Liquid chiller for air conditioning systems

Abstract

 This invention relates to a liquid chiller, particularly but without limitation a water chiller, for air conditioning in domestic, industrial and commercial environments, such as workshops, stores and offices, of the type in which a compressor (9) compresses a gas which, by evaporating in a suitable heat exchanger (10), cools the liquid to be pumped, circulated and delivered to the cooling equipment, wherefrom it comes at a higher temperature, after having extracted heat from the environments. The liquid chiller is characterized in that it comprises units (9, 10) that are grouped and assembled together on a single support frame (i), whose transverse dimension T is not larger than that of a doorway to a machine room, the compressor (9) is of the centrifugal type and the heat exchanger (10) acting as an evaporator is a plate-type exchanger.

Description

[0001] This invention relates to a liquid chiller, particularly but without limitation a water chiller, for air conditioning in domestic, industrial and commercial environments, such as workshops, stores and offices, of the type in which a compressor compresses a gas which, by evaporating in a suitable heat exchanger, cools the liquid which is pumped, circulated and delivered to the cooling equipment, wherefrom it comes at a higher temperature, after having extracted heat from the environments, in accordance with the preamble of claim 1.

[0002] As is known, liquid chillers, particularly water chillers, for air conditioning systems are comprised of various units, including a compressor, heat exchangers, circulating pumps, filters, connection piping and water and gas lines, valves and electrical control and monitoring equipment.

[0003] According to prior art, these units are individually carried into the machine room to be assembled and connected therein.

[0004] Such operations extend chiller installation time and thereby increase the overall costs for the system.

[0005] The object of this invention is to obviate the above drawback by providing a liquid chiller, particularly a water chiller, for air conditioning systems, that can be carried to the installation site in a substantially assembled condition, ready for connection to the water circulation system, and allows the provision of systems operating with a variable cooling power.

[0006] This object is fulfilled by a water chiller characterized in that its units are grouped and assembled on a single support frame, whose transverse dimension T is not larger than the transverse dimension of a doorway to a machine room, the compressor is of the centrifugal type and at least the heat exchanger acting as an evaporator is a plate-type exchanger, in accordance with the features of claim 1.

[0007] In a preferred aspect of the invention, the chiller is provided in the form of a module generating a predetermined basic cooling power, said module being adapted for connection to other modules to obtain systems having a cooling power which is a multiple of the such basic cooling power.

[0008] Preferably the basic cooling power of a module is of about 280 kW.

[0009] The characteristics and the advantages of the invention will appear from the following detailed description of several practical embodiments, which are shown without limitation in the annexed drawings, in which:

• Figure 1 is a side view of the chiller;
• Figure 2 is a front view of the chiller of Figure 1;
• Figure 3 is a rear view of the chiller of Figure 1;
• Figure 4 is an alternative embodiment of this invention.

[0010] Referring to the above figures, numeral 1 generally denotes the support frame for the various units that form the chiller.

[0011] It has a box-like shape, with front uprights 2, rear uprights 2a, lower longitudinal crossbars 3 and upper longitudinal crossbars 3 a.

[0012] The rear uprights 2a are connected together by a plate 4, whereas the upper longitudinal crosspieces 3a are held together by transverse connecting members 5. The fastening means are preferably traditional bolts and screws, such as those denoted by numeral 6, but may also include weldings, if desired.

[0013] The lower longitudinal crossbars 3 are connected by transverse members 7, which also have traditional height-adjustable support feet 8 attached thereto.

[0014] In a preferred embodiment, the overall transverse dimension T of the support frame 1, as substantially determined by the length of the transverse members 5 and 7 does not exceed 0.75 m, and is not larger than the traditional transverse dimension of a doorway to a machine room, which is typically 0.9 m.

[0015] This allows introduction of the whole assembled chiller on a single support frame 1.

[0016] A compressor, preferably an oil-less centrifugal compressor denoted by numeral 9, is mounted to the transverse members 5, and is connected to an evaporator-exchanger 10 which is shown as a plate-type exchanger having a compact design.

[0017] The exchanger 10 has tubular connections 11 and 12 to the chilled water distribution circuit, not shown, which are both placed on the rear side of the support frame 1, i.e. on the plate 4.

[0018] The connections 13 and 14 of the condenser exchanger 15 are also placed on the plate 4, next to the connections 11 and 12 of the evaporator exchanger 10.

[0019] The condenser exchanger 15 is also a plate-type exchanger and, like the evaporator exchanger 16, is placed within the box-like support frame formed by the uprights 2, 2a and the longitudinal crossbars 3 and 3a.

[0020] Thanks to the adjacent positions of the connections 11, 12, 13 and 14, multiple equal chillers may be provided, i.e. as many chillers as required to achieve the desired cooling power without using complex and bulky piping arrangement.

[0021] It should be noted that each of the modules has such transverse dimensions as to allow passage thereof through the doorway to the room where they are designed to form the system, which typically has a width of about 0.9 m and a height of about 2 m.

[0022] The cabinet for the electrical and hydraulic controls of the chiller is positioned on the side of the frame 1 opposite to the plate 4.

[0023] Such cabinet, generally denoted by numeral 16, is directly connected to the frame 1 by its bottom wall 17, and therefore is not in contact with the ground.

[0024] Thus, the door 18 to access the inside of the cabinet 16 is wholly accessible from the front side of the chiller.

