WO2024007092A1

WO2024007092A1 - Hvac system with thermoelectric conversion

Info

Publication number: WO2024007092A1
Application number: PCT/CN2022/103559
Authority: WO
Inventors: Kin Wing LIU
Original assignee: Liu Kin Wing
Priority date: 2022-07-04
Filing date: 2022-07-04
Publication date: 2024-01-11

Abstract

Provided herein is a heating, ventilation, and air conditioning (HVAC) system (100) for a building. The HVAC system (100) is configured to convert heat energy into electric energy for minimizing heat dissipation from the building. The HVAC system (100) includes a plurality of air handling units (AHUs) (140); a chiller (110) configured to provide cooling for floors in the building by circulating a circulated fluid to the plurality of AHUs (140); a cooling tower (240) at a rooftop (30) of the building; and a power generation system. The circulated fluid is in a heat exchange relationship with a cooling fluid when the chiller (110) is operating. The power generation system is disposed along a pipeline for pumping the cooling fluid from the chiller (110) to the cooling tower (240), and configured to absorb heat from the cooling fluid for generating electrical energy.

Description

HVAC SYSTEM WITH THERMOELECTRIC CONVERSION

TECHNICAL FIELD

The present disclosure generally relates to a building automation system. More particularly, the present disclosure relates to a building automation system having a HVAC system with thermoelectric conversion.

BACKGROUND

In a Commercial building or multi-storey building, such as industrial facilities, hotels, and offices, the building generally has a building automation system for controlling, monitoring, and managing equipment inside and outside the building. The building automation system may control the indoor and outdoor lights, elevators, ventilation, fire safety, power management, and security. The smart technology enhances the management of the building by receiving alerts and supporting real-time control of the equipment.

Typically, the building automation system also includes a heating, ventilation, and air conditioning (HVAC) system. The HVAC system is provided to receive the user selection of the temperature and air condition of a specific room, and adjust the air conditions accordingly. The adjustment may include both cooling system and heating system so that the building can maintain a comfortable temperature with various outside temperatures.

As the world is getting hotter, there is an increasing demand for air conditioning to satisfy the need for space cooling, especially during extreme heat events and summer time. According to an analysis by the International Energy Agency (IEA) , nearly 20%of the electricity used in buildings were consumed by the air conditioners or electric fans to keep the indoor environment cool. The electricity consumption drives up the emissions and causes pollution to the environment. The cooling tower in the building also dissipates large heat loads to the atmosphere. The continuously increasing demand for air conditioning units is inevitable, and the respective power consumption is expected to hike. In an attempt to tackle the climate crisis posed by the extension use of air conditioning systems, it is desirable to have improved design to harvest the heat energy generated and convert to electricity.

Accordingly, there is a need in the art for an improved HVAC system that can generate electric energy from the heat dissipation. Particularly, the HVAC system can reduce hot air emission and generate electricity for the building to use. Furthermore, other desirable features and characteristics will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and this background of the disclosure.

SUMMARY OF THE INVENTION

Provided herein is a HVAC system for a multi-storey building that generates electric energy from the heat dissipation to the environment. The present disclosure is inspired by the need to recover energy from the waste hot air generated from the chiller or the boiler in the HVAC system. Therefore, it is advantageous to provide a method that can effectively convert the heat energy into electricity.

In accordance with certain embodiments of the present disclosure, a HVAC system for a building is provided. The HVAC system is configured to convert heat energy into electric energy for minimizing heat dissipation from the building. The HVAC system includes a plurality of air handling units (AHUs) ; a chiller configured to provide cooling for floors in the building by circulating a circulated fluid to the plurality of AHUs; a cooling tower at a rooftop of the building; and a power generation system. The circulated fluid is in a heat exchange relationship with a cooling fluid when the chiller is operating. The power generation system is disposed along a pipeline for pumping the cooling fluid from the chiller to the cooling tower, and configured to absorb heat from the cooling fluid for generating electrical energy.

In accordance with a further aspect of the present disclosure, the power generation system comprises a thermoelectric module arranged to receive the cooling fluid from the chiller at a first end, and transfer the cooling fluid to the cooling tower at a second end.

