Patent Description:
A heat pump system which heats a liquid heating medium such as water by using heat absorbed from outside air is widely used. As an outdoor unit of such a heat pump system, PTL <NUM> discloses an outdoor unit which includes a refrigeration cycle having a compressor, an air heat exchanger, a decompression mechanism, and a water heat exchanger in a cabinet. In the outdoor unit, an internal portion of the cabinet is partitioned into a machine room in which the compressor is provided and an air path room in which an air blowing fan which blows air to the air heat exchanger is provided. In addition, a heat exchanger is disposed below the air blowing fan. The water heat exchanger is arranged below the compressor.

The outdoor unit in PTL <NUM> has the following problem. The heat exchanger disposed below the air blowing fan may obstruct the path of air blown by the air blowing fan. When the air path is obstructed, heat exchange efficiency between air and a refrigerant of the air heat exchanger may decrease.

The present invention has been made in order to solve the above-described problem, and an object thereof is to provide a heat pump apparatus capable of securing an air path of a fan which blows air to a heat exchanger to increase heat exchange efficiency of the heat exchanger.

The invention is a heat pump apparatus in accordance with claim <NUM>. In a heat pump apparatus according to the present invention, a compressor configured to compress a refrigerant, a first heat exchanger configured to exchange heat between the refrigerant compressed by the compressor and a liquid heating medium, a decompression apparatus configured to decompress the refrigerant having passed through the first heat exchanger, a second heat exchanger configured to exchange heat between the refrigerant decompressed in the decompression apparatus and air, and a fan configured to blow air to the second heat exchanger are housed in a cabinet. The cabinet is partitioned into a fan room in which the fan is installed and a machine room in which the compressor is installed by a partition plate which extends in a vertical direction. The second heat exchanger is installed along a rear surface of the cabinet in the fan room. The first heat exchanger is installed below the compressor in the machine room.

According to the heat pump apparatus of the present invention, the first heat exchanger is installed below the compressor in the machine room. Accordingly, in the fan room in which the fan is installed, it is possible to prevent the air path of the fan from being obstructed by the first heat exchanger. With this, the air path of the fan which blows air to the second heat exchanger which exchanges heat between the refrigerant and air is effectively secured, and hence it becomes possible to increase the heat exchange efficiency of the second heat exchanger.

Only embodiment <NUM> is in accordance with the invention as defined in claim <NUM>.

Hereinbelow, embodiments will be described with reference to the drawings. Common elements in the drawings are designated by the same reference numerals, and the duplicate description thereof will be simplified or omitted. In addition, the present disclosure can include any combinations of, among configurations described in the following embodiments, configurations which can be combined.

<FIG> is a front view showing the internal structure of a heat pump apparatus of Embodiment <NUM>. <FIG> is an external perspective view of the heat pump apparatus of Embodiment <NUM> when viewed obliquely from the front. <FIG> is an external perspective view of the heat pump apparatus of Embodiment <NUM> when viewed obliquely from behind. <FIG> is a view showing a refrigerant circuit and a water circuit of a heat pump hot water supply system which includes the heat pump apparatus of Embodiment <NUM>.

A heat pump apparatus <NUM> of the present embodiment is installed outdoors. The heat pump apparatus <NUM> heats a liquid heating medium. The heating medium in the present embodiment is water. The heat pump apparatus <NUM> heats water to generate hot water. The heating medium in the present invention may be brine other than water such as, e.g., a calcium chloride aqueous solution, an ethylene glycol aqueous solution, or alcohol.

As shown in <FIG>, the heat pump apparatus <NUM> includes a base <NUM> serving as a bottom plate which forms a bottom portion of a cabinet. On the base <NUM>, when viewed from the front, a machine room <NUM> is formed on the right side, and a fan room <NUM> is formed on the left side. The machine room <NUM> and the fan room <NUM> are separated from each other by a partition plate <NUM> which extends in a vertical direction.