[0025] The top side 19 of the cabinet is positioned at such a maximum height that it does not exceed the conventional height of about 2 m of the doorway, to allow the wholly assembled chiller to pass therethrough, no other part of said chiller exceeding in height said top side.

[0026] As shown in Figure 1, the exchangers 10 and 15 are placed on the support frame 1 in spacing relationship along the longitudinal axis of the support frame, to form a space, denoted by numeral 20, in which the additional components of the chiller are accommodated, particularly the pumps, the filters, the connection piping and the valves not specifically shown in Figure 1, but clearly recognizable by their conformations.

[0027] The chiller structure of the invention allows the chiller to be carried into the air conditioning system room in a substantially assembled condition, with no problems of handling and passage through the doorways and in a modular arrangement, so as to achieve the desired cooling power by connecting together a plurality of modules having equal basic powers or by disconnecting one or more modules when a lower power is required, thereby providing the highest flexibility to meet seasonal requirements.

[0028] Furthermore, thanks to the use of a centrifugal compressor, preferably having an oil-less operation, and of plate-type exchangers for both the evaporator and the condenser, the modular chiller of this invention provides high performances in terms of both delivered power and handling.

[0029] In an alternative embodiment of this invention (Figure 4), the chiller as described with reference to Figures 1 to 3 has the condenser exchanger 15 installed outside the support frame 1. Therefore, the chiller is composed of two separate units, i.e. an evaporating unit 21 and the condenser exchanger 15.

[0030] Advantageously, the evaporating unit 21 is usually installed in the machine room, whereas the condenser exchanger 15 may be installed in an open space, such as the roof of a building.

[0031] Particularly, the evaporating unit 21 comprises the compressor 9, the evaporator exchanger 10, the control panel 16 and further components such as pumps, filters, connection piping, etc.

[0032] The condenser exchanger 15 is connected to the evaporating unit 21 by pipes 22, 23, usually made of copper, with coolant flowing therein. In one of the pipes, e.g. pipe 22, the coolant is in an overheated vapor state, whereas in the other pipe, i.e. pipe 23, the coolant is in the undercooled state. As is well-known to those skilled in the art, the coolant changes its state within the condenser exchanger 15.

[0033] In the embodiment as shown in Figure 4, the condenser exchanger 15 is provided in the form of a condenser exchanger having a fume extraction fan.

[0034] As compared with traditional chillers, this solution provides the advantage of an easier maintenance, as the evaporating unit 21 can be readily accessed, and especially provides the advantage of not requiring system draining operations in Winter, as the evaporating unit 21 is installed in the machine room, that is in a closed space.

[0035] Those skilled in the art will obviously appreciate that a number of changes and variants may be made to the arrangements as described hereinbefore to meet specific needs, without departure from the scope of the invention, as defined in the following claims.

Claims

1. A liquid chiller, particularly but without limitation a water chiller, for air conditioning in domestic, industrial and commercial environments, such as workshops, stores and offices, of the type in which a compressor (9) compresses a gas which, by evaporating in a suitable heat exchanger (10), cools the liquid which is pumped, circulated and delivered to the cooling equipment, wherefrom it comes at a higher temperature, after having extracted heat from the environments, characterized in that by said liquid chiller comprises units (9, 10) that are grouped and assembled together on a single support frame (1), whose transverse dimension T is not larger than the transverse dimension of a doorway to a machine room, the compressor (9) is of the centrifugal type and at least the heat exchanger (10) acting as an evaporator is a plate-type exchanger.

2. A chiller as claimed in claim 1, characterized in that it comprises a condenser exchanger (15) installed in said single support frame (1).

3. A chiller as claimed in claim 2, characterized in that a space (20) is provided in said support frame (1), between said evaporator exchanger (10) and said condenser exchanger (15), in which chiller components, such as pumps, filters, valves and connection piping, are accommodated.

4. A chiller as claimed in claim 1, characterized in that it comprises a condenser exchanger (15) installed outside said single support frame (1).

5. A chiller as claimed in any of claims 1 to 4, wherein the transverse dimension 1 of said support frame (1) is of about 0.75 m.

6. A chiller as claimed in any of claims 1 to 5, characterized in that said condenser exchanger (15) is a plate-type condenser.

7. A chiller as claimed in any of claims 1 to 6, characterized in that the compressor (9) is an oil-less centrifugal compressor.

8. A chiller as claimed in any of claims 1 to 7, characterized in that it is provided in the form of a module generating a predetermined basic cooling power, said module being adapted for connection to and disconnection from other modules to obtain systems having a variable cooling power that is a multiple of the such basic cooling power.

9. A chiller as claimed in any of claims 1 to 8, characterized in that the connections (11, 12) of said evaporator exchanger (10) and the connections (13, 14) of said condenser exchanger (15) are in adjacent relationship and may be accessed from one of the ends (4) of said support frame (1).

10. A chiller as claimed in any of claims 1 to 9, characterized in that it comprises a cabinet (16) for the electrical controls of the component units (9, 10), which is connected to the front end of said support frame (1), opposite to the end (4) whereat the connections (11, 12, 13, 14) of said exchanger (10) and said condenser exchanger (15) open out.

11. A chiller as claimed in any of claims 1 to 10, characterized in that the height of the top wall (19) of said cabinet (16) does not exceed that of a conventional doorway, the latter being of about 2 m.

Drawing