WO2007069279A1

WO2007069279A1 - Energy saving chiller

Info

Publication number: WO2007069279A1
Application number: PCT/IT2005/000728
Authority: WO
Inventors: Giuseppe Floris
Original assignee: Giuseppe Floris
Priority date: 2005-12-12
Filing date: 2005-12-12
Publication date: 2007-06-21

Abstract

The invention is a new energy saving chiller equipped with one or more suction units (A), at least one condenser (C), at least one liquid receptacle (S), one or more pumps for cooling liquid (M), a circuit of pipes for cooling fluid, one or more evaporators (E), at least one electric/electronic circuit connected to the control panel. Both the suction units (A) and the pumps (M) are low-noise units compared to traditional units, and furthermore the system can be soundproofed in order to make it compliant with the laws actually in force, according to which it is forbidden to exceed a given number of decibels, in particular in residential areas.

Description

TITLE ENERGY SAVING CHILLER

DESCRIPTION

The present invention concerns the chillers of air conditioners, cold counters and industrial refrigerators.

Considering the continuous increase in energy costs, the chiller that is the subject of the present invention aims to adopt energy saving solutions as an alternative to the solutions normally used in the field of refrigeration to achieve the same results. The refrigerating and cooling systems used at present employ different types of compressors.

Tight scroll compressors are known, which are suitable for reduced power systems.

Also screw compressors are known, which are characterized by the maximum flexibility, can adapt to any difference in pressure and therefore can be used in systems at any temperature level, with lower efficiency compared to the other known compressors mentioned above, and wherein said difference in efficiency decreases according to their size and to the increase in their pressure difference. Therefore said compressors are to be used only in medium-high power systems .

Alternative semi-tight one-stage compressors are known, the use of which is limited to the applications with reduced difference in temperature between condensation and suction. In low temperature systems, in any case, compressors specifically conceived for this type of use should be chosen.

Alternative semi-tight two-stage compressors are known, which are suited to be used for applications with a high difference in temperature between condensation and suction.

Such compressors must therefore be used exclusively in low temperature systems, which are capable of better exploiting their efficiency compared to other types of compressors.

The cooling circuit usually comprises the following stages: suction, compression, condensation, delivery.

The compressor sucks in the coolant in the gaseous phase and compresses it, in this phase it is strongly heated due to compression and conveyed to a system called condensation system, where the coolant is cooled through a heat exchange, so that from the gaseous phase it passes to the liquid phase, and subsequently it is conveyed to the evaporator valves via delivery pipes. When the coolant expands in the evaporators it returns to the gaseous phase, absorbing the heat of the environment to be cooled and cooling it, and finally it is sucked in by the compressors to repeat the process.

AU this process needs much energy, so much that for the temperature of 0°, by optimizing the system, with these compressors it is possible to obtain approximately 2 cooling IcW from 1 KW energy, while for the low temperature only approximately 0.9 cooling IcW can be obtained. It is also important to take in consideration the various problems relating to the system, since the above mentioned compressors need lubricating, and therefore to let the oil re-circulate with the gas and obtain good operation of the system it is necessary to adopt some specific measures regarding for example the inclination of the pipes, the siphons, the choking of the suction pipes, etc.

The manufacturers of these compressors declare on average the following yields, referred for example to a 2 HP compressor with consumption equal to l.5 KW/h.

The data declared for the positive temperatures (0°) are approximately 8 m³/h for the suction and approximately 12 1/h for the delivery, which allow 3 cooling kW to be achieved, while for the low temperatures the data are approximately 9.5 m³/h for the suction and approximately 5.5 1/h for the delivery, which allow approximately 1.35 cooling kW to be achieved. As explained above, the aim of the invention is to find a system that is equally suited to drastically reduce energy consumption in the production of cold. These results and other improvements are obtained by separating the cooling process stages, and more precisely, instead of using a machine that sucks in and delivers the cooling gas, by adopting suction machines constructed in order to suck in the cooling gases, which we shall call suction units, and other machines that are suited to deliver said gases in the liquid phase, which we shall call pumps.

To demonstrate the above, we would like to take in consideration a system with the same power used in the traditional system.

With a suction unit absorbing 1.5 KW/h manufactured with all the necessary devices for sucking in cooling fluids, at the necessary pressures we can suck in approximately 80 m³/h, as shown by the tables supplied by the manufacturer.

It is clear that in the suction stage the energy saving achieved is equal to approximately 90%. With a pump that absorbs 1.5 KW/h, specifically constructed to deliver cooling gases in the liquid phase, at the pressures necessary for the good operation of the system as shown by the specifications delivered by the manufacturer, we can obtain 2400 1/h with a yield of approximately 400 cooling IcW.

