FR2825143A1 - Monobloc system and hot and cold water production installation, for air conditioning, uses a programmable automatic three way valve to control fluid circulating in principal and auxiliary circuits - Google Patents

Abstract

Installation for alternative or simultaneous production of hot or cold water by thermal transfer, has at least two systems and interlinked evaporators (6a,6b) and condensers (5a,5b) each associated with a fan ventilator (7a,7b). A water circulating system has a three way valve (8) connecting principal circuits (CP) and auxiliary circuits (CA) using programmable automatic drives. Monobloc system for alternative or simultaneous production of hot or iced water by thermal transfer. Includes at least two identical refrigerating units (Ua,Ub) each unit including a principal refrigerating unit (CP) fitted with a compressor (1a,1b), a condenser (2a,2b) and an evaporator (3a,3b), as well as a regulator (4a,4b). The condenser and evaporator are designed to respectively provide, by counteraction, hot (EC) and iced water (EG) in the air conditioning system; an auxiliary refrigerating circuit (CA), in parallel with the principal circuit (CP), has a condenser (5a,5b) and an air evaporator (6a,6b) as well as a regulator (4'a,4'b). A valve (8) circulates fluid either exclusively in the principal circuit (CP) or exclusively in the auxiliary circuit (CA), either through the condenser (2a,2b) of the principal circuit and evaporator (6a,6b) of the auxiliary circuit or vice versa. The air evaporator (6a,6b) of a given unit (Ua,Ub) is disposed in immediate proximity to the air condenser (5a,5b) of the neighboring unit (Ub,Ua), so that deicing of the evaporator is assured by the fluid circulating in the condenser of the neighboring unit.

Description

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 The present invention relates to a monobloc system and to an installation for the alternative or simultaneous production of hot water or chilled water in a room, by thermal transfer in a water air conditioning installation.

 In water air conditioning systems, the cooling of the room equipped with it is ensured by a cold battery supplied with chilled water, while the heating is ensured by a hot battery supplied by a circulation of hot water or electrically.

 These water air conditioning systems can be classified into three categories, namely the system called "two tubes 1 two wires", the system "two tubes change-over", and the system called "four tubes".

 In the system called "two tubes 1 two wires", the cooling of the atmosphere is ensured by a cold battery supplied with chilled water.

 Heating is provided by an electrically powered battery. This type of system makes it possible to produce and supply chilled water to an installation while providing it, if necessary, with heating by means of an electric battery.

 The advantage of such a system is that it is a reduced investment. Furthermore, its installation and operation are relatively simple.

 However, it has a number of drawbacks.

 The first of these is that the use of direct electric heating entails a high operating cost. It requires a large annual electrical subscription for winter use. Finally, this requires having multiple electrical installations.

 In the so-called two-tube change-over system, the same battery can be supplied with chilled water or hot water. This makes it possible to produce and supply premises with chilled water when a cooling mode is desired.

The same system also makes it possible to produce hot water for use in heating mode.

 In this system, we are also dealing with a simple installation. The same assembly of hydraulic production and distribution indeed ensures at the same time the functions of heating and cooling, so that its exploitation is relatively simple.

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 But again, such a system has a number of drawbacks.

 The first of these lies in the lack of flexibility that results from the obligation to choose a production of chilled water or hot water.

 Furthermore, it is impossible to simultaneously cool and heat premises with different thermal loads.

 In addition, the heating power of the liquid cooler in hot water production mode is often insufficient.

 It is then necessary to equip the fan coil units with additional electric batteries, which have the aforementioned drawbacks linked to the "two-tube / two-wire" system.

 In addition, there is a gap between the theoretical and actual operating costs linked to the inertia of the system and to the almost systematic addition of two wires as electrical back-up.

 Finally, there is a significant inertia of the system linked to the hydraulic volume of the installation.

 The so-called "four-tube" system requires the use of a first battery supplied with chilled water and a second battery supplied with hot water.