In accordance with a further aspect of the present disclosure, the thermoelectric module comprises one or more tubular thermoelectric devices accommodated within a water pipe, wherein the water pipe receives fresh water from a water tower at the second end, and wherein the fresh water absorbs heat from the cooling fluid.

In accordance with a further aspect of the present disclosure, the water pipe comprises plural water outlets for distributing the fresh water from the water tower to the floors of the building.

In accordance with a further aspect of the present disclosure, each of the one or more tubular thermoelectric devices comprises a pipe and a metallic layer arranged on an outer circumferential surface of the pipe, wherein the metallic layer is connected to a positive terminal and a negative terminal for power generation.

In accordance with another aspect of the present disclosure, the thermoelectric module comprises one or more tubular thermoelectric devices accommodated within a rooftop water tank, wherein the rooftop water tank receives fresh water from a water tower at the second end, and wherein the fresh water absorbs heat from the cooling fluid.

In accordance with a further aspect of the present disclosure, each of the one or more tubular thermoelectric devices comprises a pipe and a metallic layer arranged on an outer circumferential surface of the pipe. The metallic layer is connected to a positive terminal and a negative terminal for power generation. The pipe is placed across the rooftop water tank from a first side to the second side.

In accordance with a further aspect of the present disclosure, the rooftop water tank comprises a water inlet and a water outlet arranged in such a way that the fresh water and the cooling fluid flow in opposite directions.

In accordance with another aspect of the present disclosure, the HVAC system further includes a processor configured to control the chiller to perform heat exchange between the circulated fluid and the cooling fluid, wherein the cooling fluid is allowed to accumulate the energy from the circulated fluid.

In accordance with a further aspect of the present disclosure, the circulated fluid is water, glycol, or a combination thereof.

This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter. Other aspects and advantages of the present invention are disclosed as illustrated by the embodiments hereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

The appended drawings contain figures to further illustrate and clarify the above and other aspects, advantages, and features of the present disclosure. It will be appreciated that these drawings depict only certain embodiments of the present disclosure and are not intended to limit its scope. It will also be appreciated that these drawings are illustrated for simplicity and clarity and have not necessarily been depicted to scale. The present disclosure will now be described and explained with additional specificity and detail through the use of the accompanying drawings in which:

FIG. 1 depicts an internal view of a multi-storey building having a HVAC system with thermoelectric conversion in accordance with certain embodiments of the present disclosure;

FIG. 2 depicts a block diagram of the HVAC system with thermoelectric conversion in accordance with certain embodiments of the present disclosure;

FIG. 3 depicts a thermoelectric module accommodated within a water pipe for converting heat energy into electric energy in accordance with certain embodiments of the present disclosure;

FIG. 4 depicts a thermoelectric module installed accommodated within a rooftop water tank at the rooftop for converting heat energy into electric energy in accordance with certain embodiments of the present disclosure; and

FIG. 5 depicts a block diagram of the HVAC system with an alternative thermoelectric conversion in accordance with certain embodiments of the present disclosure.

DETAILED DESCRIPTION OF THE INVENTION

The following detailed description is merely exemplary in nature and is not intended to limit the disclosure or its application and/or uses. It should be appreciated that a vast number of variations exist. The detailed description will enable those of ordinary skilled in the art to implement an exemplary embodiment of the present disclosure without undue experimentation, and it is understood that various changes or modifications may be made in the function and structure described in the exemplary embodiment without departing from the scope of the present disclosure as set forth in the appended claims.

The benefits, advantages, solutions to problems, and any element (s) that may cause any benefit, advantage, or solution to occur or become more pronounced are not to be construed as a critical, required, or essential features or elements of any or all of the claims. The invention is defined solely by the appended claims including any amendments made during the pendency of this application and all equivalents of those claims as issued.

The use of the terms “a” and “an” and “the” and “at least one” and similar referents in the context of describing the invention (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The terms “comprising” , “having” , “including” , and “containing” are to be construed as open-ended terms (i.e., meaning “including, but not limited to” , ) unless otherwise noted. The use of any and all examples, or exemplary language (e.g., “such as” ) provided herein, is intended merely to illuminate the invention better and does not pose a limitation on the scope of the invention unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the invention.

