FR2539853A1 - SYSTEM FOR PRODUCING A HEATED FLUID BY RECOVERING THE CALORIES OF A REFRIGERANT - Google Patents

Abstract

1. Apparatus for producing a heated liquid, such as water supplying apparatus which consumes this liquid such as a warming tank (1), in which the liquid is heated by recycling at least the superheating heat from the vapour of a refrigerant which, to this end, after emerging from the compressor (5) and before returning to the condenser (7) of refrigerating apparatus (2) is diverted towards a main heating station (28) which contributes to the raising of the temperature of the liquid to be heated, which is tapped from at least one source (36) then heated and stored in a reservoir (43) before being sent to the apparatus (1) which consumes it via a distribution means (34) and/or being sent to the entrance to the main station (28) via a channel (44) by passing through a circulator (47), the apparatus for producing a heated liquid being characterised in that : - on the route taken by the liquid to be heated, the apparatus comprises, in addition to the main heating station (28) and upstream therefrom, a pre-heating station (18) comprising a supplementary exchanger (14) which, on the route of the vapours of the refrigerant, is mounted in series with the exchanger (13) of the main heating station (28) ; - the source (36) which re-supplies the apparatus with liquid to be heated is connected to the entrance of the pre-heating station (18) ; - in order to control the divertion of the refrigerant liquid towards at least one of the primary exchangers of the main heating station and the pre-heating station, a plurality of solenoid valves (15, 16) are provided ; - each of the exchangers (13, 14) known as primary, because they are passed through by the refrigerant liquid, penetrates into an enclosure (17, 18) which receives a certain volume of liquid (19, 20) such as water which is only an intermedary liquid between the refrigerant liquid and the liquid to be heated, the apparatus also comprising for the route of this liquid two secondary exchangers (21, 22) which, to this end, also penetrate respectively into one of the enclosures (17, 18).

Description

The invention relates to an installation of

  producing a fluid, such as water, which is heated by recovering at least the heat of overheating of the vapor of a refrigerant before it returns to the condenser of a refrigeration plant.

  In fact, it is common for a simultaneous

  heating needs, including water, and

refrigeration of products.

  For example, in a poultry slaughterhouse, prior to a phase during which the said poultry are plucked, they must generally be immersed in a scalding tank filled with water at about fifty-one degrees Celsius, whereas after this phase during which they will have been plucked, these birds will otherwise have to be frozen, at least

  up to about three degrees Celsius above zero.

  So, should such a slaughterhouse have so much

  refrigeration systems for cooling poultry-

  scalding water heating installations which water, for obvious health reasons, has to

more to be constantly renewed.

  When such refrigeration and heating needs are

  fage occur simultaneously, it seems advantageous to

  use the heat extracted from the chilled products in the refrigeration plant to heat the water

the heating system.

  In conventional refrigeration plants,

  the extraction of heat from the products takes place

  refrigerant medium that by vaporizing at low temperature in an evaporator, absorbs the heat available in the enclosure housing the cooled products and the evaporator. After its complete vaporization, the refrigerant is then, by a compressor, brought to a relatively high pressure ensuring its circulation and secondarily its reheating, after which the compressed gas obtained is brought to a condenser in which, by condensation, the refrigerant restores at least part of its heat to an agent

cooler such air.

  Obviously, when cooling, the refrigerant returns from the gaseous state to the liquid state and can then, after passing through a pressure reducer, be returned to the evaporator for a new circuit. From such a conventional installation, it is already known to recover the heat thus extracted by the vaporization of the refrigerant, and this, acting either upstream of the condenser or during its passage in the condenser

(FR-A-2,346,644).

  Obviously, on the one hand, the operating cycle of the refrigerating plant and that of the hot water demands do not necessarily match and, on the other hand, the refrigerating plant can not be stopped or switched on depending on only heating requirements; Also, to fill the deficiencies of the possibilities of recovery, conventional means of auxiliary heating are generally necessary but, if not cancel, at least strongly limit the use, such a supplementary heating on the cost price, the installation of

  recovery must be sufficiently effective.

  For this, such a facility for producing hot water by recovery must be effective: both in terms of recovery means that must be able to take a maximum of heat but not too much not to interfere with the operation of the condenser, for example, by a refrigerant precondensation, only in terms of means to store hot water

while keeping him warm.

