WO2010052419A1

WO2010052419A1 - Method and device for controlling internal physical and chemical parameters of a liquid in a hydraulic circuit

Info

Publication number: WO2010052419A1
Application number: PCT/FR2009/052117
Authority: WO
Inventors: Luc Derreumaux
Original assignee: Compagnie Industrielle De Filtration Et D'equipement Chimique (Cifec)
Priority date: 2008-11-04
Filing date: 2009-11-03
Publication date: 2010-05-14
Also published as: FR2938086B1; FR2938086A1

Abstract

The invention relates to a method for controlling at least two internal chemical or physical parameters of a liquid circulating in a hydraulic circuit, said internal parameters being sensitive to at least one parameter external to the liquid, said method comprising the following steps: 1) measuring said internal parameters; 2) measuring said external parameter; 3) predetermining at least one corrective action to be applied to at least one of said internal parameters according to the values measured during the first and second steps and according to a corrective action optionally applied to one or more other internal parameter(s); 4) generating at least one control signal for implementing at least one corrective action predetermined during the third step. The method applies in particular to controlling the quality of water in a swimming pool or a coolant circuit. The invention also relates to a device for implementing the method.

Description

METHOD AND DEVICE FOR CONTROLLING INTERNAL PHYSICAL AND CHEMICAL PARAMETERS OF A LIQUID IN A HYDRAULIC CIRCUIT.

The present invention relates to a method and a device for regulating internal physical and chemical parameters of a liquid in a hydraulic circuit. They are particularly applicable to the regulation of the characteristics of the water of a swimming pool or a cooling circuit.

In particular, the regulation applicable to public swimming pools requires the operator to respect minimum and / or maximum values for certain physical or chemical parameters of the water, for example the disinfectant rate, the pH, the concentration of byproducts of the water. disinfection. Existing control methods measure these parameters on the water leaving the pond, and introduce reagents into the water to restore each value to the allowable range. According to this principle of operation, it is expected that the value (s) have degraded (s) to correct / them. The parameters of the volume of water are thus generally at the limits of the imposed range, which is likely to cause problems, the non-respect of a limit value which can quickly be translated by an irreversible phenomenon, for example the development of algae. To improve the process, we can try to reduce the amplitude of the range, which is at the origin of other problems, such as instabilities.

However, it is known that a number of parameters have a direct influence on the physical and chemical parameters of water, for example the number of bathers and, in the case of outdoor swimming pools, air temperature and sunshine.

Moreover, there are interactions between parameters that can make a regulation difficult or very rough. For example, most disinfectants change the pH of the water, and adding fresh water lowers product concentrations in the water.

The object of the invention is therefore a method and a device that improves the regulation of internal parameters to a liquid in a hydraulic circuit.

For this purpose, the invention proposes a method of regulating at least two internal chemical or physical parameters of a liquid circulating in a hydraulic circuit, said internal parameters being sensitive to at least one parameter external to the liquid, said method comprising the following steps :

1) measuring said internal parameters, 2) measuring said external parameter,

3) determining at least one corrective action to be applied to at least one of said internal parameters as a function of the values measured in the first and second stages and as a function of corrective action possibly applied to one or more other internal parameter (s) (s),

4) generating at least one control signal for implementing the at least one corrective action determined in the third step.

The method according to the invention applies for example to a cooling circuit, or to a swimming pool when the storage volume is a bathing basin, the liquid being water.

In the latter case, the method consists in regulating at least two internal parameters of the water of the swimming pool taking into account, on the one hand, at least one external parameter which influences these internal parameters, on the other hand a interaction between these internal parameters. The goal is that each internal parameter stays close to a set value given by the pool operator and, in any case, within a range provided by the regulations.

