Building heating system

Abstract

A building heating system, including for heating water, such as tap water and/or utility water, of a building water system. The embodiments also relate to a kit of part to realize such a building heating system. The embodiments further relate to a method for controlling the building heating system.

Claims

1. A building heating system, comprising: at least one air source heat pump configured to transfer heat from air to a working fluid conducted through a working fluid line, said working fluid line comprises at least two electrical heating tubes configured to heat said working fluid during flow-through of said working fluid, wherein each of said heating tubes is, directly or indirectly, connected or connectable to said heat pump, and wherein said working fluid line is connected or connectable to at least one water heat exchanger for transferring heat from said working fluid to water conducted through at least one water line of a building water system, at least one temperature sensor configured to measure the temperature of the working fluid and/or water conducted through at least one water line, and at least one control unit connected or connectable to said at least one temperature sensor, wherein said control unit is configured to individually control the electrical heating tubes based upon the temperature detected by said at least one temperature sensor.

2. The building heating system according to claim 1, wherein the control unit is configured to individually control the electrical heating tubes and the heat pump based upon the temperature detected by said at least one temperature sensor.

3. The building heating system according to claim 1, further comprising a plurality of temperature sensors connected or connectable to said control unit, wherein at least one working fluid temperature sensor is configured to measure the temperature of the working fluid downstream of the heat pump and an upstream side of the heating tubes, and wherein at least one other working fluid temperature sensor is configured to measure the temperature of the working fluid downstream of the heating tubes.

4. The building heating system according to claim 1, further comprising a plurality of temperature sensors connected or connectable to said control unit, wherein at least one working fluid temperature sensor is configured to measure the temperature of the working fluid, and wherein at least one water temperature sensor is configured to measure the temperature of water of conducted through at least one water line of the building water system.

5. The building heating system according to claim 1, further comprising a plurality of water temperature sensors connected or connectable to said control unit, wherein at least one water temperature sensor is configured to measure the temperature of water of conducted through at least one first water line, and wherein at least one other water temperature sensor is configured to measure the temperature of water of conducted through at least one second water line.

6. The building heating system according to claim 1, wherein at least two heating tubes are positioned at a downstream side of the heat pump and an upstream side of the at least one heat exchanger.

7. The building heating system according to claim 1, wherein at least two heating tubes are connected in parallel orientation in the working fluid line, and wherein the sum of diameters of the parallel heating tubes is larger than a diameter of an adjacent conduit of the working fluid line.

8. The building heating system according to claim 1, wherein at least one electrical heating tube is an induction heating tube, and wherein said induction heating tube is connected or a connectable to an alternating current source.

9. The building heating system according to claim 8, wherein at least one frequency converter is positioned in between the alternating current source and said induction heating tube, and wherein said frequency converter is configured to increase a default frequency value of the alternating current source to a higher frequency value.

10. The building heating system according to claim 1, wherein the control unit is configured to individually switch on and off the electrical heating tubes and/or one or more parts of a heating tube, dependent on one or more temperature values measured by one or more temperature sensors.

11. The building heating system according to claim 1, further comprising at least one water temperature sensor configured to measure the temperature of water conducted through at least one first water line, wherein the control unit is configured to switch on at least one electrical heating tube in case the measured water temperature is below a first threshold value and simultaneously or successively to switch on at least one further heating tube in case the measured water temperature is below a second threshold value, wherein said second threshold value is lower than said first threshold value.

12. The building heating system according to claim 1, wherein the heat pump comprises a housing, wherein at least two heating tubes are connected to said housing and/or are accommodated within said housing.

13. The building heating system according to claim 1, further comprising at least one alternative auxiliary heating source in addition to the heat pump and in addition to or instead of at least one heating tube.

14. The building heating system according to claim 1, wherein the working fluid line comprises at least one storage container for storing heated working fluid, wherein a part of at least one water line is guided through said storage container for preheating water by said working fluid within said storage container.

15. The building heating system according to claim 1, further comprising a plurality of separated water lines of the building water system, wherein each of at least two water lines are connected to at least one water heat exchanger for heating water by the working fluid.

16. The building heating system according to claim 1, further comprising comprises at least one safety circuit configured to detect overheating and/or boiling dry of the working fluid line and for switching off the heat pump and the heating tubes in case overheating and/or boiling dry of the working fluid line is detected, wherein said safety circuit is preferably unconnected to the control unit.

