Reducing peak electrical demand by air conditioning systems and reducing water consumption by implementing an integrated thermal energy and rainwater storage system

Patent metadata

Field	Value
Publication number	US-2016282002-A1
Application number	US-201415035204-A
Country	US
Kind code	A1
Filing date	Nov 7, 2014
Priority date	Nov 15, 2013
Publication date	Sep 29, 2016
Grant date	—

Abstract

An integrated thermal energy and rainwater storage system for reducing peak electrical demand by air conditioning systems. Such a system includes a water conveyance system for collecting and conveying water to a storage tank for storing rainwater, where the rainwater functions as a lower temperature thermal reservoir while it is being held and awaiting use. The system further includes a residential air conditioning system with an air-cooled condenser unit along with an additional water-to-refrigerant heat exchanger connected to the storage tank on one side, and on the other side connected into the refrigerant lines with reconfigurable flow paths and actuated valves to control the discharging and recharging of the thermal energy storage. The lower temperature and better heat transfer capabilities of the rainwater improve operating efficiency and reduce power consumption of the compressor when used instead of the air-cooled condenser during the hottest hours of the day.

First claim

1 . An integrated thermal energy and water storage system, the system comprising:
a refrigerant circulation network; a storage tank configured to store water, wherein a thermal mass of said water is used as a thermal storage medium; a water conveyance system configured to capture, direct and move water from one or more sources into and out of said storage tank; an evaporator connected to said refrigerant circulation network, wherein said evaporator is configured to evaporate refrigerant into a refrigerant vapor thereby extracting heat from a cooled space; a compressor connected to said refrigerant circulation network, wherein said compressor is configured to pressurize and circulate said refrigerant around said system, wherein said compressor compresses said refrigerant vapor; an air-cooled condenser connected to said refrigerant circulation network, wherein said air-cooled condenser is configured to condense said refrigerant vapor thereby removing heat energy from said water in said tank and rejecting said heat energy to the atmosphere; and a water-to-refrigerant heat exchanger connected to said refrigerant circulation network, wherein said water-to-refrigerant heat exchanger is configured to either evaporate or condense said refrigerant depending on an operational mode of said system; wherein said water in said storage tank is re-cooled by said refrigerant in the late evening and/or early morning, wherein said refrigerant from said compressor is condensed by said water in said water-to-refrigerant heat exchanger during a first mode of operation of said system, wherein said refrigerant is then expanded during said first mode of operation and directed to said evaporator during peak times of electrical demand to be evaporated into said refrigerant vapor, wherein said refrigerant vapor is directed to said water-to-refrigerant heat exchanger during said first mode of operation, wherein said water from said storage tank condenses said refrigerant vapor as opposed to being directed to said air-cooled condenser during said first mode of operation thereby allowing said water from said storage tank to function as a heat sink instead of outdoor air cooling said air-cooled condenser during said peak times of electrical demand.

2 . The integrated thermal energy and rainwater storage system as recited in claim 1 , wherein in a second mode of operation, compressed and condensed refrigerant from said condenser is routed to a first expansion valve to be expanded and said expanded refrigerant is directed to said water-to-refrigerant heat exchanger to remove heat energy from said water in said storage tank to re-cool said water in said late evening and/or early morning.

3 . The integrated thermal energy and rainwater storage system as recited in claim 2 , wherein in said second mode of operation, said refrigerant vapor is routed to said compressor to be compressed by said compressor and said compressed refrigerant vapor is routed to said condenser to be condensed into said liquid thereby releasing heat absorbed from said water from said storage tank.

4 . The integrated thermal energy and rainwater storage system as recited in claim 1 , wherein in a third mode of operation, compressed and condensed refrigerant from said condenser is routed to a first expansion valve to be expanded except during said peak times of electrical demand and said expanded refrigerant is directed to said evaporator to be evaporated into said refrigerant vapor.

5 . The integrated thermal energy and rainwater storage system as recited in claim 4 , wherein in said third mode of operation, said refrigerant vapor is routed to said compressor to be compressed by said compressor and said compressed refrigerant vapor is routed to said condenser to be condensed into said liquid thereby releasing heat.

6 . The integrated thermal energy and rainwater storage system as recited in claim 1 , wherein in said first mode of operation, compressed and condensed refrigerant from said water-to-refrigerant heat exchanger is routed to a second expansion valve to be expanded during said peak times of electrical demand and said expanded refrigerant is directed to said evaporator to be evaporated into said refrigerant vapor during said peak times of electrical demand.

7 . The integrated thermal energy and rainwater storage system as recited in claim 6 , wherein in said first mode of operation, said refrigerant vapor is routed to said compressor to be compressed by said compressor during said peak times of electrical demand and said compressed refrigerant vapor is routed to said water-to-refrigerant heat exchanger to be condensed into said liquid thereby releasing heat during said peak times of electrical demand.

8 . The integrated thermal energy and rainwater storage system as recited in claim 7 , wherein said first mode of operation continues until a maximum allowable water tank temperature of said storage tank is reached or until a peak load time period ends.

9 . The integrated thermal energy and rainwater storage system as recited in claim 1 , wherein said water in said storage tank comprises one or more of the following: rainwater, municipal water, well water, gray water, treated wastewater, AC condensate, lake water, river water, ocean water and stormwater runoff.

10 . A method for reducing peak electrical demand by air conditioning systems, the method comprising:
routing compressed and condensed refrigerant from an air-cooled condenser to a first expansion valve to be expanded; directing said refrigerant expanded by said first expansion valve to a water-to-refrigerant heat exchanger to re-cool water in a storage tank during off-peak times of electrical demand in a late evening and/or early morning; routing said refrigerant from said water-to-refrigerant heat exchanger to a second expansion value or said first expansion valve to be expanded during peak times of electrical demand; directing said refrigerant expanded by said second expansion value to an evaporator during said peak times of electrical demand to be evaporated into a refrigerant vapor; and directing said refrigerant vapor to said water-to-refrigerant heat exchanger connected to said storage tank as opposed to being directed to said air-cooled condenser thereby allowing said water in said storage tank to function as a heat sink instead of said air-cooled condenser during said peak times of electrical demand.

11 . The method as recited in claim 10 further comprising:
routing compressed and condensed refrigerant from said condenser to said first expansion valve to be expanded in a first mode of operation, wherein said first mode of operation occurs during said off-peak times of electrical demand in said late evening and/or early morning; and
directing said expanded refrigerant to said water-to-refrigerant heat exchanger connected to said storage tank to re-cool said water in said first mode operation.

12 . The method as recited in claim 11 further comprising:
routing said refrigerant vapor from said water-to-refrigerant heat exchanger to a compressor to be compressed by said compressor in said first mode of operation; and
routing said compressed refrigerant vapor to said air-cooled condenser to be condensed into a liquid thereby releasing heat absorbed from said water in said storage tank in said first mode of operation.

13 . The method as recited in claim 10 further comprising:
routing compressed and condensed refrigerant from said air-cooled condenser to said first expansion valve to be expanded except during said peak times of electrical demand in a second mode of operation, wherein said second mode of operation occurs during said off-pea

Assignees

• Univ Texas

Inventors

• Upshaw Charles R
• Webber Michael E
• Rhodes Joshua D

Classifications

• F24F2005/0032

  Systems storing energy during the night · CPC title

• F24F2011/0047

  Mechanical Engineering · mapped topic

• F24F2005/0025

  using heat exchange fluid storage tanks · CPC title

• F24F5/0017 Primary

  using cold storage bodies, e.g. ice · CPC title

• F24F2140/60

  Energy consumption · CPC title