WO2012062992A1 - Boiler having a high performance factor - Google Patents

Abstract

The boiler (10) comprises a main circuit (22) for the flow of a main heat-transfer fluid, passing through heat exchange means (24) comprising at least a first heat pump (28), comprising a first evaporator (30) and a first condenser (32), and a second heat pump (36), comprising a second evaporator (38) and a second condenser (40). The main circuit (22) comprises a first inlet branch (44) for flow into the first evaporator (30) and a first outlet branch (46) for flow from the first evaporator (30). The intermediate circuit (26) comprises a first inlet branch (74) for flow into the first condenser (32) and a first outlet branch (76) for flow from the first condenser (32). The intermediate circuit (26) comprises a second inlet branch (82) for flow into the second evaporator (38) and a second outlet branch (84) for flow from the second evaporator (38). The main circuit (22) comprises a second inlet branch (48) for flow into the second condenser (40) and a second outlet branch (50) for flow from the second condenser (40).

Description

 Boiler with high coefficient of performance

 The present invention relates to a boiler with a high coefficient of performance. Such a boiler can be used for any type of application, for example for heating a room, a swimming pool or any type of liquid, for example domestic water.

 It is possible to provide a boiler, of the type comprising a first main heat-transfer liquid tank and a main circulation circuit of the main heat-transfer liquid, passing through heat exchange means.

 The invention particularly aims to improve such a boiler, in particular to optimize its coefficient of performance, that is to say the ratio between the amount of heat produced by the boiler and the electrical energy consumed.

 For this purpose, the subject of the invention is in particular a boiler, of the type comprising a main circuit for circulating a main heat transfer fluid, passing through heat exchange means, characterized in that the heat exchange means comprise at least one at least one first heat pump, comprising a first evaporator and a first condenser, and a second heat pump, comprising a second evaporator and a second condenser, such as:

 the main circulation circuit comprises a first input branch in the first evaporator, and a first output branch of the first evaporator,

 the intermediate circuit comprises a first input branch in the first condenser, and a first output branch of the first condenser,

 the intermediate circuit comprises a second input branch in the second evaporator, and a second output branch of the second evaporator, and

 the main circuit comprises a second input branch in the second condenser, and a second output branch of the second condenser.

 A boiler according to the invention may further comprise one or more of the following characteristics, taken alone or in any technically possible combination:

 the main circulation circuit comprises a junction formed downstream of the output branch of the first evaporator, from which extends a return branch connected to the input branch in this first evaporator,

 the intermediate circuit comprises a junction formed downstream of the output branch of the second evaporator, from which extends a return branch connected to the input branch in this second evaporator,

the main circuit comprises a first branch, formed downstream of the first outlet branch of the first evaporator, upstream of the second branch; entering the second condenser, and upstream of a first return branch, extending from the first branch to the first inlet branch of the first evaporator,

 the first branch is formed by a storage container, comprising an input connected to the first output branch of the first evaporator, a first output connected to the second input branch of the second condenser, and a second output connected to the first branch. back,

 the intermediate circuit comprises a second branch, formed downstream of the second outlet branch of the second evaporator, and upstream of a second return branch, extending from the second branch to the second branch of the second branch; second evaporator,

 the intermediate circuit comprises:

 a first circulation loop of a first intermediate heat transfer liquid, comprising the first inlet branch in the first condenser, the first outlet branch of the first condenser, and a second heat exchanger,

 a second circulation loop for a second intermediate heat transfer liquid, comprising the second inlet branch in the second evaporator, the second outlet branch of the second evaporator, and a second intermediate second heat transfer fluid tank, in which the second second heat exchanger,

 the second tank comprises a second tank outlet, connected to the second inlet branch of the second evaporator, and a second tank inlet, connected to the second branch,

 the intermediate circuit comprises a three-way valve, comprising:

 a first channel, connected to the second tank outlet,

 a second channel, connected to the second input branch of the second evaporator, and

 a third way, connected to the second branch of return,

the intermediate circuit comprising a temperature sensor, arranged to measure the temperature of the second intermediate heat liquid in the second input branch of the second evaporator, and valve control means as a function of the measured temperature,

the boiler comprising a first main heat-transfer liquid tank, comprising a first tank outlet, connected to the first inlet branch of the first evaporator, and a first tank inlet, connected to the second outlet branch of the second condenser,

