d shows the corresponding enthalpy diagram, and as can be seen in the figure, a COP value (Pwm / PHLMJ of about 2.5 is obtained for hot water production. Thus, hot water production takes place at a much higher cost than the heating of the radiator water. In addition, this solution provides , despite the high hot gas temperature, a maximum temperature of 50 ~ 55 ° C in the water tank ll. seen in the figure, the temperature of the hot gas in the hot gas part drops from 10 ° C to 60 ° C at the same time as the water temperature is raised only slightly or a few degrees, despite the fact that, as can be seen in figure 2d, almost 30% of the heat transfer medium energy is given off in the hot gas part. The fact that the temperature increase does not increase is partly due to the fact that the heat transfer part of the hot gas part is relatively small, and partly due to the fact that the flow is relatively large. taken out of a heat exchanger can be written as P = k * ® * AT, where ® is the water flow and AT 73633doc; 2005-07-06 10 15 20 25 30 530 40? the difference between the temperature of the water before and after the heat exchanger and k is a constant. If the flow is thus large, the temperature increase will not be very large. The low primary water temperature means that a limited hot water withdrawal can be made before the tank's top temperature drops below the 40 ° C required at the tapping points. In addition, this means that the primary water which in Fig. 2c has a return temperature of 47 ° C after a larger bottling, due to greater cooling when passing through the tank 11, has a lower temperature, perhaps only 20 ° C, which in turn leads that the heated primary water will have a temperature lower than the shown 60 ° C, e.g. perhaps as low as 30 ° C, which will further lower the tank's top temperature by passing heat down into the tank (the warmer water at the top of the tank heats the primary water, after which the primary water gives off heat to the colder water at the bottom of the tank), and thus take relatively long: id before the tank's top temperature rises again ~ reaches 50 ° C and thus enables a new larger bottling.

One way to increase the possibility of losing larger amounts of water is to raise the temperature of the heat transfer medium further, and thus the temperature of the primary water. However, this is done at the expense of poorer efficiency, for example, when the primary water is heated to about 65 ° C, a COP of about 2 is obtained.

Fig. Ba shows an exemplary embodiment according to the present invention, according to which domestic hot water can be manufactured at a much lower cost compared to the prior art. As in Fig. 1, the heat pump 30 comprises a heat pump circuit and a water tank 31 with an inlet 33 in the lower part of the tank for supplying water to be heated and an outlet 34 in the upper part of the tank for discharging heated water. Also in this case, a circulating heat transfer medium 32 absorbs heat from a heat source, evaporates and compresses. In this case 73633 (10012005-07-06 10 15 20 25 30 530 40? The primary water is circulated through a unit 36 which constitutes a condenser / subcooler, where the heat transfer medium gives off its heat to the primary water during condensation / subcooling, whereby the primary water is heated to 35 ° C for circulation by means of a circulation pump 41 through an underfloor heating system.

