EP1861664A1

EP1861664A1 - Integrated system for the production op hot and cold to be used simultaneously by cooling and heating units

Info

Publication number: EP1861664A1
Application number: EP06728503A
Authority: EP
Inventors: Mauriel Vicentini
Original assignee: Lambda SpA
Current assignee: Lambda SpA
Priority date: 2005-03-24
Filing date: 2006-03-23
Publication date: 2007-12-05
Also published as: ITVR20050038A1; WO2006100709A1

Abstract

An integrated plant engineering system for the production of hot and cold to be used simultaneously by cooling and heating units, the system using a machine (10) connected on one side to the user and output units (15) and on the other to the condenser units (13); the machine comprising at least one hot water production unit (11) and at least one cold water production unit (12), respectively comprising at least one exchanger (19), and at least one evaporation unit (23) which produces chilled water.

Description

"INTEGRATED SYSTEM FOR THE PRODUCTION OF HOT AND COLD TO BE USED SIMULTANEOUSLY BY COOLING AND HEATING UNITS"

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TECHNICAL FIELD This invention concerns a machine which, by means of an integrated system and adding a control unit for the production of hygienic cold with particular circuits and a number of heat exchangers, makes it possible to simultaneously supply the hygienic cold system, the heating system by generating hot water and the plumbing, sanitation and water services by generating hot water.

The same machine can also be used for the air- conditioning system, whether it is: a water-powered system; a direct expansion system; a mixed water-powered and direct expansion system. The technical field includes all commercial or industrial activities in which the generation of cold in order to carry out the activity is associated with thermal requirements due to the air-conditioning of the rooms in which the activities are carried out.

BACKGROUND ART

It is known that plants designed to produce cold used in the food sector by commercial or industrial businesses, represented for example by traditional refrigerated cabinets, normally use a system consisting of one or more motor-driven compressors coupled with one or more condenser units used by the coolers. Such equipment fulfils the commercial use for which it is designed, for example in cooling refrigerated cabinets or cold rooms, and industrial use, for example for freezing food or processing goods. In the businesses described above it may also be necessary to install air conditioning, and in this case another system is used, again consisting of a motor-driven compressor and a condenser unit used by the coolers which cool the air in the various rooms.

In turn, in these businesses in which the refrigeration units and the air-conditioning equipment is installed, there are also heating systems which may use:

- the inversion of the air-conditioning gas cycle described above and named "heat pump";

- the installation of a boiler to produce hot water for the air processing units;

- the installation of a hot air generator with the relative hydrodynamic distribution. The general problem for these traditional plant systems is that each system that supplies the thermal requirements indicated above, be it cooling or heating, needs one or more dedicated machines.

The immediate consequence of the use of several dedicated machines is a considerable overall waste in economic terms, due mainly to the need for space to be used as technical rooms, electrical systems and thermoregulation equipment. Each of these systems also has an initial installation cost and energy consumption needs (electricity or fuel) .

On the other hand, the use of the heat pump, that is to say the cycle inversion applied to the air-conditioning system, is not able to simultaneously produce cold for refrigeration and air conditioning, and heat, and cannot therefore be used for the purposes described above.

DESCRIPTION OF THE INVENTION

This invention proposes to provide a "centralised" system that can resolve most of the drawbacks described above .

The invention proposes in particular to provide a system which is able to simultaneously supply cooling units and heating units so that a single unit for the production of hot and cold can satisfy a wide variety of even opposite thermal requirements, whether they involve heating or cooling, avoiding the need to use one or more dedicated machines for each individual system. This is achieved by means of an integrated system for the production of hot and cold to be used simultaneously by cooling and heating units, the features of which are described in the main claim.

The dependent claims of the solution in question describe advantageous embodiments of the invention.

The main advantages of this solution, in addition to all those consequent to its construction simplicity, concern first of all the fact that in the commercial or industrial activities in which the generation of cold necessary to carry out the activity there is also a thermal requirement due to the air conditioning of the rooms in which the activities are carried out, these advantages being: first of all, winter heating is obtained without the use of additional energy with respect to what is already used for the normal functioning of the cooling system;

- the system will be smaller than the sum of all the systems with the same power which would otherwise be used for the purposes it can offer; this will allow the use of a single technical room equivalent to little more than a machine for the production of hygienic cold with the advantage of also serving the air-conditioning system and the heating system; lower energy consumption, thus lower energy requirements and reduced electrical system dimensions (control panels, cables, components) with respect to systems needing several machines each;

- reduced use of materials for the construction of the systems with a relative reduction of labour and thus in the time required for construction; less use of cooling gas with a consequent reduction in environmental impact; longer working life of the compressors due to a more consistent and constant use; greater reliability of the system thanks to electronic and mechanical control that regulates the functioning priority of the various units in the event of faults;

- unified electronic controls for management of the various units by the user, also by remote control;

- possibility of having air-conditioning systems with summer and winter humidity control guaranteed by the availability in both seasons of hot water and cooled water, all with just one machine;

- maintenance of just one machine instead of several;

- possibility of using the machine for just one of the systems for which it is designed, thus preparing it for future systems; in changing over to the new system, the machine can easily be installed in place of one of the machines that was formerly used by one of the systems the new machine is designed for; - just one intermediary to obtain the best service and product to satisfy the requirements for the various types of systems.

