Embodiments of this disclosure relate generally to chilled refrigeration systems and, more particularly, to a hydronic free cooling economizer for use with a chilled fluid refrigeration system.
Chilled fluid systems provide a temperature conditioned fluid, for use in conditioning the air within large buildings and other facilities. The chilled fluid is typically pumped to a number of remote heat exchangers or system coils for cooling various rooms or areas within a building. A chilled fluid system enables the centralization of the air conditioning requirements for a large building or complex of buildings by using water or a similar fluid as a safe and inexpensive temperature transport medium.
In general a chilled fluid system is configured to provide chilled fluid at a particular temperature, via a first fluid loop, for cooling and dehumidify air in a building. Heat and moisture are extracted from the building air, and the heat is transferred to the fluid in the first fluid loop, and is returned via the first fluid loop to the chilled fluid system. The returned fluid is again cooled to the desired temperature by transferring the heat of the fluid to the chiller's refrigerant. After the refrigerant is compressed by a compressor, the heat in the refrigerant is transported to the condenser. Some units use a water cooled condenser where heat is transferred to a second fluid, such as water for example. The second fluid loop transports waste heat from the condenser of the chiller to a cooling tower which then transfers the waste heat from the second water loop to ambient air by direct contact and evaporation of some of the water between the ambient air and the second fluid of the second loop. However, other chilled fluid systems transfer the heat directly to the air using fans and condenser coils.
In one exemplary embodiment, a hydronic economizer module is configured for use in a chiller system that has a vapor compression cycle. The hydronic economizer module includes a heat exchanger assembly located within a housing having at least one heat exchanger coil, a fan assembly having at least one fan generally aligned with at least one heat exchanger coil, and at least one valve is movable between a plurality of positions to control a flow of fluid into the heat exchanger assembly. When the at least one valve is in a first position, the economizer module is arranged in parallel with a flat plate heat exchanger. When the at least one valve is in a second position, the economizer module is arranged in series with the flat plate heat exchanger. The flat plate heat exchanger includes at least one fluid port for communicating with a component of the vapor compression cycle.
In a further embodiment of the above, the component of the vapor compression cycle that is in fluid communication with the flat plate heat exchanger is an evaporator.
In a further embodiment of any of the above, the hot plate heat exchanger fluidly separates at least one heat exchanger coil from the vapor compression cycle.
In a further embodiment of any of the above, a circulation pump for circulating the flow of fluid through at least one heat exchanger coil and the flat plate heat exchanger.
In a further embodiment of any of the above, there is an expansion tank for collecting the flow of fluid and at least two isolation valves for isolating the flat plate heat exchanger.
In a further embodiment of any of the above, at least one heat exchanger coil includes at least one first heat exchanger coil and at least one second heat exchanger coil.
In a further embodiment of any of the above, at least one first heat exchanger coil and the at least one second heat exchanger coil are arranged into at least one of a V-shaped configuration or a W-shaped configuration.
In a further embodiment of any of the above, at least one fan is a variable speed fan. The hydronic economizer includes at least one access panel aligned with at least one heat exchanger coil.
In a further embodiment of any of the above, at least one heat exchanger coil is coated in a corrosion resistant material.
In another exemplary embodiment, a chiller system includes a vapor compression cycle including an evaporator and a condenser. A hydronic economizer includes at least one economizer module removably attached to the condenser. At least one economizer module includes a heat exchanger assembly located within a housing which includes at least one heat exchanger coil. A fan assembly includes at least one fan generally aligned with at least one heat exchanger coil.
In a further embodiment of any of the above, at least one economizer module is integral with the condenser.
In a further embodiment of any of the above, at least one heat exchanger coil and the condenser are arranged parallel to each other with respect to cooling air flow. At least one heat exchanger coil includes at least one of a round tube or a flat ported tube made of at least one of copper or aluminum.
In a further embodiment of any of the above, the fan assembly includes at least one variable speed fan.
