WO2015071511A1

WO2015071511A1 - Industrial refrigeration system

Info

Publication number: WO2015071511A1
Application number: PCT/ES2014/070762
Authority: WO
Inventors: Vicente ÁVILA CHILLIDA
Original assignee: Ávila Chillida Vicente
Priority date: 2013-11-18
Filing date: 2014-10-07
Publication date: 2015-05-21
Also published as: EP3073214A4; EP3073214A1

Abstract

The invention relates to an industrial refrigeration system consisting of various independent refrigerating units (4), where each refrigerating unit (4) is installed in a thermally and acoustically insulated piece of furniture. The refrigeration system comprises a single heat dissipation unit (6) connected by a pipeline by means of a water ring (5) from which branches extend to each of the refrigerating units (4). Each of the refrigerating units (4) and the heat dissipation unit (6) are provided with individual electronic control devices which are connected to each other and to a control centre.

Description

INDUSTRIAL REFRIGERATION SYSTEM

DESCRIPTION

OBJECT OF THE INVENTION

The present invention relates to an industrial refrigeration system comprising a single heat dissipation system connected by a water ring pipe to a series of cooling units. It has application especially in the food, pharmaceutical, medical and funeral industries.

Find special application in the field of air conditioning system installation industry.

TECHNICAL PROBLEM TO BE RESOLVED AND BACKGROUND OF THE INVENTION

A variety of refrigeration systems focused on keeping the temperature constant in a given environment are known in the current state of the art.

In most existing systems, however, there are usually two cases that divide current technology.

The first of these is a cooling system consisting of a central unit from which the entire refrigeration cycle is carried out. These systems have a series of centralized compressors and condensers and of the appropriate size to be able to generate the volume of refrigerators necessary to reach the working conditions in the specified area.

The other system consists of having a centralized zone and, in the specific places where a certain temperature is required, the individual refrigeration units are available. The problem with this model is that the coolant performs the entire circuit, causing losses in the system due to communications junctions.

In both systems, the problem comes from the heat generated in the condensers, which heat the same area that is intended to cool. The present invention solves these problems by means of a system formed by individual refrigerant units in which condensation is produced in a system in which heat is evacuated by means of a pipe that leaves the enclosure that is being cooled to reach a heat sink. hot. Heat dissipation is carried out by a water exchange unit, by coolant or by geothermal energy.

DESCRIPTION OF THE INVENTION

The present invention relates to an industrial refrigeration system composed of several independent refrigeration units focused on both preservation and freezing, in which each refrigerating unit is installed in a thermally and acoustically insulated furniture.

The cooling system comprises a single heat dissipation unit connected by a water ring pipe from which shunts to each of the cooling units come out.

Each of the refrigeration units and the heat dissipation unit are equipped with individual electronic control equipment.

In a first embodiment, the refrigeration units comprise two compressors, of alternative and never simultaneous operation, so that it can continue cooling by one of the compressors even if the other compressor is damaged.

In a second embodiment, each refrigeration unit comprises a single inverter compressor, varying the frequency of the compressor's power supply according to the demand for cooling power and maintaining the operation within the optimum operating curve.

In the second embodiment, the refrigeration units comprise a gas / liquid heat exchanger that takes advantage of the return of the refrigerant in the gas phase when it returns from the evaporator to the refrigeration unit towards the inverter compressor to further lower the temperature of the refrigerant leaving the exchanger of condenser heat in liquid phase before it reaches the expansion valve. The individual electronic control units of each of the components are connected to each other and are also connected to a control unit that receives information on the status of all the components of the installation and has the capacity to detect warnings and alarms.

When a warning or alarm is detected, it is sent via SMS or email to an electronic device from which you can intervene remotely on the system or on any of the individual system components.

BRIEF DESCRIPTION OF THE FIGURES

To complete the invention that is being described and in order to help a better understanding of the features of the invention, according to a preferred embodiment of the invention, a set of drawings is attached where, for illustrative purposes and not limiting, the following figures have been represented:

- Figure 1 represents a first embodiment of a refrigeration and hydraulic scheme of a refrigeration unit with two compressors.