 - the boiler comprising devices for circulating heat transfer liquids in the main and intermediate circuits, and a temperature sensor, arranged at the first tank outlet, connected to control means of the circulating devices and pumps to heat, suitable for activating circulation devices and heat pumps when the temperature measured by the sensor is below a first predetermined threshold, and suitable for deactivating circulation devices and heat pumps when the measured temperature by the sensor is greater than a second predetermined threshold, and

 the boiler comprising an external circuit for circulating an external heat-transfer liquid, comprising a first heat exchanger housed in the first tank, so as to exchange heat between the main heat-transfer liquid contained in the first tank and the external heat-transfer liquid .

 The invention will be better understood on reading the description which follows, given solely by way of example, and with reference to the single appended figure, schematically showing a boiler according to an exemplary embodiment of the invention. .

 There is shown in the single figure, a boiler 10 for cooperating with an external circuit 12 for circulating an external heat transfer liquid.

 Such an external circuit 12 is able to convey heat from the boiler 10 to a device for using this heat, comprising for example at least one radiator 14. For this purpose, the external circuit 12 comprises a device 16 of put into circulation, for example a circulation pump.

 In order to recover heat from the boiler, the external circuit 12 comprises a first heat exchanger 18, housed in a first tank 20 of the boiler 10. This first heat exchanger 18 may be of the serpentine, tubular, plate type, or can be any type of possible heat exchanger.

 The first vessel 20 comprises a main heat-transfer liquid, for example water, the heat of which is transferred to the external heat-transfer liquid via the first heat exchanger 18.

 The boiler 10 comprises a main circuit 22 for circulating the main heat transfer liquid, passing through means 24 of heat exchange, and an intermediate circuit 26 which will be described later.

 The heat exchange means 24 comprise a first heat pump

28 comprising a first evaporator 30 and a first condenser 32, connected by a heat pump circuit 34, typically comprising a compressor and a pressure reducer. Preferably, the first heat pump 28 has a power of 24 kW.

 The heat exchange means 24 also comprise a second heat pump 36, comprising a second evaporator 38 and a second condenser 40, interconnected by a second heat pump circuit 42, also comprising, in a conventional manner, a compressor and an expander . Preferably, the second heat pump 36 has a power of 12 kW.

 The main circuit 22 comprises a first branch 44 input into the first evaporator 30, and a first branch 46 output of the first evaporator 30. This main circuit 22 also comprises a second branch 48 input into the second condenser 40, and a second output branch 50 of the second condenser 40.

 Advantageously, a device 51 for circulating the main heat-transfer liquid in the main circuit 22, for example a circulation pump, is arranged on the second outlet branch 50 of the second condenser 40. For example, the circulation device 51 allows a circulation of the main coolant at a rate of

2m ³ / h.

 In addition, the first tank 20 has a first tank outlet 52, connected to the first inlet branch 44 of the first evaporator 30, and a first tank inlet 54, connected to the second outlet branch 50 of the second condenser 40.

 In addition, the main circuit 22 comprises a first branch 56, formed downstream of the first output branch 46 of the first evaporator 30, upstream of the second input branch 48 in the second condenser 40, and upstream of a first return branch 58, extending from the first branch 56 to the first branch 44 of the first evaporator 30.

 The first branch 56 is for example formed by a storage container 64, comprising an inlet 66 connected to the first outlet branch 46 of the first evaporator 30, a first outlet 68 connected to the second inlet branch 48 of the second condenser 40 and a second output 70 connected to the first return branch 58.

Thus, the main heat transfer fluid flowing in the first branch 46 of the first evaporator 30 splits, at the first branch 56, so as to flow to the second inlet branch 48 in the second condenser 40 and in the first branch return 58 to the first inlet branch 44 in the first evaporator 30. This first return branch 58 makes it possible to cool the main heat-transfer liquid in the first inlet branch 44 in the first evaporator 30, by mixing with the main heat-transfer liquid circulating in this first return branch 58. In fact, this main heat transfer liquid flowing in this first return branch 58, from the first output branch 46 of the first evaporator 30, has been cooled in this first evaporator 30, and therefore has a relatively low temperature.

