AU2012249237B1 - Mobile, Modular, Containerised Chiller and Thermal Energy Storage Tank - Google Patents

Abstract

A mobile, modular, containerised chiller and thermal energy storage tank including a transport container having at least one opening to access an interior thereof, a thermal energy storage tank within the transport container and having at least one inlet and at least one outlet, an external condenser unit which in use is located outside the transport container and a plant room including at least one pump and at least one heat exchanger located within the transport container between the thermal energy storage tank and the at least one opening and connected to the thermal energy storage tank and the condenser and having appropriate connections to allow connection of an external fluid distribution and return network to the at least one heat exchanger.

Description

MOBILE, MODULAR, CONTAINERISED CHILLER AND THERMAL ENERGY STORAGE TANK TECHNICAL FIELD [0001] The present invention relates generally to demand reductive heating or cooling systems and components utilized in such systems and particularly to mobile containerized commercial heating or cooling system. BACKGROUND ART [0002] Chillers for commercial and industrial applications can be centralized, where a single chiller serves multiple cooling needs, or decentralized where each application or machine has its own chiller. Each approach has its advantages. It is also possible to have a combination of both centralized and decentralized chillers, especially if the cooling requirements are the same for some applications or points of use, but not all. [0003] Decentralized chillers are usually small in size and cooling capacity, usually from 0.2 tons to 10 tons. Centralized chillers generally have capacities ranging from ten tons to hundreds or thousands of tons. [0004] Chilled water is used to cool and dehumidify air in mid- to large-size commercial, industrial, and institutional (CII) facilities. Water chillers can be water-cooled, air-cooled, or evaporatively cooled. Water-cooled chillers incorporate the use of cooling towers which improve the chillers' thermodynamic effectiveness as compared to air-cooled chillers. This is due to heat rejection at or near the air's wet-bulb temperature rather than the higher, sometimes much higher, dry-bulb temperature. Evaporatively cooled chillers offer higher efficiencies than air-cooled chillers but lower than water-cooled chillers. [0005] Water-cooled chillers are typically intended for indoor installation and operation, and are cooled by a separate condenser water loop and connected to outdoor cooling towers to expel heat to the atmosphere. [00061 Air-cooled and evaporatively cooled chillers are intended for outdoor installation and operation. Air-cooled machines are directly cooled by ambient air being mechanically circulated directly through the machine's condenser coil to expel heat to the atmosphere. Evaporatively cooled machines are similar, except they implement a mist of water over the condenser coil to aid in condenser cooling, making the machine more efficient than a traditional air-cooled machine. No remote cooling tower is typically required with either of these types of packaged air-cooled or evaporatively cooled chillers. [00071 Industrial chillers are typically designed complete, closed-loop systems, including the chiller unit, condenser, and pump station with recirculating pump, expansion valve, no-flow shutdown, internal cold water tank, and temperature control. The internal tank helps maintain cold water temperature and prevents temperature spikes from occurring. Closed-loop industrial chillers recirculate a clean coolant or clean water with condition additives at a constant temperature and pressure to increase the stability and reproducibility of water-cooled machines and instruments. The water flows from the chiller to the application's point of use and back. [0008] If the water temperature differentials between inlet and outlet are high, then a large external water tank would be used to store the cold water. In this case the chilled water is not going directly from the chiller to the application, but goes to the external water tank which acts as a sort of "temperature buffer." The cold water tank is much larger than the internal water tank. The cold water goes from the external tank to the application and the return hot water from the application goes back to the external tank, not to the chiller. [0009] The less common open loop industrial chillers control the temperature of a liquid in an open tank or sump by constantly recirculating it. The liquid is drawn from the tank, pumped through the chiller and back to the tank. An adjustable thermostat senses the makeup liquid temperature, cycling the chiller to maintain a constant temperature in the tank. [0010] One of the newer developments in industrial water chillers is the use of water cooling instead of air cooling. In this case the condenser does not cool the hot refrigerant with ambient air, but uses water that is cooled by a cooling tower. [0011] Most industrial chillers use refrigeration as the media for cooling, but some rely on simpler techniques such as air or water flowing over coils containing the coolant to regulate temperature. Water is the most commonly used coolant within process chillers, although coolant mixtures (mostly water with a coolant additive to enhance heat dissipation) are frequently employed. [0012] It will be clearly understood that, if a prior art publication is referred to herein, this reference does not constitute an admission that the publication forms part of the common general knowledge in the art in Australia or in any other country. SUMMARY OF INVENTION -Y [00131 The present invention is directed to mobile, modular, containerised chiller and thermal energy storage tank, which may at least partially overcome at least one of the abovementioned disadvantages or provide the consumer with a useful or commercial choice. [0014] With the foregoing in view, the present invention in one form, resides broadly in a mobile, modular, containerised chiller and thermal energy storage tank including A. an transport container having at least one opening to access an interior thereof, B. a thermal energy storage tank within the transport container and having at least one inlet and at least one outlet, C. an external condenser unit which in use is located outside the transport container and D. a plant room including at least one pump and at least one heat exchanger located within the transport container between the thermal energy storage tank and the at least one opening and connected to the thermal energy storage tank and the condenser and having appropriate connections to allow connection of an external fluid distribution and return network to the at least one heat exchanger. [0015] In an alternative form, the present invention resides broadly in a mobile, modular, containerised chiller and thermal energy storage tank including A. At least two transport containers B. a thermal energy storage tank within one of the transport containers and having at least one inlet and at least one outlet, C. an external condenser unit which in use is located outside at least one of the transport containers and D. a plant room within another of the transport containers including at least one pump and at least one heat exchanger located within the transport container the plant room provided with appropriate connections to connect to the thermal energy storage tank and the condenser and having appropriate connections to allow connection of an external fluid distribution and return network to the at least one heat exchanger. [0016] The containerised chiller and thermal energy storage tank of the present invention are typically designed to integrate or communicate with a conventional, air cooled package or split package chiller or a watercooled chiller. [00171 Water is a convenient heat storage medium, because it has a high specific heat _r capacity. Compared with other substances it can store more heat per unit of weight (and volume). Water is non-toxic and low in cost. [00181 A chiller is a series of process steps that removes heat from a liquid via a vapor compression or absorption refrigeration cycle. This liquid can then be circulated through a heat exchanger to cool air or equipment as required. [0019] In air conditioning systems, chilled water is typically distributed to heat exchangers, or coils, in air handling units or other type of terminal devices which cool the air in its respective space(s), and then the water is re-circulated back to the chiller to be cooled again. These cooling coils transfer sensible heat and latent heat from the air to the chilled water, thus cooling and usually dehumidifying the air stream. [0020] As mentioned above, industrial chillers typically are designed as closed-loop systems, including the chiller unit, condenser, and pump station with recirculating pump, expansion valve, no-flow shutdown, internal cold water tank, and temperature control. The internal tank helps maintain cold water temperature and prevents temperature spikes from occurring. Closed-loop industrial chillers recirculate a clean coolant or clean water with condition addititives at a constant temperature and pressure to increase the stability and reproducibility of water-cooled machines and instruments. The water flows from the chiller to the application's point of use and back. [0021] If the water temperature differentials between inlet and outlet are high, then a large external water tank would be used to store the cold water. In this case the chilled water is not going directly from the chiller to the application, but goes to the external thermal energy water tank which acts as a sort of "temperature buffer." The cold water goes from the external tank to the application and the return hot water from the application goes back to the external tank, not to the chiller. [0022] The chiller plant is typically contained within a container during transport and with minimal assembly, becomes operational. Assembly typically involves mounting the condenser to the outside of the container for efficiency. The condenser may be transported in the transport container or may be provided on site. [0023] The containerised chiller preferably allows use in a retrofit situation or when a modular heating or cooling system is provided in a new build. [0024] The particular containerised device provided will be sized according to the site load.