- Figure 2 represents a refrigeration and hydraulic scheme of the cooling system.

- Figure 3 represents a second embodiment of a refrigeration and hydraulic scheme of a refrigeration unit (4) with inverter compressor.

The following is a list of the references used in the figures:

1. Evaporator.

2. Fan.

3. Expansion valve.

4. Refrigeration unit.

5. Water ring.

6. Heatsink.

7. Compressor.

7 '. Inverter compressor

8. Heat exchanger.

9. Flow switch. 10. High pressure switch.

1 1. Low pressure switch.

12. Dehydrator filter.

13. High pressure probe.

14. Low pressure probe.

15. Pressure valves.

16. Suction pressure probe.

17. Suction temperature probe.

18. Coolant tank.

19. Liquid temperature probe.

20. Gas / liquid heat exchanger.

21. Water temperature probes.

22. Oil recovery.

23. Discharge pressure probe.

24. Discharge temperature probe

25. Capillary liquid cooler.

26. Suction vessel.

DESCRIPTION OF A PREFERRED EMBODIMENT OF THE INVENTION

The present invention relates to an industrial refrigeration system focused on both preservation and freezing, consisting of individual refrigeration units (4), a common dissipation system and a management system for the regulation and control of the elements of both individually as jointly throughout the installation.

The application of the system is especially suitable for the food, pharmaceutical, medical and hospitality industries, although it is not exclusive.

The refrigerating units (4) are compact units, of horizontal construction under furniture, with function of capturing heat from food. One of the main characteristics that defines the system of the present invention is that the refrigeration units (4) can be incorporated in solidarity in a linear refrigerator cabinet, a showcase or a freezing island.

The dissipation system comprises an individual dissipating element (6) common to all the system for indoor or outdoor mounting, with heat dissipation function captured by the different cooling units (4) through the common coolant.

The management system for regulation and control is a system composed of a software program and electronic elements with remote management function that is responsible for food safety, energy efficiency control, system alarm management, modes of operation and protection of communication systems. The control system can be given in face-to-face format or in remote format via web, GPRS or standard telephone line.

As shown in Figure 1 in a first embodiment in which it has focused on the food industry, the refrigeration units (4) have redundant 1 +1 systems for capturing feed heat. These are two identical and totally autonomous compressors (7). This redundant system is realized in such a way that the compressors (7) come into operation alternately, one at a time, so that the time of use of both is similar. In the same way, if one of the compressors (7) fails, the operation of the system would not be affected, since the second compressor (7) is available.

Each refrigeration unit (4) also has an individual control automaton for the handling, management and communication of each of the elements of the refrigeration unit (4), through its own management software. The global system recognizes each refrigeration unit (4) individually to take control of the management of the entire system.

The system has a heat sink element (6), common for all refrigeration units (4), which has, without having been shown in the figures, a heat exchanger, a water inertia tank, and redundant pump recirculation of the closed water circuit. The management of the mode of operation, the management of alarms and the efficiency of the heat sink (6) is carried out by means of proprietary software in an automaton installed in the own furniture of the heat sink (6).

The own management system communicates each and every one of the elements of the system independently through a Modbus communications network with an open protocol, in a secure way and protected against external attacks. The system counts with a program of management of the mode, efficiency and alarms individually and globally.

The implementation of the system of the invention allows a series of advantages that are described below.

1. Adjust cold production to demand. The start-up of a refrigeration unit (4) occurs exclusively when an increase in temperature is detected in that particular area. Each refrigeration unit (4) has independent evaporators (1) and is controlled by the temperature of the product.

2. Reduction of electricity costs. The individualized management of the system components, counting each individual refrigeration unit (4) with its own compressors (7, 7 '), as detailed above, the condensation at low temperatures working the refrigeration units (4) at low temperature condensation by means of a water ring (5), the use of outside temperatures, the intelligent management of defrosts through the introduction of control automatons that also manage the electronic expansion valves (3) and the rotation of compressors (7), the Proportional evaporation and the remote control of the setpoints, allow to offer the most efficient cold food system on the market.