17. The building heating system according to claim 1, further comprising at least one water temperature sensor is configured to measure the temperature of water of conducted through at least one first water line as well as at least one flow sensor to measure the flow of water through said first water line, wherein control unit is configured to switch on at least one electrical heating tube in case the measured water temperature is below a temperature threshold value and/or in case the measured water flow exceeds a flow threshold value, and wherein the control unit is further configured to simultaneously or successively to switch on at least one further heating tube in case the measured water flow exceeds a predefined, period of time and/or in case the measured temperature increase over a predefined period of time remains below a temperature threshold value.

18. A kit of parts for a building heating system according to claim 1, comprising: at least one heat pump, at least two working fluid heating tubes connectable, directly or indirectly, to said heat pump, at least one working fluid temperature sensor, and at least one control unit connectable to said at least one temperature sensor, wherein said control unit is configured to individually control the electrical heating tubes at least partially based upon the working fluid temperature detected by said at least one working fluid temperature sensor.

19. A computer-implemented method for controlling the building heating system according claim 1, comprising a step of operating the control unit to individually control and switch on and/or off, one or more electrical heating tubes and optionally the heat pump, at least partially based upon at least one temperature detected by said at least one temperature sensor.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention will be elucidated on the basis of non-limitative exemplary embodiments shown in the following figures, wherein

(2) FIG. 1 schematically shows a flow diagram of a first embodiment of the heating system according to the invention, and

(3) FIG. 2 schematically shows a flow diagram of a second embodiment of the heating system according to the invention.

(4) Within these figures, similar reference numbers correspond to similar or equivalent elements or features.

DETAILED DESCRIPTION OF THE EMBODIMENTS

(5) FIG. 1 schematically shows a flow diagram of a heating system 1 according to the invention. The heating system 1 comprises a heat pump 2 connected to a working fluid line comprising a working fluid W. The heat pump 2 comprises an inlet 3 configured to conduct the working fluid W through the heat pump 2 and an outlet 4 configured to discharge the working fluid W from the heat pump 2. The heat pump 2 is configured to heat the working fluid W from a first temperature T1 to a second higher temperature T2.

(6) The heating system 1 of the shown embodiment further comprises two electrical heating tubes 5. Each of the shown heating tubes 5 comprises a first end 7 and a second end 8. The heating tubes 5 are connected to the working fluid line. The heating tubes 5 of the shown embodiment are provided downstream of the heat pump 2. It is, however, imaginable that the heating tubes 5 are provided upstream of the heat pump 2. The heating tubes 5 of the shown embodiment are provided in series with the heat pump 2. The heating tubes 5 allow the working fluid W of the working fluid line to pass, in particular from the first end 7 to the second end 8. The heating tubes 5 of the shown embodiment are connected in parallel orientation in the working fluid line. It is, however, imaginable that the heating tubes 5 are connected in series in the working fluid line. The shown heating tubes 5 each comprise a heating element 6. The heating element 6 of the shown embodiment is at least partially arranged between the first end 7 and the second end 8 of the heating tube 5. It is imaginable that at least one heating tube 5 comprises more than one heating element 6. The heating tubes 5 are configured to heat the working fluid W during flow-through of the working fluid W.

(7) The heating tubes 5 may be configured to heat the working fluid W from a third temperature T3 to a fourth higher temperature T4. The temperature of the working fluid W, which has passed the heating tubes 5, may increase with the number of heating tubes 5 being switched on. The fourth temperature T4 may therefore increase with the number of heating tubes 5 being switched on. It is imaginable that the third temperature T3 is substantially equal to the second temperature T2, in particular when the heating tubes 5 are provided downstream of the heat pump 2. It is imaginable that the fourth temperature T4 is substantially equal to the first temperature T1, in particular when the heat pump 2 is provided downstream of the heating tubes 5.

(8) The shown heating system 1 further comprises a heat exchanger 8 connected to the working fluid line. In the shown embodiment, the heat exchanger 8 is arranged downstream of the heat pump 2 and downstream of the heating tubes 5. The heat exchanger 8 comprises a first inlet 9 configured to conduct the working fluid W through the heat exchanger 8 and a first outlet 10 configured to discharge the working fluid W from the heat exchanger 8. The heat exchanger 8 further comprises a second inlet 11 configured to conduct a fluid F, such as water, through the heat exchanger 8 and a second outlet 12 configured to discharge the fluid F from the heat exchanger 8. The working fluid W and the fluid F are at least partially in heat exchanging contact to at least partially heat the fluid F. It is imaginable that the working fluid W and the fluid F are at least partially in heat exchanging contact within the heat exchanger 8. The working fluid W enters the heat exchanger 8 with a higher fifth temperature T5 and exits the heat exchanger 8 with a lower sixth temperature T6. The heat of the working fluid W is at least partially transferred to the fluid F upon heat exchanging contact of the working fluid W and the fluid F. The fluid F enters the heat exchanger 8 with a lower seventh temperature T7 and leaves the heat exchanger 8 with a higher eight temperature T8 upon heat transfer from the working fluid W to the fluid F.

