Patent Description:
To prevent over compression and abnormally high temperature of a compressor body, the temperature of a gas discharged from the compressor is measured. Patent Literature <NUM> (<CIT>) discloses a discharge temperature switch in which a temperature probe of the discharge temperature switch is disposed at a position downstream of the compressor body where pulsation of the compressor body is sufficiently attenuated.

However, according to the technique of Patent Literature <NUM> described above, the response of the temperature measurement is sometimes delayed because the temperature of the discharged gas is not measured immediately after being compressed. As a result of this, the reliability of the compressor can be decreased.

<CIT> shows a refrigeration cycle apparatus including a discharge sensor, a liquid line sensor and an ambient sensor, as well as a calculation unit.

Aim of the present invention is to provide a compressor and a refrigeration cycle apparatus which improve the state of the art indicated above. This aim is achieved by the compressor in the refrigeration cycle apparatus according to the corresponding appended claims.

A compressor of a first aspect includes a casing, a compression mechanism, a discharge tube, a first temperature sensor, and a second temperature sensor. The compression mechanism is disposed inside the casing, compresses a sucked refrigerant, and discharges the compressed refrigerant to a refrigerant channel formed in an inner space of the casing. In the discharge tube, the compressed refrigerant flows from the inner space of the casing to the outside. The first temperature sensor includes a temperature sensing portion. The temperature sensing portion is disposed in the refrigerant channel. The temperature sensing portion directly measures the temperature of the refrigerant. "Directly measure" means directly measuring the temperature of the refrigerant instead of measuring the temperature of a pipe in which the refrigerant flows or a part that receives heat transmission from the refrigerant. The second temperature sensor is disposed at a different position from the first temperature sensor and measures the temperature of one of the surface of the discharge tube, an inner space of the discharge tube, and the surface of the casing. According to such a configuration, a temperature reflecting an influence of the heat capacity and heat dissipation of constituent members of the compressor can be measured, and a compressor of high reliability can be disposed.

A compressor of a second aspect is the compressor of the first aspect, and the second temperature sensor measures the temperature of the surface of the discharge tube. According to such a configuration, the temperature of the compressor can be measured with higher accuracy.

A compressor of a third aspect is the compressor of the first aspect or the second aspect, and the first temperature sensor is disposed to penetrate the casing. In addition, the first temperature sensor is detachably attached to the casing from the outside. According to such a configuration, maintenance can be performed easily.

A compressor of a fourth aspect is the compressor of any one of the first aspect to the third aspect, and the temperature sensing portion of the first temperature sensor is thermally insulated from the casing. According to such a configuration, the temperature of the refrigerant can be measured with high accuracy.

A compressor of a fifth aspect is the compressor of any one of the first aspect to the fourth aspect, and further includes a guide plate that is disposed inside the casing and reduces a channel cross-sectional area of the refrigerant channel. In addition, the first temperature sensor measures the temperature of a space defined by the guide plate. According to such a configuration, the temperature of the refrigerant of high flow rate is measured, and therefore the responsiveness can be improved.

A compressor of a sixth aspect is the compressor of the fifth aspect, and further includes a motor that is disposed below the compression mechanism inside the casing and drives the compression mechanism. The motor is disposed to form a refrigerant channel in part of a space between the outer periphery of the motor and the inner wall of the casing. In addition, the guide plate is disposed so as to guide the refrigerant to the refrigerant channel between the outer periphery of the motor and the inner wall of the casing. According to such a configuration, reduction of size and cost of the apparatus can be realized.

A compressor of a seventh aspect is the compressor of the fifth aspect or the sixth aspect, and, in a region near the inner wall of the casing, the discharge tube is disposed on the opposite side to a region defined by the guide plate in plan view. According to such a configuration, the second temperature sensor can measure a temperature reflecting information not influenced by the first temperature sensor.

A compressor of an eighth aspect is the compressor of any one of the first aspect to the seventh aspect, and the second temperature sensor is disposed within a range where a channel length from the casing is <NUM> or less. According to such a configuration, influence of heat transfer loss and heat capacity can be suppressed.

A refrigeration cycle apparatus according to the invention includes a refrigeration cycle in which the refrigerant flows in the order of the compressor of any one of the first aspect to the eighth aspect, a condenser, an expansion mechanism, and an evaporator. In addition, the refrigeration cycle apparatus further includes a calculation unit that calculates the temperature of a refrigerant discharged from the compression mechanism, by using the first temperature sensor and the second temperature sensor. According to such a configuration, a refrigeration cycle apparatus in which the refrigerant temperature immediately after a discharge port of the compression mechanism can be estimated with high accuracy can be disposed.

A refrigeration cycle apparatus of a tenth aspect is the refrigeration cycle apparatus according to the invention, and the compressor includes a motor that is disposed below the compression mechanism inside the casing and drives the compression mechanism. In addition, the refrigeration cycle apparatus further includes a rotation number control unit that controls the number of rotations of the motor on the basis of the temperature of refrigerant calculated by the calculation unit. According to such a configuration, a compressor of high reliability can be disposed.