3. Maximum energy efficiency. Condensation at very low temperatures by means of a water ring (5), the control of overheating by thermostatic expansion valves (3) and the management of defrosts by necessity and not by routine, and the use of free-cooling in the ring ( 5), regardless of the outside temperatures and the use of these temperatures in intermediate and winter seasons guarantees the maximum efficiency of the compressors (7, 7 ').

4. Elimination of costs due to leaks. The individual design of each refrigeration unit (4), requires minimum refrigerant charges and has been replaced by mechanical joints by welding. The refrigeration units (4) will be factory tested by means of a 30 bar break test and leak detection, and will be delivered preloaded.

Environmental impact reduction. Due to the elimination of refrigerant leaks the individual refrigeration units (4) through the use of multiple watertight circuits with a minimum amount of refrigerant in each of them.

6. Control of technical alarms. The system is equipped with components and open communication protocols for each and every one of the refrigeration units (4), sending remote and instantaneous information to the central alarm, on any incident of each of the elements considered critical, by SMS and / or email, of the selected alarms.

7. Reduction of installation, maintenance and renovation costs. Use of economic elements for installation, possibility of realization by unskilled personnel and simplicity of the system and use of refrigeration units (4) that do not require special elements depending on their location.

8. Efficiency management. Remote control of all the elements of the system both to be able to act on them and to obtain historical operation that allow to increase the efficiency of the system and that serves to perform preventive maintenance.

9. Records. Compliance with current regulations regarding the traceability over time of product temperatures as well as the necessary records for the analysis of energy efficiency and the need for scheduled maintenance.

10. Redundancy. Provision of all critical redundancy components through duplication in order to guarantee the food cold chain in the first embodiment.

1 1. Sound Level. Minimum sound level both inside the sales room and outside through the use of low sound emission elements equipped with fairings and thermal and acoustic insulation.

The cooling system is as described below.

Each cooling zone has a moto-compressor producing equipment that is connected to the evaporator system (1), including a thermostatic expansion valve (3). The condensation of the refrigerant is carried out by water.

The cooling of the condensation water is carried out with outside air in a dry-cooler or by means of a high-temperature and free-cooling chiller.

The control system of each evaporator-condenser-compressor set is included in each producing equipment, by means of an independent automaton and including the operating program of each set. The control system will have modbus communication.

Each refrigeration unit (4) has the drive and power protection elements of the evaporator-condenser-compressor assembly.

All evaporator-condenser-compressor assemblies, as well as the water cooling system, are connected via modbus to an electronic device, in which all the installation information will be received graphically and from which the drive can be accessed and status of each element and that will have the system of sending technical alarms immediately and records via SMS or email to a switchboard.

In one of the embodiments, the refrigeration units (4) have cooling redundancy and bypass system of the control automaton to an electromechanical system.

The hydraulic installation consists of a redundant pump with frequency variation control, automatic filling system expansion vessel, and fan redundancy.

In one of the embodiments, the refrigeration unit (4) redundantly has the following mechanical components:

- Two horizontal rotary compressors (7) with silencer for HFC / HFCS refrigerant.

- Two exchangers (8) of water-cooling condenser plates. - A dehydrator filter (12).

- Independent water service keys by plate exchanger.

- General water service keys.

- High (10) and low (11) pressure switches in each refrigeration circuit (pressure probes).

- Pressure valves (15) solenoids in refrigeration circuits.

- Manual operated coolant keys.

- Flow switch (9).

- Condensation control by water flow regulation.

The refrigeration unit (4) also has the following electrical components:

- Control automaton.

- Electronic expansion valve (3) (linear).

- Suction and discharge temperature probes, (linear suction).

- Water inlet and outlet temperature probes.

- Humidity detector.

- Power contactors for contactors.