[00251 The containerised chiller and thermal energy storage tank of the preferred embodiment is adapted for use with an external fluid distribution and return network. Typically, this external network includes one or more pipes to distribute fluid at a required temperature and to return depleted fluid to the containerised device of the invention for thermal adjustment and redistribution on a substantially continuous basis. [0026] The external network will typically be a part of a cooling system or a heating system, according to which fluid of the required heat load flows from the heat exchanger of the containerised device, through the external fluid distribution and return network (typically referred to in the art as "the field") to provide the fluid as required by the heating or cooling requirements. [00271 The device of the present invention may be provided in different configurations dependent upon the site load. For example, a smaller site load may utilise a single container model whereas a larger site load may require multiple container models that are interconnectable in order to suit the site load. In this way, the device of the present invention is a modular device which can be used either singly or in cooperation with other similar units in order to provide functionality for larger site loads. [00281 Typically, the transport container is a shipping container preferred for portability and its standardised sizing. Shipping containers are also known as intermodal freight containers which is basically a container designed to be moved from one mode of transport to another, without unloading and reloading contents. [0029] The containers are generally rigid and typically manufactured from metal. The external container protects items located in the interior of the container which may be fragile or at least more prone to damage them be more robust shipping container. [0030] The container walls preferably provide extra or mounting points for mounting the components of the containerised chiller and thermal energy storage tank relative to the interior of the container, particularly in relation to mounting pipe headers and the like on the interior side of the walls of the container. [0031] The at least one opening in the transport container is generally provided as part of or as one of the end walls of the container. There may be more than one opening provided into the container. Generally, a pair of doors are provided as one of the end walls of the container and which open across the width of the container providing access to the interior. [0032] Appropriate connection points are preferably provided to allow movement in securing of the container as required. [00331 Appropriate connections are also provided to allow attachment of the external piping network to carry fluid to and from the field. Typically these are provided outside the container volume but they may be inside for increased protection. Typically, flanged connections are provided extending through one or more of the walls of the shipping container to allow the connection to occur. [0034] Attendant pipework is provided within the container in order to connect the components of the plant and system to each other. [0035] The containerised chiller and thermal energy storage tank of the present invention includes an external chiller unit which, in use, is located outside the transport container. As discussed briefly above, typically the condenser unit will be located and secured within the container for transport and is then relocated outside the container for use. Typically, appropriate connections will be provided outside, that is from within the container to the outside of the container to allow the condenser unit to be connected to the attendant pipework within the container to connect the condenser to the other components of the plant. [00361 According to preferred embodiment, the condenser unit will have one of two preferred configurations, namely the condenser unit will either be an air cooled, vertical style condenser unit or a watercooled tower. One or more of these units can be provided depending upon the rating of the containerised chiller and thermal energy storage tank. [00371 Where provided in the air cooled configuration, the condenser unit will normally be located on a side wall of the container, adjacent the plant room but on the outside of the container. Normally, such a condenser unit operates by radiant heat transfer. [00381 Where provided in the watercooled tower configuration, the condenser unit will normally be provided on an upper wall of the container in order to relocate what is normally a larger condenser unit then the air cooled vertical style condenser unit into a more convenient location to reduce the footprint of the containerised chiller and thermal energy storage tank of the present invention. [00391 A watercooled condenser does not cool the hot fluid with ambient air, but uses water that is cooled by a cooling tower. This development allows a reduction in energy requirements by more than 15% and also allows a significant reduction in the size of the chiller, due to the small surface area of the water based condenser and the absence of fans. Additionally, the absence of fans allows for significantly reduced noise levels. [0040] The containerised chiller of the present invention includes a plant room. Normally the plant room includes the components of the chiller cycle, including the chiller unit, and pump station with recirculating pump, expansion valves, and temperature control, all connected appropriately with the thermal energy storage tank and the externally mounted condenser. [0041] Normally, at least one pump and preferably a number of pumps will be provided in order to drive the working fluid through the components of the chiller cycle. Typically, the dual pumps are utilised in order to operate the cycle in either direction to heat or cooled the working fluid as required. Further, the pumps will normally be variable speed pumps in order to provide adjustability within the cycle. [0042] Typically, at least two pumping groups and preferably three or more pumping groups are provided. A primary pumping group will typically be provided in order to pump the fluid through the chiller unit and the thermal energy storage tank. A second pumping group will normally be provided from the thermal energy storage tank to the field and back to the return piping header for the suction side of the primary pumping group. A final pumping group will normally include a small injection valve/pump assembly in order to control the field return water temperature. [0043] Typically, the pumps are sized appropriately to drive the working fluid about the cycle and where necessary, to the field and possibly from the field. One or more external pumps may be provided outside the containerised chiller of the present invention in order to distribute in return working fluid to or from the field if required. [0044] At least one heat exchanger is also normally provided in order to exchange heat with the fluid in the pipework extending to end from the field. The heat exchanger can be of any type and more than one heat exchanger can be provided if required. Either a co-current or to the current heat exchanger may be used depending upon the heating or cooling requirements. [0045] Typically, the heat exchanger is provided in the plant room section of the containerised chiller with appropriate connections provided to attach to the field pipework. Preferably, the heat exchanger will be provided adjacent the opening in the container. The connections can be provided within the container or alternatively, connections can be provided through the wall of the container to allow accessibility and connection from the outside of the container.

