Patent Issued for Heat Pump System for Vehicle and Method of Controlling the Same (USPTO 9829237)

Journal of Engineering |

By a News Reporter-Staff News Editor at Journal of Engineering -- According to news reporting originating from Alexandria, Virginia, by VerticalNews journalists, a patent by the inventors Kang, Sungho (Daejeon, KR); Kim, Hakkyu (Daejeon, KR); Choi, Youngho (Daejeon, KR); Lee, Jungjae (Daejeon, KR); Kim, Taeeun (Daejeon, KR); Seo, Jeonghun (Daejeon, KR), filed on , was published online on .

The assignee for this patent, patent number 9829237, is Hanon Systems (Daejeon, KR).

Reporters obtained the following quote from the background information supplied by the inventors: "Field of the Invention

"The present invention relates to a heat pump system for a vehicle and a method of controlling the same, and more particularly, to a heat pump system for a vehicle and a method of controlling the heat pump system, which determines that frosting begins on an exterior heat exchanger and carries out a defrosting control if a difference value between outdoor temperature and refrigerant temperature of an outlet side of the exterior heat exchanger is above a frosting decision temperature in a heat pump mode.

"Background Art

"In general, an air conditioner for a vehicle includes a cooling system for cooling the interior of the vehicle and a heating system for heating the interior of the vehicle. At an evaporator side of a refrigerant cycle, the cooling system converts air into cold air by heat-exchanging the air passing outside an evaporator with refrigerant flowing inside the evaporator so as to cool the interior of the vehicle. At a heater core side of a cooling water cycle, the heating system convers air into warm air by heat-exchanging the air passing outside the heater core with cooling water flowing inside the heater core so as to heat the interior of the vehicle.

"In the meantime, differently from the air conditioner for the vehicle, a heat pump system which can selectively carry out cooling and heating by converting a flow direction of refrigerant using one refrigerant cycle has been applied. For instance, the heat pump system includes two heat exchangers: one being an interior heat exchanger mounted inside an air-conditioning case for heat-exchanging with air blown to the interior of the vehicle; and the other one being an exterior heat exchanger for heat-exchanging outside the air-conditioning case, and a direction-adjustable valve for changing a flow direction of refrigerant. Therefore, according to the flow direction of the refrigerant by the direction-adjustable valve, the interior heat exchanger serves as a heat exchanger for cooling when the cooling mode is operated, and serves as a heat exchanger for heating when the heating mode is operated.

"Various kinds of the heat pump system for the vehicle have been proposed, and FIG. 1 illustrates a representative example of the heat pump system for the vehicle.

"As shown in FIG. 1, the heat pump system for the vehicle includes: a compressor 30 for compressing and discharging refrigerant; a high-pressure side heat exchanger 32 for radiating heat of the refrigerant discharged from the compressor 30; a first expansion valve 34 and a first bypass valve 36 mounted in parallel for selectively passing the refrigerant passing through the high-pressure side heat exchanger 32; an exterior heat exchanger 48 for heat-exchanging the refrigerant passing through the first expansion valve 34 or the first bypass valve 36 outdoors; a low-pressure side heat exchanger 60 for evaporating the refrigerant passing through the exterior heat exchanger 48; an accumulator 62 for dividing the refrigerant passing through the low-pressure side heat exchanger 60 into a gas-phase refrigerant and a liquid-phase refrigerant; an interior heat exchanger 50 for heat-exchanging refrigerant supplied to the low-pressure side heat exchanger 60 with refrigerant returning to the compressor 30; a second expansion valve 56 for selectively expanding the refrigerant supplied to the low-pressure side heat exchanger 60; and a second bypass valve 58 mounted in parallel with the second expansion valve 56 for selectively connecting an outlet side of the exterior heat exchanger 48 and an inlet side of the accumulator 62.

"In FIG. 1, the reference numeral 10 designates an air-conditioning case in which the high-pressure side heat exchanger 32 and the low-pressure side heat exchanger 60 are embedded, the reference numeral 12 designates a temperature-adjustable door for controlling a mixed amount of cold air and warm air, and the reference numeral 20 designates a blower mounted at an inlet of the air-conditioning case.

"According to the heat pump system having the above structure, when a heat pump mode (heating mode) is operated, the first bypass valve 36 and the second expansion valve 56 are closed, and the first expansion valve 34 and the second bypass valve 58 are opened. Moreover, the temperature-adjustable door 12 is operated as shown in FIG. 1. Accordingly, the refrigerant discharged from the compressor 30 passes through the high-pressure side heat exchanger 32, the first expansion valve 34, the exterior heat exchanger 48, a high pressure side 52 of the interior heat exchanger 50, the second bypass valve 58, the accumulator 62, and a low pressure side 54 of the interior heat exchanger 50 in order, and then, is returned to the compressor 30. That is, the high-pressure side heat exchanger 32 serves as a heater and the exterior heat exchanger 48 serves as an evaporator.

"When an air-conditioning mode (cooling mode) is operated, the first bypass valve 36 and the second expansion valve 56 are opened, and the first expansion valve 34 and the second bypass valve 58 are closed. Furthermore, the temperature-adjustable door 12 closes a passage of the high-pressure side heat exchanger 32. Therefore, the refrigerant discharged from the compressor 30 passes through the high-pressure side heat exchanger 32, the first bypass valve 36, the exterior heat exchanger 48, the high pressure side 52 of the interior heat exchanger 50, the second expansion valve 56, the low-pressure side heat exchanger 60, the accumulator 62, and the low pressure side 54 of the interior heat exchanger 50 in order, and then, is returned to the compressor 30. That is, the low-pressure side heat exchanger 360 serves as an evaporator and the high-pressure side heat exchanger 32 closed by the temperature-adjustable door 12 serves as a heater in the same with the heat pump mode.