- Magnetothermic for compressor protection (7).

- Magnetothermal for protection of maneuver and control.

- Manual auto-stop selector.

The automaton incorporated in the refrigeration unit (4) has an indicator and operating screen in any of the locations in which it is located, whether it is a linear refrigerator cabinet, a showcase or a freezing island.

- Compressor timing routines (7).

- Compressor rotation management (7).

- Communication via modbus with the management software.

- Proportional management of the electronic expansion valve (3).

- Intelligent defrost management.

- Management, where appropriate, of anti-fog systems.

- Routines of alarms and protections.

- Management of fans (2) and evaporators (1).

The refrigeration system also incorporates a comprehensive management and control system for the Efficiency and alarms.

Among other functions, this control system performs remotely or from the touch screen:

- Modification of setpoints.

- Time programming.

- Immediate high temperature alarms in refrigeration.

- Limitation of maximum and minimum adjustments.

- Immediate communication failure alarm.

- History of consumption.

- History of technical alarms and incidents.

- Subcooling and reheating history.

- Modification of parameters in automatons.

- Predictive maintenance notices required.

- SMS and email notification system.

The hydraulic network of the cooling system is arranged from the water cooling unit or dry-cooler to the refrigeration units (4), by means of uninsulated plastic pipe closing the ring circuit and making the corresponding derivations to each cooling unit (4).

The diameter of the pipe will be that corresponding to a water velocity of less than two meters per second corresponding to the maximum instantaneous flow.

A particular feature of the refrigeration system of the present invention is in regard to the routine of working at high temperature of the water, whereby the cooling of the condensation water can be carried out with the ambient air by using a dry-cooler or, where appropriate and, in order to reduce the consumption of the compressors (7) of the refrigeration units (4) terminals, install an air condensed water chiller with free-cooling system to work at a lower temperature and reduce the electrical consumption .

The dry-cooler or the water chiller will always have fan redundancy. Depending on the installation, the fans will be axial or radial. The dry-cooler or the chiller are also communicated to the control unit and to the refrigeration units (4) to check their condition.

In a first embodiment described below, the refrigeration unit (4) has two single stage compressors (7). The capacity of the compressors (7) is redundant. Only one compressor (7) will work on demand. The two will never work at the same time. A rotation of operating hours between compressors (7) FIFO will be established.

Standard programmable start-up timings will be established, between compressors (7), minimum operating time and minimum stop time.

Each of the compressors (7) will have an operating hours counter with maintenance notice.

Together with the compressor activation signal (7), a second signal in solidarity with it is available for activation of pressure valves (15) circuit solenoids. There is a programmable delay timing between the two signals, so that first the solenoid pressure valves (15) are activated and then their corresponding compressor (7).

As for the protections available to the system, the following can be listed:

Each compressor (7) has a winding thermal. This alarm is not timed. For the corresponding compressor (7) and activate the twin compressor (7).

In general liquid line a high pressure probe is available. An alarm setting is available as well. This alarm is timed at the start of the compressor (7) while the pressure pressure valve (15) is opened. Once the timing has elapsed at the time of alarm, the corresponding compressor (7) will stop.

When the high pressure switch trip (10) occurs, the compressor signal (7) is deactivated, but the activation signal of the solenoid pressure valves (15) is keeps active for a programmable time to gain speed in pressure balancing. Then the twin compressor (7) is driven.

In general, a low pressure probe is available. A Programmable Trigger Setting is available.

Trigger activation is timed.

Triggering a low alarm does not lead to compressor shutdown (7). The automatic manual reset routine is available. If a programmable number of shots occurs during a predetermined time, it will go to manual reset.

When the low pressure switch (1 1) is triggered, being in automatic reset mode if the twin compressor (7) does not enter, the same compressor (7) will be activated again after the reset.

If manual reset trip occurs, the compressor signal (7) is deactivated, but the activation signal of the solenoid pressure valves (15) remains active for a programmable time to gain rapid pressure balancing. Then the twin compressor (7) is driven.