This invention concerns a machine which, by means of an integrated plant engineering system, can satisfy the thermal requirements of a cooling system and, if required, an air-conditioning system guaranteeing, without any additional energy consumption, the requirements of a heating system and/or plumbing, sanitation and water services or other systems requiring heat.

The purpose of a cooling system or an air-conditioning system is to generate cold (better defined as the removal of heat) in a certain environment which, in the case of cooling systems, is a well-defined and well thermally insulated area, such as for example a refrigerated cabinet or a cold room. In the case of air-conditioning systems, it is a building with heat loss and heat entry from the exterior. In both cases the machines which power these systems absorb electrical energy and produce heat as a waste product which is dispersed into the environment.

The principle of the machine according to the invention is the recovery of the heat removed from the air- processed spaces (cold rooms, building) plus the heat generated by the mechanical functioning of the compressors almost equivalent to the electrical energy absorbed (electrical absorption), which would otherwise be completely lost in the environment, and its use for a series of functions which need this energy in the form of heat.

The creation of the machine starts with the construction of a unit for generating hygienic cold that uses cooling gas compressed and then expanded to remove heat from a thermally insulated environment, generally represented by refrigerated cabinets and cold rooms.

Compressors are used to compress the gas, while condensers are used for condensation of the gas (change from gas to liquid). Finally, expansion valves connected to an exchange battery, consisting of an evaporator, are used to expand the liquid gas .

For the production of cold for air-conditioning a tube nest (or plate) evaporator is used, while in order to recover the hot water heat another tube nest (or plate) exchanger is used.

The machine can consist of modular structures, for example with standard europallet dimensions, specifically constructed to be assembled by the installer after transport to the final technical room, in order to satisfy the requirements of size and space in activities located in old buildings or which in any case have a limited amount of space available.

DESCRIPTION OF THE DRAWINGS

Other features and advantages of the invention will become evident on reading the following description of one embodiment of the invention, given as a non-binding example, with the help of the accompanying drawings in which: figure 1 is a schematic view of the system according to the invention comprising the machine and the integrated plant engineering system, the external unit and the cooling unit of the sale area; figure 2 shows a schematic view of the hot water production circuit and unit; figure 3 is a schematic view of the cooled water circuit and unit; - figure 4 shows a schematic view of a system according to another embodiment, according to a solution with an absorption unit. DESCRIPTION OF ONE EMBODIMENT OF THE INVENTION

With reference to the accompanying drawings, the machine with the integrated plant engineering system is generally indicated with 10 in figure 1 and comprises a hot water production circuit 11 and a chilled water production circuit 12.

The machine 10 is in turn connected on one side to an external unit 13 comprising the condenser 14 and on the other to the sales area unit 15 which includes the refrigerated cabinets 16, the split units 17 and the air- processing unit 18.

The hot water production circuit 11 is shown in detail in figure 2 and comprises an exchanger 19 which on one hand is supplied by the hot gas circuit 20 for the condensers 14, and on the other hand supplies hot water to the circuit 21 connected to the air processing unit 18, whose outlet 22 provides hot air for heating the rooms .

The chilled water production circuit 12 is, on the other hand, shown in figure 3 and comprises an evaporator 23 to which a duct 24 is connected for the entry of liquid gas and another duct 25 for the output of expanded gas.

The evaporator 23 produces gas flows which reach the air processing unit 18 through the ducts 24 and 25 of liquid gas and expanded gas respectively. In this way, the air processing unit 18 will produce cooled air to cool the rooms in the summer months.

Both the hot water production unit 11 and the chilled water production unit 12 comprise components that cause the passage of flows of liquid, aeriform and gaseous substances to supply the system.

The components used in the system can comprise compressors 26, 1 liquid receiver, 1 plate exchanger and 1 tube nest exchanger. The system also uses maximum pressure safety pressure switches on each compressor, general automatic-reset minimum pressure switches, general automatic-reset maximum pressure switches, a maximum pressure gauge and suction manifolds for the parallel-connected compressors.