  In addition, the installation must also be able to respond rapidly to a very important need for hot water and in all cases to provide water of quality and in particular safe from any contamination by the refrigerant

  even in the event of a failure such as a leak in his circuit.

  A result that the invention aims to obtain is an installation that allows to take a maximum of heat but not too much not to interfere with the proper operation of the condenser and store hot water while retaining

its heat.

  Another result that the invention aims to achieve is an installation that can quickly respond to a very important need for hot water and provide in all cases a quality water and in particular safe from any

refrigerant contamination -

  For this purpose, it relates to an installation of the type mentioned above, characterized in that, at the outlet of the storage tank, is connected a pipe of

  return of water to the entrance of the exchanger.

  It will be well understood using the description

  BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1: an overview of the installation, FIG. 2: a perspective view of the main heat exchanger,

  Figure 3 a sectional view of an annex exchanger.

  Referring to the drawing, we see that the facility serves at least one equipment 1 consuming hot water,

  such as a scalding tank, and at least one production equipment 2

  cooling, such as a refrigerator, by evaporation

  refrigerant in an evaporator 3.

  In known manner, at the outlet of the evaporator, the vapors are led through a pipe 4 to a

  compressor 5 which carries them at relatively high pressure.

  After possible passage in a deshui them, the compressed gas is, by a pipe 6, brought to a condenser 7 in which, by condensation it restores at least a part

  from its heat to a coolant 8 such as air.

  From the gaseous state, the refrigerant returns to the liquid state and a pipe 9 then leads it to an expansion valve before a pipe 11 returns to

  the evaporator 3 for a new circuit.

  So that the water 12 supplied to the scalding tank 1 is heated by recovering the heat of superheating of the vapor of the refrigerant which normally flows from the compressor 5 to the condenser 7 through the pipe

  6, this steam is diverted to at least the main heat exchanger

  13 in series with which is mounted an annex exchanger 14.

  This diversion takes place under the control of

15, 16.

  Each exchanger 13, 14 enters an enclosure 17, 18 which is filled with a certain volume of an intermediate fluid 19, 20, such as water, which in a closed circuit, is set in motion so that after having passed through the exchanger 13, 14, traversed by the refrigerant vapor, this intermediate fluid can pass through a secondary heat exchanger 21, 22 which, for this purpose, also enters the enclosure 17, 18 above and which, meanwhile, is traversed by the fluid to be heated, as in the example shown,

  the water that will feed the tank scald 1.

  Thanks to this arrangement, even in the event of refrigerant leakage, it could only mix with the intermediate fluid. The disturbance that would then result in the refrigerating machine would be immediately detected and the leak could therefore always be repaired before the secondary exchanger is itself attacked and that the fluid

to heat is contaminated.

  Obviously, in the case where the final fluid is not

  not - "food", the use of intermediate fluid to-

  should be neglected and this would reduce the cost price.

  Thanks to the closed-circuit circulation of the intermediate fluid, it is already a hot fluid that flows back to the main exchanger or annex 13, 14 and, as a result,

  fluid quickly reaches a high temperature.

  In addition, this fluid deposits once for all its cal-

  because of this, there is no reason to fear

  disadvantages related to scaling.

  The setting in motion of the intermediate fluid can be

  by natural convection or by a circulating pump.

  23 intercalated in a return circuit of the

secondary changer 21.

  The main exchanger 13 (FIG. 2) is advantageously composed of several elements 25 each housed in the bottom of

  one of the cells 26-present for this purpose the enclosure 17.

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  At the inlet of each of the cells 26, under the control of solenoid valves, the intermediate fluid is divided between the only elements 25 in which the refrigerant vapor

is at sufficient temperature.

  At the outlet of the elements 25, the enclosure has walls 27 capable of grouping the intermediate fluid of the different cells to lead it to the inlet of a compartment 28 housing the secondary exchanger 21 It is at the outlet of this compartment 28 that is connected the return pipe 24

sheltering the circulation pump.

  The amount of intermediate fluid flowing through

  towards this main exchanger will preferably be relatively large and for example about one thousand two hundred liters to provide a good thermal inertia which places both and water and refrigerant away from

  sudden changes in temperature.