There are two differentiated digital inputs for water level alarm: water unit input and high water level in the linear tank.

This alarm does not stop the compressor (7), it is simply informative.

There is an entrance for door contact. At the moment of activation, the compressors (7), fans (2) and evaporator (1) always stop.

The activation of this alarm occurs on a scheduled basis. It has a schedule / daily in which it is established when the door contact emits an alarm, communicating it via modbus.

If the opening occurs during the time program in which it is uninhibited, but the opening time exceeds one previously programmed in minutes, will produce the alarm warning and start the corresponding compressor (7).

The refrigeration unit (4) has the different defrosting options common in the cold food maneuvers, but in addition the defrosting maneuver can be inhibited by daily time programming, so that defrosts are not carried out during a certain period of time and with the option to establish on which days of the week that inhibition occurs.

High temperature alarms should not occur during defrosts.

You have the option of setting the last temperature on the linear screen before starting defrost.

The evaporator fan (2) maneuver (1) is the standard for island cooling, linear furniture and display cabinets for both preservation and freezing.

In the fans (2) of the evaporators (1) the option of a digital flow switch input will be available. This entry will be informative and will not cause the shutdown of compressors (7) or fans (2).

At the set points, the adjustment of the refrigeration unit (4) will be by temperature.

Three inputs are available for NTC probe. One of them in evaporator battery for defrost routines and the other two for temperature readings in the linear (drive and product or return and product).

By program it is selected which of the two temperature probes is the one that acts as a set point.

The setpoint has the possibility to change by schedule; A minimum of three time phases per day will be available.

Both the setpoint and the schedule must be remotely modified via the communication bus. High temperature alarm with differential and time delay is available. In addition there is a time schedule by which the alarm can be disabled during certain daily periods of time.

The temperature alarm does not work in defrosts or with the door contact open (according to the routines indicated above).

The high temperature alarm is communicated via modbus.

By way of understanding the operation of the system, a brief summary follows.

When the temperature probe of the food product detects that the temperature rises above the set point set, the PLC issues a start order of one of the redundant systems as specified in the program maneuver.

When activation is performed, the compressor (7) raises the pressure and temperature of the refrigerant in the gas phase, sending it to the heat exchanger (8) of the water refrigerant.

In the heat exchanger (8), the refrigerant condenses by giving energy to the water, reducing its sensitive temperature and enthalpy but maintaining the constant pressure (in fact, the pressure is reduced by the effect of friction 0.5 bar).

Due to the movement of the compressor (7), the refrigerant exits in the liquid phase of the heat exchanger (8) at a condensing temperature between 35 ° and 50 °, being sent to the evaporators (1) located on the linear, wall or island .

Before entering the evaporator (1), the refrigerant, in liquid phase, passes through an automatically adjustable expanded orifice located in the expansion valve (3).

In the expansion system the liquid refrigerant reduces its pressure to a certain evaporation temperature (variable depending on the type of food to be refrigerated).

In the evaporator (1) the liquid refrigerant evaporates by capturing the energy of the product to be cooled, leaving the evaporator (1) in the gas phase.

When the refrigerant in the gas phase leaves the evaporator (1) it returns to the aspiration of the compressor (7) to repeat the process.

This process is repeated until the temperature of the food drops to the desired set point.

When the demand reoccurs, the automaton starts the twin compressor (7) so that the operating hours of the compressors (7) are kept matched.

When the cooling unit (4) has no demand for heat collection, the entry of water to the plate exchangers (18) is interrupted by the action of the pressure switch valve (15).

The heat dissipated in the plate exchanger (8) from the food is transferred to a volume of water that is maintained in recirculation by means of closed-circuit water recirculating pumps.

The system collects all the water from the different refrigeration units (4) that are running, sending them by means of a water recirculation pump to the heat sink (6).

The recirculation pumps regulate the flow that they move, necessary for the operation of the system, by means of a frequency inverter commanded by a differential water pressure probe that keeps constant the pressure difference between the suction and the pump drive.