The method comprises steps of measuring the concerned parameters, internal and external, and then determining corrective actions to be applied to at least one of the internal parameters of the water as a function of the values measured at a given moment for each of the parameters. parameters, as well as corrective actions already possibly applied to the other internal parameter during a previous application of the method, so as to take into account the interaction between internal parameters. In a final step, the method consists in generating control signals for the implementation of at least one corrective action, these control signals being generally intended for actuators. By actuator is meant any device, in particular mechanical or electrical, capable of acting on the internal parameters of the water, for example pump, valve, fan, radiator, etc.

In its third step, the method implements at least one control module of the internal parameters as a function of at least one external parameter and as a function of a corrective action possibly applied to one or more other parameter (s) internal (s), which can be determined during a step preceding the different steps of the process.

In a particular application, the internal parameters regulated by the process are the concentration of disinfectant, for example a chlorinated compound, hypochlorite ... and the pH of the water. These parameters are subject to strict regulations providing for a minimum value and a maximum value. It is also known that, for example, the addition of hypochlorite causes the pH to rise, which characterizes an interaction between these parameters.

An external parameter may be the number of bathers entering the pool enclosure. It is known that the number of bathers in a pool has a direct effect on the concentration of disinfectant. Moreover, number of bathers entering the pool is a parameter directly available because the regulation imposes its measure.

In this particular application, the method uses a regulating means, or regulator, which comprises a module for regulating the concentration of disinfectant in water and a pH regulation module. By regulation module is meant a series of steps of the method according to the invention but specific to an internal parameter and which may for example comprise sequences of instructions in the form of programs executable by a programmable logic controller or a microprocessor. In the application of the method to a swimming pool hydraulic circuit comprising a disinfectant pump capable of adding disinfectant to water, the disinfectant concentration control module in the water can use as input, in addition to the instantaneous concentration in water. disinfectant and the concentration setpoint: ® the water temperature, β the air temperature, ® the sunshine,

»The number of incoming bathers in the pool enclosure. Water temperature affects the solubility of the disinfectant in water as Henry's constant varies with temperature, disinfectant consumption increases with air temperature and sunshine, and disinfectant consumption increases with the number of bathers.

The module for regulating the concentration of disinfectant uses information on the volume of new water that may be added, since this addition dilutes the disinfectant products. This information can be provided manually or by using another control module.

The corresponding corrective action is an addition of disinfectant in the bathing water, by means of a control signal transmitted to the disinfectant pump. In the application of the method to a swimming pool hydraulic circuit comprising an acid or base pump, able to add an acid or a base to the water, the water pH regulation module can use as input, in addition to the pH and the pH setpoint: β information generated by the disinfectant concentration control module, to take into account an effect of the disinfectant on the pH of the water; for example, adding sodium hypochlorite raises the pH of the water. The pH control module uses information on the volume of new water that may be added, because the pH of the added water may be different from the target pH. This information can be provided manually or by using another control module.

The corresponding corrective action is an addition of acid or base in the bathing water, by means of a control signal transmitted to the acid pump and / or base.

The method may advantageously also relate to the regulation of fresh water inputs. For this purpose, it applies to a swimming pool hydraulic circuit further comprising: a buffer tank connected in series in the water circuit, at least one level sensor of said buffer tank, a valve connected to a water supply and said buffer tank, so as to add fresh water, a means for measuring the amount of fresh water added, a purge valve of said buffer tank, said regulating means further comprising a control module of the contributions of new water, using as input: the water level in the buffer tank, the maximum height setpoint of the water in the buffer tank, the number of bathers entering the pool enclosure, the inflow new water per bather entering. In this case, the corrective action consists of a supply of new water, and the disinfectant concentration control and pH regulation modules also advantageously use as input information generated by said water supply regulation module. new.

The corrective action of the corresponding regulation module is generally a supply of new water. The regulation module uses a fresh water intake guideline per bather entering the enclosure of the pool, which is a regulatory data, for example a contribution of at least 30 liters per bather entering. At the output, this module generates information that is advantageously used by the disinfectant concentration and pH control modules because the new water that is added does not have the required characteristics and contributes to diluting the products present in the water. ; it is assumed that the new water added, whether it comes from the network or a catchment, has all the sanitary qualities to be used as swimming pool water.

