Abstract:
A method indicates to a user the fuel consumption and/or efficiency of a heating installation having a heat pump with a thermal compressor, a heating fluid distribution circuit and radiators receiving a first quantity of energy Q 1.  The method includes the steps: A- of determining, over a predetermined time period a second quantity of energy Q 2,  corresponding to the supply of heat energy used to drive the compressor, B- of determining, over the same predetermined time period, a third quantity of energy Q 3  corresponding to free energy taken from the external environment, C- of displaying the quantities Q 2  and Q 3,  in relation to the predetermined time period, on a display screen and/or in a document for invoicing the customer.

Description:
BACKGROUND 
       [0001]    1. Technical Field 
         [0002]    The present invention relates to heating units and to methods and devices for indicating the consumption and/or efficiency of said heating units. 
         [0003]    More specifically it concerns a heating unit comprising at least one heat pump, a circuit for heating fluid distribution and a plurality of convectors or radiators. 
       DESCRIPTION OF THE RELATED ART 
       [0004]    From the prior art it is known to determine a performance factor (or efficiency factor) for the heat pump in question, in particular the devices using an electric compressor. However, the efficiency factor of such a unit depends on climatic conditions, in particular the outside temperature of the environment in which the calories are gathered. In practice, it is common to add a backup heating device to take over for the heat pump in order to get through cold critical periods. 
         [0005]    But in the known art, the user of such a heating unit has few means for comparing the actual performance compared to the stated performance and for verifying that the expected savings from the heat pump system are materialized as actual savings. In particular, the user (the payer) cannot deduce from their electricity bill the savings that they got from the heat pump and has no information on the ecological footprint of their unit. 
       BRIEF SUMMARY 
       [0006]    It thus appears attractive to improve the information made available to the paying user concerning the heating unit, the energy performance thereof and the economic and ecological relevance thereof. 
         [0007]    According to the present invention, a method for indicating the consumption and/or efficiency of a heating unit to the user is proposed, where said heating unit includes at least one heat pump with a thermal compressor driven by means of a thermal energy feed, a heating fluid distribution circuit and a plurality of convectors or radiators receiving a first energy quantity Q 1 , 
         [0008]    where the method comprises at least: 
         [0009]    determining, over a preset time period, a second energy quantity Q 2 , corresponding to said thermal energy feed and comprising a billed energy Q 2 F corresponding to a billable quantity of fuel consumed by the heat pump, 
         [0010]    determining, over the same preset time period, a third energy quantity Q 3  corresponding to a free energy gathered in the outside environment, either (B1-) directly by means of temperature and flow-rate sensors relative to an outside unit of the heat pump, or (B2-) indirectly by measuring, over the same preset time period, the first energy quantity Q 1  supplied to the distribution circuit and deducing Q 3  from it by using Q 3 =Q 1 −Q 2 , 
         [0011]    displaying at least the quantities Q 2 F and Q 3 , corresponding to the preset time period, on the display screen and/or a document intended for billing the client. 
         [0012]    Because of these arrangements, the various energy quantities put to use for the heating unit can be measured and this information can be made available to the user, in particular to the user in charge of paying the energy bill for the billed fuel. The user can thus get useful information on the economic and ecological performance of their heating unit. The determination of this information can be relative to a cumulative metering (meaning integration) over one or more preset periods. 
         [0013]    Additionally note that the thermal compressor mainly uses the heating fluid distribution circuit as the cold source; thereby all the calories which are made available for operating the thermal compressor can be delivered in the heating fluid distribution circuit; since no calories are dissipated (and therefore lost) in any auxiliary cooling circuit. 
         [0014]    In various embodiments of the method according to the invention, one and/or another of the following arrangements could furthermore be used: 