The primary water then passes through an immersion heater 39. Unlike the prior art, where heat and hot water are generated alternately by switching the flow by means of the changeover valve 3G in Figure 1, a shunt valve is used according to the present invention which diverts a partial flow 42 from the primary water 37. Outstanding flow 43 of the primary water is circulated through the property's underfloor heating system, while the partial flow 42, which is controllable and for example amounts to 20% of the total flow, is led to a hot gas heat exchanger 35. Due to the lower flow, the ratio between heat transfer surface and flow will increase markedly. which means that the partial flow can be heated to a significantly higher temperature. As shown in Figures 3a and 3b (which corresponds to Figure 2e), in this case the partial flow (according to the formula P = k * ® * AT) is heated to 60 ° C at the same time as the heat pump operates with the same COP as in Figure 2b. The partial flow is then used for heating domestic hot water which can thus be heated to 55-60 ° C to the same COP which would give 35 ° C according to the prior art. After passing through the water tank, the partial flow is led out to the main flow for new circulation. If radiators are used instead in the property, with the consequence that the radiator water, for example, is heated to 60 ° C instead of 35 ° C, the present invention means that the partial flow can instead be heated to an even higher temperature, if e.g. the temperature of the hot gas at the entrance to the hot gas heat exchanger has a temperature of 110 ° C as in fig. 2c the water in the tank can be heated up to a basically arbitrary temperature, however the top temperature should be kept at a maximum of 95 ° C to avoid boiling. Through this possibility to charge the water tank to a very high 7363311643, 2Ü05-07-U6 10 15 20 25 30 530 40? At this temperature, a heat pump is obtained which allows an extremely much larger hot water outlet at the same manufacturing cost. How great the improvement is is easy to understand since it is the 40 ° C required at the tapping points which constitute the reference, and the actual temperature range for mixing hot water is thus 55 ° C (95 * 40) according to the present example compared to 10 ° C (50-40 ), which in percentage is a very large improvement with the same COP that previously gave 50 ° C hot water. This also has the advantage that the risk of growth of legionella bacteria can be significantly reduced because the water is heated to a higher temperature, in addition the tank can be heated through to a high temperature with heat pump operation, which further reduces the need for the immersion heater. The flow can be controlled so that no condensation takes place in the hot gas exchanger part. The hot partial flow has the advantage that a rapid heating is obtained at the top of the water tank, and due to the layering in the hot water heater, a certain amount of usable hot water is obtained quickly even after a large drain. Even with a total emptying of the water heater, the recharging at the top takes place quickly and thus quickly results in a usable amount of new hot water. The solution according to the invention also means that significantly more hot water is obtained compared to the prior art, since the water is heated to a higher temperature, alternatively the size of the heat pump's water tank can be reduced. The flow of the partial flow can be regulated so that it is always ensured that the temperature of the flow that enters the top of the water tank does not fall below 50 ° C, or is always 5 ° C above the top temperature, however the top temperature should be kept at a maximum of 95 ° C as above for to avoid boiling.

In today's heat pumps, where hot water and heat are produced alternately, the water in the radiators can stand still in e.g. 20 minutes when hot water is produced. When then the radiator water is put into circulation again, a hot water column will go out in 7363 3 doc. 2005-07-00 10 15 30 530 40? 11 system as a transient, which causes rapid heating of the pipes in the walls, which may have cooled to 20 ° C, which in turn causes the pipes to expand in heat and try to push the wall bolts apart. When this does not work, clicks occur that can be likened to gunshots. This problem can be avoided with the present invention because water is constantly circulated in the radiator loop and temperature changes occur without transients.

The present invention has a further advantage in that the accumulated water in the property's heating system can be used to speed up the heating of the domestic hot water.

This is exemplified in Fig. 4. If a large hot water withdrawal from the water tank is carried out, the return temperature of the partial flow, ie. the temperature after passage through the water tank, to be lowered from, in an example with 50 ° C water in the radiator loop, 70 ° C to for example 15 ° C as in Fig. 4 (the figure shows the partial flow temperature after the hot water withdrawal, for this reason temperature in the figure 67 ° C and not 70 ° C). This 15 ° C hot water is then mixed with the return flow of the radiator loop.

If the partial flow is about 9%, as in the figure (l6g / (l6g + l68g)), of the total flow, this means that the return flow of the radiator water is reduced by about 2 ° C (according to the formula R * (l6 + l68) = (l5 * l6 + 40 * l68), where R = resulting temperature, which in turn means that the maximum flow of the partial flow is lowered to about 67 ° C. If, as may be the case in a normal villa, the radiator loop consists of 400 kg of iron and holds 100 liters of water in pipelines and elements, the number of liters of L extra 40 ° C hot water obtained by lowering the temperature in the radiator loop can be calculated as 2 * (100 * 4, l8 + 400 * 0, 46) = 30 * (L * 4.18}, days: 4, 18 = the heat capacity of the water: 0.46 ll the heat capacity of the iron 73ó33.doC; 2005-07-06 10 15 30 530 40? 12 30 = temperature difference from 10 ° C incoming water to 40 ° C water, which gives 10 liters extra 40 ° C water, with a throughput time of 'a total of 10 minutes (ie the time it takes to replace the radiator water with the specified flow). When no hot water outlet is made for a period, the radiator system and water tank are recharged with the help of the heat pump. Fig. 5 shows another example where an even larger part of the energy accumulated in the radiator system is “borrowed” for hot water production. In this example, the partial flow is larger, about 58%, which leads to a lower maximum temperature for the partial flow. The return temperature of the partial flow will in this case be slightly higher due to the larger flow, e.g. 20 ° C as in the figure. This 20 ° C hot water is mixed as before with the return flow of the radiator loop, which means that the return flow of the radiator water in this case, as above, is reduced by about 12 ° C. With the same input data as above, 58 liters of extra 40 ° C hot water are obtained in this case with a throughput time of a total of 21 minutes.