 However, a heat pump is more effective than its cold source has a low temperature. The first return branch 58 makes it possible to lower the temperature of this cold source (formed by the first circuit, which exchanges heat with the evaporator), by re-injecting, at least in part, the coolant leaving the evaporator in the inlet branch in the evaporator. Indeed, because the heat transfer liquid gives heat to the evaporator, its temperature at the outlet of this evaporator is particularly low, so that this liquid can be used to cool that arriving at the inlet of the evaporator.

 The return branch 58 thus makes it possible to obtain a cold source whose temperature is particularly low, which makes it possible to improve its coefficient of performance, and thus to improve the coefficient of performance of the boiler.

In order to desirably distribute the main heat transfer liquid to the second inlet branch 48 in the second condenser 40 and to the return branch 58, the second inlet branch 48 in the second condenser 40 comprises a valve 60, and the return branch 58 comprises a device 61 for circulating the main coolant liquid, preferably a circulation pump 61 at a high flow rate. For example, the circulation device 61 allows circulation of the main coolant at a rate of 10 m ³ // i.

The valve 60 is set for a flow rate of 2m ³ / h, so that about 10% of the main heat transfer fluid flowing in the first output branch 46 of the first evaporator 30 is routed to the second input branch 48 of the second condenser 40.

 Advantageously, the first input branch 44 in the first evaporator

30 comprises, between the return branch 58 and the first tank outlet 52, a non-return valve 62, preventing the main heat-transfer liquid coming from the return branch 58 from flowing back towards the first tank 20.

Furthermore, the intermediate circuit 26 includes a first loop 72 for circulating a first intermediate heat transfer fluid, for example water, comprising a first input branch 74 in the first condenser 32, a first output branch 76 of the first condenser 32 and a second heat exchanger 78. Advantageously, a device 79 for circulating the heat transfer liquid in the first loop 72, for example a circulation pump, is arranged on the first branch of input 74 in the first condenser 32. For example, the circulation device 79 allows a circulation of the first intermediate heat transfer liquid at a flow rate of 6m ³ / h.

 The intermediate circuit 26 also comprises a second circulation loop 80 of a second intermediate heat transfer liquid, for example water, comprising a second inlet branch 82 in the second evaporator 38, a second outlet branch 84 of the second evaporator 38 and a second tank 86 of second intermediate heat transfer fluid, in which is housed the second heat exchanger 78, so that the first intermediate heat transfer fluid gives heat to the second intermediate heat transfer liquid contained in the second tank 86.

 Advantageously, a device 87 for circulating the coolant in the second loop 80, for example a circulation pump, is arranged on the second inlet branch 82 in the second evaporator 38.

 The second loop 80 comprises a second branch 88, formed downstream of the second outlet branch 84 of the second evaporator 38, and upstream of a second return branch 90, extending from this second branch 88 to the second input branch 82 of the second evaporator 38. Thus, the second low-temperature intermediate heat transfer liquid flowing in the second outlet branch 84 of the second evaporator 38 is capable of being reinjected into the second inlet branch 82 in the second evaporator 38, in order to reduce the temperature of the second intermediate heat transfer fluid circulating therein.

 For this purpose, the second loop 80 comprises a three-way valve 92 comprising a first channel 92A connected to a second tank outlet 94 of the second tank 86, a second channel 92B connected to the second inlet branch 82 of the second evaporator 38, and a third path 92C connected to the second return branch 90.

 A temperature sensor 96 is arranged in the second input branch 82 of the second evaporator 38 to measure the temperature of the second intermediate heat liquid. This temperature sensor 96 is connected to means 98 for controlling the valve 92 as a function of the measured temperature, making it possible to modulate the temperature in the second input branch 82 of the second evaporator 38 by regulating the flow rates of the first 92A and second 92B channels of the valve 92.

It will be noted that the second tank 86 also comprises a second tank inlet 100, connected to the second branch 88, so that the second liquid intermediate coolant from the second branch 84 output of the second evaporator 38 which is not reinjected into the second input branch 82 of the second evaporator 38, supplies the second tank 86.