To obtain the same results with the traditional compressors, with positive temperatures we would need an electric absorption of approximately 200

KW/h as against 6.5 KW/h, that is, 4 suction units absorbing 1.5 KW/h each, plus 1.5 KW/h absorbed by the pump for a total of 7.5 KW/h, so that energy consumption is 50 times less than with traditional compressors.

The new chiller also offers other considerable advantages.

Neither the suction unit nor the pump need lubricating, and therefore the systems and the laying of pipes will be simplified. There are less noise and vibrations, since the noise generated by the compressor pistons has been eliminated.

Also the noise generated by the fans of the traditional condenser can be eliminated, since, considering the great cooling efficiency, condensation can be obtained through heat exchange with a fluid previously cooled by the same system.

Said system is partly or completely soundproofed in order to make it compliant with laws actually in force, which do not allow a given number of decibels to be exceeded, especially in residential areas.

The suction units and the pumps can work in parallel, and the ones can be alternated to the others in operation, depending of the requirements of the system in terms of cooling efficiency.

Both the suction units and the pumps can be provided with a frequency regulator controlled by a vacuum meter and by a pressure switch in order to optimize both suction and delivery, so that the operation and the speed of these machines are set according to the actual requirements of the system, with further considerable energy saving that is also optimized according to the actual requirements of the system. The suction units that operate independently of the delivery function, thanks to an automatic setting at the pressures set in the vacuum meter by means of pressure regulating valves (KVP) that regulate suction in the evaporators, allow a single pipe to be carried out both for the low temperature (-25°) and for the positive temperature (>0°), which is not possible in the traditional system since the units used work at different suction pressures and consequently, using these valves, there would be a power drop and an efficiency reduction in terms of delivery. The new energy saving chiller comprises at least one or more cooling gas suction units (A) equipped with a frequency variator (Va) that in turn is regulated by a suction pressure sensor or vacuum meter (Ra) that optimizes its operation.

The gas sucked in is conveyed to the suction unit (A) in a heat exchanger or condenser (C) that, by compressing or cooling it, changes it from the gaseous phase into the liquid phase, and then is conveyed to a properly sized liquid receptacle (S).

The liquid gas is sucked in by at least one or more delivery pumps (M), equipped with a frequency variator (Vm) controlled by a delivery pressure sensor or pressure switch (Rm) that optimizes its flow and its outlet pressure, and is made circulate in the system (E).

Therefore, with reference to the above description and the enclosed drawing, the following claims are expressed.

Claims

1. Energy saving chiller, characterized in that it comprises one or more suction units (A), at least one condenser (C), at least one fluid receptacle (S), one or more pumps for a cooling liquid (M), a circuit of pipes for the cooling liquid, one or more evaporators (E), at least one electric/electronic circuit connected to the control panel.

2, Energy saving chiller according to claim 1, characterized in that said suction units (A) and pumps (M), according to the power used, can also operate in a dry process, with no need to be lubricated.

3. Energy saving chiller according to the previous claims, characterized in that said suction units (A) are equipped with a frequency variator (Va) regulated by a suction pressure sensor or vacuum meter (Ra) that optimizes its operation and guarantees a constant optimal pressure.

4. Energy saving chiller according to the previous claims, characterized in that said pumps (M) are equipped with a frequency variator (Vm) regulated by a pressure sensor or pressure switch (Rm) that optimizes its operation and guarantees a constant optimal pressure during delivery.

5. Energy saving chiller according to the previous claims, characterized in that said suction units (A) and said pumps (M) are installed in parallel and are set so that they can intervene singularly or all together, if necessary alternating in such a way as to be in operation for the same number of hours.

6. Energy saving chiller according to the previous claims, characterized in that in the condensation stage (considering the high cooling efficiency) a heat exchange with liquid previously cooled by the same system is carried out.

7. Energy saving chiller according to the previous claims, characterized in that the suction units (A) that operate independently of the delivery function thanks to the automatic setting at the pressures set in the vacuum meter (Ra), by using pressure regulating valves (KVP) that regulate suction in the evaporators (E) make it possible to carry out a single pipe for both low temperature (-25°) and positive temperature (0°>).

8. Energy saving chiller according to the previous claims, characterised in that it is equipped with all or part of the instrumentation used in the traditional systems, like filters, valves, temperature sensors, absorption sensors, shock absorbing devices, etc..

9. Energy saving chiller according to the previous claims, characterized in that it is equipped with an electric/electronic system connected to a control panel.

10. Energy saving chiller according to the previous claims, characterized in that both the suction units (A) and the pumps (M) are low-noise units compared to the traditional units, and wherein said system is partly or completely soundproofed in order to make it compliant with the laws actually in force, according to which it is forbidden to exceed a given number of decibels, in particular in residential areas.