[00461 Preferably, the field pipework is simply attached to the distribution in return pipes from the heat exchanger in order to connect the field to the chiller unit. [00471 As with any process apparatus, a number of valves and sensors will typically be provided in order to control the flow and the particular parameters of the working fluid within the cycle. Any number and/or type of sensors may be provided but temperature sensors are particularly important within the cycle in order to maintain efficiency and to track the performance and as well as to locate any problems which may occur within the cycle. There will normally be a number of temperature sensors provided to monitor the temperature at various locations within the cycle. [00481 There will also typically be a number of valves, both isolation valves end non-return valves in order to control fluid flow and the direction of fluid flow within the cycle. [0049] The containerised chiller includes a thermal energy storage tank with at least one inlet and at least one outlet. [0050] The thermal energy storage tank may be pressurised if required due to circumstances or positioning at the site and if so, the pressurised thermal energy storage tank will typically be manufactured from metal and will normally be pressure rated. Alternatively, the thermal energy storage tank may be non-pressurised. In this situation, the non-pressurised thermal energy storage tank can be manufactured of other materials such as plastic for example. [0051] The thermal energy storage tank will typically include an outer vessel having at least one wall bounding the vessel volume and having at least one vessel inlet and at least one vessel outlet, a plurality of internal dividing walls to divide the vessel volume into a number of separate chambers and a connection conduit between adjacent separate chambers to allow fluid flow between adjacent chambers. [0052] The outer vessel of the thermal energy storage tank of the invention may be of any shape and manufactured of any material. However, two particularly preferred embodiment are a cylindrical outer vessel (whether oriented with the longitudinal axis substantially horizontally or substantially vertically) and a rectangular outer vessel. [0053] As the thermal energy storage tank of the preferred embodiment is non-pressurised, the materials used for manufacture can be more variable. For example, in order to create a pressure vessel, typically metal is used. However, for a nonpressurised thermal energy storage tank, the materials used can include plastic or nonmetallic materials which are typically much lighter in weight, and generally much less expensive. [0054] Where the vessel is provided in the cylindrical embodiment, the vessel may be oriented with the main longitudinal axis of the vessel substantially horizontally or substantially vertically. Where provided with the main longitudinal axis of the vessel substantially vertically, the vessel will normally be provided with a substantially planar or flat basewall and a substantially cylindrical sidewall. Normally, a partially spherical top wall is provided to close the vessel. The partially spherical top wall can be hemispherical or torispherical. [0055] In this configuration, an inlet/outlet is typically provided at a lower portion of the vessel and inlet/outlet is provided at an upper portion of the vessel. Each inlet/outlet is identified as such as the vessel will normally be connected to process apparatus in such a way that fluid can flow through the thermal energy storage tank in either direction and therefore, each inlet/outlet can be an inlet or an outlet depending upon the direction of fluid flow through the tank. [00561 In this configuration, the fluid flow through the separate chambers will normally be in a radial direction which is described more fully below. [00571 The cylindrical vessel may alternatively be provided with the main longitudinal axis oriented substantially horizontally. [00581 Where provided in the rectangular configurations, the vessel will normally include a number of planar walls. In particular, the rectangular vessel will normally include a pair of substantially planar end walls, a substantially planar base wall and a substantially planar top wall with a pair of substantially planar side walls. Typically, the inlet/outlet will be provided in one of the end walls. Again normally, there will be an inlet/outlet in an upper portion and an inlet/outlet in a lower portion of the end wall. Further, the upper and lower inlet/outlets will be offset laterally from one another. [0059] Typically, the inlet/outlet provided at the upper portion of the vessel of this embodiment will include an elongate conduit which extends from one end of the vessel into the separate chamber furthest from the end wall through which the inlet/outlet is provided. Typically, this will require that the elongate conduit extend through each of the internal dividing walls used to divide the vessel volume into the separate chambers. [00601 Further, an air bleed conduit may be provided in an upper region of the vessel. Preferably, the air bleed conduit may be unitary and maybe tapped into an upper portion of each separate chamber in order to allow air to escape from each of the separate chambers into the air IU bleed conduit. [00611 A manhole or access hatch may also be provided. Typically, the manhole or access hatch will be provided in the end wall through which the inlet/outlets extend. [0062] The tank of the present invention and also includes a plurality of internal dividing walls to divide the vessel volume into a number of separate chambers. Each separate chamber is formed to provide a separate fluid column and the provision of many walls allows one vessel volume to be divided into a number of separate fluid columns. This allows stratified hot water storage to occur which is also known by other names including stratified thermal storage, thermocline tank and water stratified tank storage, in each of the separate chambers. [00631 The chambers may be provided radiantly (such as in the cylindrical embodiment with the main longitudinal axis substantially vertically) or longitudinally. The configuration which is used is typically dependent upon the shape of the vessel and/or the orientation of the vessel. [0064] Each of the internal dividing walls is typically a bulkhead wall which is designed to prevent fluid flow from one chamber to another chamber except has allowed through the respective connection conduit. [00651 Typically, the dividing walls will be planar embarked this does not need to be the case. Normally, each internal dividing wall will extend from one wall of the vessel to another wall of the vessel and from the base wall to the top of the vessel. However, depending upon the configuration chosen, an internal dividing wall may meet another internal dividing wall at a central or other location within the vessel in order to form separate chambers. [00661 Any material of construction can be used as outlined above with the materials of construction chosen dependent upon the use of the vessel. For example, a non-pressurised vessel can be formed from a nonmetallic material such as plastic. Further, a nonpressurised vessel does not have to be rigid but will preferably be rigid. [00671 The internal dividing walls will typically be shaped to seal the internal volume of the vessel into a number of internal chambers. Any number of chambers can be formed within the vessel which means that any number of internal dividing walls can be provided. Typically, the number and size of the separate chambers is designed for the efficient and effective thermal energy storage given the fluid used for the energy storage. [00681 Water is a convenient heat storage medium, because it has a high specific heat I I capacity. Compared with other substances it can store more heat per unit of weight (and volume). Water is non-toxic and low in cost. [00691 The tank of the present invention will include a connection conduit between adjacent separate chambers to allow fluid to flow between adjacent chambers. Typically, each connection conduit will extend from a lower region in one chamber to an upper region in and adjacent chamber. Typically, each connection conduit will be tubular but may be of any shape. [00701 As mentioned above, it is preferred that the connection conduit be as large as possible in order to reduce fluid velocity through the conduits to as low as possible in order to maintain the temperature stratification within each chamber. [00711 Normally, a single connection conduit is provided in each bulkhead wall. All of the connection conduits are preferably oriented in the same direction. Further, all of the connection conduits are normally provided towards one lateral side of the vessel and all are preferably positioned on the same lateral side of the vessel. [0072] Each connection conduit is typically substantially L-shaped when viewed from the side. Each connection conduit preferably includes a horizontal foot portion in a substantially upright leg portion. Normally, an arcuate transition will be used between the foot portion and the leg portion, again, typically to reduce fluid velocity. [0073] Preferably, the substantially upright leg portion of each connection conduit will terminate from the top wall of the vessel in each chamber. [0074] Each connection conduit will normally have an inlet/outlet at either end thereof. The upper inlet/outlet from each connection conduit maybe a divergent inlet/outlet. [00751 The lower inlet/outlet of each connection conduit may be flush with the surface of the bulkhead wall through which it extends or alternatively, may stand slightly proud of the service. [00761 Typically, the connection conduits are provided on the opposite lateral side of the vessel to the upper vessel inlet/outlet. The particular location of the connection conduits within each chamber, and within the vessel itself may assist with the formation of thermal stratification within each chamber. [00771 Typically, the storage fluid will be at different temperatures at different locations within each chamber, as well as at different temperatures between different chambers depending I /_ upon the direction of flow into or out of the thermal energy storage tank. [0078] Further, the preferred nonmetallic construction may act to further insulate adjacent chambers from one another. [00791 More than one thermal energy storage tank may be provided and connected to one another in series. For example, an inlet/outlet of one vessel is typically connected to an inlet/outlet of another vessel from upper to lower in series allowing the use of multiple vessels to function as a single thermal energy storage tank. [0080] A diffusion device or arrangement may be provided at one or both ends of the connection conduit. The diffusion device or arrangement can be as simple as a tubular portion with openings in a side wall thereof or more complex arrangements or devices can be provided. [0081] Any of the features described herein can be combined in any combination with any one or more of the other features described herein within the scope of the invention. [0082] The reference to any prior art in this specification is not, and should not be taken as an acknowledgement or any form of suggestion that the prior art forms part of the common general knowledge. BRIEF DESCRIPTION OF DRAWINGS [0083] Various embodiments of the invention will be described with reference to the following drawings, in which: [0084] Figure 1 is a view from above of a containerized chiller and thermal energy storage tank according to a preferred embodiment of the present invention. [0085] Figure 2 is a piping schematic of a containerized chiller and thermal energy storage tank according to a preferred embodiment of the present invention. [0086] Figure 3 is a sectional view from above of a non-pressurized thermal energy storage tank according to a preferred embodiment of the present invention. [00871 Figure 4 is a sectional view from the side of the thermal energy storage tank illustrated in Figure 3. [0088] Figure 5 is an end view of the thermal energy storage tank illustrated in Figure 4.