Terms such as “inner” , “outer” , “front” , “rear” , “top” , “bottom” , and any variations thereof are used for ease of description to explain the positioning of an element, or the positioning of one element relative to another element, and are not intended to be limiting to a specific orientation or position. Terms such as “first” , “second” , and the like are used herein to describe various elements, components, regions, sections, etc., and are not intended to be limiting.

The term “processor” , as used herein, includes one or more central processing units, microprocessors, micro-computers, single-chip computers, cloud computing system, integrated circuits, and the like, and systems incorporating the same.

Referring to the Figures, the present disclosure is generally linked to a building automation system having a heating, ventilation, and air conditioning (HVAC) system with thermoelectric conversion. More specifically, but without limitation, the present disclosure provides a HVAC system that can convert heat energy into electric energy to minimize the heat dissipation to the environment and harvest extra energy by a thermoelectric module. One having ordinary skill in the art would understand that the current disclosure is also applicable in other infrastructures and applications.

In general, a building automation system is a computer-based system of device configured to control, monitor, and manage mechanical and electrical equipment in or around a building or a group of buildings. The building automation system may include HVAC system, a power management system, a security system, a fire alarm system, a lighting system, and an elevator or escalator system. The building automation system has a centralized control platform that allows the user to collect, process, and compute data (sensor data, performance data, etc. ) collected from various systems, and alert the user of any abnormality. The user can also use the building automation system to manage and control the various system to perform different functions. Typically, the building automation system also supports scheduling and automations so that the systems can interact with each other to ensure that the safety requirements are met.

FIG. 1 illustrates an exemplary internal view of a building with a basement 10, a rooftop 30, and a plurality of storeys 20 having the building automation system in accordance with an exemplary embodiment of the present disclosure. The corresponding block diagram is shown in FIG. 2. In the illustrated embodiments, only four floors are shown, which apparently the number of floors may be otherwise. The building is serviced by a building automation system comprising a HVAC system 100 with thermoelectric conversion for converting heat energy into electric energy. The HVAC system 100 can include a plurality of devices, such as boiler 120, chiller 110, a plurality of air handling units (AHUs) 140, air filtration system, ventilation, temperature and humidity sensors, fans, pump system 130, etc. The plurality of devices are configured to provide heating, cooling, filtering, ventilation, and other services to the building.

The plurality of AHUs 140 may be placed in each storey 20 of the building for providing an airflow to that floor for conditioning the air, such as controlling the temperature, changing the humidity, etc. The airflow may be supplied to and returned from the building via air valves 141. In certain embodiments, the airflow may be outside air, return air, or a combination of return air and outside air.

The chiller 110 is configured to provide cooling for floors in the building. The boiler 120 is configured to provide heating for floors in the building. The chiller 110 and the boiler 120 may circulate a circulated fluid to the plurality of AHUs 140, wherein the circulated fluid may be water, glycol, or a combination thereof. Depending on whether heating or cooling is required in the building, the circulated fluid may be heated in the boiler 120 or cooled in the chiller 110. In certain embodiments, the boiler 120 may add heat to the circulated fluid by fuel combustion or by electric heating. The chiller 110 may be configured to provide cooling using a cooling fluid, such that the circulated fluid is in a heat exchange relationship with the cooling fluid when the chiller 110 is operating. In certain embodiments, the cooling fluid may be a refrigerant, such as hydrocarbon or water. The refrigerant absorbs heat from the circulated fluid to achieve the cooling effect. The circulated fluid is pumped to each floor by a pumping system 130 via a plurality of pipes 131. The conditioned air can be supplied to the whole floor or particular zones of the floor via air supply ducts 150, which may be located on the ceiling. The AHU 140 may place the circulated fluid in a heat exchange relationship with the airflow passing through the AHU 140. Therefore, the AHU 140 transfers heat between the airflow and the circulated fluid to provide heating or cooling for the airflow. For example, the AHU 140 may include one or more fans or blowers configured to pass the airflow over or through a heat exchanger containing the circulated fluid. The circulated fluid may then return to the chiller 110 or the boiler 120 via the plurality of pipes 131.