As shown in <FIG>, the cabinet forming an outer shell of the heat pump apparatus <NUM> further includes a front panel <NUM>, a side panel <NUM>, and a top panel <NUM>. The front panel <NUM> is constituted by a front surface portion 18a which covers a front surface of the heat pump apparatus <NUM>, and a left side surface portion 18b which covers a left side surface thereof. The side panel <NUM> is constituted by a rear surface portion 19a which covers part of a rear surface of the heat pump apparatus <NUM>, and a right side surface portion 19b which covers a right side surface thereof. These constituent elements of the cabinet are formed from, e.g., sheet metal material. An exterior surface of the heat pump apparatus <NUM> is covered with the cabinet except an air-refrigerant heat exchanger <NUM> which is disposed on the side of the rear surface and will be described later. An opening for discharging air having passed through the fan room <NUM> is formed in the front panel <NUM>, and a lattice 18c is attached to the opening. Note that <FIG> shows a state in which the individual portions of the cabinet other than the base <NUM> are detached. In addition, in <FIG>, the depiction of part of constituent equipment is omitted.

As shown in <FIG>, the heat pump apparatus <NUM> includes a refrigerant circuit in which a compressor <NUM>, a water-refrigerant heat exchanger <NUM> serving as a first heat exchanger, an air-refrigerant heat exchanger <NUM> serving as a second heat exchanger, and an expansion valve <NUM> for decompressing a refrigerant are annularly connected via a refrigerant pipe <NUM>. The heat pump apparatus <NUM> performs an operation of a refrigerant cycle, i.e., a heat pump cycle.

As shown in <FIG>, the compressor <NUM>, the water-refrigerant heat exchanger <NUM>, the expansion valve <NUM> (the depiction thereof is omitted), and the refrigerant pipe which connects these elements are incorporated into the machine room <NUM>. The compressor <NUM> compresses low-pressure refrigerant gas. The refrigerant may also be, e.g., carbon dioxide. The water-refrigerant heat exchanger <NUM> exchanges heat between a high-temperature high-pressure refrigerant discharged from the compressor <NUM> and water. The detail of an installation structure of the water-refrigerant heat exchanger <NUM> will be described later.

The expansion valve <NUM> is an example of a decompression apparatus which decompresses a high-pressure refrigerant to change the high-pressure refrigerant into a low-pressure refrigerant. The low-pressure refrigerant subjected to the decompression is brought into a gas-liquid two-phase state. The air-refrigerant heat exchanger <NUM> exchanges heat between the low-pressure refrigerant and the air. In the air-refrigerant heat exchanger <NUM>, the low-pressure refrigerant evaporates by absorbing heat of the air. The fan <NUM> blows air to the air-refrigerant heat exchanger <NUM>, and heat exchange in the air-refrigerant heat exchanger <NUM> can be thereby accelerated. Low-pressure refrigerant gas having evaporated in the air-refrigerant heat exchanger <NUM> is sucked into the compressor <NUM>.

On the other hand, in order to secure an air path, the fan room <NUM> has space larger than that of the machine room <NUM>. The fan <NUM> is incorporated into the fan room <NUM>. The fan <NUM> includes two to three propeller blades, and a motor which rotationally drives the propeller blades. The motor and the propeller blades rotate with electric power supplied from the outside. On the side of a rear surface of the fan room <NUM>, the air-refrigerant heat exchanger <NUM> is installed so as to face the fan <NUM>. The air-refrigerant heat exchanger <NUM> includes a large number of fins formed of aluminum thin plates, and a long refrigerant pipe which is in intimate contact with a large number of the fins formed of aluminum thin plates and is folded back several times. The air-refrigerant heat exchanger <NUM> has a flat outer shape which is bent into an L shape. The air-refrigerant heat exchanger <NUM> is installed so as to extend from the rear surface of the heat pump apparatus <NUM> to the left side surface thereof. An end portion on the side of a rear surface of the air-refrigerant heat exchanger <NUM> extends to a rear side of the machine room <NUM>. Accordingly, the partition plate <NUM> has a flat outer shape which is bent into an L shape, and is installed so as to partition space from the front surface of the heat pump apparatus <NUM> to the end portion on the side of the rear surface of the air-refrigerant heat exchanger <NUM>. In the air-refrigerant heat exchanger <NUM>, heat is exchanged between the refrigerant in the refrigerant pipe and air around the fins. The amount of air flowing between and passing through the individual fines is increased and adjusted by the fan <NUM>, and the amount of heat exchange is thereby increased and adjusted.

