FR2770623A1 - Retail sales establishment specific humidity control procedure - Google Patents

Abstract

The procedure consists of setting and maintaining the humidity inside a supermarket so that it is at a level of 1.8 - 3g/kg at a distance of 0.3 m from freezer cabinets (2); 3 - 4g/kg where the freezer cabinets are installed; 4 - 6g/kg at 20 m from them; 6 - 8g/kg in the general sales area; and 8 to 10g/kg in the market gallery. The air conditioners (3) for the building are set in the roof of the building (1) and controlled by regulators connected to sensors (5) to give the required humidity levels in the different areas.

Description

 The present invention relates to refrigerated cabinets and sales windows, installed in stores with large or medium sales area, which can maintain at low temperature food products offered for sale.

 In these refrigerated cabinets, one or more air curtains protect their speakers against the warmer and wetter ambient air, the cooling of the air stream (s) forming these curtains being ensured by means of refrigerating evaporators fed by a refrigerant.

 By the French patent No. 94.15547 (2728662) of the same applicant it has been proposed, to almost completely eliminate the formation of frost in the cold storage of sales equipping the food retail stores, to maintain in the near environment furniture (c that is to say in an area of less than one meter from the opening of this piece of furniture) a partial pressure of low water vapor by blowing into this zone of air whose specific humidity is less than or equal to at 3g / kg of dry air. The interior of the refrigerating cabinet is thus isolated from the ambient air with a high specific moisture content, which prevents the migration, inside the cabinet, of the water vapor contained in the ambient air.

 By the patent application No. 97.06776, also from the same applicant, there has been proposed a device designed to blow a laminar wall of dry air, with a specific humidity of between 0.5 and 3 g / kg of dry air in front of the Aeraulic curtain of a refrigerated furniture of sale.

 However, the applicant has found that it is economically undesirable to maintain, in a large volume, a small area with very low specific humidity. Indeed, a dry air wall with 2 or 3g / kg of specific moisture, according to the above-mentioned patent application No. 97.06776, in a general atmosphere at 8 or 9g / kg of specific humidity of a large amount. or average sales area is obviously expensive.

 The production of dry air at 1.5 or 2g / kg of specific humidity requires energy (electricity, gas, steam, heat discharges) and, even if this energy is (still to this day) inexpensive in the period when the specific humidity is high (half-season and summer), it should be used rationally.

 However, we notice that currently, in large and medium sales areas, cold food surfaces are no longer air-conditioned by the store's air-conditioning installations, and that it is the sales refrigeration units that self-condition the air-conditioning units. areas in which they are installed.

 The investment relating to air conditioning installations can be reduced, although often the facilities are completely completed, but they are stopped in the cold zone because they disrupt the operation of refrigerated sales furniture. On the other hand, this cooling of the cold surfaces with the refrigerated cabinets and showcases entails an expense, linked to the energy consumption, which is nearly two and a half times higher.

 The present invention therefore proposes, for a rational use of energy that makes it possible to reduce costs, new principles of air-conditioning of sales areas when these include large areas of cold food, so as to ensure the control of the specific humidity inside these sales areas.

As mentioned above, the refrigerated furniture of sale currently have a function of self-dehumidification of large and medium sales areas, and the applicant has found that it leads, within these surfaces, to metastable states of the world. specific humidity of the order of
at 0,30m furniture 5 to 6g / kg
in the installation area of furniture 6 to 8g / kg
at 20 m from the perimeter of furniture 8 to 9g / kg
in the sales area 9 to 11g / kg
in the gallery 10 to 14g / kg for theoretical ambient temperatures of 19 to 20C in winter and 25 to 270C in summer.

 Thus, naturally, depending on the hygrothermal conditions of such or such areas, significant differences in specific humidity and, consequently, vapor tension are naturally established in the same closed volume, certainly, but vast.

According to the invention, it is proposed to gradually control, depending on the distance of the refrigerated sales furniture, the specific humidity of the air from the sales areas to obtain
at 0,30 m of furniture 1,8 to 3g / kg
in the furniture installation area 3 to 4g / kg
at 20 m from the perimeter of furniture 4 to 6g / kg
in the sales area 6 to 8g / kg
. in the gallery 8 to 10g / kg
This control of the specific humidity inside the sales areas requires according to the invention a new design of packaging facilities and air handling units that generally condition large and medium sales areas.

 For this purpose, it is proposed to lower the condensing temperature of evaporators and batteries to increase the dehumidification phenomena of return air and fresh air.

 It is also proposed that the regulation of these devices comprises specific humidity management regulators. In particular, in the case of store refreshment provided by free outdoor air (so-called "free cooling" process), it will be necessary to control not only the temperature but also the specific humidity of the outside air, so to use this method only when the external dry temperature would for example be lower from 5 to 60C at the desired ambient temperature and lower from 2 to 3g / kg to the specific humidity prevailing in the store (within a radius of 20m since the perimeter of the surface of the food cold).