(9) The heating system 1 further comprises a at least one working fluid temperature sensor 13 configured to measure the temperature of the working fluid W in the working fluid line. In the shown embodiment, the temperature sensor 13 is located between the heat pump 2 and the heating tubes 5, although it may also, additionally or alternatively, be preferred to locate at least one working fluid temperature sensor 13 at a downstream side of the heating tubes 5. Additionally or alternatively, the heating system 1 may comprise one or more water temperature sensors (not shown), which are configured to measure the seventh (water) temperature T7 and/oroften more preferredthe eight (water) temperature T8. The heating system 1 further comprises a control unit 14 directly or indirectly connected to the temperature sensor 13. The control unit 14 is configured to control the heating tubes 5 based upon the temperature detected/measured by the working fluid temperature sensor(s) 13 and/or the water temperature sensor(s). It is imaginable that when the temperature of the working fluid W is below a (predetermined) threshold value one or more heating tubes 5 are switched on to further heat the working fluid W to a desired temperature. Optionally, when the detected temperature of the working fluid W is above a (predetermined) threshold value one or more heating tubes are switched off to not further heat the working fluid W.

(10) FIG. 2 schematically shows a second embodiment of the heating system 1 according to the invention. The heating system 1 comprises an air source heat pump 2 configured to heat the working fluid W of the working fluid line. It is imaginable that the shown heat pump 2 has replaced a (central heater) boiler by making use of the existing air conducting infrastructure of a heating system of a building. In the shown embodiment, the heat pump 2 is, directly or indirectly, connected to an existing air inlet pipe 105 and/or to an existing air inlet opening 109. In the shown embodiment, the air inlet opening 109 is provided in a roof 106 of the building. The air inlet opening 109 may, however, be provided in any wall of the building. The shown heat pump 2 is further, directly or indirectly, connected to an existing flue gas discharge pipe 104 and/or an existing flue gas outlet opening 110. In the shown embodiment, the existing flue gas outlet opening 110 is provided in a roof 106 of the building. The existing flue gas outlet opening 110 may, however, be provided in any wall of the building. In particular, the air intake duct Ai is connected to the existing flue gas discharge pipe 104 and the air outlet duct Ao is connected to the existing air inlet pipe 105. Therewith, the heat pump 2 is configured to discharge relatively cold air via the existing air inlet pipe 105 and to extract relatively warm or hot air via the existing flue gas discharge pipe 104. This configuration is favourable, since the existing air inlet pipe 105 is designed to conduct relatively cold air and the existing flue gas discharge pipe 104 is designed to conduct relatively hot gas. It is, however, also imaginable that the air intake duct Ai is connected to the existing air inlet pipe 105 and the air outlet duct Ao is connected to the existing flue discharge pipe 104. The heat pump 2 comprises a compressor 23, a condenser 24, an expansion valve 25, and an evaporator 22 which are connected by fluid conduits carrying a heat pump fluid H. The evaporator 22 is provided with an air intake duct Ai and an air outlet duct Ao. The air intake duct Ai is provided with an air fan 21 or a ventilator which is preferably provided in or connected to the air inlet duct Ai. The air fan 21 is configured to direct relatively hot air into the heat pump 2. The evaporator 22 is configured to at least partially heat the heat pump fluid H, for example by absorbing heat from the relatively hot air. The shown condenser 24 is provided with an working fluid duct configured to connect the heat pump 2 to the working fluid line. The heat pump fluid H is at least partially in heat exchanging contact with the working fluid W, preferably at least partially in the condenser 24, to heat the working fluid W from a first temperature T1 to a second higher temperature T2. The temperature difference Ta between the first temperature T1 and the second temperature T2 is preferably maximal 40 degrees Celsius.

(11) Downstream of the heat pump 2, the shown heating system 1 comprises three heating tubes 5. The heating tubes 5 are connected to the working fluid line W in a parallel orientation.