I -Y [00891 Figure 6 is a sectional side view of a pressurized thermal energy storage tank according to a preferred embodiment of the present invention. [0090] Figure 7 is a sectional view from an end of the pressurized thermal energy storage tank illustrated in Figure 6. DESCRIPTION OF EMBODIMENTS [0091] According to a particularly preferred embodiment of the present invention, a mobile, modular containerised chiller and thermal energy storage tank 25 is provided. [0092] The mobile, modular, containerised chiller and thermal energy storage tank 25 illustrated in layout in Figure 1 and in a flow diagram in Figure 2 includes an transport container 26 having an opening 27 to access an interior thereof, a thermal energy storage tank 10 within the transport container 26 and having at least one inlet 60 and at least one outlet 70, an external condenser unit 28 which in use is located outside the transport container 26 and a plant room 29 including at least one pump and at least one heat exchanger located within the transport container between the thermal energy storage tank and the at least one opening and connected to the thermal energy storage tank and the condenser and having appropriate connections to allow connection of an external fluid distribution and return network to the at least one heat exchanger. [0093] Water is a convenient heat storage medium, because it has a high specific heat capacity. Compared with other substances it can store more heat per unit of weight (and volume). Water is non-toxic and low in cost. [0094] A chiller is a series of process steps that removes heat from a liquid via a vapor compression or absorption refrigeration cycle. This liquid can then be circulated through a heat exchanger to cool air or equipment as required. [0095] In air conditioning systems, chilled water is typically distributed to heat exchangers, or coils, in air handling units or other type of terminal devices which cool the air in its respective space(s), and then the water is re-circulated back to the chiller to be cooled again. These cooling coils transfer sensible heat and latent heat from the air to the chilled water, thus cooling and usually dehumidifying the air stream. [0096] The chiller plant is contained within a container 26 during transport and with minimal assembly, becomes operational. Assembly typically involves mounting the condenser 28 to the outside of the container for efficiency.