 Such a system makes it possible to produce and distribute chilled water for supplying the cold coil of a fan coil.

 It also makes it possible to produce and distribute hot water to supply the hot coil of another fan coil.

 The advantages of such a system lie essentially in the flexibility of the assembly thus formed and the thermal independence of the production and distribution of chilled / hot water induced by this system.

 Again, there are a number of drawbacks associated with the use of this four-tube system.

 Firstly, it requires a penalizing and significant investment since it requires a chiller, a chilled water circulation network, a boiler room and a hot water circulation network.

 In addition, it requires the simultaneous consumption of two energies in the event of different requests for premises with opposite thermal loads.

 It causes significant expansion penalizing the performance of the entire installation.

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 It also requires the operation of two installations for producing hot water and chilled water.

 Finally, it requires a boiler room, with the related regulatory implications.

 Reading what has just been explained, it will be understood that the problem of these known systems is economic and usual.

 In economic terms, we understand that the investment cost of such systems is penalized by the obligation to have recourse to two modes of production of cooling and heating.

 The operating cost is penalized by the possible simultaneous demand for cooling and heating of premises which have opposite thermal loads.

 In the field of use, flexibility and comfort imply the obligation to have a permanent supply, from any point of the building in use, of sufficient power to provide heating or cooling.

 Once this problem has been posed, the ideal system must therefore require a limited investment, be simple to operate, make cooling and heat capacities immediately available in the event of simultaneous requests, allow energy recovery linked to the cooling need to be ensured to ensure the calorific needs in the event of simultaneous requests, and finally to constitute a unique and autonomous refrigeration and calorific production unit.

 The aforementioned systems do not make it possible to achieve all of these objectives because the technical obstacle of producing heating at low outdoor temperatures involves the implementation of complex refrigeration regulation, linked in large part to the necessary cycle inversions. when defrosting the external batteries.

 Unexpectedly, the present applicant has realized that with simple means, it was possible to achieve the above objectives.

 The present invention therefore aims to provide a one-piece system for alternative or simultaneous production of hot water and chilled water by thermal transfer, which is essentially characterized by the fact that it comprises at least two identical refrigeration units, each unit comprising, - a so-called main refrigeration circuit, equipped with a compressor, a condenser and a water evaporator, as well as a pressure reducer, these condensers and

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 evaporator being able to supply, by counter-current circulation, respectively hot water and chilled water in said room; - an auxiliary refrigeration circuit, connected in parallel to the main circuit, equipped with a condenser and an air evaporator, as well as a pressure reducer; - Means capable of circulating a heat transfer fluid either exclusively in the main circuit, or exclusively in the auxiliary circuit, or by the condenser of the main circuit and the evaporator of the secondary circuit or vice versa, and that the air evaporator a determined unit is placed in the immediate vicinity of the air condenser of a neighboring unit, so that the defrosting of said evaporator is ensured by the circulation of heat transfer fluid in the condenser of the neighboring unit.

 This system in fact makes it possible to circumvent the technical difficulty of defrosting by cycle inversion of systems with two change-over tubes, by coupling two independent refrigeration circuits with power on either side in the nested battery of the neighboring circuit.

 Cycle reversal is therefore no longer necessary since the refrigeration assembly itself avoids it by "crossing" during construction.

 This same defrost can be carried out, if requested by the regulation, with simultaneous production of chilled water.

 Furthermore, according to other characteristics and advantages of this system: - said condenser and evaporator are nested one inside the other; - the air condenser and evaporator are each associated with at least one fan.

 - Said means consist on the one hand of three-way valves connecting together the main and auxiliary circuits and, on the other hand, automatic control means, for example with a programmable controller.

 Furthermore, the invention relates to an alternative or simultaneous installation for producing hot water and chilled water by thermal transfer, which is essentially characterized by the fact that it comprises at least two systems conforming to one of the characteristics mentioned above. .

 Other characteristics and advantages of the invention will appear on reading the detailed description which follows of a preferred embodiment.