The cooling fluid is allowed to accumulate the energy from the circulated fluid. Preferably, the chiller 110 of the present invention is configured to increase the temperature of the cooling fluid to at least 50 degrees, and more preferably to more than 60 degrees. The cooling fluid is then pumped to a cooling tower 240 at a rooftop 30 of the building to cool down the cooling fluid. Between the cooling tower 240 and the chiller 110, there is provided a power generation system.

The power generation system includes at least two thermoelectric modules 200. The thermoelectric modules 200 can be used to generate electric energy by a power generator 310, and the energy is stored in a power storage 320 or supplied to other electrical devices, such as lightings or sensors. A processor 300 is configured to control the chiller 110 to perform heat exchange between the circulated fluid and the cooling fluid. The processor 300 may also control other mechanical and electric devices in the building to realize the building automation system. A control panel 301 or a computer device may be configured to execute control actions, including initiating and programming automation algorithms, which can control the HVAC and other apparatus, minimize overall energy usage, and generate energy from the power generation system.

The hot cooling fluid from the chiller 110 is pumped up to the rooftop 30, which is used as the hot-side of the thermoelectric generation. The pipe 211 for transferring the hot cooling fluid is accommodated within a water pipe 404, which holds fresh water running in an opposite direction and acting as the cold-side of the thermoelectric generation. A water tower 402 is located at the rooftop 30, which drains the water from main water supply 401 to the building along the water pipe 404. So, the water pipe 404 comprises plural water outlets 405 for distributing the fresh water from the water tower 402 to the floors of the building. The fresh water in the water pipe 404 is generally low in temperature, and the fresh water may be supplied to each floor. The temperature difference between the fresh water and the cooling fluid can cool down the cooling fluid and generate energy. The temperature rise of the fresh water caused by the hot cooling fluid is rather insignificant as the fresh water is pumped to each floor and discharged for use from time to time.

The two thermoelectric modules 200 may be arranged along the water pipe 404 or in a rooftop water tank 230. For both cases, the thermoelectric module is arranged to receive the cooling fluid from the chiller 110 at a first end, and transfer the cooling fluid to the cooling tower 240 at a second end. Therefore, the fresh water is received at the second end and travels in an opposite direction as the cooling fluid. The fresh water absorbs heat from the cooling fluid.

The first thermoelectric module 200 is installed along the water pipe 404, which is conceptually shown in FIG. 3. The thermoelectric module 200 comprises one or more tubular thermoelectric devices accommodated within the water pipe 404. In another word, the thermoelectric module 200 is an inner pipe while the water pipe 404 is an outer pipe. The inner pipe is provided within the outer pipe for reducing the temperature of the cooling fluid along the pipe when the cooling fluid is pumped to the rooftop. Each of the one or more tubular thermoelectric devices comprises a pipe 211 and a metallic layer 213 arranged on an outer circumferential surface of the pipe 211. In certain embodiments, the water pipe 404 may accommodate two or more pipes 211. The metallic layer 213 is connected to a first terminal 321 at the first end, and to a second terminal 322 at the second end. The first terminal 321 and the second terminal 322 are connected to a power generator 310 for power generation.

The thermoelectric module 200 is designed to significantly reduce the temperature, yet the residual temperature can further be reduced in the cooling tower 240. After the cooling fluid is cooled down in the cooling tower 240, the cooling fluid is pumped down along the pipe 212 to the chiller to complete the cycle.