The system is also equipped with oil separators, nonreturn valves mounted on the outlet of the oil separator, oil receivers, oil level controls, dewaterer solid- cartridge filters and suction mesh-cartridge filters. The tube nest evaporator 23 is mounted on the same frame and comprises a thermostat valve, a flow control valve, a control fitted on the electrical panel of the central unit, a safety thermostat and flow meter and the plate heat exchanger 19. The system also comprises a pump 27 for hot water heating, a pump 29 for cold water cooling, expansion tanks charges with nitrogen, flow meters, automatic system-supply units complete with non-return valves, mesh filters, pressure gauge, on-off and by-pass valves, and other safety components, including pressure gauges complete with scale- test valve and thermometers.

The system comprises an electrical control panel on the machine, complete with electrical components to control the compressors and the pumps, and an electronic control unit for adjustment of the TN compressors, with a compressor rotation start-up delay system, and for condensation control, shutdown warning lights and compressor preheating and start-up manual selectors.

The use of an emergency system is foreseen in the event of faults with the TN control unit, consisting of a minim pressure switch with a timer to disconnect the control unit, a minimum pressure switch to control the compressors, an electrical control panel complete with all components for its functioning and a condenser for remote control or three-phase motors.

The machine can consist of modules that can be transported individually, for example five modules, and assembled on site.

The electrical control panel can be installed on the machine coupled with the end modules of the machine, or on the wall close to the machine.

The circuit of the integrated plant engineering system, the heart of the machine according to the invention, thus foresees the implementation of the following system: a) in the discharge line of the compressors 10 a plate or tube nest exchanger 19 is positioned in series with the normal condenser, and in which a circuit containing gas 20 exchanges heat with the other circuit containing water 11; b) the hot water obtained in this way, through a pumping system 27, is sent towards the heating system ducts 21 and/or the plumbing systems.

The suction line of the compressors 26 is connected to a circuit supplying the air-conditioning system, which can be constructed in four different ways:

1 ) Chiller type cooled water solution: a tube nest exchanger 23 is used connected to the suction line 25, limiting the suction pressure with a pressure relief valve; the gas contercurrent circuit contains water 28 which cools by transferring heat to the gas and through a pumping system 29 is sent to the exchange batteries 30 of the air processing units 18 (air processing control units, fan coils, etc.); 2) Split type direct expansion solution: a suction line is directly connected to the direct expansion evaporators 17 of the air processing units (one or more) limiting the suction pressure with pressure relief valves (one for each evaporator);

3) Combination of solution 1) with solution 2): this makes it possible to create both a water-driven air conditioning system for areas that require more precise temperature control (e.g. offices, meeting rooms, areas open to the public, primary air processing, humidity control, etc.) and a direct expansion system for areas requiring less control (production areas, machining departments, warehouses, etc. )

4) Absorption unit solution (figure 4): the discharge line of the compressors which contains the high temperature gas is connected to an absorption unit 31, which replaces the exchanger 19, and then to the condensers; in this way the heat transported by the gas discharged by the compressors is used by the absorption unit to produce chilled water to be used for the air-conditioning system.

The invention is described above with reference to a preferred embodiment. It is nevertheless clear that the invention is susceptible to numerous variations within its scope, within the framework of technical equivalents.

Claims

1) An integrated plant engineering system for the production of hot and cold to be used simultaneously by cooling and heating units, characterised in that the system uses a machine (10) connected on one side to the user and output units ( 15 ) and on the other to the condenser units (13) and in that the machine comprises at least one hot water production unit (11) and at least one cold water production unit (12), respectively comprising at least one exchanger (19), and at least one evaporation unit (23) which produces chilled water.

2) An integrated plant engineering system according to claim 1, characterised in that the machine (10) is connected on one side to an external unit (13) comprising at least one condenser (14) and on the other to the sales area unit (15) which includes the refrigerated cabinets (16), the split units (17) and the air processing unit (18).

3) An integrated plant engineering system according to either of the foregoing claims, characterised in that the hot water production circuit (11) comprises at least one tube nest or plate exchanger (19) which on one hand is supplied by the hot gas circuit (20) for the condensers (14), and on the other provides hot water in the circuit (21) supplying the air processing unit (18), which delivers hot air for heating though its outlet (22).

4) An integrated plant engineering system according to any of the foregoing claims, characterised in that the chilled water production circuit (12) comprises at least one tube nest or plate evaporator (23) to which a duct (24) is connected for the entry of liquid gas and another duct (25) for the output of expanded gas. 5) An integrated plant engineering system according to any of the foregoing claims, characterised in that the evaporator (23) produces flows of chilled water which reach the air processing unit (18) through the tubing (28).

6) An integrated plant engineering system according to any of the foregoing claims, characterised in that it foresees a solution with an absorption unit (31): the discharge line of the compressors which contains the high temperature gas, subsequently conveyed to the condensers, is connected to an absorption unit (31), which replaces the exchanger (19); the heat transferred by the gas discharged from the compressors is used by the absorption unit to produce chilled water to be used for the air conditioning unit.