I -r [0100] The containerised chiller and thermal energy storage tank of the preferred embodiment is adapted for use with an external fluid distribution and return network. Typically, this external network includes one or more pipes to distribute fluid at a required temperature and to return depleted fluid to the containerised device of the invention for thermal adjustment and redistribution on a substantially continuous basis. [0101] The external network will typically be a part of a district cooling system or a district heating system, according to which fluid of the required heat load flows from the heat exchanger of the containerised device, through the external fluid distribution and return network (typically referred to in the art as "the field") to provide the fluid as required by the heating or cooling requirements of the district cooling or heating system. [0102] Typically, the transport container is a shipping container preferred for portability and its standardised sizing. Shipping containers are also known as intermodal freight containers which is basically a container designed to be moved from one mode of transport to another, without unloading and reloading contents. [0103] The containers are generally rigid and typically manufactured from metal. The external container 26 protects items located in the interior of the container which may be fragile or at least more prone to damage them be more robust shipping container. [0104] The container walls preferably provide extra or mounting points for mounting the components of the containerised chiller and thermal energy storage tank relative to the interior of the container, particularly in relation to mounting pipe headers and the like on the interior side of the walls of the container. [0105] The opening 27 in the transport container 26 is generally provided as part of or as one of the end walls of the container. Generally, a pair of doors 24 are provided as one of the end walls of the container 26 and which open across the width of the container 26 providing access to the interior. [0106] The containerised chiller and thermal energy storage tank of the preferred embodiment includes an external condenser 28 which, in use, is located outside the transport container 26. As discussed briefly above, the condenser unit 28 can be located and secured within the container 26 for transport and is then relocated outside the container 26 for use. Typically, appropriate connections will be provided outside, that is, from within the container to the outside of the container to allow the condenser unit 28 to be connected to the attendant pipework within I -) the container 26 to connect the condenser to the other components of the plant. [01071 Where provided in the air cooled configuration as illustrated in Figure 1, the condenser unit 28 is normally located on a side wall of the container 26, adjacent the plant room 29 but on the outside of the container. [01081 The containerised chiller of the preferred embodiment includes a plant room 29 as illustrated in Figure 1. Normally the plant room 29 includes the process components of the chiller cycle, one preferred embodiment of which is illustrated in Figure 2. [0109] According to the embodiment illustrated, the chiller unit and process is operating in a cooling configuration. Warm water is extracted from the thermal energy storage tank 10 and exits the tank at approximately 14'C. A temperature sensor 30 is provided at the outlet of the thermal energy storage tank to monitor this temperature. [0110] This water is then supplemented by return water from the heat exchanger 31 and proceeds through the primary pump 32 and into the chiller unit 33 where it is chilled to approximately 5 0 C (again a temperature sensor 30 is provided). The cooled water is then divided between the thermal energy storage tank 10 and proceeding through the plate heat exchanger 31 in order to exchange heat with the return working fluid returning from the field. A tertiary pump 34 is provided to assist with the movement of the working fluid through the heat exchanger 31 and back through the primary pump 32 to the chiller unit 33 in a recirculating loop. [0111] Normally the water returning from the field is at approximately 14.5 0 C whereupon it is directed through the heat exchanger 31 and the heat from the field water is absorbed by the working fluid in the chiller unit 25 cooling the water from the field before it is returned to the field normally at approximately 5 to 6 0 C. [0112] The primary pump 32 is provided in order to pump the fluid through the chiller unit 33 and the thermal energy storage tank 10. The ternary pump 34 is provided to move the water from the thermal energy storage tank 10 to the heat exchanger and back to the return piping header for the suction side of the primary pump. A secondary pump 35 will normally include a small injection valve/pump assembly in order to control the field return water temperature. [01131 Typically, the heat exchanger 31 is provided in the plant room 29 of the containerised chiller with appropriate connections provided to attach to the field pipework. [0114] Preferably, the field pipework is simply attached to the distribution and return pipes IV in the field side of the heat exchanger 31 in order to connect the field to the chiller unit 25. [0115] As with any process apparatus, a number of valves and sensors will typically be provided in order to control the flow and the particular parameters of the working fluid within the cycle. Any number and/or type of sensors may be provided but temperature sensors are particularly important within the cycle in order to maintain efficiency and to track the performance and as well as to locate any problems which may occur within the cycle. There will normally be a number of temperature sensors 30 provided to monitor the temperature at various locations within the cycle. [01161 Two preferred embodiments of thermal energy storage tank are illustrated in Figures 3 to 5 (non-pressurised tank) and Figures 6 and 7 (pressurised tank). Both include an outer vessel having one or more walls bounding a vessel volume and having a vessel inlet and a vessel outlet, a plurality of internal dividing walls 11 to divide the vessel volume into a number of separate chambers (A, B, C etc) and a connection conduit 12 between adjacent separate chambers to allow fluid flow between adjacent chambers. [01171 Where provided in the non-pressurised configuration illustrated in Figures 3 to 5, the vessel includes a number of planar walls. In particular, the rectangular vessel includes a pair of substantially planar end walls 17, a substantially planar base wall 18 and a substantially planar top wall 19 with a pair of substantially planar side walls 20. Again normally, there is an inlet/outlet in an upper portion and an inlet/outlet in a lower portion of the end wall. Further, the upper and lower inlet/outlets will be offset laterally from one another. In this configuration, the upper inlet/outlet 60 is for warm water and the lower inlet/outlet 70 is for cold water. [0118] The upper, warm water inlet/outlet 60 includes an elongate conduit 21 which extends from one end of the vessel into the separate chamber A furthest from the end wall 17 through which the inlet/outlet 60 is provided. This configuration requires that the elongate conduit 21 extend through each of the internal dividing walls 11 used to divide the vessel volume into the separate chambers. [0119] Further, an air bleed conduit 23 is provided in an upper or lower region of the vessel. The air bleed conduit may be unitary and may be tapped into an upper portion of each separate chamber in order to allow air to escape from each of the separate chambers into the air bleed conduit. [0120] A manhole or access hatch 22 is provided as illustrated.