Next, a description will be given of the water circuit of the heat pump apparatus <NUM> and a hot water storage apparatus <NUM>. As shown in <FIG>, a heat pump hot water supply system <NUM> is constituted by the heat pump apparatus <NUM> and the hot water storage apparatus <NUM>. The hot water storage apparatus <NUM> includes a hot water storage tank <NUM> having a capacity of, e.g., about several hundred litters, and a water pump <NUM> for sending water in the hot water storage tank <NUM> to the heat pump apparatus <NUM>. The heat pump apparatus <NUM> and the hot water storage apparatus <NUM> are connected via an external pipe <NUM>, an external pipe <NUM>, and electrical wiring (the depiction thereof is omitted).

A lower portion of the hot water storage tank <NUM> is connected to an inlet of the water pump <NUM> via a pipe <NUM>. The external pipe <NUM> connects an outlet of the water pump <NUM> and a water inlet valve <NUM> of the heat pump apparatus <NUM>. The external pipe <NUM> connects a hot water outlet valve <NUM> of the heat pump apparatus <NUM> and the hot water storage apparatus <NUM>. The external pipe <NUM> can communicate with an upper portion of the hot water storage tank <NUM> via a pipe <NUM> in the hot water storage apparatus <NUM>.

The hot water storage apparatus <NUM> further includes a mixing valve <NUM>. To the mixing valve <NUM>, a hot water supply pipe <NUM> which branches off from the pipe <NUM>, a water supply pipe <NUM> through which water supplied from a water source such as a water supply passes, and a hot water supply pipe <NUM> through which hot water supplied to a user side passes are connected. The mixing valve <NUM> adjusts the temperature of supplied hot water by adjusting a mixing ratio of hot water which flows in from the hot water supply pipe <NUM>, i.e., high-temperature water and water which flows in from the water supply pipe <NUM>, i.e., low-temperature water. Hot water obtained by the mixing by the mixing valve <NUM> is sent to terminals on the user side such as, e.g., a bathtub, a shower, a faucet, and a dishwasher through the hot water supply pipe <NUM>. A water supply pipe <NUM> which branches off from the water supply pipe <NUM> is connected to the lower portion of the hot water storage tank <NUM>. Water which flows in from the water supply pipe <NUM> is stored on a lower side in the hot water storage tank <NUM>.

Next, a description will be given of the operation of the heat pump apparatus <NUM> in heat accumulating operation. The heat accumulating operation is operation in which hot water is accumulated in the hot water storage tank <NUM> by sending hot water heated in the heat pump apparatus <NUM> to the hot water storage apparatus <NUM>. The heat accumulating operation is as follows. The compressor <NUM>, the fan <NUM>, and the water pump <NUM> are operated. The rotation speed of the motor of the compressor <NUM> can change in a range of about several tens of rps (Hz) to about several hundred of rps (Hz). With this, it is possible to adjust and control heating power by changing the flow rate of the refrigerant.

It is possible to adjust and control the amount of heat exchange between the refrigerant and air in the air-refrigerant heat exchanger <NUM> by changing the rotation speed of the motor of the fan <NUM> to the rotation speed of about several hundred rpm to about several thousand rpm to change the flow rate of air passing through the air-refrigerant heat exchanger <NUM>. Air is sucked from the rear of the air-refrigerant heat exchanger <NUM> installed at the rear side of the fan <NUM>, passes through the air-refrigerant heat exchanger <NUM>, passes through the fan room <NUM>, and is discharged toward the front of t the front panel <NUM> on a side opposite to the air-refrigerant heat exchanger <NUM>.

The expansion valve <NUM> adjusts the degree of the flow path resistance of the refrigerant. With this, it is possible to adjust and control the pressure of each of the high-pressure refrigerant on the upstream side of the expansion valve <NUM> and the low-pressure refrigerant on the downstream side thereof. The rotation speed of the compressor <NUM>, the rotation speed of the fan <NUM>, and the degree of the flow path resistance of the expansion valve <NUM> are controlled in accordance with an installation environment and use conditions of the heat pump apparatus <NUM>.