         [0015]    According to an aspect, the thermal energy feed is mainly provided by means of a combustible burner; by this means the electric grid is not called on to provide the calories moving the compressor; 
         [0016]    According to another aspect, the combustible is gas and the billed consumption is measured by means of a gas meter; thereby this means a very common combustible is used and the consumption of this combustible can be easily known; 
         [0017]    According to another aspect, the combustible is domestic fuel oil and the billed consumption is measured by means of a fuel oil meter; thereby this means this very common combustible is used and the consumption of this combustible can be easily known; 
         [0018]    According to another aspect, the combustible is wood pellets and the billed consumption is measured by means of a meter, for example by weighing; thereby this means a renewable combustible is used and the consumption of this combustible can be easily known. 
         [0019]    According to another aspect, the first energy quantity Q 1  supplied to the distribution circuit is measured by means of first and second temperature sensors respectively arranged on the outbound and on the return of the distribution circuit and by means of a heating fluid flow-rate sensor; by this means reliable information is obtained about the first energy quantity Q 1 ; 
         [0020]    According to another aspect, a financial equivalent for the nonbillable energy quantities is additionally displayed, specifically for the energy quantity Q 3 , and if relevant/appropriate for the energy quantity Q 2 NF, knowing that Q 3 +Q 2 NF is equal to Q 1 −Q 2 F; by this means the user can directly know the savings achieved through the performance of their heating unit; 
         [0021]    According to another aspect, the heat pump does not have an electric pump and the electric consumption of the heating unit is far below Q 1 , for example less than 10% of Q 1 nom, where Q 1 nom corresponds to the nominal power of the heating unit; such that the heating unit places very little demand for electric energy. 
         [0022]    The invention additionally targets a device for indicating the consumption and/or efficiency of a heating unit, said heating unit including at least one heat pump having a thermal compressor moved by means of a thermal energy feed, a heating fluid distribution circuit and a plurality of convectors or radiators, where the device comprises: 
         [0023]    means for determining a first energy quantity Q 1  provided to the convectors or radiators, or means for determining the energy quantity Q 3  corresponding to free energy collected in the outside environment; 
         [0024]    means for determining the quantity of energy corresponding to a billed consumption (Q 2 , Q 2 F) of combustible consumed by the heat pump, 
         [0025]    an electronic unit to which the means for determining the energy quantities Q 3 , Q 2  are connected, 
         [0026]    characterized in that this electronic unit is adapted for calculating energy quantities (Q 2 , Q 3 ) over a preset time period, and/or for displaying this information on a display screen, and/or for preparing printing of a document intended for billing the client. 
         [0027]    In various embodiments of the device according to the invention, one and/or another of the following arrangements could furthermore be used: 
         [0028]    According to an aspect, the thermal energy feed is mainly done by means of a combustible burner, where the combustible is preferably gas, domestic fuel oil or wood pellets, where the billed consumption Q 2 F is measured by means of the gas, fuel oil or other meter; by means of which a very common combustible is used and reliable information about the billable energy quantity Q 2 F is obtained; 
         [0029]    According to another aspect, the device can furthermore include temperature and flow-rate sensors for a unit outside the heat pump in order to measure the energy quantity Q 3  corresponding to a free energy gathered in the outside environment; such that the measurement of the third energy quantity Q 3  can be obtained directly and reliably; 
         [0030]    According to another aspect, the device can furthermore comprise temperature and flow-rate sensors relative to the heating distribution circuit in order to measure the energy quantity Q 1  provided to the heating distribution circuit; such that the measurement of the first energy quantity Q 1  can be obtained directly and reliably; 
         [0031]    According to another aspect, the heat pump does not have an electric pump and the electric consumption of the heating unit is far below Q 1 , for example less than 10% of Q 1 nom, where Q 1 nom corresponds to the nominal power of the heating unit; such that the heating unit has very little demand for electric energy. 
     
