Systems, methods and devices for measurement of rate of heat exchange of airflow systems

• US 9,933,320 B2
• Filed: 03/11/2014
• Issued: 04/03/2018
• Est. Priority Date: 03/12/2013
• Status: Active Grant

• Current Assignee: Enverid Systems, Inc.
• Original Assignee: Enverid Systems, Inc.
• Inventors: Meirav, Udi, Biran, Israel, Fisher, Tzvi, Meruham, Asael
• Primary Examiner(s): Fan, Bo
• Application Number:
  US14/775,500
• Publication Number:
  US 20160025578A1
• Time in Patent Office: 1,484 Days
• Field of Search: 702127
• CPC Class Codes: G01K 17/06 Measuring quantity of heat conveyed by flowing media, e.g. in heating systems G01K17/02, G01K17/04 take precedencee.g. the quantity of heat in a transporting medium, delivered to or consumed in an expenditure device
• CPC Class Codes: G01K 17/10 between an inlet and an outlet point, combined with measurement of rate of flow of the medium if such, by integration during a certain time-interval

Abstract

Method, systems, and devices for determining instantaneous heat exchange between an airflow and a heat exchange element of an HVAC system are disclosed. In some embodiments, methods and systems include receiving or otherwise obtaining airflow data, temperature and humidity data. The airflow data may be used to calculate the volumetric airflow rate, and the temperature and humidity data may be processed with enthalpy data to determine the change in enthalpy (Δh) of the airflow after encountering a heat exchange element. The instantaneous rate of heat exchange (E) between the airflow and the heat exchange element may then be determined from the volumetric airflow rate and change in enthalpy.

Claims

1. A non-transitory computer readable medium having stored thereon computer instructions operational on one or more processors for performing a computer implemented method for determining instantaneous heat exchange rate between an airflow and a heat exchange element of an HVAC system, comprising:

obtaining;

airflow data corresponding to at least one of a velocity and a static pressure of an airflow over and/or through a heat exchange element of an HVAC system or airflow data corresponding to a fan power of a fan within the HVAC system;

a first temperature and a first humidity level data of the airflow prior to encountering the heat exchange element; and

a second temperature and a second humidity level data of the airflow after encountering the heat exchange element;

accessing at least one database having stored thereon data including at least enthalpy data for a plurality of temperatures and humidity levels or utilizing a formula for converting temperature and humidity to enthalpy so as to determine a first enthalpy based at least partially on the first temperature and the first humidity level and a second enthalpy based at least partially on the second temperature and the second humidity level;

processing the airflow data corresponding to the at least one of the velocity and the static pressure or the fan power so as to determine a volumetric airflow rate (Q) of the airflow;

determining a change in enthalpy (Δ

h) of the airflow after encountering the heat exchange element based at least partially on the first enthalpy and the second enthalpy; and

determining an instantaneous rate of heat exchange (E) between the airflow and the heat exchange element based on the determined volumetric airflow rate and change in enthalpy.

2. The medium of claim 1, wherein the method further comprises outputting at least the determined instantaneous heat exchange rate between the airflow and the heat exchange element to at least one of a database, a display, a computer, a server, a printer, and a mobile device.

3. The medium of claim 1, wherein at least one of the obtaining, accessing, processing and determining steps are carried out substantially in real-time.

4. The medium of claim 1, wherein obtaining comprises receiving the airflow data via at least one of wired or wireless communication.

5. The medium of claim 1, wherein the airflow data comprises an instantaneous reading of the at least one of the velocity and static pressure.

6. The medium of claim 1, wherein the data stored on the at least one database includes performance properties of the fan or a blower of the HVAC system.

7. The medium of claim 6, wherein the data stored on the at least one database includes parameters for converting at least one of velocity and static pressure data to a volumetric flow rate specific to the HVAC system.

8. The medium of claim 1, wherein the data stored on the at least one database includes historical data including at least one of weather, energy consumption, system operation, and system performance associated with the HVAC system.

9. A system for determining instantaneous heat exchange rate between an airflow and a heat exchange element of an HVAC system, the system comprising:

an HVAC system comprising;

an air handling unit configured to receive and effect heat exchange via a heat exchange element on an airflow at least partially received from an interior space and return the airflow after heat exchange to the interior space;

the heat exchange element;

at least one airflow sensor arranged proximate the heat exchange element and configured to generate at least one of a velocity signal and a static pressure signal determinative of at least one of a velocity and a static pressure, respectively, of an airflow over and/or through the heat exchange element;

a first temperature sensor and a first humidity sensor arranged proximate the heat exchange element on an upstream side thereof, each first temperature and first humidity sensor configured to generate respective first signals determinative of a first temperature and a first humidity level, respectively, of the airflow prior to encountering the heat exchange element; and