The water passes to a heat exchanger (8) water-air, through which the heat collected in the refrigeration units (4) food terminals to the outside air is transferred.

Figure 3 represents a refrigeration scheme of a production unit (4) in a second embodiment in which the refrigeration units (4) use individual inverter compressors (7 ') instead of the traditional compressors (7) in redundant mode mentioned above. In this embodiment, the incorporation of a gas / liquid heat exchanger (20) between the invert condenser (7 ') and the evaporator (1) that takes advantage of the return of the refrigerant in the gas phase when returning from the evaporator (1) is also contemplated. ) to the refrigeration unit (4) towards the inverter compressor (7 ') to further lower the temperature of the refrigerant leaving the heat exchanger (20) of the condenser in liquid phase before it reaches the expansion valve (3) to enter the evaporator (1).

This new embodiment is due to the fact that the inverter compressors (7 ') do not stop working as the target temperatures are reached, as is the case with traditional compressors (7), but rather a decrease in the speed of the inverter compressor occurs (7 '), so that it focuses on maintaining this temperature. In the absence of starts and stops, the inverter compressor (7 ') does not suffer so much and it is not necessary to incorporate a redundant system for the prevention of breakdowns.

In figure 3 it can be seen how the water from the closed ring (5) enters and exits the heat exchanger (8) of each of the cooling units (4) controlled by two water temperature probes (21).

On the other hand, the refrigerant, coming from the evaporator (1) and after passing through a pressure aspiration probe (16) and through a temperature probe (17), arrives at the gas / liquid heat exchanger (20) to go to the inverter compressor (7 ') and continue to enter the heat exchanger (8) of the condenser. As when leaving the evaporator (1), at the outlet of the inverter compressor (7 ') the refrigerant passes through a pressure discharge probe (23) and through a temperature discharge probe (24).

At the outlet of the inverter compressor (7 ') the refrigerant passes through an oil recuperator (22) which is responsible for collecting part of the oil incorporated in the refrigerant and taking it to a liquid cooling capillary (25) in which it condenses.

Subsequently, the refrigerant leaves the heat exchanger (8) after having transferred the heat to the water of the ring (5) to go to a gas / liquid heat exchanger (20), incorporated with the aim of providing greater efficiency to the system.

In the refrigerant circuit there is also a refrigerant tank (18) so that the circuit is over-supplied and refrigerant is absorbed according to the necessary quantities.

From the outlet of the gas / liquid heat exchanger (20), the refrigerant leaves the refrigeration unit (4) to go to the expansion valve (3) and to the evaporator (1), both elements already represented in Figure 2, which represents a refrigeration and hydraulic scheme of the cooling system.

As shown in Figure 2, the system is mainly composed of a water ring (5) connected to a heat sink (6). From the water ring (5) outlets to the heat exchanger (8) of the condensers (7, 7 ') of the different cooling units (4) that make up the system. On the refrigerant side, the refrigeration units (4) are connected to the evaporators (1) through the expansion valves (3). The system represented in Figure 2 is valid for both forms of representation, with traditional redundant compressors (7) and with inverter compressors (7 '). In the same way, the common heat dissipation system described for the first embodiment with traditional compressors (7), is also valid for the second embodiment with inverter compressors (7 ').

The operation of the circuit for the second embodiment is as follows:

When starting, the inverter compressor (7 ') raises the pressure and temperature of the refrigerant in the gas phase, sending it to the condenser.

In the heat exchanger (8) of the condenser, the refrigerant condenses by giving energy to the water, reducing its sensitive temperature and enthalpy but maintaining the constant pressure.

The refrigerant exits in the liquid phase of the heat exchanger (8) of the condenser at a condensing temperature between 35 ° and 50 °, being sent to the evaporator (1).

In the expansion system the liquid refrigerant reduces its pressure to a temperature of evaporation determined (variable depending on the type of product to be refrigerated).

In the evaporator (1), the liquid refrigerant evaporates by capturing the energy of the product to be cooled, leaving the evaporator (1) in the gas phase.