The supply of new water may be preceded or not by a partial purge of a buffer tank; partial purge is necessary when the buffer tank is already at its maximum level and as a result a fresh water supply could be evacuated by the overflow devices and therefore be ineffective. One way to proceed is for example to leave open the purge valve of the buffer tank for a time sufficient to empty a volume equal to the expected intake. It should be noted that only the level of the buffer tank is to be taken into account because the bathing pond is generally at its maximum level, the surplus water being collected by overflow devices.

The method may advantageously also relate to the regulation of the concentration of undesirable products in water. For this purpose, the regulating means further comprises a module for regulating the concentration of undesirable products in the water, which uses the following data as input: • the setpoint concentration of undesirable products, ^β the concentration of undesirable products in the water,

The temperature of the water, β the air temperature, and the fresh water supply control module also uses as input information generated by said module for regulating the concentration of undesirable products.

Disinfectant consumption by bathers results in the appearance of products such as chloramines, chlorides ... It is preferable that the concentration of these undesirable products does not exceed a certain threshold set by the regulations. A simple way to comply with this directive is to dilute these products when their concentration approaches the threshold, that is to say to add new water. Thus it is not necessary to implement specific actuator. The module for regulating the concentration of undesirable products sends information to the module for regulating fresh water supplies, which manages inputs of new water.

As with the disinfectant, the temperature of the water can affect the dissolution of certain undesirable products through their Henry's constant. The air temperature can influence the dissolution of some undesirable products by modifying the water temperature at the water-air interface and thus modifying the Henry's constant.

The invention also relates to a device for regulating at least two internal parameters of the liquid of a hydraulic circuit as a function of at least one external parameter, said internal parameters being sensitive to at least one parameter external to the liquid, said hydraulic circuit comprising:

a storage volume, comprising an inlet and a liquid outlet, ^β a liquid circuit connected to said liquid inlet and outlet of said basin,

• a means of circulation of water,

At least one sensor of said internal parameters, at least one sensor of said external parameter,

At least two actuators each for varying one of said internal parameters.

The circuit further comprises regulating means for regulating said internal parameters as a function of a measurement of the external parameter, a measurement of each of the internal parameters, at least one setpoint value for each of said internal parameters, said means being able to generate a control signal for said actuators.

Such a device is particularly suitable for regulating the physical and chemical parameters of the water of a swimming pool, when the storage volume is a bathing pond.

The advantages of the process are numerous: β it prevents degradation of the internal parameters by taking preventive corrective measures, ® it makes it possible to control the coherence of the corrective actions with respect to the parameters measured during operation; this coherence will be controlled by means of adjustable thresholds on the treatment rate corresponding to the corrective action. The regulation can not exceed these thresholds, corresponding to the maximum treatment rates, and will trigger a warning to the operator if the corrective action causes a treatment rate that reaches one of these thresholds;

• it allows to control the sensors, analyzers and actuators: in case of failure or drift of one of them, the corrective actions calculated on the basis of the internal and external parameters will not be enough to keep the set of the internal parameters, who will come to the limit of the regulatory range, causing a reaction of the device and / or the operator.

It is obvious that the method is more generally applicable to the regulation of two physical parameters of a liquid bonded together, for example its temperature and its viscosity, sensitive to an external parameter, for example the external temperature.

Several embodiments and variants will be described below, by way of non-limiting examples, with reference to the accompanying drawings in which:

Figure 1 is a block diagram of a swimming pool whose control system uses the method according to the invention, Figure 2 is a block diagram of the regulations implemented by the method.

The pool shown schematically in Figure 1 comprises a bathing pond 1, a buffer tank 2, a circulation pump 4 and a battery of filters 5, connected in series in a closed circuit 3 which comprises:

a pipe 3a which conducts the water from the bathing basin 1 to the buffer tank 2,

a pipe 3b which conducts water from the buffer tank 2 to the circulation pump 4, a pipe 3c which conveys the water from the circulation pump 4 to the filters 5,

and a 3d pipe which in turn conducts water from the filters 5 to the bathing basin 1.