This description will be made with reference to the accompanying drawings in which:

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 - Figure 1 is a block diagram of a system according to the invention; - Figure 2 is a diagram similar to that of Figure 1, more particularly intended to illustrate the production of chilled water by air condensation; - Figure 3 is still a view of the same system, with which it is proposed to produce hot water using a cycle similar to that of an air / water heat pump; - Figure 4 is still a view of the same system, intended to simultaneously supply hot water and chilled water; - Figure 5 is a view of the same system in which it is proposed to defrost the condenser of one of the circuits.

 Throughout the description which follows as well as in the claims, the expression "production of hot water" means the fact of producing water having a temperature of the order of 40 to 45. By the expression "production of chilled water" is meant the fact of providing water having a temperature of the order of 7 to 12.

 To facilitate the reading of the attached figures, the heat transfer fluid which flows inside the system is represented in the form of broken lines when it is hot, and in the form of dashed lines when it is cold.

 When the terms downstream / upstream, before / after, or inlet / outlet are used below, reference will always be made to the direction of flow of the heat transfer fluid which is identified in the figures appended by the arrow f.

 An example of a system for the simultaneous alternative production of hot water and chilled water in a room by thermal transfer according to the invention and in particular shown in FIG. 1.

 The system according to the invention here comprises two identical refrigeration units identified Ua and Ub. The elements which constitute each of the units are identified by the same reference numeral and bear the index a when they belong to the unit Ua and the index b when they belong to the unit Ub.

 We will describe below the structure of the unit Ua. In order not to unnecessarily burden this text, this description will not be repeated for the Ub unit, insofar as its structure is completely identical to that of the first unit.

 The unit Ua comprises a main refrigeration circuit CP and an auxiliary refrigeration circuit CA.

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 The main refrigeration circuit is equipped with a compressor, connected, as it should be, to the electrical network, with a high pressure outlet to which a pressure switch 10a is connected and by which a refrigerant of known type is evacuated under high pressure and to the gaseous state, via a pipe 90a.

 This pipe is connected, by a three-way valve 8, to a pipe 9la which opens into a water condenser 2a. This condenser is equipped with a counter-current water circulation pipe which makes it possible to obtain, by thermal transfer, hot water EC intended for supplying for example the radiators of a building.

 At the outlet of the condenser is mounted a non-return valve CL. At the outlet of this valve is connected a line 92a to which are connected, in the direction of fluid flow, a stop valve VA, a charge load VC, a filter drier FD, a liquid sight glass system VL , and a second stop valve VA. The downstream end of the pipe 92a is connected to a second three-way valve 8, one outlet of which is connected to a thermostatic expansion valve 4a and at the outlet of which is mounted a water evaporator 3a. This evaporator is equipped with a counter-current water circulation system capable of generating, by heat exchange, chilled water EG, which can be used to cool a room by air conditioning.

 The evaporator outlet pipe is referenced 93a. It carries substantially at mid-distance, a non-return valve CL. Finally, the output of this pipe 93a is connected to the low pressure input of the compressor la. At this level is mounted a pressure switch 11a.

 The auxiliary refrigeration circuit CA is connected in parallel to the main circuit.

 In this case, on the third channel of the valve 8 which equips the pipe 90a is connected another pipe 94a which is extended by an air condenser Sa arranged inside an enclosure called Ba battery.

 At the outlet of this condenser is provided a return pipe 95a which is connected to the pipe 92a, just after the outlet of the condenser 2a. At this level, a non-return valve CL is provided.

 Furthermore, the second three-way valve 8 is provided with a pipe 96a, the downstream end of which is equipped with a thermostatic expansion valve 4'a, itself connected to an air evaporator 6a. At the outlet of this evaporator is connected a return pipe 97a connected to the pipe 93a, upstream of the low pressure pressostat 11a.

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 At least one fan 7a, preferably a helical fan, is associated with the battery Ba.