I / [01211 The internal dividing walls 11 divide the vessel volume into a number of separate chambers. Each chamber is formed to provide a separate fluid column and the provision of many walls allows one vessel volume to be divided into a number of separate fluid columns. This allows stratified hot water storage to occur which is also known by other names including stratified thermal storage, thermocline tank and water stratified tank storage, in each of the separate chambers but within the same vessel. [0122] Each of the internal dividing walls 11 is typically a substantially planar, bulkhead wall designed to prevent fluid flow from one chamber to another chamber except has allowed through the respective connection conduit. [01231 Any material of construction can be used dependent upon the use of the vessel. For example, a non-pressurised vessel can be formed from a nonmetallic material such as plastic. Further, a nonpressurised vessel does not have to be rigid but will preferably be rigid. A pressurised vessel will normally be metallic. [0124] Water is a convenient heat storage medium, because it has a high specific heat capacity. Compared with other substances it can store more heat per unit of weight (and volume). Water is non-toxic and low in cost. [0125] Each connection conduit 12 extends from a lower region in one chamber to an upper region in an adjacent chamber. A single connection conduit 12 is provided in each wall 11. In both illustrated embodiments, all of the connection conduits 12 are oriented in the same direction and are provided on the same lateral side of the vessel as illustrated best in Figure 3. In the pressurised tank illustrated in Figures 6 and 7, the connection conduits 12 are located in line, along a mid line of the generally cylindrical vessel. [0126] Each connection conduit 12 of the illustrated embodiments is substantially L-shaped when viewed from the side including a horizontal foot portion in a substantially upright leg portion. Normally, an arcuate transition is used between the foot portion and the leg portion, again. [01271 Preferably, the substantially upright leg portion of each connection conduit will terminate from the top wall of the vessel in each chamber as illustrated in Figure 7 in particular. [0128] The upper inlet/outlet from each connection conduit maybe a divergent inlet/outlet as illustrated in Figure 6.