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
         [0032]    Other aspects, goals and advantages of the invention will appear upon reading the following description of two embodiments thereof given as nonlimiting examples with the help of the attached drawings in which: 
           [0033]      FIG. 1  shows a schematic drawing of a heating unit according to an embodiment of the invention; 
           [0034]      FIG. 2  schematically shows an electronic unit and the peripherals thereof used in the unit from  FIG. 1 ; and 
           [0035]      FIG. 3  shows a sample bill illustrating the information made available to the user. 
       
    
    
       [0036]    In the various figures, the same references designate identical or similar items. 
       DETAILED DESCRIPTION 
       [0037]      FIG. 1  schematically shows a heating unit including a heating fluid distribution circuit  2 , where the fluid delivers calories to a plurality of receivers-exchangers, of convective or radiative type  20  as known in the state-of-the-art. 
         [0038]    In the shown example, the fluid can be water or an aqueous solution, but the use of air or another fluid for the distribution circuit is not excluded. The receivers-exchangers can take the form of a radiant floor, conventional wall heating radiators or any other type of exchangers serving to deliver calories to the inside of a building  5 . The building in question can be an individual house, a shared use building, an industrial building or any other type of room requiring a heating unit. The distribution circuit can also serve several buildings or several rooms. The distribution circuit is a closed circuit; a circulating pump  22  also called ‘circulator’  22  delivers a closed loop flow-rate to the heating fluid. The distribution circuit can supply private or community swimming pools. The distribution circuit can supply industrial processes requiring heat or cold feeds. 
         [0039]    The distribution circuit  2  is thermally coupled to a heat pump device  1 . This heat pump device  1 , also more simply called “heat pump” includes a heat-transfer fluid circuit  3  (also sometimes called refrigerant fluid). In the example shown here, carbon dioxide (CO 2 ) is preferably selected as the heat-transfer fluid, but any other compressible fluid suitable to a heat pump circuit can be selected. 
         [0040]    The amount of calories provided to the distribution circuit and the various radiators and convectors will be called the first energy quantity Q 1  in the remainder of this document. 
         [0041]    The heat pump device  1  includes an inside exchanger  11 , an outside exchanger  12 , a pump assembly  10  comprising a compressor  14 , and an expansion valve  17 . 
         [0042]    The outside exchanger  12  allows heat-transfer fluid  3  to receive calories coming from the outside environment, in a well-known manner, for example from the outside air, a geothermal circuit, a waterway or any other element from which calories can be collected. 
         [0043]    The inside exchanger  11  allows the heat-transfer fluid  3  to release calories to the aforementioned heating circuit  2  in a well-known manner. 
         [0044]    The expansion valve  17  is also a well-known component and is therefore not described in detail here. 
         [0045]    The compressor  14  is a “thermal” compressor. A “thermal” compressor is a compressor moved by means of a thermal energy feed, like for example a compressor described in U.S. Patent Publication No. 2013/0323102. A compressor driven by a gas engine or a compression machine operating by heat absorption can also be called a “thermal” compressor. 
         [0046]    Under these conditions, there is no electric compressor in the pump assembly  10  of the heat pump; the energy is mainly fed in thermal form; a negligible quantity of electrical energy can however be used for accessories or the instrumentation. The thermal energy feed for driving the compressor can be produced by various means and serves to feed a quantity of energy called second energy quantity Q 2  to the pump assembly  10  and in particular to the compressor  14 . The thermal feed can come from the combustion of a fossil fuel like gas, fuel oil or any other similar combustible; this energy supply will be noted by Q 2 A. 
         [0047]    The thermal feed can additionally come from the combustion of a renewable combustible like wood  51 , for example wood pellets or granules, biogas, dried vegetal material or even waste of every type that can be burned; this energy feed coming from renewable combustibles will be noted Q 2 B. “Free” waste effluents from industrial process(es) can also be burned. 
         [0048]    Finally, the thermal feed can come additionally from the combustionless energy source like for example a solar collector  52 . This combustionless energy feed will be noted Q 2 C. Energy can also be recovered from hot graywater intended for the drain as an additional energy feed. 
         [0049]    Thus the total thermal feed to the entire pump can be expressed in the form Q 2 =Q 2 A+Q 2 B+Q 2 C. It should be noted that in a simple sample implementation, only the gas fossil combustible source will be called on; in which case the formula will be Q 2 =Q 2 A. 
         [0050]    Additionally, the thermal feed can be expressed in the form Q 2 =Q 2 F+Q 2 NF, where Q 2 F is the part of the thermal feed which is billable and therefore to be paid by the user, whereas Q 2 NF designates the part of the thermal feed which is not billable, like the solar energy or the combustion of effluents available from burning (case of an industrial building with collective heating). 
         [0051]    Q 2 F includes the portion Q 2 A and all or part of the portion Q 2 B. 
         [0052]    Concerning the feed coming from the fossil combustible, this is burned in the burner  15  supplied by a channel on which is disposed a meter or flow-rate meter D 2 . 
         [0053]    As is known in the art, the quantity of energy supplied to the heating circuit Q 1  can be written as the sum of the energy feed Q 2  fed to the pump assembly  10  and a quantity of “free” energy called third energy quantity, noted Q 3 , and collected in the outside environment by means of the aforementioned outside unit  12 . 
         [0054]    In other words: Q 1 =Q 2 +Q 3 . In established regime, P 1 =P 2 +P 3  can be written if P 1 , P 2 , P 3  are instantaneous powers corresponding to the energy quantities Q 1 , Q 2 , Q 3 . 
         [0055]    The second energy quantity Q 2  can be determined by means of the already mentioned flow-rate meter or meter D 2 . In the case of a conventional meter, the integration over time is already done and it will suffice, in particular for an electronic meter, to take the difference between the value at an end of period moment and the value at the beginning of period moment. 
         [0056]    It needs to be noted that a portion of Q 2  is transferred directly to the fluid of the heating circuit by means of one or more exchangers  26  which serve to cool the compressor  14  using the heating fluid whose temperature generally does not exceed 80° C. No calorie fed for operating the pump assembly  10  is thus lost; advantageously the system does not have a cooling device which removes calories from the pump assembly anywhere else than in the heat-transfer fluid. The calculations done are that way even more accurate. 
         [0057]    The energy quantity Q 3  can for its part be determined directly or indirectly. 
         [0058]    The direct method calls both on temperature sensors T 3 , T 4  preferably disposed at the terminals of the outside unit  12  of the heat pump and also a measurement of the flow-rate D 3  of the heat-transfer fluid  3 . 
         [0059]    Starting from the instantaneous expression P 3 =D 3  ×(T 3 −T 4 ), one integrates over time as follows: 
         [0000]        Q 3=∫[ D 3×( T 3− T 4)] dt over a period of time considered.
 