"However, in the heat pump mode (heating mode), the conventional heat pump system for the vehicle carries out heating because the high-pressure side heat exchanger 32 serves as a heater, and the exterior heat exchanger 48 is mounted outside the air-conditioning case 10, namely, at the front side of an engine room of the vehicle, and serves as an evaporator for heat-exchanging with the outdoor air.

"In this instance, temperature of the refrigerant introduced into the exterior heat exchanger 48 lowers below the freezing point while the refrigerant heat-exchanges with the outdoor air, so that frosting begins on the surface of the exterior heat exchanger 48.

"If frosting on the surface of the exterior heat exchanger 48 is expanded continuously, because the exterior heat exchanger 48 cannot absorb heat, temperature and pressure of the refrigerant inside the system lower, and hence, the heating performance is remarkably reduced since temperature of air discharged to the interior of the vehicle lowers, and stability of the system is also decreased due to introduction of liquid refrigerant into the compressor."

In addition to obtaining background information on this patent, VerticalNews editors also obtained the inventors' summary information for this patent: "Accordingly, the present invention has been made to solve the above-mentioned problems occurring in the prior arts, and it is an object of the present invention to provide a heat pump system for a vehicle and a method of controlling the heat pump system, which determines that frosting begins on an exterior heat exchanger and carries out a defrosting control if a difference value between outdoor temperature and refrigerant temperature of an outlet side of the exterior heat exchanger is above a frosting decision temperature in a heat pump mode, thereby increasing frost-prevention and defrosting effects and enhancing heating performance and stability of the system because the system recognizes the beginning of frosting on the exterior heat exchanger at a proper time so as to carry out the defrosting control.

"To achieve the above objects, the present invention provides a heat pump system for a vehicle comprising: a compressor mounted on a refrigerant circulation line for compressing and discharging refrigerant; an interior heat exchanger mounted inside an air-conditioning case for exchanging heat between the air inside the air-conditioning case and the refrigerant discharged from the compressor; an evaporator mounted inside the air-conditioning case for exchanging heat between the air inside the air-conditioning case and the refrigerant supplied to the compressor; an exterior heat exchanger mounted outside the air-conditioning case for exchanging heat between the refrigerant circulating through the refrigerant circulation line and the outdoor air; first expansion means mounted on the refrigerant circulation line of an inlet side of the evaporator for expanding refrigerant; second expansion means mounted on the refrigerant circulation line located between the interior heat exchanger and the exterior heat exchanger for expanding refrigerant; and a controlling part for controlling the heat pump system to defrost after determining that frosting is formed on the external heat exchanger if a difference value between outdoor temperature and refrigerant temperature of an outlet side of the exterior heat exchanger is above a frosting decision temperature in a heat pump mode.

"In another aspect of the present invention, the present invention provides a method of controlling a heat pump system for a vehicle comprising the steps of: determining whether or not the heat pump system is in a heat pump mode; as the determination result of the step, when the system is in the heat pump mode, determining whether or not a difference value between outdoor temperature and refrigerant temperature of an outlet side of the exterior heat exchanger is above a frosting decision temperature; and as the determination result of the step, when the difference value is above the frosting decision temperature, controlling the heat pump system to defrost after determining that frosting is formed on an external heat exchanger.

"In the heat pump mode, if the difference value between outdoor temperature and refrigerant temperature of the outlet side of the exterior heat exchanger is above the frosting decision temperature, the present invention decides that frosting begins on an exterior heat exchanger and carries out the defrosting control, thereby increasing frost-prevention and defrosting effects and enhancing heating performance and stability of the system because the system recognizes the beginning of frosting on the exterior heat exchanger at a proper time so as to carry out the defrosting control.

"Moreover, the present invention variably sets the frosting decision temperature by outdoor temperature and judges frosting of the exterior heat exchanger so as to judge frosting by outdoor temperature with a high accuracy.

"Furthermore, if the difference value (.DELTA.T) is above the frosting decision temperature, the present invention additionally judges a waste heat of electronic units of the vehicle, refrigerant pressure of the inlet side of the exterior heat exchanger, or a decrease range of discharge air temperature of the interior of the vehicle and uses it in determining frosting on the exterior heat exchanger so as to increase accuracy more in determination of frosting on the exterior heat exchanger and enhance frost-prevention and defrosting effects."

For more information, see this patent: Kang, Sungho; Kim, Hakkyu; Choi, Youngho; Lee, Jungjae; Kim, Taeeun; Seo, Jeonghun. Heat Pump System for Vehicle and Method of Controlling the Same. U.S. Patent Number 9829237, filed , and published online on . Patent URL: http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=9829237.PN.&OS=PN/9829237RS=PN/9829237

Keywords for this news article include: Hanon Systems.

Our reports deliver fact-based news of research and discoveries from around the world. Copyright 2017, NewsRx LLC

DISCLOSURE: The views and opinions expressed in this article are those of the authors, and do not represent the views of equities.com. Readers should not consider statements made by the author as formal recommendations and should consult their financial advisor before making any investment decisions. To read our full disclosure, please go to: http://www.equities.com/disclaimer

Comments

Emerging Growth

Alliance Growers Corp

Alliance Growers Corp is a Canada based diversified cannabis company. The company is primarily focused on the development of Cannabis Botany Centres in Canada.