  The exchanger annex 14 (Figure 3) also comprises several elements 29 disposed near the base of the chamber 18. Heated by the elements 29, the intermediate fluid 20 tends to rise by natural convection to the top of the enclosure which has a shape, for example substantially in piles of pebbles, capable of causing the acceleration of the movement of the

intermediate fluid 20.

  Arrived at the top of the enclosure, this intermediate fluid

  falls behind the side walls 30 that said

enclosed for this purpose.

  Behind these partitions are mounted the elements 31 of the secondary exchanger 22 on which flows the intermediate fluid before returning to the base of the enclosure

for a new circuit.

  The amount of intermediate fluid flowing through

  towards this exchanger annex 14 will be for example six hundred

to seven hundred liters.

  As is apparent from FIG. 1, as soon as they exit at approximately ninety-five or one hundred degrees Celsius, the refrigerant vapors travel through the main exchanger 13 from which they emerge at about fifty or seventy

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  degrees Celsius to travel this time the exchanger annex 14 and come out at about forty degrees Celsius before

return to the condenser.

  In this arrangement, via their intermediate fluid 19, the auxiliary exchanger 14 contributes to the preheating of the water which, by about ten or twelve degrees Celsius, is brought to about twenty-five or twenty-eight degrees Celsius, whereas the exchanger 13 concurs at the final heating of the water which, for example, twenty five or twenty eight degrees celsius

  is raised to fifty or sixty degrees Celsius.

  The maximum of the heat of overheating and the latent heat of the steam is thus recovered and used to heat the water without the condenser having to suffer from a too great drop in temperature as that would be the case if, instead of two successive exchangers, there was only one more powerful exchanger, capturing in one

  times a significant part of the overheating heat.

  In order to remain available in large quantities and at times that do not necessarily coincide with the operating periods of the refrigerating machine, the water

  thus heated must of course be stored.

  For this purpose, at the outlet of the secondary heat exchanger 21 of the main heating station 28, the heated water is, via a pipe 32, led to a tank 43, for example twenty thousand liters, at the exit of which a pipe 33 conducts to a network 34 distributing water under control

solenoid valves 35.

  The entire installation is connected to a source of water, such as a distribution network, by a pipe 36 also controlled in particular by solenoid valves 37 and

  means 38 for regulating the pressure.

  This inlet pipe 36 is connected to a

  end of the secondary exchanger 22 of the preheating station

  fage 18 whose other end is itself connected by 3.5 a pipe 39, at the inlet of the secondary heat exchanger 21

the main heating station.

  The preheating station can be short-circuited by a pipe 40 controlled by a three-way motorized valve.

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  voles 41 controlled by a temperature probe 42 diving

  in the intermediate fluid 20 of the preheating station 18.

  At the outlet of the storage tank 43 is also connected a pipe 44 for returning the water to the inlet of the secondary heat exchanger 21 of the main heating station 28, which return is effected in particular under the control of valves or solenoid valves. 45 and a non-return valve 46 and under the possible control of a pump

circulation 47.

  The tank is divided into compartments 48, 49, 50 by partitions 51, 52 leaving free a narrow passage

  53, 54 between the contiguous compartments.

  For each compartment, the inlet and the outlet of the fluid are located opposite each other, one at the bottom, the other at the very top of the tank-to create a bafflement. In each compartment 48, 49, 50, plunges a probe

  , 56, 57 for measuring the temperature.

  In the first compartment 48 plunges a pipe 58 for sampling the fluid to bring it back to the exchanger

  secondary 22 of the main station 28 of the heating

  or via the aforementioned pipe 44 -

  As a result, during the refueling of the

  tion, it is possible to recycle only the first

  until it reaches the temperature of the following, which avoids cooling the water of the following compartments

by a passage from one to the other.

  In a poultry slaughterhouse benefiting from such an installation, the water heating process will for example be the following: in the morning, a day-night / weekly clock with power reserve will open the solenoid valves 37 water inlet The tank scald will then fill with the water that was stored whose

  the temperature is about fifty degrees Celsius.

  Automatically, an auxiliary heater, such as an oil fired boiler or electric heaters, will start to raise this water temperature to that desired,

  in this example, at fifty-one degrees Celsius.