(12) Between the heat pump 2 and the heating tubes 5 the heating system comprises a temperature sensor 13 configured to measure the temperature of the working fluid W before entering the heating tubes 5. The temperature sensor 13 is connected or connectable to the control unit 14. The heating tubes 5 are preferably configured to cooperatively heat the working fluid W up to 95 degrees Celsius. A temperature difference Tb may be defined by the difference in temperature of the working fluid W prior to entering the heating tubes 5 and the temperature of working fluid W after flow-through the heating tubes 5. Preferably, the maximum temperature difference Tb is 85 degrees Celsius. The working fluid W is preferably heated by the heating tubes 5 and the heat pump 2. Preferably, the maximum temperature of the working fluid W passed through both the heating tubes 5 and the heat pump is 95 degrees Celsius.

(13) The shown heating system 1 further comprises working fluid sensors 13, 41. The temperature sensors 13 are provided at various locations configured to measure the temperature of the working fluid W. A temperature sensor 13 may for example be provided downstream of the heating tubes 5 and upstream of a first heat exchanger 81. The shown heating system 1 furthermore comprises a pressure sensor 41 configured to measure the pressure of the working fluid W in the working fluid line. The pressure sensor 41 is, directly or indirectly, connected or connectable to the control unit 14. The shown pressure sensor 41 is provided downstream of the heating tubes 5 and upstream of the heat exchangers 81. It is imaginable, that when the pressure measured by the pressure sensor 41 is above a threshold value that a safety valve 37 opens to decrease the pressure in the working fluid line. The shown heating system 1 further comprises a safety circuit 42 configured to detect overheating and/or boiling dry of the working fluid W in the working fluid line. In case overheating and/or boiling dry of the working fluid W in the working fluid line is detected, the safety circuit 42 is configured to switch off the heat pump 2 and/or at least one of the heating tubes 5.

(14) The control unit 14 is configured to modularly control the heating tubes 5 and optionally the heat pump 2, preferably based upon the input of at least one temperature sensor 13, 131. For example, if the measured temperature of working fluid W measured by the temperature sensor 13 located upstream from the heating tubes 5 is below a threshold value the control unit may be configured to switch on one or multiple heating tubes 5 to further heat the working fluid W to a desired temperature.

(15) The shown control unit 14 is connected or connectable to a an external device 44, such as a display to allow persons or users to communicate building heating system related data and/or to monitor the status of the heating system.

(16) Downstream of the heating tubes 5 the heating system 1 of the shown embodiment comprises two exchangers 81, 82 which are serially connected to the working fluid line. A first heat exchanger 81 comprises a first inlet 91 and a first outlet 92 configured to be connected to the working fluid line. The first heat exchanger 81 further comprises a second inlet 93 and a second outlet 94 connected or connectable to a first fluid line comprising a first fluid F1.

(17) Preferably, the first fluid line is a tap water line comprising tap water. Preferably, the tap water line comprising tap water is heated in the first heat exchanger, provided upstream from the second heat exchanger, to allow the tap water to be heated relatively quickly. The first heat exchanger 81 is configured to transfer heat from the working fluid W to the first fluid F1, such as water, of the first fluid line. The temperature of the first fluid F1 prior to entering the first heat exchanger 81 may be between 10-65 degrees Celsius. It is imaginable that the first fluid F1 is heated by the first heat exchanger 81 up to 65 degrees Celsius. In the shown embodiment, the first fluid line comprises a flow sensor or flow switch 46. The flow switch 46 is arranged upstream of the first heat exchanger 81. The flow switch 46 may be configured to monitor the flow rate and/or the pressure of the first fluid F1 in the first fluid line.

(18) Preferably, the flow switch 46 is configured to activate the first heat exchanger 81 when the first fluid F1 exceeds a predetermined flow rate. It is imaginable that a flow switch 46 is (also) provided in a second fluid line and/or in the working fluid line. In the shown embodiment, a water temperature sensor 131 is provided to measure the temperature of the first fluid F1. The shown temperature sensor 131 is provided downstream of the first heat exchanger 81. The temperature sensor 131 may be connected or connectable to the control unit 14, wherein the control unit 14 is configured to control the heat first exchanger 81 based upon the temperature detected by the temperature sensor 131. For example, if the measured temperature of the first fluid F1 measured by the temperature sensor 131 located upstream of the first heat exchanger 81 is below a threshold value the control unit may be configured to switch on one or multiple heating tubes 5 to (further) heat the first fluid F1 to a desired temperature.