The control of how large a partial flow is to be diverted from the main flow can always be regulated with the help of the heat pump's control computer. Examples of control parameters may consist of one or more of: - the main water flow temperature after the condenser, - the main water flow return flow temperature, - the main water flow flow, - one or more temperatures in the water tank, - the partial river temperature after the hot gas heat exchanger, - the hot stream, , - hot water outlet, 73ó33.doc; 2005-07-06 10 15 25 30 530 40? 13 - the pressure of the refrigerant circuit on the high- and low-pressure side fl f ~ of the compressor delivered power.

The regulation can thus be arranged to prioritize different things at different times. For example. In some cases, hot water production can be given priority, while in other cases heating of the property can be given priority. Furthermore, the compressor can consist of a capacity-controlled compressor. This has e.g. the advantage that when a bottling of hot water has been made, the capacity of the compressor, provided that it does not already work with maximum capacity, can be increased so that the same flow temperature is obtained at all times despite the colder return water.

Fig. 6 shows an alternative embodiment of the present invention. In this case, the return of the partial flow 62 is connected to the output of the condenser 60. This means that the energy loan described above is not possible, however, this embodiment has the advantage that when the water tank 61 is fully charged, the return of the partial flow 62 can help to heat the radiator water. In addition, this has the advantage that, when the water tank 61 is charged, the return flow of the partial flow 62 does not increase the return temperature of the radiator water, which in turn means that the condensing temperature in the condenser is not increased, with improved efficiency as a result.

However, the hot gas exchanger in this case must be made larger to cope with the entire heating during the summer fall as no flow goes through the radiators and the condenser is thus not used. In an alternative (not shown) embodiment, a changeover valve can be provided in order to be able to controllably couple the return of the partial flow according to Fig. 3A or Fig. 6. In this way, the return of the partial flow can always be connected according to what is currently most advantageous.

The present invention also has a further great advantage.

There are today systems with condenser and hot gas heat exchanger, where the condenser is used for e.g. heating and hot gas heating- 736331J0c: 2005-07-06 10 15 20 30 530 40? 14 the exchanger for other. For example. the hot gas heat exchanger can be placed in the accumulator tank to heat the surrounding accumulator water in this way. If a hot water tap is left slightly open in this case, or hot water otherwise leaks into the system, the heat demand in the accumulator tank can increase so much that the hot gas begins to condense in the hot gas exchanger, ie. the power required in the accumulator exceeds the available power in the hot gas. If the heat demand is large enough, in the worst case the condensation can take place completely over the hot gas heat exchanger, ie. all energy is taken over this. Apart from the fact that this leads to the system having a very poor efficiency (due to the heat pump being forced to release the energy at a large temperature difference), there is no energy left for heating radiator water via the condenser, which in turn leads to the property being cooled and frozen. Another example of using the hot gas heat exchanger, which can have the same result, is when the hot gas heat exchanger is used in combination with VVC in water circulation system, and too much load (eg floor heating, towel dryers) is connected to the hot gas heat exchanger. Even in this case, the entire condensation can then take place over the hot gas heat exchanger with the above problems as a result. With the present invention, however, this problem is avoided. In the proposed invention, the return from the tap water tank is mixed with the return from the radiator system, which ensures that the condensation can take place in the condenser. If the control computer finds that the hot water production is insufficient, ie. the return is too cold for a long time, e.g. 2 hours, despite being prioritized, the partial flow can be switched off completely or reduced so much that condensation in the hot gas heat exchanger does not take place, which is easily ensured by reading the temperatures in the system and regulating the partial flow based on these.