 Advantageously, the main circuit 22 and the intermediate circuit 26 of circulation comprise expansion vessels of conventional type, to compensate for the expansion of heat transfer liquids as a function of their temperature.

 For example, an expansion vessel 102 is arranged on the second inlet branch 48 of the second condenser 40, an expansion vessel 104 is arranged on the first outlet branch 72 of the first condenser 32, and an expansion vessel 106 is arranged on the second loop 80, between the second branch 88 and the second tank inlet 100.

 In order to maintain the main heat transfer liquid in the first tank 20 at a substantially constant temperature, the boiler 10 comprises a temperature sensor 108 connected to means 10 for controlling the circulation devices 51, 61, 79, 87 and heat pumps 28, 36, adapted to activate these devices circulating 51, 61, 79, 87 and these heat pumps 28, 36 when the temperature measured by the sensor 108 is less than a first predetermined threshold, and suitable for deactivating the circulation devices 51, 61, 79, 87 and the heat pumps 28, 36 when the temperature measured by the sensor 108 is greater than a second predetermined threshold.

 In the following, we will describe an example of operation of the boiler 10. In order to obtain a temperature of about 55 ° C in the external heat-transfer liquid, it is expected to implement the boiler 10 to obtain a temperature of about 60 ° C of the main coolant in the first tank 20.

 For this purpose, the first predetermined temperature threshold at the sensor 108 is

58 ° C and the second predetermined temperature threshold at this sensor 108 is 60 'Ό.

 When the temperature at the sensor 108 is less than δδ'Ό, for example equal to 55 ° C, the boiler 10 is turned on.

In order to cool the temperature in the first inlet branch 44 of the first evaporator 30, main heat transfer liquid from the first outlet branch 46 of the first evaporator 30 is reinjected into the first inlet branch 44 of the first evaporator 30. through the first return branch 58. Thus, a temperature of 25 ^ is obtained for the main heat transfer liquid flowing in the first inlet branch 44 of the first evaporator 30, and a temperature of Ι Ο'Ό for the heat transfer fluid main circulating in the first output branch 46 of the first evaporator 30. This main heat transfer liquid at 10 ° C. is then conveyed to the second input branch 48 of the second condenser 40, where it recovers heat from the second heat pump 36 to obtain a temperature of 60 ° C. in the second 50 outlet branch of the second condenser 40. This main coolant at 60 ° C is then conveyed to the first tank 20.

 In the intermediate circuit 26, the first intermediate heat transfer fluid flowing in the first outlet branch 76 of the first condenser 32 has a temperature of 40 ° before supplying heat to the second intermediate heat transfer fluid contained in the second tank 86.

The valve 92 is controlled by the control means 98 so as to provide a temperature of about 9 ^<C in the second inlet leg 82 of the second evaporator 38. To this end, at least a portion of the second intermediate heat transfer liquid circulating in the second output branch 84 of the second evaporator 38, cools to a temperature of δ'C, and is re-injected to the valve 92 so as to be mixed with the second intermediate heat transfer fluid from the second tank 86.

 It appears that the coefficient of performance of such a boiler 10 is particularly high. In the example shown, this coefficient of performance is 4.7 for a temperature of 60 ° C of the main coolant in the first tank 20.

 Note that the invention is not limited to the embodiment described above and could have various variants without departing from the scope of the claims.

 One could also imagine a boiler with no return branch, comprising a main circuit passing in series by the evaporator of a first heat pump and the condenser of a second heat pump.

 Optionally, such a boiler could comprise an intermediate circuit passing in series through the condenser of the first heat pump, and by the evaporator of the second heat pump.