A 3rd diversion on line 3a leads water samples to an analyzer 6 which makes it possible to measure the parameters internal to the volume of water such as disinfectant concentration, pH or by-products of disinfection.

The excess water from the bathing basin 1 is recovered by the overflow 1a of this basin and led to the buffer tank 2 via the pipe 3a. The buffer tank 2 is provided with an overflow device 2a which conducts the excess water to the sewer. It is also equipped with level 9 sensors which make it possible to know the volume of water in the buffer tank and therefore in the installation, the bathing pond 1 being constantly full in use.

A sensor (not shown) measures the temperature of the water in the bathing basin 1 or at a point in the closed circuit 3.

The supply of fresh water is in the buffer tank 2 through a solenoid valve 10 mounted on a pipe 3 f connected to the network. A water meter 7 mounted on the pipe 3f makes it possible to instantly measure the volume of water added. The bathing pond 1 and the buffer tank 2 comprise purges, for example solenoid valves 8a and 8b, which make it possible to empty all or part of these containers in the sewer.

The installation also comprises reservoirs for disinfectant product 11a and acid and base 12a connected to pumps 11b and 12b, which make it possible to inject calibrated quantities of products into line 3d.

The installation also includes external parameter sensors to the volume of water:

a bathing counter 20,

an air temperature sensor 21, a sunshine sensor 22.

The analyzer 6 as well as the external parameter sensors are connected to a computer 30 which fulfills the function of regulator of the installation. This calculator 30 is also connected to the water meter 7, the pumps 1 Ib and 12b and the solenoid valve 8b purge the buffer tank. The computer 30 includes in particular an internal memory and means (s) of dialogue with a user, such as a keyboard and a reader of computer support, which in particular make it possible to enter the setpoint values and the sequence of executable instructions which constitutes the regulation modules. The measurements of the internal parameters made by the analyzer 6 as well as measurements of the external parameters are processed by the computer 30, which generates commands for the actuators following the execution of the regulation modules.

The regulator 50, the organization of which is shown diagrammatically in FIG. 2, comprises four regulation modules, a disinfectant concentration control module 51, a pH regulation module 52, a new water supply regulation module 53 and a module These regulation modules take the form of sequences of instructions stored in memory in the computer 30, executable by said computer. The disinfectant concentration control module 51 uses as input the value of the instantaneous concentration by disinfectant 60, the value of the disinfectant concentration setpoint 61, the value of sunshine 62, the temperature of the water 63, the temperature of the air 64, as well as the number of incoming bathers 70 and information on the volume of new water possibly added, from the freshwater supply control module 53 to take into account the dissolution of the products when new water is added. At the output, this module sends an activation signal of the disinfectant pump 1 lb and information to the pH control module 52. The disinfectant concentration control module is a linear control module whose main variable is the difference between the set point and the measurement of the concentration of disinfectant and the secondary variables are the number of incoming bathers 70, the temperature of the water 63, the air temperature 64, the sunshine 62 and the volume of the water. new water possibly added, and whose proportionality coefficients are determined empirically, in particular to adapt them to the installation on which the regulator is installed. The pH control module 52 uses as input the instantaneous pH value of the water 71, the pH setpoint 72, as well as information from the disinfectant concentration regulator 51 so as to take account of the influence of a disinfectant addition to the pH of the water, and information on the volume of new water possibly added, resulting from the modulus of regulation of the freshwater inputs 53, to take account of the dissolution of the products when new water is added. At the output, this module sends an activation signal of the acid pump or base 12b. It is also a linear module, whose main variables are the difference between the setpoint and the pH measurement and the information on the volume of new water possibly added.