In the above description, the device has only been described with a diverted partial flow. However, the device can be used on 73633.doc1 2005-07-06 10 15 530 40? 15 normally sat, especially during summer operation, when no heating takes place. In this case, the entire flow is used for hot water production, and the heat pump works in principle as in the prior art.

Furthermore, in the above description, the hot gas exchanger 35 has been described as a pure hot gas exchanger. By using the heat pump's control computer, however, the temperatures can be controlled by controlling the river and compressor, which enables some condensation to take place in the hot gas heat exchanger, or alternatively that the condenser / subcooler 36 is partly used as a hot gas heat exchanger. Thus, the system in all laws can be optimized for the circumstances prevailing at any given time.

Table I below shows a summary of the most common operating cases for the loupe heating modes) and for which the COP hot water is manufactured.

Operation- Heating- Hot water- Remark case needs need l Large Large Continuous operation. For large instantaneous hot water wells, energy in the radiator system is used as a buffer. COP for hot water production will be equal to COP for the current heating operation case. 2 Large small Continuous operation. COP for heating in water supply. becomes equal to COP for the current heating operation case. 3 Small Small Intermittent operation in case of heat demand. COP for hot water production. 7363 3 dot: 2005-0706 10 15 530 40? 16 becomes equal to COP for the current heat operating case. 4 Small Large Intermittent operation in case of heat demand. In the event of a large drain, the heat pump is run with the heat switched off.

Then the condenser will heat the hot water which then passes the hot gas exchanger which further raises the temperature. COP for hot water production. gets a little better in the summer case. 5: None Normal (Summer case) No help of hot gas when running hot. COP for hot water production. as driving without a hot gas exchanger.

In the above description, the heat transfer to the water in the water tank takes place by means of a pipe loop. However, it is of course possible to perform this heat transfer in another way, e.g. by using a double jacketed water tank with an outer jacket surrounding the tank, and where the partial flow is circulated through the space between the tank and the jacket, or with another type of heat exchanger such as a plate heat exchanger, or a charge exchanger, where radiator water accumulates in a tank, and where the top water in the tank is circulated through charge exchangers against domestic hot water. In this case, a circulation pump ensures that the flow from the tank is large enough to provide sufficient heating of the tapVâlfmVâttnê fi.

Furthermore, in the above description, a shunt valve has been used to divert the partial flow. Instead of a snout valve can 73633, doc'_ 2005-0106 530 40? However, other means can also be used to divert the partial flood, e.g. a choke can be used.

The condenser and the hot gas heat exchanger have been described in the above description as separate units. However, these can also consist of an integrated unit, where the total flow is led through a part of the integrated unit, and the partial flow through another part of the unit. 736331106; 2005-07-06

Claims (1)