  Obviously, the recovery installation is dimensioned so as to limit at most if not completely cancel the use of this auxiliary heater Therefore, in the above example, the recovery facility tends to bring the water to fifty five degrees Celsius is slightly above the desired temperature Optionally, the clocks may have the mission of shunting the thermostats of the refrigerating installations in order to operate them at

  when there is a high demand for water.

  during work, through the exchangers and the storage tank 43, the scalding tank will be fed with city water at a rate of about three thousand liters per hour This power supply may, for example, be managed

for a float.

  in the evening, the main heating station and the storage tank will operate in closed circuit For this purpose, the

  solenoid valves 37 of city water supply will be closed.

  The water of the storage tank 43 will then be constantly recycled.

  key that will allow him to recover calories and

rise in temperature.

  The closed circuit could of course, instead of a clock, be obtained by action on a manual control especially if it is difficult to predict the time of

  the end of the use of the scalding tray.

  This closed circuit will cause the start of the circulation pump with a delay of fifteen to

thirty minutes.

  In the closed circuit position, the installation will be controlled by a differential regulator -: temperature information will be taken at the inlet of the secondary heat exchanger and at the storage tank; the two pieces of information will be compared and the circulation pump stopped if the temperature of the storage tank is greater than or equal to 3.5 that of the main heating station The regulator will only restore the order of operation to the pump if the temperature of the tank less storage than the main heating station

V 3 2539853

  In the event of prolonged stoppage, for example at noon, the

  can be piloted in the same way as for the evening.

Claims (7)

  1 Installation for producing a hot fluid, such as water supplying an installation consuming this fluid such as a tank (1) scalding machine, in which the fluid is heated by recovering at least the heat of overheating of the steam; a refrigerant which, for this purpose, after its exit from the compressor (5) and before it returns to the condenser (7) of a refrigeration plant (2), can under the control of solenoid valves (15, 16) be diverted to the exchanger (13) of a main heating station (28) which contributes to the temperature rise of the fluid to be heated which is taken from at least one source (36) and then heated and stored in a tank (43) before its sending to the installation (1) consuming it via a distribution means (34), this installation for producing a hot fluid being CHARACTERIZED in that, at the outlet of the storage tank (43) is connected a pipe (44). ) back   water at the entrance to the exchanger.   2 Installation according to claim 1, characterized   on the one hand, in that the reservoir is divided into compartments   partitions (51, 52) leaving only a narrow passage (53, 54) between the adjacent compartments, inlet and outlet of the fluid are located opposite each other, one at the bottom, the other while   top of the tank to create a quibble.   3 Installation according to claim 1 or 2, characterized   in that in the first compartment (48), a fluid withdrawal pipe (58) is plunged back to   the exchanger of the main station (28) of the heating.   4 Installation according to any one of the claims   1 to 3, characterized in that on the refrigerant vapor path, in series with the exchanger (13) of the main heating station (28), is mounted a heat exchanger annex (14).   Installation according to any one of the claims   1 to 4, characterized in that the heat exchanger (13, 14) enters an enclosure (17, 18) which is filled with a certain volume of an intermediate fluid (19, 20) such as water which , in a closed circuit, is set in motion so that after passing through the exchanger (13, 14) traversed by the refrigerant vapors, this intermediate fluid can pass through a secondary exchanger (21, 22) which, for this purpose, also penetrates into the aforementioned enclosure (17, 18) and which,   as for him, is traversed by the fluid to be heated.   6 Installation according to any one of the claims   1 to 5, characterized in that the main heat exchanger (13) is composed of a plurality of elements (25) each housed at the bottom of one of the cells (26) provided for this purpose. enclosure, and, secondly, in that it comprises at the inlet of each of the cells (26), solenoid valves controlling the distribution of intermediate fluid between the only elements (25) in which the refrigerant vapor is at sufficient temperature.   Installation according to any one of the claims   1 to 6, characterized in that the adjoining exchanger (14) comprises a plurality of elements (29) arranged near the base of the enclosure (18), and internally has lateral partitions (30) conferring on it a shape adapted to causing the acceleration of the upward movement of the intermediate fluid which, when it reaches the top of the chamber, falls behind the said side walls (30) where the elements are mounted.   (31) of the secondary exchanger 22).