Mitsubishi Electric Corporation

Takahito Hikone

Kimitaka Kadowaki

Masahiro Ito

Takuya Ito

Yasushi Okoshi

Takeshi Sugimoto

Kazuyuki Ishida

Yoshio Yamano

Masaaki Sugawa

Naoya Mukaitani

Shohei Takenaka

Takahiro Akizuki

Yuji Tarumi

Takenori Matsumoto

Shoichi Hirano

Junichi Miyai

Toru Kuriyama

Nobuhide Sakamoto

Hiroyuki Nakata

Katsunori Horiuchi

Yasushi Ookoshi

A refrigeration cycle apparatus includes a refrigerant circuit, a water circuit, a water heat exchanger, and a controller. The water circuit includes: a water pump; an inlet-side pressure sensor configured to detect an inlet-side water pressure that is a pressure of the heat medium which flows into the water heat exchanger; and an outlet-side pressure sensor configured to detect an outlet-side water pressure that is a pressure of the heat medium that flows out from the water heat exchanger. The controller is configured to determine whether air enters the water circuit or not based on the inlet-side water pressure and the outlet-side water pressure.

Refrigeration cycle apparatus

A chilling unit includes: air heat exchangers each including heat transfer tubes and fins; and a machine room unit on which the air heat exchangers are provided. The air heat exchangers each have a long-side portion that extends in a longitudinal direction of the machine room unit. The air heat exchangers includes a pair of air heat exchangers that are inclined such that a spacing between upper end portions of the heat exchangers is greater than a spacing between lower end portions thereof. In each pair, the long-side portion of at least one air heat exchanger has a heat-exchanger end portion located at a unit end portion of the machine room unit in the longitudinal direction, and from the heat-exchanger end portion, heat transfer tubes that protrudes from an outermost one of the fins in an arrangement direction thereof and that extend linearly in the lateral direction do not extend.

Chilling unit

A chilling unit includes a casing, a refrigerant circuit in which a compressor, a heat-source heat exchanger, a first expansion unit, a second expansion unit, and a refrigerant-to-heat medium heat exchanger are connected by a refrigerant pipe and through which refrigerant flows, the refrigerant circuit being placed in the casing, and an injection circuit in which a portion between the first expansion unit and the second expansion unit is connected to the compressor by an injection pipe, the injection circuit being placed in the casing.

A chilling unit includes a machine room unit to accommodate a compressor and a heat exchanger, and a plurality of air heat exchangers placed on top of the machine room unit. The air heat exchangers include a pair of air heat exchangers including two air heat exchangers opposite to each other in a lateral direction. They are inclined such that respective upper end portions of the two air heat exchangers have a spacing between each other greater than a spacing between respective lower end portions of the two air heat exchangers. In the lateral direction, the machine room unit has a top width greater than a heat-exchanger bottom width, the top width is one between side walls in a top face portion of the machine room unit, the bottom width is defined as a width between outer side faces of the respective lower end portions of the two air heat exchangers.

Chilling unit and chilling unit system

Chiller unit

A free cooling outdoor unit includes: a refrigerant circuit through which refrigerant circulates; a brine circuit through which brine circulates; a water circuit through which water circulates; a fan configured to send air to the second heat exchanger; a flow control valve configured to control a circulation amount of the brine in the brine circuit; a water temperature detection sensor configured to detect a water temperature in the water circuit; an outside air temperature sensor; and a controller configured to control, where the outside air temperature is equal to or lower than a freezing temperature of the brine, the circulation amount of the brine based on the water temperature such that a brine temperature is prevented from reaching a temperature equal to or lower than the freezing temperature of the brine.

Free cooling outdoor unit

A cold water supply system cools water flowing through a water pipe, and supplies the water cooled to a cooling load, the cold water supply system including: an independent refrigerant circuit unit including a first compressor and a first water heat exchanger configured to exchange heat between refrigerant and the water to cool the water; a composite unit configured to cool the water, and a controller configured to control operation of the independent refrigerant circuit unit and operation of the composite unit, wherein the composite unit includes a free cooling unit including a pump and a second water heat exchanger configured to exchange heat between a heat medium and the water to cool the water, and a coupled refrigerant circuit unit including a second compressor and a third water heat exchanger configured to exchange heat between refrigerant and the water to cool the water, and the controller controls an operating frequency of the first compressor, an operating frequency of the second compressor, and an operating frequency of the pump based on a temperature of the water flowing out from the water pipe.

Cold water supply system

A free cooling system includes a plurality of free cooling outdoor units each including a heat medium circuit, a controller, and a communication unit, the heat medium circuit being configured by connecting a heat medium pump, a first heat exchanger, and a heat source side of a second heat exchanger by pipes, a heat medium circulating in the heat medium circuit, the controller configured to control the heat medium pump, and the communication units performing communication with each other, wherein the plurality of free cooling outdoor units are coupled with each other by a load pipe that allows a load heat medium to flow to or flow out from a load side of each second heat exchanger.

Free cooling system

A heat source system includes heat source apparatuses each with refrigerant circuit and water heat exchanger. A water supply header pipe merges and supplies, to a load, water flowing in from the heat exchangers. A water return header pipe splits, into the heat exchangers, water flowing in from the load. Pumps feed water to the heat exchangers. A bypass pipe with bypass valve connects the supply and return header pipes. A differential pressure gauge measures a water pressure difference between supply and return. A controller determines the number of heat source apparatuses to operate, from heat generated by refrigerant circuits and heat required, determines whether an operating frequency of the pump connected to a heat source apparatus to be operated is a minimum frequency, and controls the pump operating frequency and/or an opening degree of the bypass valve such that the water pressure difference falls within a target range.

Heat source system

A refrigeration cycle apparatus includes: a compressor configured to compress refrigerant and discharge the refrigerant to a refrigerant pipe; an air heat exchanger configured to exchange heat between air and the refrigerant flowing through the refrigerant pipe; an expansion valve configured to adjust pressure of the refrigerant flowing through the refrigerant pipe; a water heat exchanger configured to exchange heat between water supplied from the water return header pipe and the refrigerant and send out the water to the water delivery header pipe; an outlet pressure sensor provided on a water outlet side of the water heat exchanger and configured to measure water pressure; and a controller, in which the controller controls an opening degree of the bypass valve such that a value of water pressure measured by the outlet pressure sensor is equal to a preset target value.

Growing community of inventors

Tokyo, Japan

Takahito Hikone