Patent Application
20160290682
The present disclosure relates to methods, devices, and systems, for an aqueous heat pump.
Heat pumps based on vapor compression can suffer efficiency degradation from a theoretical maximum due to a number of practical limitations, such as a lack of environmentally inert refrigerants with desirable thermodynamic properties. The desirable thermodynamic properties can include a relatively high value of enthalpy of vaporization and/or adequate vapor pressure. In addition, there can also be degradation factors due to mechanical and heat transfer inefficiencies.
Devices, methods, and systems for an aqueous heat pump are described herein. For example, one or more embodiments can include a system comprising a compressor to lower a first pressure of a first chamber and increase a second pressure of a second chamber, a liquid pump to remove a liquid from the first chamber and provide the liquid to the second chamber (e.g., recalculate liquid between the first chamber and the second chamber), wherein the liquid is capable of absorbing and desorbing a gas (e.g., CO2, etc.), and a heat exchanger to alter a temperature of the liquid when the liquid is removed from the first chamber and provided to the second chamber. In some examples, the heat exchanger can be utilized to remove heat from the liquid leaving the second chamber and a counter-flow heat exchanger can be utilized to allow heat exchanges between the liquid leaving the second chamber and liquid entering the second chamber.
The thermodynamic cycle of the aqueous heat pump can be based on a physical-chemical interaction between gas and an aqueous solution. For example, the aqueous heat pump can be based in part on an endothermic desorption of carbon dioxide in a depressurization chamber and an exothermic absorption of carbon dioxide in a pressurization chamber. The pressure difference between a depressurization chamber (e.g., desorption chamber) and a pressurized chamber (e.g., absorption chamber) can be maintained using a compressor (e.g., gaseous compressor, carbon dioxide compressor).
The aqueous heat pump can utilize a liquid pump to keep liquid (e.g., aqueous carbon dioxide solution) at a sufficient rate of liquid recirculation between the depressurization chamber and the pressurization chamber. In some embodiments, the sufficient rate of liquid recirculation can be needed to maintain a relatively constant CO2 concentration in the aqueous solution throughout the system. These embodiments can prevent CO2 depletion in the aqueous solution within the first chamber. The liquid pump can be located at a number of different locations between the depressurization chamber and the pressurization chamber. In some embodiments, a recuperation heat exchanger can be utilized to prevent thermal “leak back”. For example, the recuperation heat exchanger can be utilized to prevent cooler liquid from the depressurization chamber from being provided to the pressurization chamber and to prevent warmer liquid from the pressurization chamber from being provided to the depressurization chamber.
The liquid provided to the depressurization chamber and the pressurization chamber can be provided by a liquid dispersion system. The liquid dispersion system can create a mist and/or spray of the liquid to increase a surface area of the liquid that is provided to the depressurization chamber and the pressurization chamber. The liquid dispersion system can increase (e.g., accelerate) the rate limiting process of carbon dioxide absorption and/or desorption by increasing the surface area of the provided liquid. Increasing the surface area of the provided liquid can increase an interaction between the aqueous carbon dioxide solution and the gaseous carbon dioxide within the depressurization chamber and the pressurization chamber.
In the following detailed description, reference is made to the accompanying drawings that form a part hereof. The drawings show by way of illustration how one or more embodiments of the disclosure may be practiced.
These embodiments are described in sufficient detail to enable those of ordinary skill in the art to practice one or more embodiments of this disclosure. It is to be understood that other embodiments may be utilized and that process changes may be made without departing from the scope of the present disclosure.
As will be appreciated, elements shown in the various embodiments herein can be added, exchanged, combined, and/or eliminated so as to provide a number of additional embodiments of the present disclosure. The proportion and the relative scale of the elements provided in the figures are intended to illustrate the embodiments of the present disclosure, and should not be taken in a limiting sense.
The figures herein follow a numbering convention in which the first digit or digits correspond to the drawing figure number and the remaining digits identify an element or component in the drawing. Similar elements or components between different figures may be identified by the use of similar digits.