The low-pressure refrigerant is sucked into the compressor <NUM> through piping. The low-pressure refrigerant is compressed in the compressor <NUM> to become the high-temperature high-pressure refrigerant. The high-temperature high-pressure refrigerant is discharged from the compressor <NUM> to the refrigerant pipe. The high-temperature high-pressure refrigerant flows into a refrigerant inlet portion of the water-refrigerant heat exchanger <NUM> through the piping. The high-temperature high-pressure refrigerant exchanges heat with water in the water-refrigerant heat exchanger <NUM> to heat water and generate hot water. The refrigerant is reduced in enthalpy and temperature while the refrigerant passes through the water-refrigerant heat exchanger <NUM>. The high-pressure refrigerant reduced in temperature flows into an inlet portion of the expansion valve <NUM> from a refrigerant outlet portion of the water-refrigerant heat exchanger <NUM> through the refrigerant pipe. The high-pressure refrigerant is reduced in temperature by being decompressed in the expansion valve <NUM> to become a low-temperature low-pressure refrigerant. The low-temperature low-pressure refrigerant flows into an inlet portion of the air-refrigerant heat exchanger <NUM> from an outlet portion of the expansion valve <NUM> through the refrigerant pipe. The low-temperature low-pressure refrigerant exchanges heat with air in the air-refrigerant heat exchanger <NUM>, is increased in enthalpy, flows into the refrigerant pipe from an outlet portion of the air-refrigerant heat exchanger <NUM>, and is sucked into the compressor <NUM>. Thus, the refrigerant circulates and the heat pump cycle is performed.

At the same time, by driving the water pump <NUM>, water in the lower portion in the hot water storage tank <NUM> is caused to flow into a water inlet portion of the water-refrigerant heat exchanger <NUM> through the pipe <NUM>, the external pipe <NUM>, the water inlet valve <NUM>, and an internal pipe <NUM>. The water exchanges heat with the refrigerant in the water-refrigerant heat exchanger <NUM> and is heated, and hot water is thereby generated. The hot water flows into the upper portion of the hot water storage tank <NUM> through an internal pipe <NUM>, the hot water outlet valve <NUM>, the external pipe <NUM>, and the pipe <NUM>. By performing the heat accumulating operation described above, hot water having high temperature is gradually accumulated from the upper portion toward the lower portion in the hot water storage tank <NUM>.

Note that hot water heated in the heat pump apparatus <NUM> may be directly supplied to the user side without being stored in the hot water storage tank <NUM>. In addition, the heating medium heated in the heat pump apparatus <NUM> may be used for indoor heating or the like.

Next, a description will be given of the structure and arrangement of the water-refrigerant heat exchanger <NUM> provided in the heat pump apparatus <NUM> of Embodiment <NUM>. The water-refrigerant heat exchanger <NUM> performs heat exchange between water serving as the heating medium which circulates in the water circuit and the refrigerant which circulates in the refrigerant circuit. <FIG> is a configuration diagram showing a principal portion of the water-refrigerant heat exchanger. The water-refrigerant heat exchanger <NUM> includes heating medium piping <NUM> and refrigerant piping <NUM>. Water serving as the heating medium flows through the heating medium piping <NUM>. A high-temperature refrigerant sent from the compressor <NUM> flows through the refrigerant piping <NUM>. In the heating medium piping <NUM>, one or a plurality of continuous spiral grooves <NUM> are formed in an outer peripheral surface of the piping. The number of spiral grooves is not particularly limited. In an example of the water-refrigerant heat exchanger <NUM> shown in <FIG>, two spiral grooves <NUM> are formed in the heating medium piping <NUM>.

The refrigerant piping <NUM> branches at some midpoint such that a plurality of flow paths arranged in parallel are formed. In the example of the water-refrigerant heat exchanger <NUM> shown in <FIG>, the refrigerant piping <NUM> branches into first refrigerant piping <NUM> and second refrigerant piping <NUM>. The first refrigerant piping <NUM> and the second refrigerant piping <NUM> are fitted in in a state in which the first refrigerant piping <NUM> and the second refrigerant piping <NUM> are spirally wound along the two spiral grooves <NUM> formed in the heating medium piping <NUM>.

The water-refrigerant heat exchanger <NUM> of Embodiment <NUM> configured in the above manner has a configuration in which the refrigerant piping <NUM> is caused to branch into a plurality of the refrigerant pipings and the refrigerant pipings are fitted in the spiral grooves of the heating medium piping <NUM>, and hence it is possible to increase a contact heat transfer area between the refrigerant piping <NUM> and the heating medium piping <NUM>. In addition, it is also possible to prevent adjacent refrigerant pipings from coming into contact with each other, and hence it is possible to prevent leakage of heat. Further, it is possible to change the contact heat transfer area between the refrigerant piping <NUM> and the heating medium piping <NUM> by changing the number of branching of the refrigerant piping <NUM>, and hence it becomes possible to easily optimize flow path design.