 It should be noted that the condenser 5a and the evaporator 6a of the unit Ua are not mounted within the same battery Ba. On the contrary, and in accordance with the invention, the air evaporator 6a of the unit Ua is arranged in the immediate vicinity of the air condenser 5b of the neighboring unit Ub.

 It will be understood, later in the description, the advantage of such an arrangement.

 We will now explain, with reference to FIGS. 2 to 5, several possible uses of the system according to the invention. By convention, and in each figure, the stationary mechanical elements and the pipes not used to actively transport the heat transfer fluid do not bear any reference.

 Of course, the starting up of the system of the invention, the opening and closing of the three-way valves, as well as, more generally, the operation of all the mechanical, electrical and electronic elements, is ensured automatically, for example via a programmable controller. He is in particular capable of managing the operation of the system, including, if necessary, detecting faults.

 In the case of FIG. 2, it is proposed to supply, for example to a room, exclusively chilled water intended to be directed to an air conditioning system, for example with a fan.

 In the case presented here, both units work. However, in the context of air conditioning requiring less energy, we can afford to control only one or the other of the two units.

Again, we will just describe the operation of the unit
Ua.

 The heat transfer liquid which exits at high pressure and at high temperature from the compressor 1a is directed, via the three-way valve 8 and the line 94a, to the air condenser 5a of the battery Ba.

 The fan 7a being in operation, it brings the cooler outside air into contact with the condenser and thus causes the condensation of the fluid inside said condenser. The calories extracted therefrom are then released to the outside by the fan.

 The condensed fluid is then routed via line 95a and line 92a to the regulator 4a. On leaving it, the fluid, the pressure of which, and jointly the temperature have dropped, is sent into the evaporator at

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 water 3a. The circulation of water against the current then collects EG chilled water which is directed to the air conditioning system (not shown) of the room.

 In the example of FIG. 3, it is proposed to supply the building exclusively with hot water, for example with a view to supplying radiators.

 The operation of the system is then similar to that of an air / water heat pump.

 In this specific case, the high pressure heat transfer fluid which leaves the compressor 1a is directed, via the three-way valve 8, to the water condenser 2a, which makes it possible, by circulation of water against the current, to recover from EC hot water to supply the space's radiators.

 The heat transfer fluid which is discharged from the condenser is then directed via the second three-way valve 8 and the line 96a, to the regulator 4'a which equips the battery Bb of the second unit.

 The cooled low pressure fluid is returned to the compressor via line 97a.

 Of course, the Ub unit of the system works in exactly the same way.

 In the example in Figure 4, we assume that we want to simultaneously supply the same building with hot water and chilled water. This is for example the situation in which a building oriented on the one hand to the east and on the other to the west needs, at the same time of the day, to be cooled on the east side and heated from Western coast.

 Again, both units were considered to be in service.

However, depending on the desired power, we can afford to operate only one.

 The high pressure fluid which leaves the compressor 1a is directed via the pipe 90a and the three-way valve 8 to the water condenser 2a, which makes it possible to supply hot water EC to the radiators of the building.

 The fluid which leaves the condenser is evacuated via line 92a and the second three-way valve 8 to the regulator 4a. It then enters in liquid form and at low temperature inside the water regulator 3a, which makes it possible to produce chilled water EG for the air conditioning of the building.

 The cold fluid at low pressure then joins the compressor 1a via the return line 93a.

 Everyone knows that when you use a refrigeration system like an air / water heat pump, the air evaporator that is used becomes covered

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 gradually frost. It is then necessary to periodically defrost this device, otherwise the performance of the system as a whole is markedly reduced.

 According to the prior art, this is done in what is called a cycle inversion, so that the evaporator then becomes condenser and vice versa, which makes it possible to quickly melt the ice which has formed at the outer surface of the evaporator.

 As mentioned above, this generates multiple drawbacks, in particular in terms of cost and risk of premature wear of the installation.