         [0060]    The indirect method consists of first determining the first energy quantity Q 1  by means of temperature sensor T 1  and T 2  disposed respectively on the heating fluid leaving and returning to the inside unit  11  of the heat pump and also information about heat-transfer fluid flow-rate D 1 . 
         [0061]    One can write the following equations: 
         [0000]        P 1= D 1×( T 1− T 2)
 
         [0000]        Q 1=∫[ D 1×( T 1− T 2)]dt over a given period of time.
 
         [0062]    After having determined the first energy quantity Q 1 , the third energy quantity Q 3  collected in the outside environment can be determined from Q 1  by knowing the second energy quantity Q 2  over the same given time, by using the formula: 
         [0000]        Q 3= Q 1− Q 2.
 
         [0063]    Advantageously according to the invention, using the energy quantities Q 2  and Q 3  is proposed for quantifying the performance of the heating unit. 
         [0064]    More precisely, and as it emerges from  FIGS. 1 and 2 , an electronic unit  8  is provided to which are connected the means for determining the second energy quantity Q 2  and either the means for determining directly the third energy quantity Q 3  or the means for first determining the first energy quantity Q 1  and deducing from it the third energy quantity Q 3 . 
         [0065]    Additionally, a display screen  19  is optionally provided on which can be displayed, on the one hand one or more time periods corresponding to the calculations of the second and third energy quantities Q 2 , Q 3  over said time periods and on the other hand the values in kilowatt hours of the second and third energy quantities Q 2  and Q 3  for each time period. The time periods in question can for example be a week, month, quarter, heating season, half-year and full-year. 
         [0066]    Referring to  FIG. 2 , the electronic unit  8  includes a first functional calculation module  41 , optional, handling determination of the first energy quantity Q 1  by means of the temperature T 1 , T 2  and flow-rate D 1  information and does so over a preset time period. 
         [0067]    Additionally the electronic unit  8  includes the second functional calculation module  42  handling determination of the second energy quantity Q 2  by means of the meter information D 2  and does so over the same preset time period. In case of a single number, the billable quantity is obtained directly from a single meter D 2 , because in this case Q 2 F=Q 2 . 
         [0068]    Additionally, the electronic unit  8  includes (optionally as an alternative to the first calculation module  41 ) a third functional calculation module  43 , optional, handling determination of the third energy quantity Q 3  from temperature T 3 , T 4  and flow-rate D 3  information and does so over the same preset time period. 
         [0069]    A summary calculation module  6  formulates the energy quantities Q 2 F and Q 3  in order to make them available for display and/or printing as will be detailed later. The summary calculation module  6  furthermore calculates as necessary an efficiency factor Q 1 /Q 2  (or Q 1 /Q 2 F instead if additional means of thermal feed are used) similar to a heat pump performance factor known in the art. 
         [0070]    The control unit  8  thus prepares a set of information meant for local display and made available for any remote electronic equipment, where the set of information contains once or several times: 
         [0071]    The preset time period, 
         [0072]    The billable second energy quantity Q 2 F, and also as applicable the financial equivalent thereof representing the cost thereof if the information is available locally; 
         [0073]    The third energy quantity Q 3 , and optionally, and if the equivalent cost information is available locally, the financial equivalent of this third energy quantity Q 3  representing the savings achieved through the presence of the heat pump. As applicable, Q 3  can be supplemented by Q 2 NF (“free” portion of the thermal feed Q 2 ). 
         [0074]    After transmission to electronic equipment or a computer, this information can be printed in the form of a bill  9 , an example of which is shown in  FIG. 3 . 
         [0075]    It should be noted the position of the temperature sensors T 1  to T 4  and the flow-rate sensors D 1 , D 2 , D 3  can vary from the position shown in the example illustrated. 
         [0076]    The circulating pump  22  can be driven by an electric motor, but it is appropriate to note that the total electric consumption of the heating unit, even including this electric consumption by the circulating pump  22  remains much less than the energy quantity Q 1  provided to the heating distribution circuit, in particular less than 10% of Q 1 nom, were Q 1 nom corresponds to the nominal power of the heating unit.