As used herein, “a” or “a number of” something can refer to one or more such things. For example, “a number of widgets” can refer to one or more widgets. Additionally, the designator “N”, as used herein, particularly with respect to reference numerals in the drawings, indicates that a number of the particular feature so designated can be included with a number of embodiments of the present disclosure.
The system 100 can include a first chamber 102 (e.g., desorption chamber, depressurization chamber, etc.) that is coupled to a second chamber 104 (e.g., absorption chamber, pressurization chamber, etc.) by a compressor 106 (e.g., carbon dioxide compressor, etc.). The compressor 106 can remove gaseous carbon dioxide from the first chamber 102 to lower a pressure within the first chamber 102. In some embodiments, the compressor 106 can lower the pressure of the first chamber 102 to approximately 3 BAR (e.g., 2 BAR-4 BAR, etc.). The compressor 106 can utilize the gaseous carbon dioxide removed from the first chamber 102 to increase a pressure of the second chamber 104. In some embodiments, the compressor 106 can increase the pressure of the second chamber 104 to approximately 8 BAR (e.g., 7 BAR-9 BAR, etc.).
The difference in pressure between the first chamber 102 and the second chamber 104 can move the liquid from the second chamber 104 to the first chamber 102 via a number of coupled liquid lines 116, 118. For example, liquid 124-2 can accumulate at a bottom portion of the second chamber 104. In this example, the difference in pressure between the first chamber 102 and the second chamber 104 can move the liquid 124-2 through a heat exchanger 112-2, through a counter-flow energy recover heat exchanger 110, and to a dispersion unit 114-1 of the first chamber 102. The liquid flow from the first chamber 102 to the second chamber 104 through lines 116 and 122 can be driven by liquid pump 108-1 to overcome the pressure difference between the two chambers.
As described herein, the process of carbon dioxide desorption and/or absorption within the first chamber 102 and the second chamber 104 respectively can be a rate limiting step within the system 100. The absorption and/or desorption rate of carbon dioxide or other gas that is capable of absorption and desorption as described herein can be increased within the system 100 by increasing the surface area of the provided liquid via the liquid dispersion units 114-1, 114-2. The liquid dispersion units 114-1, 114-2 can increase the surface area of the provided liquid by creating a plurality of droplets 126-1, 126-2 from the provided liquid. For example, the liquid dispersion units 114-1, 114-2 can create a mist with the provided liquid so that a plurality of droplets 126-1, 126-2 of the provided liquid can interact with the gaseous carbon dioxide.
In some embodiments, the first chamber 102 can be a desorption chamber that is utilized to desorb carbon dioxide from the plurality of droplets 126-1 into the first chamber 102 (e.g., decreasing a concentration of carbon dioxide in the plurality of droplets 126-1, etc.). Desorbing the carbon dioxide from the plurality of droplets 126-1 can produce an endothermic reaction and cool the droplets 126-1 and liquid 124-1 within the first chamber 102. In some embodiments, the first chamber 102 and other components between the first chamber 102 and counter-flow heat exchanger 110 (e.g., liquid lines 116, 118, liquid dispersion unit 114-1, liquid pump 108, etc.) can be referred to as a “cold side”. That is, the first chamber 102 and other components of the “cold side” can maintain a temperature of the liquid that is relatively colder than the “warm side” (e.g., second chamber 104 and components between counter-flow heat exchanger 110 and the second chamber 104). In some embodiments, the “cold side” can maintain a temperature lower than 10 degrees C.
In some embodiments, the second chamber 104 can be an absorption chamber that is utilized to absorb carbon dioxide from the second chamber 104 into the plurality of droplets 126-2 (e.g., increasing a concentration of carbon dioxide in the plurality of droplets 126-2). Absorbing the carbon dioxide into the plurality of droplets 126-1 can produce an exothermic reaction and warm the droplets 126-2 and liquid 124-2 within the second chamber 104. The second chamber 104 and other components between the second chamber 104 and counter-flow heat exchanger 110 can be referred to as a “warm side”. That is, the second chamber 104 and other components of the “warm side” can maintain a temperature of the liquid that is relatively warmer than the “cold side”. In some embodiments, the “warm side” can maintain a temperature higher than 35 degrees C. As described herein, an efficiency degradation factor can include thermal “leak back” from liquid solution recirculation (e.g., pumping warm liquid to a “cold side” and/or pumping cool liquid to the “warm side, etc.).