The second thermoelectric module 200 is installed in a rooftop water tank 230, which is conceptually shown in FIG. 4. The rooftop water tank 230 has a water inlet 403 at a second end, and a water outlet 406 at a first end. The thermoelectric module 200 comprises one or more tubular thermoelectric devices accommodated within the rooftop water tank 230. Each of the one or more tubular thermoelectric devices comprises a pipe 232 and a metallic layer 233 arranged on an outer circumferential surface of the pipe 232. The hot cooling fluid enters the pipe 232 from the first end, and leaves the pipe 232 from the second end. Therefore, the fresh water and the cooling fluid flow in opposite directions. In certain embodiments, the rooftop water tank 230 may accommodate two or more pipes 232. The metallic layer 233 is connected to a first terminal 321 at the first end, and to a second terminal 322 at the second end. The first terminal 321 and the second terminal 322 are connected to a power generator 310 for power generation.

Apart from the described thermoelectric modules, the power generation system may implement other power generation strategy without departing from the scope and spirit of the present disclosure. For example, a semiconductor based device may be used to covert the waste heat into energy based on the Seebeck effect.

Another method is to use the thermal energy from the waste heat to power a turbine generator 510 for generating electricity, as illustrated in FIG. 5. A heat recovery boiler 520 is installed, preferably at the rooftop 30 for recovering heat energy from the cooling fluid. The working fluid heat up from the heat recovery boiler 520 is vaporized and drive the turbine for power generation. The vapor is then condensed in the condenser 530 back to liquid and pressurized to the heat recovery boiler 520.

This illustrates the fundamental structure and mechanism of the HVAC system with thermoelectric conversion in accordance with the present disclosure. It is apparent that the present disclosure is also applicable in various air conditioning system without departing from the spirit or essential characteristics thereof. The present embodiment is, therefore, to be considered in all respects as illustrative and not restrictive. The scope of the disclosure is indicated by the appended claims rather than by the preceding description, and all changes that come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

Claims

A heating, ventilation, and air conditioning (HVAC) system for a building, the HVAC system configured to convert heat energy into electric energy for minimizing heat dissipation from the building, the HVAC system comprising:

a plurality of air handling units (AHUs) ;

a chiller configured to provide cooling for floors in the building by circulating a circulated fluid to the plurality of AHUs, wherein the circulated fluid is in a heat exchange relationship with a cooling fluid when the chiller is operating;

a cooling tower at a rooftop of the building; and

a power generation system disposed along a pipeline for pumping the cooling fluid from the chiller to the cooling tower, and configured to absorb heat from the cooling fluid for generating electrical energy.
The HVAC system of claim 1, wherein the power generation system comprises a thermoelectric module arranged to receive the cooling fluid from the chiller at a first end, and transfer the cooling fluid to the cooling tower at a second end.
The HVAC system of claim 2, wherein the thermoelectric module comprises one or more tubular thermoelectric devices accommodated within a water pipe, wherein the water pipe receives fresh water from a water tower at the second end, and wherein the fresh water absorbs heat from the cooling fluid.
The HVAC system of claim 3, wherein the water pipe comprises plural water outlets for distributing the fresh water from the water tower to the floors of the building.
The HVAC system of claim 3, wherein each of the one or more tubular thermoelectric devices comprises a pipe and a metallic layer arranged on an outer circumferential surface of the pipe, wherein the metallic layer is connected to a positive terminal and a negative terminal for power generation.
The HVAC system of claim 2, wherein the thermoelectric module comprises one or more tubular thermoelectric devices accommodated within a rooftop water tank, wherein the rooftop water tank receives fresh water from a water tower at the second end, and wherein the fresh water absorbs heat from the cooling fluid.
The HVAC system of claim 6, wherein each of the one or more tubular thermoelectric devices comprises a pipe and a metallic layer arranged on an outer circumferential surface of the pipe, wherein the metallic layer is connected to a positive terminal and a negative terminal for power generation; and wherein the pipe is placed across the rooftop water tank from a first side to the second side.
The HVAC system of claim 7, wherein the rooftop water tank comprises a water inlet and a water outlet arranged in such a way that the fresh water and the cooling fluid flow in opposite directions.
The HVAC system of claim 1 further comprises a processor configured to control the chiller to perform heat exchange between the circulated fluid and the cooling fluid, wherein the cooling fluid is allowed to accumulate the energy from the circulated fluid.
The HVAC system of claim 1, wherein the circulated fluid is water, glycol, or a combination thereof.