In a further embodiment of any of the above, a controller is in electrical communication with the vapor compression cycle and the hydronic economizer.
In a further embodiment of any of the above, at least one first heat exchanger coil includes a plurality of heat exchanger coils arranged into at least one of a V-shaped configuration or a W-shaped configuration.
In a further embodiment of any of the above, at least one economizer module includes at least one access panel.
In a further embodiment of any of the above, at least one access panel is aligned with at least one heat exchanger coil.
In a further embodiment of any of the above, the hydronic economizer includes at least one valve movable between a plurality of positions to control a flow of fluid into the heat exchanger assembly. When at least one valve is in a first position, the economizer module is arranged in parallel with a component of the vapor compression cycle. When at least one valve is in a second position, the economizer module is arranged in series with the component of the vapor compression cycle.
In a further embodiment of any of the above, at least one heat exchanger coil is coated in a corrosion resistant material.
In a further embodiment of any of the above, the vapor compression cycle includes a chiller controller. The hydronic economizer includes an economizer controller in electrical communication with the chiller controller.
The chiller system 5 additionally includes a secondary system 30, such as an air handler for example, fluidly coupled to the vapor compression cycle 10 of the chiller system 5. As shown, a fluid F, such as water or glycol for example, is provided from the secondary system 30 to the evaporator 14. Within the evaporator 14, heat is rejected from the fluid F to the refrigerant R, such that a cool fluid F is returned to the secondary system 30. Within the secondary system 30, the fluid F may be circulated to a building or conditioned space to cool and dehumidify air associated therewith.
To improve the overall efficiency of both the vapor compression cycle 10 and the secondary system 30, a hydronic or fluid economizer 40 may be connected to the fluid circuit extending between the vapor compression cycle 10 and the secondary system 30. The economizer 40 may be used in place of, or in addition to the evaporator 14, to cool the fluid F. Fluid or hydronic economizers 40 are typically located exterior to a building to allow for cooling of the fluid F using ambient air. As a result, inclusion of the fluid economizer 40 may be particularly beneficial in cooler climates where the ambient temperature is sufficient to cool the fluid F.
Furthermore, a chiller controller 32 is in electrical communication with the compressor 12, evaporator 14, condenser 16, and the expansion valve 18 to monitor the refrigerant R in the respective devices or to control operation of the respective devices. Additionally, an economizer controller 34 is in electrical communication with the economizer 40 to monitor and control operation of the economizers 40. Additionally, the economizer controller 34 can communicate with the existing chiller controller 32. Alternatively, the economizer controller 34 could be integrated into the chiller controller 32.
By cooling the refrigerant R in the second flow path, inclusion of the economizer heat exchanger 20 further cools the refrigerant R provided to the expansion valve 18. The refrigerant in the second flow path absorbs heat from the first refrigerant flow path and becomes a vapor. This vapor is then provided directly to an intermediate portion of the compressor 12, thereby bypassing the expansion valve 18 and evaporator 14 of the vapor compression cycle 10. Inclusion of the economizer heat exchanger 20 increases the overall efficiency of the vapor compression cycle 10. However, it should be understood that vapor compression systems that do not include an economizer heat exchanger 20 or have another configuration are also contemplated herein.
Referring now to
With reference to
With reference now to
The cross-section of the heat exchanger assembly 50 is generally constant over a length of the economizer module 42, such as between a front surface 52 and a back surface (not shown) for example. The heat exchanger assembly 50 includes at least one heat exchanger coil 54A, 54B, that may include a round tube plate fin heat exchanger coil or a ported flat tube heat exchanger coil formed having copper coils and aluminum fins. In examples where the heat exchanger assembly 50 includes a plurality of heat exchanger coils 54A, 54B, the heat exchanger coils 54A, 54B may, but need not be, arranged generally symmetrically or equidistantly spaced from a center of the economizer module 42 between the opposing longitudinal sides 46A, 46B, as illustrated schematically by line C. The heat exchanger coils 54A, 54B can also include a corrosive resistant coating and the heat exchanger coils 54A, 54B are round or flat tubes and made from at least one of copper or aluminum.
