Air-conditioning apparatus

Patent metadata

Field	Value
Publication number	US-9829205-B2
Application number	US-201113879653-A
Country	US
Kind code	B2
Filing date	Jan 20, 2011
Priority date	Jan 20, 2011
Publication date	Nov 28, 2017
Grant date	Nov 28, 2017

Abstract

In an air-conditioning apparatus including a refrigerant circulating circuit A and a heat medium circulating circuit B that performs passing of heat to and from the refrigerant circulating circuit A, the heat medium circulating circuit is a closed circuit, the maximum pump head Pp of a pump of the heat medium circulating circuit is 150 kPa or more, and a pressure near at least a suction side of the pump is set to a charged pressure that is maintained equal to or higher than the atmospheric pressure during operation of the pump.

First claim

The invention claimed is:

1. An air-conditioning apparatus comprising:
a refrigerant circuit in which a compressor, a heat-source-side heat exchanger, an expansion device, and a refrigerant-side passage of a heat exchanger related to heat medium are connected in series and through which a heat-source-side refrigerant circulates;
a heat medium circulating circuit in which a heat-medium-side passage of the heat exchanger related to heat medium, a pump, a use-side heat exchanger, and a heat medium flow control device are connected and through which a heat medium circulates;
a relief valve that controls a pressure in the heat medium circulating circuit not to be equal to or higher than a specific set pressure; and
a pressure detecting device provided near the suction side of the pump,
wherein the compressor and the heat-source-side heat exchanger are arranged in an outdoor unit,
wherein the heat exchanger related to heat medium, the expansion device, the pump, and the heat medium flow control device are arranged in a heat medium relay unit,
wherein the use-side heat exchanger is arranged in an indoor unit,
wherein the heat medium circulating circuit is a closed circuit and the maximum pump head Pp of the pump is 175 kPa or more,
a pressure near at least a suction side of the pump or a pressure near at least a highest position in the heat medium circulating circuit is set to a charged pressure that is maintained equal to or higher than an atmospheric pressure during operation of the pump,
wherein the charged pressure satisfies “charged pressure [kPa G]≧(pump maximum pump head Pp/2) [kPa]” and is set within a range between approximately 80 and approximately 500 [kPa G] on the basis of a set pressure for the relief valve,
wherein operation is controlled such that a detected pressure detected by the pressure detecting device is always maintained equal to or higher than a specific pressure that is higher than 0 [kPa G], and
wherein the relief valve is separate from the heat medium flow control device.

2. The air-conditioning apparatus of claim 1 , wherein pressure from a connection entrance of the heat medium relay unit on a return side thereof from the indoor unit to an inlet of the pump on the suction side thereof is set to the charged pressure that is maintained equal to or higher than the atmospheric pressure during the operation of the pump.

3. The air-conditioning apparatus of claim 1 , further comprising:
an automatic air discharging unit that automatically discharges air in the heat medium circulating circuit,
wherein when the automatic air discharging unit is placed at a position higher than the pump, the charged pressure [kPa G] satisfies “(Pmax+Pl)/2−65 kPa<charged pressure <(Pmax+Pl)/2+65 kPa”, where a head differential pressure between the automatic air discharging unit and the pump is represented by Pl [kPa] and the lower limit of the set pressure for the relief valve is represented by Pmax [kPa G], and
wherein when the automatic air discharging unit is located at a position lower than the pump, the charged pressure [kPa G] satisfies “(Pmax/2−65 kPa<charged pressure <(Pmax/2)+65 kPa”, where the lower limit of the set pressure for the relief valve is represented by Pmax [kPa G].

4. The air-conditioning apparatus of claim 1 , wherein when the detected pressure detected by the pressure detecting device is equal to or lower than the specific pressure or when it is estimated that the detected pressure detected by the pressure detecting device is equal to or lower than the specific pressure, a rotation speed of the pump is reduced or an opening area of the heat medium flow control device is increased.

5. The air-conditioning apparatus of claim 1 , wherein when the detected pressure detected by the pressure detecting device is equal to the specific pressure or it is estimated that the detected pressure detected by the pressure detecting device is equal to or lower than the specific pressure, operation of the air-conditioning apparatus is stopped and an error alert is issued.

6. The air-conditioning apparatus of claim 1 , wherein the specific pressure is a head differential pressure based on a difference of elevation between the pump and the automatic air discharging unit.

7. The air-conditioning apparatus of claim 6 , wherein the head differential pressure is approximately 80 kPa.

8. The air-conditioning apparatus of claim 1 , further comprising:
An automatic air discharging unit that automatically discharges air in the heat medium circulating circuit; and
a pressure detecting device that is provided near the suction side of the pump,
wherein in a case where the automatic air discharging unit is placed at a position lower than the pump, the operation is controlled such that the detected pressure detected by the pressure detecting device is always maintained higher than 0 [kPa G], and when the detected pressure detected by the pressure detecting device is equal to or lower than a predetermined specific pressure or when it is estimated that the detected pressure detected by the pressure detecting device is equal to or lower than the specific pressure, the rotation speed of the pump is reduced or the opening area of the heat medium flow control device is increased.

9. The air-conditioning apparatus of claim 8 , wherein when the detected pressure detected by the pressure detecting device is equal to the specific pressure or when it is estimated that the detected pressure detected by the pressure detecting device is equal to or lower than the specific pressure, the operation of the air-conditioning apparatus is stopped and an error alert is issued.

10. The air-conditioning apparatus of claim 1 , wherein when the automatic air discharging unit that automatically discharges air in the heat medium circulating circuit is placed at a position higher than the pump by h [m], the charged pressure satisfies “charged pressure [kPa G]>(pump maximum pump head Pp/2) [kPa]−9.8×water density ρ [kg/m 3 ]×h [m]/1000”.

Assignees

• Morimoto Hiroyuki
• Yamashita Koji
• Mitsubishi Electric Corp

Inventors

• Morimoto Hiroyuki
• Yamashita Koji

Classifications

• F24F11/85

  using variable-flow pumps · CPC title

• F24F11/84

  using valves · CPC title

• F24F2001/0077

  Mechanical Engineering · mapped topic

• F25B2313/02732

  using two three-way valves · CPC title

• F25B2313/02741

  using one four-way valve · CPC title