The thermal “leak back” from liquid solution recirculation can be reduced by coupling a counter-flow energy recovery heat exchanger 110 between the first chamber 102 and the second chamber 104. The counter-flow energy recovery heat exchanger 110 can utilize cool liquid from the “cold side” to cool liquid from the “warm side” and vice versa. For example, liquid from the first chamber 102 can enter the counter-flow energy recovery heat exchanger 110 and cool liquid from the second chamber 104 entering the counter-flow energy recovery heat exchanger 110. In this example, liquid from the second chamber 104 can enter the counter-flow energy recovery heat exchanger 110 and warm liquid from the first chamber 102.
The counter-flow energy recovery heat exchanger 110 can be utilized to warm liquid from the first chamber 102 before the liquid is provided to the second chamber 104. For example, liquid from the first chamber 102 can be approximately 10 degrees C. when entering the counter-flow energy recovery heat exchanger 110. In this example, liquid from the second chamber 104 can be approximately 35 degrees C. and utilized to warm the liquid from the first chamber 102. In this example, the liquid from the second chamber 104 can warm the liquid from the first chamber 102 to approximately 35 degrees C. prior to being provided to the second chamber 104. Thus, the counter-flow energy recovery heat exchanger 110 can be utilized to ensure that liquid being provided to the first chamber 102 is approximately 10 degrees C. and that liquid being provided to the second chamber is approximately 35 degrees C. The system 100 can be utilized to provide a cooling heat exchanger 112-1 and a warming heat exchanger 112-2 that can provide cooling and/or heating resources to a building.
In some embodiments, the liquid pump 208-1 can be utilized to control a rate of liquid circulation within the system 200. In addition to the liquid pump 208-1, a recuperation motor 208-2 (e.g., recuperation pump, etc.) can be utilized to control a rate of liquid circulation within the system 200. For example, the liquid pump 208-1 can pump liquid from the first chamber 202 through the counter-flow energy recovery heat exchanger 210 to provide the liquid to the second chamber 204. In this example, the recuperation motor 208-2 can pump liquid received through the counter-flow energy recovery heat exchanger 210 from the second chamber 204 and provide the liquid to the first chamber 202.
In some embodiments, the recuperation motor can generate power from the liquid flow from the second chamber 204 to the first chamber 202. For example, the liquid pump 208-1 can be mechanically linked with the energy recuperation motor 208-1 through a common shaft wherein the recuperated power from motor 208-2 is fed to pump 208-1. Thus, in this example can reduce the power consumption of pump 208-1 to conserve power and improve efficiency of the system 200.
Although specific embodiments have been illustrated and described herein, those of ordinary skill in the art will appreciate that any arrangement calculated to achieve the same techniques can be substituted for the specific embodiments shown. This disclosure is intended to cover any and all adaptations or variations of various embodiments of the disclosure.
It is to be understood that the above description has been made in an illustrative fashion, and not a restrictive one. Combination of the above embodiments, and other embodiments not specifically described herein will be apparent to those of skill in the art upon reviewing the above description.
The scope of the various embodiments of the disclosure includes any other applications in which the above structures and methods are used. Therefore, the scope of various embodiments of the disclosure should be determined with reference to the appended claims, along with the full range of equivalents to which such claims are entitled.
In the foregoing Detailed Description, various features are grouped together in example embodiments illustrated in the figures for the purpose of streamlining the disclosure. This method of disclosure is not to be interpreted as reflecting an intention that the embodiments of the disclosure require more features than are expressly recited in each claim.
Rather, as the following claims reflect, inventive subject matter lies in less than all features of a single disclosed embodiment. Thus, the following claims are hereby incorporated into the Detailed Description, with each claim standing on its own as a separate embodiment.