The water-refrigerant heat exchanger <NUM> is formed into a hollow cylindrical shape by spirally stacking the heating medium piping <NUM> around which the refrigerant piping <NUM> is wound. As shown in <FIG>, the water-refrigerant heat exchanger <NUM> is installed on the base <NUM> in a lower portion of the machine room <NUM>. In the hollow of the water-refrigerant heat exchanger <NUM>, a column <NUM> is provided to stand upward from the base <NUM>. The compressor <NUM> is supported on the column <NUM>. According to such an arrangement of the machine room <NUM>, the water-refrigerant heat exchanger <NUM> is disposed below the compressor <NUM>.

According to the present embodiment, the following effect is obtained by providing the water-refrigerant heat exchanger <NUM> in the machine room <NUM>. The air path of the fan room <NUM> is not obstructed by the water-refrigerant heat exchanger <NUM>. With this, the air path of the fan <NUM> which blows air to the air-refrigerant heat exchanger <NUM> is effectively secured, and hence it becomes possible to increase heat exchange efficiency of the air-refrigerant heat exchanger <NUM>. With this, it is possible to increase thermal efficiency of the heat pump cycle.

Next, a heat pump apparatus of Embodiment <NUM> will be described. <FIG> is a front view showing the internal structure of the heat pump apparatus of Embodiment <NUM>. A heat pump apparatus <NUM> shown in <FIG> has a structure common to the heat pump apparatus <NUM> of Embodiment <NUM> except that a sound absorbing material <NUM> is provided. The sound absorbing material <NUM> is disposed so as to integrally cover the water-refrigerant heat exchanger <NUM> and the compressor <NUM>. The sound absorbing material <NUM> is formed of a material having fine voids. The sound absorbing material <NUM> may include at least one of, e.g., felt, glass wool, and rock wool. The above sound absorbing material <NUM> has a heat insulation function in addition to the function of absorbing sound.

As described above, the water-refrigerant heat exchanger <NUM> is disposed below the compressor <NUM>. Accordingly, it is possible to configure the sound absorbing material <NUM>, which is usually disposed around the compressor <NUM>, such that the sound absorbing material <NUM> covers the compressor <NUM> together with the water-refrigerant heat exchanger <NUM>. According to such a configuration, it is possible to suppress a reduction in the temperature of the water-refrigerant heat exchanger <NUM>. With this, it is possible to increase the heat exchange efficiency in the water-refrigerant heat exchanger <NUM>, and hence it becomes possible to increase the efficiency of the heat accumulating operation.

Claim 1:
A heat pump apparatus (<NUM>; <NUM>; <NUM>) in which a compressor (<NUM>) configured to compress a refrigerant, a first heat exchanger (<NUM>) configured to exchange heat between the refrigerant compressed by the compressor (<NUM>) and a liquid heating medium, a decompression apparatus (<NUM>) configured to decompress the refrigerant having passed through the first heat exchanger (<NUM>), a second heat exchanger (<NUM>) configured to exchange heat between the refrigerant decompressed in the decompression apparatus (<NUM>) and air, and a fan (<NUM>) configured to blow air to the second heat exchanger (<NUM>) are housed in a cabinet,
wherein the cabinet is partitioned into a fan room (<NUM>) in which the fan (<NUM>) is installed and a machine room (<NUM>) in which the compressor (<NUM>) is installed by a partition plate which extends in a vertical direction,
the second heat exchanger (<NUM>) is installed along a rear surface of the cabinet in the fan room (<NUM>), and
the first heat exchanger (<NUM>) is formed into a hollow cylindrical shape obtained by spirally stacking heating medium piping (<NUM>) and is installed below the compressor (<NUM>) in the machine room (<NUM>),
wherein a spiral groove (<NUM>) is formed in an outer peripheral surface of the heating medium piping (<NUM>) and refrigerant piping (<NUM>) is spirally wound along the spiral groove (<NUM>),
the compressor (<NUM>) is supported on a column (<NUM>) which is installed in a hollow of the first heat exchanger (<NUM>), and
wherein the heat pump apparatus (<NUM>; <NUM>; <NUM>) comprises a sound absorbing material (<NUM>) integrally covering the compressor (<NUM>) and the first heat exchanger.