When the refrigerant in the gas phase leaves the evaporator (1) it returns to the aspiration of the inverter compressor (7 ') to repeat the process.

This process is repeated until the temperature of the product to be cooled drops to the desired set point.

As an improvement in energy efficiency, an energy transfer occurs in a gas / liquid heat exchanger (20) between the liquid phase refrigerant at the outlet of the condenser heat exchanger (8) and the gas phase refrigerant when it returns from the evaporator (1) to the refrigeration unit (4) towards the inverter compressor (7 ').

The heat dissipated in the heat exchanger (8) of the condenser from the products is transferred to a volume of water that is maintained in recirculation in a closed ring system (5) by means of water recirculation pumps that are located in the heat sink (6), not shown in the figures.

The system collects all the water from the different cooling units (4) that are running by sending them to the water ring (5) by means of the water recirculation pumps until they reach the heat sink (6).

The recirculation pumps regulate the flow that they move, necessary for the operation of the system, by means of a frequency inverter commanded well by a differential water pressure probe that keeps constant the pressure difference between the suction and the pump drive or by the modulating output that the control board of the unit has for water flow management.

In the heat sink (6), the water passes through a water-air heat exchanger, by means of which the heat captured in the terminal cooling units (4) is transferred to the outside air. The advantages of the refrigeration system of the present invention, in any of its two forms of representation, are the following:

1. Greater energy efficiency, by increasing the refrigeration capacity compared to a reduction in consumption.

The highest energy efficiency occurs both in the terminal refrigeration units (4) and in the ring cooling unit (5).

In the refrigeration units (4) terminals the efficiency is produced by the reduction of the condensation temperature by being able to work with low temperatures of hot water in the condenser being able to work with water 30 ° c / 35 ° C and condense at 40 °, by below the facilities of plants that condense at 50 ° C. This reduction of condensation positions the refrigeration units (4) terminals with POPs close to 3, instead of POPs with a value close to 2 that can be achieved with the gas central system.

In the chiller unit of the ring (5), in seasons with outside ambient temperature below 25 ° C, the compressors (7) of the chiller unit will not need to start, due to having these freecooling drycooler type and the installation in the chillers of adiabatic cooling of the air entering the batteries.

On the other hand, with temperatures above 25 ° C, because the cooling of the water is done only with jumps of 30 ° C / 35 ° C, instead of the typical 7 ° C / 12 ° C of a chiller, they can achieve COP close to 5, efficiency superior to that of any other system.

2. Simultaneity. The regulations and good work indicate that production must meet demand.

In a hot ring system, cold production is adjusted exactly linear to linear, since only individual compressors (7) that have a cold demand from the linear would work.

In centralized systems, despite having partitions in the compressors (7) and even to have some central frequency variation systems in the compressors (7), there are many moments in which the minimum production of the gas plant is higher than the demand of a few linear, then producing an expense of unnecessary energy.

This adaptation of the production to the demand reduces energy consumption considerably.

3. Lower refrigerant load in the installation, since the refrigerant is concentrated exclusively in compact refrigeration units (4) without the need to move kilograms of refrigerant through the pipes of the installation.

The refrigeration units (4) are supplied pre-charged from the factory, both the chiller and the terminal refrigeration units (4), which are equipped with quick connections for easy installation, so it is not necessary for the installer to incorporate No refrigerant gas charge during the assembly process.

We reduce the cost of the installation with respect to the classic plants by not using transported refrigerant gas and drastically reduce the cost of maintenance and the cost of leaks.

4. Pipe losses, due to temperature transmission. Although attempts are made to mitigate these losses, it is easy to see that the transmission between the ambient temperature and the pipes with very cold media, at -30 ° C or -5 ° C, both in coolant plants and in water plants, these losses will be greater than if the fluid is between 30 ° and 35 ° C, in fact and in a very possible way the pipe of the hot ring (5) will not be necessary to insulate, since the losses in the false ceilings will be minimal and otherwise, to occur , come well to the operation of the installation.