In the illustrated, non-limiting example, the heat exchanger assembly 50 includes at least a first heat exchanger coil 54A mounted to the first longitudinal side 46A of the housing 44 and at least a second, heat exchanger coil 54B mounted to the second longitudinal side 46B of the housing 44. The first heat exchanger coil 54A and the second heat exchanger coil 54B may, but need not be, substantially identical. The plurality of heat exchanger coils 54A, 54B may be arranged within the housing 44 such that at least a portion of the heat exchanger assembly 50 has a generally V-shaped configuration, as is known in the art. In the illustrated, non-limiting example, the at least one first heat exchanger coil 54A includes a pair of heat exchanger coils arranged in a V-shaped configuration and the at least one second heat exchanger coil 54B includes a pair of heat exchanger coils arranged in a V-shaped configuration. However, alternative configurations of the heat exchanger assembly 50, such as the generally W-shaped configuration (
The economizer module 42 additionally includes a fan assembly 60 including one or more fans 62A, 62B configured to circulate air through the housing 44 and the heat exchanger assembly 50. The fans 62A, 62B can also be variable speed fans or single speed fans. Depending on the characteristics of the economizer module 42, the fan assembly 60 may be positioned either downstream with respect to the heat exchanger assembly 50 (i.e. “draw through configuration”) as shown in the
Operation of the at least one fan 62 associated with the at least one heat exchanger coil 54 causes air to flow through an adjacent air inlet and into the housing 44 of the economizer module 42. As the air passes over the heat exchanger coil 54 (See arrows in
With reference again to
In an example, the plurality of spray nozzles 64 are be formed in a grid and located directly upstream from the heat exchanger assembly 50 with respect to the flow of air through the module 42. The spray nozzles 64 are selectively operable to generate a mist adjacent the underside of the heat exchanger coils 54. The mist is configured to reduce the local ambient temperature surrounding the heat exchanger assembly 50 to a temperature close to the wet bulb temperature and facilitate evaporative cooling. Accordingly, operation of the spray nozzles 64 changes the temperature and humidity of the air passing through the coils 54 without adding condensation thereto. In an example, the spray nozzles 64 are operated only if two conditions are met. First, the wetbulb temperature must be less than the temperature of the fluid F by a predetermined amount and second, the wetbulb temperature must be less than the dry bulb temperature by a predetermined amount.
With reference again to
In a second, free cooling mode, the valves 43 are positioned to direct the entire fluid flow F into the one or more modules 42 of the fluid economizer 40. Within the heat exchanger assemblies 50 of each module, the fluid F is arranged in a heat exchange relationship with cool ambient air. The cooled fluid F is then returned directly to the secondary system 30. Accordingly, in free-cooling mode, the evaporator 14 is not used to cool the fluid F. In such examples, the vapor compression cycle 10 need not be operational since all cooling is performed by the fluid economizer 40. In the second mode of operation, the ambient temperature is below the predetermined threshold such that the ambient air alone is capable of cooling the fluid F. In a third pre-cooling mode of operation, the fluid F is provided to the fluid economizer 40 and then to the evaporator 14 in series. In an example, the system is operated in a pre-cooling mode when the ambient temperature is too warm to fully cool the fluid F. It should be understood that the spray nozzles 64 may be used in either the second, free-cooling mode, or the third pre-cooling mode of operation.
Although the different non-limiting examples are illustrated as having specific components, the examples of this disclosure are not limited to those particular combinations. It is possible to use some of the components or features from any of the non-limiting examples in combination with features or components from any of the other non-limiting examples.