a second temperature sensor and a second humidity sensor arranged proximate the heat exchange element on a downstream side thereof, each second temperature and second humidity sensor configured to generate respective second signals determinative of a second temperature and a second humidity level, respectively, of an airflow after encountering the heat exchange element;

at least one database having stored thereon data including at least enthalpy data for a plurality of temperatures and humidity levels;

at least one computer processor which is configured;

to obtain the at least one of a velocity signal and a static pressure signal, the first signals and the second signals generated by the sensors, and/or the at least one of the velocity and the static pressure, the first temperature and the first humidity level, and the second temperature and the second humidity level corresponding thereto,

to access the at least one database, and the at least one computer processor having computer instructions operational thereon for;

processing the at least one of the velocity signal and the static pressure signal, and/or the at least one of the velocity and the static pressure corresponding thereto so as to determine a volumetric airflow rate (Q) of the airflow;

processing the first signals and the second signals and/or the first temperature and the first humidity level, and the second temperature and the second humidity level corresponding thereto with the enthalpy data from the database so as to determine a change in enthalpy (Δ

h) of the airflow after encountering the heat exchange element; and

determining the instantaneous rate of heat exchange (E) between the airflow and the heat exchange element based on the determined volumetric airflow rate and change in enthalpy.

10. The system of claim 9, wherein the computer instructions are further operational to output at least the determined instantaneous heat exchange rate between the airflow and the heat exchange element to at least one of a database, a display, a computer, a server, a printer, and a mobile device.

11. The system of claim 9, wherein at least one of the obtaining, the accessing, the processing and the determining steps are performed substantially in real-time.

12. The system of claim 9, wherein the at least one of the velocity signal and the static pressure signal generated from the air flow sensor comprises an instantaneous reading of the velocity and/or static pressure.

13. The system of claim 9, wherein one or more of the at least one airflow sensor, the first temperature sensor, the first humidity sensor, the first temperature sensor and the first humidity sensor are configured to provide corresponding generated signals via at least one of wire or wireless communications to the processor or to an intermediary computer or a communication device in communication with the processor.

14. The system of claim 9, wherein the processor comprises at least one remote computer.

15. The system of claim 9, wherein the HVAC system includes a blower or a fan, and wherein the data stored on the at least one database includes performance properties of the blower or the fan.

16. The system of claim 15, wherein the performance properties of the fan or the blower comprises a characteristic pressure-volumetric airflow rate curve of the fan or the blower.

17. The system of claim 9, wherein the data stored on the at least one database includes parameters for converting the at least one of the velocity signal and the static pressure signal to the volumetric flow rate specific to the HVAC system.

18. The system of claim 9, wherein the data stored on the at least one database includes historical data including at least one of weather, energy consumption, system operation, and system performance associated with the HVAC system.

19. A computer implemented method for presenting to a user a value representing an instantaneous rate of heat exchange (E) between an airflow and a heat exchange element of an HVAC system, comprising:

obtaining by a computer readable medium;

airflow data corresponding to at least one of a velocity and a static pressure of an airflow over and/or through a heat exchange element of a HVAC system or airflow data corresponding to a fan power of a fan within the HVAC system;

a first temperature and a first humidity level data of the airflow prior to encountering the heat exchange element; and

a second temperature and a second humidity level data of the airflow after encountering the heat exchange element;

accessing at least one database having stored thereon data including at least enthalpy data for a plurality of temperatures and humidity levels or utilizing a formula for converting temperature and humidity to enthalpy so as to determine a first enthalpy based at least partially on the first temperature and the first humidity level and a second enthalpy based at least partially on the second temperature and the second humidity level;

processing the airflow data corresponding to the at least one of the velocity and the static pressure or the fan power so as to determine a volumetric airflow rate (Q) of the airflow;

determining a change in enthalpy (Δ

h) of the airflow after encountering the heat exchange element based at least partially on the first enthalpy and the second enthalpy;

determining an instantaneous rate of heat exchange (E) between the airflow and the heat exchange element based on the determined volumetric airflow rate and change in enthalpy; and

displaying the value representing the instantaneous rate of heat exchange (E) in a graphical user interface.

20. An evaluation method for evaluating energy efficiency of an HVAC system, comprising:

performing steps of claim 19 so as to generate a first value representing an instantaneous rate of heat exchange (E) for a HVAC system employing an improved energy utilization practice;

performing steps of claim 19 so as to generate a second value representing an instantaneous rate of heat exchange (E) for a HVAC system lacking an improved energy utilization practice;

performing a comparison of the first value and the second value so as to generate a third value representing an energy efficiency of the HVAC system; and

displaying the third value in the graphical user interface.