The intake control module in new water 53 uses as input the number of incoming bathers 70, the value of the water level in the buffer tank 80, the maximum level setpoint 81, the value of the volume of instantaneous added water 82 , for example, measured by the water meter 7, the new water supply setpoint for the incoming bather 83, as well as information from the unwanted product concentration regulation module 54. At the output, this module sends a information to the disinfectant concentration control modules 51 and pH 52, and an activation signal to the water supply valve 10 and, where appropriate, previously to the bleed valve 8b. The latter must be activated for a sufficient time to partially empty the buffer tank 2 before adding new water when it is already at the maximum level. It is also a linear module, the main variable of which is the number of incoming bathers 70 by application of the regulatory regulation of water intake by bather entering.

The module for regulating the concentration of undesirable products 54 uses as input the instantaneous concentration of undesirable products 92, the unwanted product concentration setpoint 91, the water temperature 63 and the air temperature 64. information to the module regulating inputs of new water 53 in the case where the only way to fight against an excessive concentration of these products is to dilute them. The instructions in disinfectant concentration 61, pH 72 and concentration of undesirable products 90 are chosen by the operator within the regulatory ranges. Their use in the modules makes it possible to know the target value to be reached for the regulation.

Claims

claims

A method of regulating at least two internal chemical or physical parameters of a liquid flowing in a hydraulic circuit, said internal parameters being sensitive to at least one parameter external to the liquid, said method comprising the following steps:

1) measure said internal parameters,

2) measuring said external parameter, 3) determining at least one corrective action to be applied to at least one of said internal parameters as a function of the values measured in the first and second steps and as a function of corrective action applied to one or more other (s) ) internal parameter (s),

2. Control method according to claim 1, characterized in that it is preceded by a step of determining at least one control module (51, 52) of said internal parameters as a function of said external parameter and as a function of a corrective action possibly applied to one or more other internal parameter (s), said at least one control module being implemented during the third step of the method.

3. Control method according to claim 2, characterized in that it applies to the hydraulic circuit of a pool, said liquid being water.

4. Control method according to claim 3, characterized in that the at least two internal parameters regulated by said process are a concentration of disinfectant in water and the pH of the water.

5. Control method according to one of claims 3 or 4, characterized in that said at least one external parameter is the number of entering bathers in the pool enclosure (70).

6. A method of regulation according to one of claims 3 to 5, characterized in that it implements a regulating means (50) comprising at least two control modules: a module for regulating the concentration of disinfectant in the 'water

(51), a module for regulating the pH of the water (52).

7. Control method according to claim 6, characterized in that it applies to a swimming pool hydraulic circuit comprising a disinfectant pump (Hb), able to add disinfectant to water, in that said module of regulating the concentration of disinfectant in water (51) uses as input:

"The temperature of the air (64),

• the temperature of the water (63),

* 1 'sunshine (62),' the set concentration in disinfectant (61),

La the concentration of disinfectant in the water (60), β the number of bathers entering the pool enclosure (70), and that, in the fourth step, the corrective action consists of a signal of disinfectant pump control (Hb) to add disinfectant to water.

8. Control method according to claim 6 or 7, characterized in that it applies to a swimming pool hydraulic circuit comprising an acid pump and / or base (12b), suitable for adding an acid or a base to the water, in that said water pH regulating module (52) uses as input:

• pH measurement (71),

The pH setpoint (72),

An information generated by said disinfectant concentration control module (51), and that, in the fourth step, the corrective action consists of a control signal of the acid and / or base pump ( 12b) to add an acid or base to the water.

9. Control method according to one of claims 6 to 8, characterized in that it applies to a swimming pool hydraulic circuit further comprising: a buffer tank (2) connected in series in the water circuit, at least one level sensor (9) of said buffer tank, a valve (10) connected to a water supply and said buffer tank (2), so as to add fresh water, measuring means (7) of the amount of fresh water added, a purge valve (8b) of said buffer tank, in that said regulating means (50) further comprises a fresh water supply control module (53), using as input: the water level in the buffer tank (80), the maximum height setpoint of the water in the buffer tank (81), the number of bathers entering the pool enclosure (70), the supply setpoint in new water per incoming bather (83), and in that: the corrective action consists of a fresh water supply, said modules for regulating the disinfectant concentration (51) and the pH regulator (52) also use, as input, information generated by said freshwater supply control module (53).