It should be understood that like reference numerals identify corresponding or similar elements throughout the several drawings. It should also be understood that although a particular component arrangement is disclosed and illustrated in these exemplary examples, other arrangements could also benefit from the teachings of this disclosure.
The foregoing description shall be interpreted as illustrative and not in any limiting sense. A worker of ordinary skill in the art would understand that certain modifications could come within the scope of this disclosure. For these reasons, the following claim should be studied to determine the true scope and content of this disclosure.
This application claims priority to U.S. Provisional Application No. 62/858,574, which was filed on Jun. 7, 2019 and is incorporated herein by reference.
Filing Document | Filing Date | Country | Kind |
---|---|---|---|
PCT/US2020/032440 | 5/12/2020 | WO |
Publishing Document | Publishing Date | Country | Kind |
---|---|---|---|
WO2020/247154 | 12/10/2020 | WO | A |
Number | Name | Date | Kind |
---|---|---|---|
5924088 | Shaw | Jul 1999 | A |
7114349 | Lifson et al. | Oct 2006 | B2 |
9103571 | Yang et al. | Aug 2015 | B2 |
9278303 | Somani et al. | Mar 2016 | B1 |
9476657 | Pettis | Oct 2016 | B1 |
9587867 | Lee et al. | Mar 2017 | B2 |
9797640 | Umeda et al. | Oct 2017 | B2 |
9869487 | Nickey et al. | Jan 2018 | B2 |
10119717 | Matsuo | Nov 2018 | B2 |
10215470 | Nikaido | Feb 2019 | B2 |
20080053114 | Zhao | Mar 2008 | A1 |
20090126399 | Takegami | May 2009 | A1 |
20100242532 | Kopko | Sep 2010 | A1 |
20110192188 | Nickey | Aug 2011 | A1 |
20140096547 | Boehde | Apr 2014 | A1 |
20140202177 | Rush | Jul 2014 | A1 |
20140338391 | Keisling | Nov 2014 | A1 |
20150354849 | Matsuo | Dec 2015 | A1 |
20160209087 | Reytblat | Jul 2016 | A1 |
20160305702 | Nikaido | Oct 2016 | A1 |
20170227263 | Kopko | Aug 2017 | A1 |
20170234559 | Federspiel et al. | Aug 2017 | A1 |
20170268792 | Costakis | Sep 2017 | A1 |
20180224149 | Lazzari | Aug 2018 | A1 |
20190301819 | Nagata | Oct 2019 | A1 |
20200200445 | Rajendran | Jun 2020 | A1 |
20200284480 | Tolouei Asbforoushani | Sep 2020 | A1 |
20200309433 | Wang | Oct 2020 | A1 |
20210088260 | Silva | Mar 2021 | A1 |
Number | Date | Country |
---|---|---|
106766332 | Dec 2016 | CN |
102015221346 | May 2017 | DE |
2102569 | Jun 2017 | EP |
3273169 | Jan 2018 | EP |
2011019909 | Feb 2011 | WO |
2017160346 | Sep 2017 | WO |
2018187570 | Oct 2018 | WO |
Entry |
---|
Emerson Network Power. Energy Efficient Cooling Solutions for Data Centers: Introducing an Emerson Network Power tool for evaluating cooling system total cost of ownership. Nov. 2007. pg. 3. |
Rogan, M. Arctic Chiller Group. Free Cooling Fundamentals in Modular HVAC Chillers. pg. 5. |
Brett, G. Environmental Systems Design, Inc. Digital Realty—Data Center Solutions. Sep. 2012. pp. 4-6. |
International Search Report and Written Opinion for International Application No. PCT/US2020/032440 dated Aug. 26, 2020. |
International Preliminary Report on Patentability for International Application No. PCT/US2020/032440 dated May 12, 2020. |
Number | Date | Country | |
---|---|---|---|
20210262705 A1 | Aug 2021 | US |
Number | Date | Country | |
---|---|---|---|
62858574 | Jun 2019 | US |