10 [01291 The lower inlet/outlet of each connection conduit 12 may be flush with the surface of the bulkhead wall through which it extends or alternatively, may stand slightly proud of the surface as illustrated in Figure 4. [01301 The connection conduits 12 are provided on the opposite lateral side of the vessel to the elongate conduit 21. The particular location of the connection conduits within each chamber, and within the vessel itself may assist with the formation of thermal stratification within each chamber. [01311 Typically, the storage fluid will be at different temperatures at different locations within each chamber, as well as at different temperatures between different chambers depending upon the direction of flow into or out of the thermal energy storage tank. [0132] Further, the preferred nonmetallic construction of the non-pressurised tank may act to further insulate adjacent chambers from one another. [01331 In the present specification and claims (if any), the word 'comprising' and its derivatives including 'comprises' and 'comprise' include each of the stated integers but does not exclude the inclusion of one or more further integers. [0134] Reference throughout this specification to 'one embodiment' or 'an embodiment' means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, the appearance of the phrases 'in one embodiment' or 'in an embodiment' in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more combinations. [01351 In compliance with the statute, the invention has been described in language more or less specific to structural or methodical features. It is to be understood that the invention is not limited to specific features shown or described since the means herein described comprises preferred forms of putting the invention into effect. The invention is, therefore, claimed in any of its forms or modifications within the proper scope of the appended claims (if any) appropriately interpreted by those skilled in the art.

Claims (21)

1. A mobile, modular, containerised chiller and thermal energy storage tank including a transport container having at least one opening to access an interior thereof, a thermal energy storage tank within the transport container and having at least one inlet and at least one outlet, an external condenser unit which in use is located outside the transport container and a plant room including at least one pump and at least one heat exchanger located within the transport container between the thermal energy storage tank and the at least one opening of the transport container and connected to the thermal energy storage tank and the condenser and having appropriate connections to allow connection of an external fluid distribution and return network to the at least one heat exchanger wherein the thermal energy storage tank is used to store water which is then provided to the at least one heat exchanger via the at least one pump in a closed loop to exchange heat with a fluid of the external fluid distribution and return network.

2. A mobile, modular, containerised chiller and thermal energy storage tank as claimed in claim 1 wherein water is used as a heat storage medium.