1. 0 15 20 25 30 530 40? CLAIMS Claim control device intended for use in a heat pump (10) with an evaporator (23) and a condenser (25; 36; 60), wherein a heat transfer medium heated by the evaporator (23) and a compressor (24) in a heat transfer circuit is arranged to via a first heat exchanger portion (36; 60) and a second heat exchanger portion (35) deliver heat to a main liquid flow, the device including means for diverting, at least in a heating mode, a partial flow (42; 62) from said main liquid flow for passage through the second the heat exchanger portion (35), said partial flow (42: 62) being arranged to, after passage through the second heat exchanger portion (35), be used for heating domestic hot water, and that said main liquid flow is arranged to be circulated by means of a circulation means (41) radiator and / or underfloor heating system, characterized in that the device further comprises control means for regulating the share of the partial flow (42; 62) of the total flow. Control device according to claim 1, characterized in that the device includes means (40) for diverting said partial flow (42; 62) from said main liquid flow after passage of the main liquid flow through the first heat exchanger portion (36: 60). Control device according to any one of claims 1-2, further comprising means for conducting heated partial flow (42: 62) through or adjacent to a water tank (3l; 61) for dissipating heat from the partial flow (42; 62) to water in the container ( 3l; 61) at the passage of the partial flow (42: 62), the water tank (3l; 61) including a 7363313; 2008-03-03 10 15 20 25 30 530 40? 19 inlets (33) for supplying water to be heated and an outlet (34) for discharging heated water. Control device according to claim 3, wherein said water container (3l; 61) includes a pipe loop through which said partial flow (42; 62) passes for delivering heat to the water in the container (31: 61). Control device according to any one of claims 1-4, wherein said control means (40) consists of a controllable shunt valve or throttle valve. Control device according to any one of claims 1-5, characterized in that it further comprises control means, such as a control computer (12), for controlling said control means (40) - Control device according to claim 6, wherein control of said control means (40) takes place based on one or more of the criteria: - temperature of the main liquid flow after the condenser (25: 36; 60), - return flow temperature of the main liquid flow, - flow of the main liquid flow, - one or more temperatures in the water tank (31; 61), - temperature of the partial flow (42: 62) after the second heat exchanger portion (35), - the temperature of the hot gas, - the return flow temperature of the partial flow (42: 62), - the flow of the partial flow (42: 62), - hot water outlet, - the pressure of the refrigerant circuit on the high and low pressure side, - the compressor (24) output . 7363311; 2008-03 -03 10 15 20 25 30 10. ll. 530 40? Control device according to one of Claims 1 to 7, characterized in that the return flow of the partial flow (42; 62) and the return flow of the main liquid flow are arranged to be interconnected on the cold water side of the first heat exchanger portion (36: 60). Control device according to one of the preceding claims, characterized in that the first heat exchanger portion consists essentially of a condenser (36; 60), and the second heat exchanger portion essentially consists of a hot gas heat exchanger (35). Control device according to one of the preceding claims, characterized in that the first heat exchanger portion (36: 60) and the second heat exchanger portion (35) consist of separate units. Control method intended for use in a heat pump with an evaporator (23) and a condenser (36: 60), wherein a heat transfer medium heated by evaporation and compression in a heat transfer circuit delivers heat to a main liquid flow via a first heat exchanger portion (36; 60) and a second. the heat exchanger portion (35), the method further comprising the step of, at least in a heating mode, diverting a subflow (42; 62) from said main liquid stream for passage through the second heat exchanger portion (35), the method further comprising the steps of using said subflow (42; 62) for heating domestic hot water after passage through the second heat exchanger portion (35), and circulating said main liquid flow through a radiator and / or underfloor heating system, characterized in that the share of the partial flow (42; 62) of the total flow is regulated. 73633b; 2008-03-03 10 15 20 25 30 12. l3 14 15. 530 40? The control method according to claim 11, wherein the method further comprises the step of diverting said partial flow (42; 62) from said main liquid flow after passage of the main liquid flow through the first heat exchanger portion (36; 60). The control method according to claim 11 or 12, further comprising the step of conducting heated partial flow (42; 62) through or adjacent to a water tank (3l; 61) for delivering heat from the partial flow (42; 62) to water in the tank (3l; 61) at the passage of the partial flow (42; 62). A control method according to claim 13, wherein said partial flow (42; 62) passes said water container (31: 61) through a pipe loop arranged inside the water container (3l; 61). Control method according to one of Claims 11 to 14, in which the subflow (42; 62)'s share of the total flow is regulated based on one or more of the criteria: - main liquid flow temperature after the condenser (25: 36; 60), - main liquid flow return flow temperature, - main liquid flow , - one or more temperatures in the water tank (31; 61), - the temperature of the partial flow (42; 62) after the second heat exchanger portion (35), - the temperature of the hot gas, - the return flow temperature of the partial flow (42; 62), - the partial flow (42; 62) flow, - hot water outlet, - the pressure of the refrigerant circuit on the high- and low-pressure side, respectively, - the power delivered by the compressor (24). 73633b; 2008-03 -03 10 16. 17. 18 19. 530 40? Control method according to one of Claims 11 to 15, characterized in that the return flow of the partial flow (42; 62) and the return flow of the main liquid flow are interconnected on the cold water side of the first heat exchanger portion (36; 60). Control method according to one of Claims 11 to 16, characterized in that the first heat exchanger portion consists essentially of a condenser (25:36; 60), and the second heat exchanger portion consists essentially of a hot gas heat exchanger (35). Heat pump, characterized in that it comprises a control device according to any one of claims 1-10. Heating system, characterized in that it comprises a control device according to any one of claims 1-10. 73633b; 2008-03-03