Claims

1. Boiler (10), of the type comprising a main circuit (22) for circulating a main heat transfer liquid, passing through heat exchange means (24), characterized in that the heat exchange means (24) comprise at least one at least one first heat pump (28), comprising a first evaporator (30) and a first condenser (32), and a second heat pump (36), comprising a second evaporator (38) and a second condenser (40), as :  the main circulation circuit (22) comprises a first input branch (44) in the first evaporator (30), and a first output branch (46) of the first evaporator (30),  the intermediate circuit (26) comprises a first input branch (74) in the first condenser (32), and a first output branch (76) of the first condenser (32),  the intermediate circuit (26) has a second input branch (82) in the second evaporator (38), and a second output branch (84) of the second evaporator (38), and  the main circuit (22) comprises a second input branch (48) in the second condenser (40), and a second output branch (50) of the second condenser (40).  The boiler (10) according to claim 1, wherein:  the main circulation circuit (22) comprises a branch (56) arranged downstream of the output branch (46) of the first evaporator (30), from which extends a return branch (58) connected to the branch inlet (44) in this first evaporator (30), and / or  - the intermediate circuit (26) comprises a branch (88) formed downstream of the output branch (84) of the second evaporator (38), from which extends a return branch (90) connected to the input branch (82) in this second evaporator (38).  3. Boiler (10) according to claim 1 or 2, wherein the main circuit (22) comprises a first branch (56), formed downstream of the first outlet branch (46) of the first evaporator (30), upstream the second input branch (48) in the second condenser (40), and upstream of a first return branch (58), extending from the first branch (56) to the first branch of inlet (44) of the first evaporator (30).  4. Boiler (10) according to claim 3, wherein the first branch (56) is formed by a storage container (64) including an inlet (66) connected to the first output branch (46) of the first evaporator (30), a first output (68) connected to the second input branch (48) of the second condenser (40), and a second output (70) connected to the first branch back (58).  Boiler (10) according to any one of the preceding claims, wherein the intermediate circuit (26) comprises a second branch (88), formed downstream of the second outlet branch (84) of the second evaporator (38), and upstream of a second return branch (90), extending from the second branch (88) to the second inlet branch (82) of the second evaporator (38).  The boiler (10) according to any one of the preceding claims, wherein the intermediate circuit (26) comprises:  a first loop (72) for circulating a first intermediate heat transfer fluid, comprising the first input branch (74) in the first condenser (32), the first output branch (76) of the first condenser (32), and a second heat exchanger (78),  a second loop (80) for circulating a second intermediate heat transfer fluid, comprising the second input branch (82) in the second evaporator (38), the second output branch (84) of the second evaporator (38), and a second tank (86) of second intermediate heat transfer fluid, in which is housed the second heat exchanger (78).  The boiler (10) according to claims 5 and 6 taken in combination, wherein the second vessel (86) has a second vessel outlet (94) connected to the second inlet branch (82) of the second evaporator (38). ), and a second tank inlet (100) connected to the second branch (88).  Boiler (10) according to claim 7, wherein the intermediate circuit (26) comprises a three-way valve (92) comprising:  a first channel (92A), connected to the second tank outlet (94),  a second path (92B), connected to the second input branch (82) of the second evaporator (38), and  a third channel (92C), connected to the second return branch (90), the intermediate circuit (26) having a temperature sensor (96) arranged to measure the temperature of the second intermediate heat liquid in the second input branch (82) of the second evaporator (38), and control means (98) of the valve (92) as a function of the measured temperature. Boiler (10) according to any one of the preceding claims, comprising a first main heat transfer liquid tank (20), comprising a first tank outlet (52), connected to the first inlet branch (44) of the first evaporator (30), and a first vessel inlet (54) connected to the second outlet branch (50) of the second condenser (40).  10. Boiler (10) according to claim 9, comprising devices (51, 61, 79, 87) for circulating heat transfer liquids in the main (22) and intermediate (26) circuits, and a temperature sensor (108). ), arranged at the first vessel outlet (52), connected to means (1 10) for controlling circulation devices (51, 61, 79, 87) and heat pumps (28; activating the circulation devices (51, 61, 79, 87) and the heat pumps (28; 36) when the temperature measured by the sensor (108) is lower than a first predetermined threshold, and capable of deactivating the circulation devices (51, 61, 79, 87) and the heat pumps (28; 36) when the temperature measured by the sensor (108) is greater than a second predetermined threshold.  1 1. Boiler (10) according to claim 9 or 10, comprising an outer circuit (12) for circulating an external heat-transfer liquid, comprising a first heat exchanger (18) housed in the first tank (20), so as to exchange heat the heat between the main coolant contained in the first tank (20) and the external coolant.