(19) Downstream of the first heat exchanger 81, the heating system 1 of the shown embodiment comprises a second heat exchanger 82. Between the first heat exchanger 81 and the second heat exchanger 82 a temperature sensor 13 is provided to measure the temperature, and optionally to monitor a possible temperature decay. The second heat exchanger 82 comprises a first inlet 95 and a first outlet 96 configured to be connected to the working fluid line. The second heat exchanger 82 further comprises a second inlet 97 and a second outlet 98 connected or connectable to a second fluid line comprising a second fluid F2. Preferably, the second fluid line is a central heating water line comprising central heating water. The second heat exchanger 82 is configured to transfer heat from the working fluid W to the second fluid F2, such as water, of the second fluid line. The temperature of the second fluid F2 prior to entering the second heat exchanger 82 may be between 10-65 degrees Celsius. It is imaginable that the second fluid F2 is heated by the second heat exchanger 82 up to 65 degrees Celsius. The second fluid line further comprises a pump 39 configured to pump the second fluid F2 in the second heat exchanger 82. In the shown embodiment, a water temperature sensor 131 is provided to measure the temperature of the second fluid F2. The shown temperature sensor 131 is provided downstream of the second heat exchanger 82. The temperature sensor 131 may be connected or connectable to the control unit 14, wherein the control unit 14 is configured to control the second first exchanger 82 based upon the temperature detected by the temperature sensor 131. Additionally, a pressure sensor 141 may be provided in the second fluid line to measure the pressure of the second fluid F2. In case, for example, the measured pressure of the second fluid F2 is below a threshold value a signal is given by the control unit to refill the second fluid line with the second fluid F2. The shown pressure sensor 141 is provided downstream of the second heat exchanger 82. A temperature sensor 13 is present downstream of the second heat exchanger 82 and upstream of a storage container 30, to measure the temperature of the working fluid W, and optionally to monitor and optionally to monitor a possible temperature decay.

(20) The working fluid line further comprises a vent 45 configured to vent the working fluid line of air (bubbles) or gas (bubbles). The first fluid line and/or second fluid line may comprise a vent 45 configured to vent the first fluid line and/or the second fluid line of air (bubbles) or gas (bubbles).

(21) The shown heating system 1 further comprises a storage container 30, such as a buffer tank. The shown storage container 30 comprises a first inlet 31 for conducting the working fluid W to the storage container 30 and a first outlet 32 for discharging the working fluid W from the storage container 30. The storage container 30 is configured to store the heated working fluid W. The storage container 30 further comprises a second inlet 33 and a second outlet 35 connected or connectable to the first fluid line. A part of the first fluid line is guided through the storage container 30, in particular at least between the second inlet 33 and the second outlet 34 of the storage container 30. The shown storage container 30 is configured to preheat the first fluid F1 by transferring heat from the heated working fluid W to the first fluid F1. It is imaginable that the storage container 30 is configured to heat the first fluid F1 at least to approximately 10 degrees Celsius, preferably up to approximately 75 degrees Celsius. It is imaginable that the temperature of the working fluid W is maximal 95 degrees Celsius prior to entering the storage container 30. The temperature of the working fluid W may decrease to 10 degrees Celsius when discharged from the storage container 30, in particular after heat has been transferred to the first fluid F1. Optionally, the first fluid line guided through the storage container 30 comprises a coiled portion 35. The coiled portion 35 increases the length of the conduct part, and hence the heat transfer capacity from the working fluid W to the first fluid F1. The shown storage container 30 is provided upstream of the heat pump 2 and the heating tubes 5. The shown heating system 1 further comprises a second storage container 38 configured to store working fluid W. Additionally, the shown heating system 1 comprises a working fluid pump 40 configured to pump the working fluid W in the working fluid line.

(22) The above-described inventive concepts are illustrated by several illustrative embodiments. It is conceivable that individual inventive concepts may be applied without, in so doing, also applying other details of the described example. It is not necessary to elaborate on examples of all conceivable combinations of the above-described inventive concepts, as a person skilled in the art will understand numerous inventive concepts can be (re)combined in order to arrive at a specific application.

(23) It will be apparent that the invention is not limited to the working examples shown and described herein, but that numerous variants are possible within the scope of the attached claims that will be obvious to a person skilled in the art.

(24) The ordinal numbers used in this document, like first, second, third and fourth, are used only for identification purposes. Hence, the use of the expression third temperature does therefore not necessarily require the co-presence of a first temperature. The expression heating tube may be replaced by the expression auxiliary heat source.

(25) The verb comprise and conjugations thereof used in this patent publication are understood to mean not only comprise, but are also understood to mean the phrases contain, substantially consist of, formed by and conjugations thereof.