Method for operating building climate control system using integrated temperature and humidity models

• US 8,958,921 B2
• Filed: 06/29/2012
• Issued: 02/17/2015
• Est. Priority Date: 06/29/2012
• Status: Active Grant

• Current Assignee: Mitsubishi Electric Research Laboratories, Inc. (Mitsubishi Electric Corporation)
• Original Assignee: Mitsubishi Electric Research Laboratories, Inc. (Mitsubishi Electric Corporation)
• Inventors: Xu, Jingyang, Nikovski, Daniel Nikolaev
• Primary Examiner(s): Ali, Mohammad
• Assistant Examiner(s): Rao, Sheela S
• Application Number:
  US13/538,696
• Publication Number:
  US 20140000836A1
• Time in Patent Office: 963 Days
• Field of Search: 700/31, 700/276, 236/44.R, 236/1.C, 165/288, 703/2, 703/13
• US Class Current: 700/276
• CPC Class Codes: F24F 11/30 for purposes related to the operation of the system, e.g. for safety or monitoring
• CPC Class Codes: F24F 11/62 characterised by the type of control or by internal processing, e.g. using fuzzy logic, adaptive control or estimation of values
• CPC Class Codes: F24F 11/63 Electronic processing
• CPC Class Codes: F24F 2110/00 Control inputs relating to air properties
• CPC Class Codes: F24F 2110/10 Temperature
• CPC Class Codes: F24F 2110/12 of the outside air
• CPC Class Codes: F24F 2110/20 Humidity
• CPC Class Codes: F24F 2110/22 of the outside air
• CPC Class Codes: F24F 2110/40 Pressure, e.g. wind pressure
• CPC Class Codes: F24F 2120/10 Occupancy
• CPC Class Codes: F24F 2140/20 Heat-exchange fluid temperature
• CPC Class Codes: F24F 2140/50 Load
• CPC Class Codes: G05D 22/02 characterised by the use of electric means
• CPC Class Codes: G05D 23/1917 using digital means
• CPC Class Codes: G05D 27/02 characterised by the use of electric means

Abstract

A climate control system for a building includes air conditioning systems and ventilation (HVAC) systems. The system is controlled by determining sensible cooling and heating rates using temperature differences at inlets and outlets at evaporators, as well as moisture absorption, moisture desorption, ventilation influences, human activities, and condensation at the evaporator. Humidity differences and temperature differences are determined as driving forces for moisture absorption, desorption, and temperatures and humidities of interior fabrics. The differences are obtained from a thermal circuit model. A latent cooling rate is determined using the humidity differences. The model integrates a temperature model and a humidity model for jointly predicting temperatures and humidities for operating the HVAC systems using a mass transfer process.

Claims

1. A method for operating a climate control system for a zone of a building, comprising the steps of:

determining sensible cooling and heating rates for the climate control system using temperature differences at an inlet and outlet of an evaporator;

determining moisture absorption, moisture desorption, ventilation influences, human activities, and condensation at the evaporator;

determining humidity differences and temperature differences as driving forces for moisture absorption and the moisture desorption at the interior fabrics, where the temperature difference is obtained from a thermal circuit model; and

determining a latent cooling rate using the humidity differences, wherein the model integrates a temperature model and a humidity model for jointly predicting a temperature and humidity for operating the climate control system

acquiring temperatures Tz and humidities h_z of the zone, and temperatures T_Isurf and humidities h_Isurf of interior fabrics in the zone;

determining a mass transfer process

2. The method of claim 1, further comprising:

approximating a saturation specific humidity using a linear function of the temperatures in the zone.

3. The method of claim 1, wherein the climate control system includes a ventilation system, and further comprising:

approximating a specific humidity at an outlet of the ventilation system using a linear function of an indoor humidity and an outdoor humidity.

4. The method of claim 1, wherein an integrated temperature and humidity model considers thermal characteristics of the building, human activities, and outside climatic conditions.

5. The method of claim 4, wherein the integrated temperature and humidity model considers absorption and desorption of moisture of interior fabrics in the zone, moisture condensation at an evaporator, air exchange by a ventilation systems, and moisture generation by the human activities in the zone.

6. The method of claim 1, wherein the mass transfer process uses sensible cooling and latent cooling based on temperature and humidity differences at an evaporator of the climate control system.

7. The method of claim 3, further comprising:

approximation a saturation specific humidity and a specific humidity at the outlets of the ventilation system.

8. The method of claim 1, further comprising:

providing an integrated temperature and humidity model for operating the climate control system, wherein the model is based on joint temperature and humidity dynamics.

9. The method of claim 1, further comprising:

estimating a sensible cooling rate and a latent cooling rate using temperatures and humidities at an inlet and outlet of an evaporator of the climate control system.

10. The method of claim 1, wherein a relation between a saturation specific humidity and an inside air temperature is nonlinear.

11. The method of claim 1, further comprising:

training the temperature model to predict the temperatures in the zone; and

training the humidity model using measured and predicted data.

12. The method of claim 11, wherein the predicted data include weather forecasts, sensor data from the climate control system, airflows at an evaporator of the climate control system, inside air humidities h_z, and inside surface temperatures T_z.