With hot ring (5) not only transmission losses are eliminated but also the cost of installation is eliminated by removing the insulating shell.

5. Freezes. Naturally, the need to use glycol water is eliminated because it is hot water. 6. Maintenance In the case of compact units with hermetic compressors (7, 7 ') both in the chiller and in the terminal refrigeration units (4), the economic cost of maintenance is drastically reduced.

On the other hand, since they are unit and compact productions, the problems existing in the expansion plants, in the concepts of liquid blow in the compressor (7, 7 ') and oil maintenance control, disappear completely.

7. Reduction of installation cost. The installations of expansion plants, the installation of pipes must be carried out in copper and insulation pipes, using welding and pressurization and vacuum systems.

In hot water systems plastic is used, without insulation and with normal water valves, so the cost of the installation is drastically reduced compared to any other system.

8. The linear ones are the market standards. No special transformation is necessary as it is a normal refrigerant, and not C02.

9. Compact refrigeration units (4), and simple to install. The philosophy of the units is plug & play, simply connect the evaporator (1) in quick connections, feed the single-phase current and connect the hot water ring (5). The unit is ready to operate.

On the other hand, the expensive and "complicated" electrical panels existing in the expansion plants disappear completely, as the chillers have their own individual panel, and the refrigeration units (4) also have their own. Since it is possible to communicate via modbus loop all the refrigeration units (4), there is a total system of tele-management, management and control of each and every one of the producing units (4).

It is simply necessary to have a power panel with a series of magneto-thermal and single-phase differentials to protect the power lines, since each of the refrigeration units (4) already have their own electrical protection elements. On the other hand, these power panels can be equipped with auxiliary trip contacts that are remotely controlled at the alarm and control receiver.

As they are refrigeration units (4) terminals of very small dimensions and chillers that can be designed with a modular philosophy, the replacement of classic systems of expansion plants is very simple.

On the other hand, the problem disappears that when the plant falls the entire cooling system disappears.

Finally, we must consider that the pre

I established invention should not be limited to the embodiment described herein. Other configurations can be made by those skilled in the art in view of the present description. Accordingly, the scope of the invention is defined by the following claims.

Claims

1. - Industrial refrigeration system composed of several independent refrigeration units (4) focused on both conservation and freezing, characterized in that:

- each refrigeration unit (4) is installed in a thermally and acoustically insulated furniture, and

- the refrigeration system comprises a single heat dissipation unit (6) connected by a pipe by means of a water ring (5) from which branches to each of the cooling units (4) leave, and each of the cooling units being (4) and the heat dissipation unit (6) equipped with individual electronic control equipment.

2. - Industrial refrigeration system according to claim 1, characterized in that the refrigeration units (4) comprise two compressors (7), of alternative operation and never simultaneous, to continue cooling even if a compressor (7) is damaged.

3. - Industrial refrigeration system according to claim 1, characterized in that each refrigeration unit (4) comprises a single inverter compressor (7 '), varying the frequency of power supply of the compressor according to the demand for cooling power and maintaining the operation within the optimal operating curve.

4. - Industrial refrigeration system according to claims 1 or 2, characterized in that the individual electronic control equipment of each of the components are connected to each other and are also connected to a control unit that receives information on the status of all the components of the installation and has the capacity to detect warnings and alarms.

5. - Industrial refrigeration system according to claim 4, characterized in that a detected warning or alarm is sent by SMS or email to an electronic device from which it is possible to intervene remotely on the system or on any of the individual components of the system .

6. - Industrial refrigeration system according to claim 3, characterized in that the refrigeration units (4) comprise a gas / liquid heat exchanger (20) which take advantage of the return of the refrigerant in the gas phase when it returns from the evaporator (1) to the refrigeration unit (4) towards the inverter compressor (7 ') to lower the temperature of the refrigerant that leaves the heat exchanger (8) of the condenser in phase liquid before it reaches the expansion valve (3).