For a better understanding of the invention will be described hereinafter, by way of example without limitation, a preferred embodiment, with reference to the attached schematic drawing in which
Figure 1 is a schematic representation of a sales area with food cold zone and sound. conditioning system, giving the gradual slope of specific moisture and
Figure 2 is a perspective view of a device according to the invention for packaging a sales area.

 Referring to Figure 1, there is shown in 1 the volume of a large sales area, inside which is schematized in 2 a refrigerated sales cabinet in front of which is blown a laminar wall of dry air d specific humidity of between 1.8 and 3 g / kg.

 There is shown at 3 the air conditioning units arranged in the roof of the sales area, connected to air diffusers 4 placed at a lower height inside the volume 1. Probe devices, schematized in 5, capture the specific humidity inside the volume 1 to slave the conditioning apparatus 3.

Within zone 1 of the sales area, the following areas are distinguished: zone A: up to 0.3m from furniture 2 zone B: furniture installation area 2 zone C: 20 meters from the floor installation surface of
furniture 2 zone D: general area of the shop zone E: shopping arcade.

By means of the control of the conditioning system, the conditions of temperature and specific humidity indicated in the following tables are realized inside volume 1: a) in winter

<tb><SEP> zone <SEP> A <SEP> zone <SEP> B <SEP> zone <SEP> C <SEP> zone <SEP> D <SEP> zone <SEP> E
<tb> Tempe <SEP> 170C <SEP> 18 / 190C <SEP> 18 / 200C <SEP> 19 / 200C <SEP> 19 / 200C
<tb><SEP> erasures
<tb> Humidity
<tb><SEP> specific <SEP> 1,8 / 3g <SEP> I <SEP> 3 / 4g <SEP> 4 / 5g <SEP> 6 / 7g <SEP> 8 / long <SEP>
<tb> b) in the summer

<tb><SEP> zone <SEP> A <SEP> zone <SEP> B <SEP> zone <SEP> C <SEP> zone <SEP> D <SEP> zone <SEP> E
<tb> Tempe <SEP> 180C <SEP> 21 / 220C <SEP> 25 / 260C <SEP> 25 / 260C <SEP> 25 / 260C
<tb><SEP> erasures
<tb> Humidity
<tb><SEP> specific <SEP> 1,8 / 3g <SEP><SEP> 3 / 4g <SEP> 4 / 6g <SEP> 6 / 8g <SEP> 8 / 10g
<Tb>
FIG. 1 diagrammatically shows the gradual slope of the specific humidity inside volume 1, going from zone A to zone E.

 In Figure 2, there is shown an air conditioning apparatus according to the invention, the general type referred to as the "roof top", intended to be placed in the roof of the sales area.

 The device 6 comprises, at its lower part, a dehumidified air blowing outlet 7 between 4 and 6 g / kg with which is associated a specific humidity sensor 8. Laterally, also at its lower part, the device 6 comprises a duct 9 of ambient air intake which is associated with a specific humidity sensor 10. At its upper part the apparatus 6 has a mouth 11 for suctioning the outside air.

 To a specific moisture transmitting apparatus 12 are connected the probes 8 and 10, as well as a specific humidity ambient probe 13 and a specific outdoor humidity probe 14. A regulator 15 ensuring the management of humidity Specifically transmits to the apparatus 6, depending on the different specific humidity values sensed by the probes, the controls necessary to maintain the area of the sales area, in which the apparatus 6 is placed, at a specific humidity determined according to the invention.

 It will be understood that the above description has been given by way of example, without limitation, and that additions or constructive modifications could be made without departing from the scope of the invention.

Claims (3)

 1. A method for controlling the specific humidity inside the sales areas comprising a food cold zone characterized in that one carries out and maintains a conditioning of the air inside the sales area such that the specific humidity of the air is - from 1,8 to 3g / kg to 0,3m of the refrigerated furniture, - from 3 to 4g / kg in the installation surface of the  refrigerated furniture, - from 4 to 6g / kg at 20m from the installation surface of  refrigerated cabinets, - from 6 to 8g / kg in the general area, - from 8 to 10g / kg in the shopping arcade.  2. Device for implementing the method according to claim 1, characterized by the provision of air conditioning apparatus in the roof of the sales area, control means being associated with said air conditioning apparatus to control them in order to have in each zone of the sales area a specific humidity corresponding to the desired determined values.  3. Device according to claim 2, characterized in that said air conditioning apparatus comprises a dehumidified air outlet and outside air and return air inlets, specific humidity probes associated with this output and these two inputs being connected to a specific humidity transmitter, connected to a specific humidity regulator, ensuring the control of the conditioning apparatus according to the desired specific humidity in the area of the sales area where find the packaging machine.