3. A mobile, modular, containerised chiller and thermal energy storage tank as claimed in claim 1 or claim 2 adapted for use with an external fluid distribution and return network including one or more pipes to distribute fluid at a required temperature and to return depleted fluid to the containerised chiller for thermal adjustment and redistribution on a substantially continuous basis.

4. A mobile, modular, containerised chiller and thermal energy storage tank as claimed in claim 3 wherein the external fluid distribution and return network is a part of a demand reduction cooling or heating system.

5. A mobile, modular, containerised chiller and thermal energy storage tank as claimed in any one of the preceding claims wherein the transport container includes a number of rigid walls providing mounting points for mounting the components of the containerised chiller and thermal energy storage tank relative to the interior of the container.

6. A mobile, modular, containerised chiller and thermal energy storage tank as claimed in any one of the preceding claims wherein the at least one opening in the transport container is provided as part of or as one of the end walls of the transport container.

7. A mobile, modular, containerised chiller and thermal energy storage tank as claimed claims 4U wherein 3 or 4 wherein appropriate connections are provided to allow attachment of the external piping network to carry fluid to and from the field, the connections extending through one or more of the walls of the shipping container to allow the connection to occur.

8. A mobile, modular, containerised chiller and thermal energy storage tank as claimed in any one of the preceding claims wherein includes an external condenser unit which is located and secured within the transport container for transport and is then relocated outside the transport container for use.

9. A mobile, modular, containerised chiller and thermal energy storage tank as claimed in claim 8 wherein the condenser unit is an air cooled, vertical style condenser unit located on a side wall of the container in use, adjacent the plant room but on the outside of the container.

10. A mobile, modular, containerised chiller and thermal energy storage tank as claimed in claim 8 wherein the condenser unit is a watercooled tower.

11. A mobile, modular, containerised chiller and thermal energy storage tank as claimed in claim 10 wherein the condenser unit is provided on an upper wall of the transport container in use in order to relocate the condenser unit into a more convenient location to reduce the footprint of the containerised chiller and thermal energy storage tank.

12. A mobile, modular, containerised chiller and thermal energy storage tank as claimed in any one of the preceding claims wherein the plant room includes process components of the chiller unit connected appropriately with the thermal energy storage tank and the externally mounted condenser.

13. A mobile, modular, containerised chiller and thermal energy storage tank as claimed in any one of the preceding claims wherein the thermal energy storage tank includes an outer vessel having at least one wall bounding the vessel volume and having at least one vessel inlet and at least one vessel outlet, a plurality of internal dividing walls to divide the vessel volume into a number of separate chambers and a connection conduit between adjacent separate chambers to allow fluid flow between adjacent chambers.

14. A mobile, modular, containerised chiller and thermal energy storage tank as claimed in claim 13 wherein the thermal energy storage tank is a pressurised vessel.

15. A mobile, modular, containerised chiller and thermal energy storage tank as claimed in claim 13 wherein the thermal energy storage tank is a non-pressurised vessel.

16. A mobile, modular, containerised chiller and thermal energy storage tank as claimed in any one of claims 13 to 15 wherein an inlet/outlet is provided at a lower portion of the vessel and inlet/outlet is provided at an upper portion of the vessel, the inlet/outlet provided at the upper portion of the vessel of this embodiment including an elongate conduit which extends from one end of the vessel into the separate chamber furthest from an end wall through which the inlet/outlet is provided.

17. A mobile, modular, containerised chiller and thermal energy storage tank as claimed in any one of claims 13 to 16 wherein the plurality of internal dividing walls divide the vessel volume into a number of separate chambers, each separate chamber formed to provide a separate fluid column to allow stratified hot water storage to occur in each of the separate chambers.

18. A mobile, modular, containerised chiller and thermal energy storage tank as claimed in any one of claims 13 to 17 a non-pressurised vessel is formed from a non-metallic material.

19. A mobile, modular, containerised chiller and thermal energy storage tank as claimed in any one of claims 13 to 18 wherein each connection conduit between adjacent separate chambers extends from a lower region in one chamber to an upper region in an adjacent chamber.

20. A mobile, modular, containerised chiller and thermal energy storage tank as claimed in claim 19 wherein each connection conduit is substantially L-shaped when viewed from the side including a substantially horizontal foot portion and a substantially upright leg portion.

21. A mobile, modular, containerised chiller and thermal energy storage tank including at least two transport containers, a thermal energy storage tank within one of the transport containers and having at least one inlet and at least one outlet, an external condenser unit which in use is located outside at least one of the transport containers and a plant room within another of the transport containers including at least one pump and at least one heat exchanger located within the transport container the plant room provided with appropriate connections to connect to the thermal energy storage tank and the condenser and having appropriate connections to allow connection of an external fluid distribution and return network to the at least one heat exchanger wherein the thermal energy storage tank is used to store water which is then provided to the at least one heat exchanger via the at least one pump to exchange heat with a fluid of the external fluid distribution and return network.