10. Control method according to claim 9, characterized in that said supply of new water is preceded by a partial purge of the buffer tank.

11. The method of regulation according to one of claims 9 or 10, characterized in that said regulating means (50) further comprises a module for regulating the concentration of undesirable products in water (54) which uses input the following data:

• the concentration instruction in undesirable products (91),

• the concentration of undesirable products in water (92), "the temperature of the water (63),

• the air temperature (64), and in that said new water supply control module (53) further uses as input information generated by said unwanted product concentration control module (54).

12. Device for regulating at least two internal liquid parameters of a hydraulic circuit as a function of at least one external parameter, said internal parameters being sensitive to at least one parameter external to the liquid, said hydraulic circuit comprising: a storage volume (1), comprising an inlet and a liquid outlet,

A liquid circuit (3a, 3b, 3c, 3d) connected to said water inlet and outlet of said storage volume (1),

A liquid circulation means (4), at least one sensor of said internal parameters,

At least one sensor of said external parameter, At least two actuators each for varying one of said internal parameters, characterized in that it further comprises regulating means (50) for regulating said internal parameters as a function of a measurement of the external parameter, a measurement of each of the internal parameters, of at least one setpoint value for each of said internal parameters, of a corrective action applied to at least one other internal parameter, said means being able to generate a control signal for said actuators.

13. Device according to claim 12, characterized in that it applies to a swimming pool and in that the storage volume is a bathing basin, the liquid being water.

14. Device according to claim 13, characterized in that: the internal parameters are the concentration of disinfectant and the pH of the water, the external parameter is the number of bathers entering the enclosure of the pool, and said actuators are a disinfectant pump (1 Ib), able to add disinfectant to water, an acid pump and / or base (12b), able to add an acid or a base to water.

15. Device according to claim 14, characterized in that said regulating means (50) comprises a module for regulating the concentration of disinfectant in water (51), said module using as input:

• the temperature of the air (64), * the temperature of the water (63),

• sunshine (62), * the set concentration in disinfectant (61),

• the concentration of disinfectant (60),

• measurement of the number of incoming bathers in the pool enclosure (70), ® information on the added volume of new water, and that the corrective action consists of an addition of disinfectant in the water.

16. Device according to claim 14 or 15, characterized in that said regulating means comprises a water pH regulation module (52), said module using as input:

the pH of the water (71), the pH set point (72),

® information generated by said disinfectant concentration control module (51), ® information on the amount of new water added, and that the corrective action is an acid or base addition in the 'water.

Device according to claim 16, characterized in that: said circuit further comprises: a buffer tank (2) connected in series in said circuit, at least one level sensor of said buffer tank (9), a valve (10) connected to a water supply and to said buffer tank (2), so as to add fresh water, a purge valve (8b) of said buffer tank, said regulating means (50) further comprises a control module of supply of fresh water (53) which uses as input: the water level in the buffer tank (80), the maximum height setpoint of the water in the buffer tank (81), The measurement of the number of bathers entering the swimming pool enclosure (70), the new water intake regulation according to the bather inputs (83), and in that: the corrective action consists of a contribution of In new water, the disinfectant concentration (51) and pH (52) control modules additionally use, as input, information generated by the new water supply regulation module (53).

18. Device according to claim 17, characterized in that said regulating means (50) further comprises a module for regulating the concentration of undesirable products in water (54) which uses as input: β the concentration of undesirable products in water (92),

• the concentration instruction in undesirable products (91),

* the water temperature (63), β the air temperature (64), and in that the new water supply control module (53) also uses as input information generated by said module of water regulating the concentration of undesirable products (54).