Air-conditioning apparatus and heat-medium flow-rate calculation method

Patent metadata

Field	Value
Publication number	US-11892218-B2
Application number	US-201917441295-A
Country	US
Kind code	B2
Filing date	May 22, 2019
Priority date	May 22, 2019
Publication date	Feb 6, 2024
Grant date	Feb 6, 2024

Abstract

An air-conditioning apparatus includes: a heat-source-side device that heats or cools a heat medium; a pump that sucks and transfers the heat medium; use-side heat exchangers; a heat medium circuit; flow rate control devices; indoor-side pressure sensors; a pump inlet-side pressure sensor and/or a pump outlet-side pressure sensor; a flow rate detection device that detects a pump flow rate; and a controller that performs a first operation in which the flow rate control devices are individually opened or closed and data regarding a flow passage resistance at a path related to each of the heat exchangers is obtained, and a second operation in which heat is supplied to indoor air, and calculates calculate flow rates of the heat medium that flows through the heat exchangers in the second operation, from pump flow rates and pressures detected by the pressure sensors in the first and second operations.

First claim

The invention claimed is:

1. An air-conditioning apparatus comprising:
a heat-source-side device configured to heat or cool a heat medium serving as a medium that transfers heat;
a pump configured to suck the heat medium and transfer the heat medium;
a plurality of use-side heat exchangers each configured to cause heat exchange to be performed between the heat medium transferred by the pump and indoor air to be conditioned;
a heat medium circuit that includes a common pipe at which the heat-source-side device and the pump are provided, and parallel pipes that branch off from the common pipe and that are pipes at each of which an associated one of the plurality of use-side heat exchangers is provided, the heat medium circuit being provided such that the common pipe and the parallel pipes are connected, whereby the heat medium circulates;
a plurality of flow rate control devices provided in association with the use-side heat exchangers and at least upstream or downstream of the use-side heat exchangers, the plurality of flow rate control devices being configured to control flow rates of the heat medium that passes through the use-side heat exchangers;
a plurality of indoor-side pressure sensors each configured to detect a pressure of the heat medium at least on a heat-medium inflow side or a heat-medium outflow side of an associated one of the flow rate control devices;
at least one of a pump inlet-side pressure sensor configured to detect a pressure of the heat medium on a suction side of the pump and a pump outlet-side pressure sensor configured to detect a pressure of the heat medium on a transferring side of the pump;
a flow rate detection device configured to detect a pump flow rate that is a flow rate of the heat medium that flows in the pump; and
a controller configured to control components included in the heat medium circuit,
wherein the controller is configured to:
perform a first operation in which the heat medium circuit is caused to circulate the heat medium, the flow rate control devices are individually opened or closed in a predetermined pattern, and data regarding flow rates and pressures of the heat medium that flows through the respective use-side heat exchangers is obtained, and a second operation in which after the first operation, the heat medium is caused to pass through the use-side heat exchangers that supply heat to the indoor air, and
calculate flow rates of the heat medium that flows through the respective use-side heat exchangers in the second operation, from pump flow rates and pressures in the first operation and the second operation, the pressures being detected by the indoor-side pressure sensors associated with the respective flow rate control devices and the pump inlet-side pressure sensor or the pump outlet-side pressure sensor.

2. The air-conditioning apparatus of claim 1 , wherein
the controller includes a storage unit configured to store data, and
the controller is configured to
store, as data in the storage unit, a relationship between the flow rate and the pressure of the heat medium in a path along which the heat medium flows, the relationship being obtained from the pump flow rate and pressures detected by the indoor-side pressure sensors associated with the respective flow rate control devices in the first operation, and
calculate flow rates of the heat medium that flows through the respective use-side heat exchangers from the pump flow rate, pressures detected by the indoor-side pressure sensors associated with the respective flow rate control devices, and a pressure detected by the pump inlet-side pressure sensor or the pump outlet-side pressure sensor in the second operation, based on the data regarding the relationship between the flow rate and pressure of the heat medium and stored in the storage unit.

3. The air-conditioning apparatus of claim 1 , wherein the controller is configured to perform, in the first operation, an operation in which the heat medium is circulated, with one of the flow rate control devices opened and an other or others of the flow rate control devices closed, and the operation is performed while the flow rate control devices are successively opened.

4. The air-conditioning apparatus of claim 3 , wherein the controller is configured to performs, in the first operation, an operation in which the heat medium is circulated, with one of the flow rate control devices closed and an other or others of the flow rate control devices opened, and the operation is performed while the flow rate control devices are successively closed.

5. The air-conditioning apparatus of claim 3 , wherein the controller is configured to open and close the flow rate control devices in a predetermined order to perform an operation of circulating the heat medium.

6. The air-conditioning apparatus of claim 1 , further comprising both the pump inlet-side pressure sensor and the pump outlet-side pressure sensor,
wherein the controller is configured to calculate the pump flow rate based on a pressure difference between a pressure detected by the pump inlet-side pressure sensor and a pressure detected by the pump outlet-side pressure sensor.

7. The air-conditioning apparatus of claim 1 , wherein the controller is configured to perform the first operation at certain intervals to update pressures related to detection performed by the pressure sensors.

8. The air-conditioning apparatus of claim 1 , further comprising:
a plurality of use-side heat exchanger temperature sensors that are provided upstream and downstream of the respective use-side heat exchangers and are each configured to detect a temperature of the heat medium,
wherein the controller is configured to calculate heat exchange amounts of the use-side heat exchangers from temperatures detected by the use-side heat exchanger temperature sensors and flow rates of the heat medium that flows through the use-side heat exchangers.

9. The air-conditioning apparatus of claim 1 , wherein
the heat-source-side device includes
an outdoor unit including a compressor configured to compress refrigerant and an outdoor heat exchanger configured to cause heat exchange to be performed between the refrigerant and air, and
a refrigerant circuit in which a relay unit that includes an expansion device and an intermediate heat exchanger is connected to the outdoor unit by a pipe, the expansion device being configured to reduce a pressure of the refrigerant, the intermediate heat exchanger being configured to cause heat exchange to be performed between the refrigerant and the heat medium.

10. A heat-medium flow-rate calculation method that is carried out using a controller configured to control a heat medium circuit in which for a heat-source-side device and a pump, a plurality of use-side heat exchangers and a plurality of flow rate control devices are connected in parallel by pipes, the heat-source-side device being configured to heat or cool a heat medium serving as a medium that transfers heat, the pump being configured to suck and transfer the heat medium, the plurality of use-side heat exchangers being each configured to cause heat exchange to be performed between the heat medium and indoor air to be conditioned, the flow rate control devices being control flow rates of the heat medium that passes through the use-side heat exchangers,
the heat-medium flow-rate calculation method comprising:
performing a first operation in which an operation of circulating the heat medium, with one of the flow rate control devices opened and an other or others of the flow rate control devices closed is performed, while the flow rate control devices are successively opened, and obtaining data regarding paths that extend from the pump to the respec

Assignees

• Mitsubishi Electric Corp

Inventors

• Nishio Jun
• Ikeda Soshi
• Takenaka Naofumi
• Motomura Yuji
• Ishimura Katsuhiro

Classifications

• F25B5/02 Primary

  arranged in parallel · CPC title

• F25B41/20

  Disposition of valves, e.g. of on-off valves or flow control valves (expansion valves F25B41/31) · CPC title

• F24F11/89 Primary

  Arrangement or mounting of control or safety devices · CPC title

• F24F11/83

  by controlling the supply of heat-exchange fluids to heat-exchangers · CPC title

• F24F3/065

  with a plurality of evaporators or condensers · CPC title