 The invention makes it possible to overcome these drawbacks insofar as the air evaporator of one of the two units is arranged in the immediate vicinity of the air condenser of the neighboring unit, so that the defrosting of said evaporator is ensured by the circulation of heat transfer fluid in the condenser of the neighboring unit.

 When the system is used in the manner described in FIG. 3, the two evaporators 6a and 6b of the two units have their outer surface gradually covered with frost.

 It is then necessary to plan their defrosting. Figure 5 shows how this defrosting takes place. In this figure, we consider that we simply want to defrost the evaporator 6a from the unit Ua. To do this, said unit Ua is for example completely stopped. In another hypothesis, it works, but only by making use of the condenser and evaporator with water.

 The second unit Ub is started up so as to circulate the heat transfer liquid under pressure, via line 94b, to the condenser 5b. Because this condenser is placed near the evaporator to be defrosted, this is enough to completely rid it of its frost in a few seconds.

 In a particular embodiment, the condenser and the evaporator are completely nested one in the other so that the contact of the hot and cold fluids is further improved.

 The fluid leaving the condenser 5b is then returned, via line 95b and the evaporator 6b to the compressor 1b.

 The system according to the invention therefore makes it possible to circumvent the technical difficulty of defrosting by cycle inversion by coupling two independent refrigeration circuits with supply on either side in the nested battery of the neighboring circuit.

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 Cycle reversal is therefore no longer necessary, since the refrigeration assembly itself avoids it by crossing it during construction. This same defrost can be carried out, if requested by the regulation, with simultaneous production of chilled water.

 In the examples which have just been described, the system comprises only two units. Of course, in other embodiments, this number could be greater, for example equal to three or four. However, in such a case and in accordance with the invention, the air evaporator of a given unit is always placed in the immediate vicinity of the air condenser of a neighboring unit.

 If necessary, it can be envisaged to implement an alternative or simultaneous production plant for hot water and chilled water by thermal transfer, which comprises at least two systems such as that described with reference to the appended figures.

Claims (5)

1. One-piece system of alternative or simultaneous production of hot water and chilled water in a room by thermal transfer, characterized in that it comprises at least two identical refrigerating units (Ua; Ub), each unit comprising, - a so-called main refrigeration circuit (CP) equipped with a compressor (1 a; 1 b), a condenser (2a; 2b) and a water evaporator (3a; 3b), as well as a pressure reducer (4a ; 4b), these condenser and evaporator being able to supply, by counter-current circulation, respectively hot water (EC) and chilled water (EG) in said room; - an auxiliary refrigeration circuit (CA), connected in parallel to the main circuit (CP), equipped with a condenser (Sa; 5b) and an air evaporator (6a; 6b), as well as a pressure reducer ( 4'a; 4'b); - Means (8) capable of circulating a heat transfer fluid either exclusively in the main circuit (CP), or exclusively in the auxiliary circuit (CA), or by the condenser (2a; 2b) of the main circuit (CP) and l 'evaporator (6a; 6b) of the auxiliary circuit (CA) or vice versa, and that the air evaporator (6a; 6b) of a specific unit (Ua; Ub) is arranged in the immediate vicinity of the air condenser (5a; 5b) of a neighboring unit (Ub; Ua), so that the defrosting of said evaporator is ensured by the circulation of heat transfer fluid in the condenser (5a; Sb) of the neighboring unit.  2. System according to claim l, characterized in that said evaporator (6a; 6b) and condenser (5a; Sb) are nested one inside the other.  3. System according to one of claims 1 or 2, characterized in that the condenser (5a; 5b) and air evaporator (6a; 6b) are each associated with at least one fan (7a; 7b).  4. System according to one of claims 1 to 3, characterized in that said means consist on the one hand of three-way valves (8) connecting together the main (CP) and auxiliary (CA) circuits and, on the other hand, by means of automatic piloting, for example with a programmable controller.  5. Installation for alternative or simultaneous production of hot water and chilled water by thermal transfer, characterized in that it comprises at least two systems according to one of claims 1 to 4.