A refrigeration cycle apparatus of an eleventh aspect is the refrigeration cycle apparatus according to the invention or the tenth aspect, and further includes an injection pipe, a flow rate adjustment mechanism, and an opening degree control unit. The injection pipe is branched from part of a pipe extending from the condenser to the expansion mechanism and connects to the compressor. The flow rate adjustment mechanism adjusts the flow rate of the refrigerant in the injection pipe. The opening degree control unit controls the opening degree of the flow rate adjustment mechanism on the basis of the temperature of refrigerant calculated by the calculation unit. According to such a configuration, a refrigeration cycle apparatus of high reliability can be disposed.

A refrigeration cycle apparatus of a twelfth aspect is the refrigeration cycle apparatus of the eleventh aspect, and further includes a gasification mechanism that gasifies a liquid refrigerant flowing in the injection pipe. According to such a configuration, control can be performed with higher accuracy such that the discharge temperature reaches a target value. To be noted, the "gasification" used herein can be used as long as at least part of the liquid refrigerant is gasified, and does not necessarily mean gasifying all of the liquid refrigerant.

<FIG> is a schematic diagram for describing a configuration of a longitudinal section of a scroll compressor <NUM> according to an embodiment. <FIG> is an enlarged view of a part of <FIG>. To be noted, <FIG> and <FIG> are not precise sectional views, and are sectional views as viewed in different directions, that is, sectional views of right side and left side as viewed from the center. In addition, some parts of constituent members are appropriately omitted.

As illustrated in <FIG>, the scroll compressor <NUM> includes a casing <NUM>, a partitioning member <NUM>, a scroll compression mechanism <NUM> including a fixed scroll <NUM> and a movable scroll <NUM>, a housing <NUM>, a driving motor <NUM>, a crank shaft <NUM>, and a lower bearing portion <NUM>.

In the description below, expressions such as "upward" and "downward" may be used for describing positional relationships and the like of constituent members. Here, the direction of an arrow U in <FIG> will be referred to as an upward direction, and a direction opposite to the arrow U will be referred to as a downward direction. In addition, in the description below, expressions such as "vertical", "horizontal", "longitudinal", and "lateral" may be used, and an up-down direction will be referred to as a vertical direction and also a longitudinal direction.

The scroll compressor <NUM> includes the casing <NUM> of a sealed dome type having an elongated cylindrical shape. The casing <NUM> includes a body portion <NUM> having an approximately cylindrical shape opening on the upper side and the lower side, and an upper lid 22a and a lower lid 22b respectively disposed at the upper end and lower end of the body portion <NUM>. The body portion <NUM>, the upper lid 22a, and the lower lid 22b are fixed to each other by welding so as to keep airtightness.

The casing <NUM> accommodates constituent devices of the scroll compressor <NUM> including the scroll compression mechanism <NUM>, the driving motor <NUM>, the crank shaft <NUM>, and the lower bearing portion <NUM>. The scroll compression mechanism <NUM> is disposed in an upper portion in the body portion <NUM>. In addition, an oil reservoir space So is defined in a lower portion of the casing <NUM>. A refrigerating machine oil O for lubricating the scroll compression mechanism <NUM> and the like is reserved in the oil reservoir space So.

An inlet tube <NUM> penetrating through the upper lid 22a is provided in an upper portion of the casing <NUM>. A lower end of the inlet tube <NUM> is connected to an inlet connecting port of the fixed scroll <NUM>. As a result of this, the inlet tube <NUM> communicates with a compression chamber Sc of the scroll compression mechanism <NUM> that will be described later. A low-pressure refrigerant of a refrigeration cycle before being compressed by the scroll compressor <NUM> flows into the inlet tube <NUM>. Then, a gas refrigerant is supplied to the scroll compression mechanism <NUM> through the inlet tube <NUM>.

A discharge tube <NUM> through which a refrigerant to be discharged to the outside of the casing <NUM> passes is provided in the body portion <NUM> of the casing <NUM>. A high-pressure gas refrigerant compressed by the scroll compression mechanism <NUM> flows out from an inner space of the casing <NUM> to the outside through the discharge tube <NUM>.

To be noted, as the refrigerant of the scroll compressor <NUM>, for example, R32 can be used.

The scroll compression mechanism <NUM> is disposed inside the casing <NUM>, compresses a sucked refrigerant, and discharges the compressed refrigerant to refrigerant channels (including refrigerant channels R1 to R3) formed in the inner space of the casing <NUM>.

Specifically, as illustrated in <FIG> and <FIG>, the scroll compression mechanism <NUM> includes the fixed scroll <NUM> disposed above the housing <NUM> and the movable scroll <NUM> that defines the compression chamber Sc in combination with the fixed scroll <NUM>.

As illustrated in <FIG> and <FIG>, the fixed scroll <NUM> includes a fixed-side mirror plate <NUM> having a flat plate shape, a fixed-side lap <NUM> having a spiral shape and projecting from a front surface of the fixed-side mirror plate <NUM>, and an outer edge portion <NUM> surrounding the fixed-side lap <NUM>. The fixed-side lap <NUM> is formed to extend in a spiral shape from a discharge port 32a that will be described later to the outer edge portion <NUM>. In addition, an inlet port is provided in the outer edge portion <NUM> of the fixed scroll <NUM>. A refrigerant flowing in through the inlet tube <NUM> is introduced, through this inlet port, into the compression chamber Sc of the scroll compression mechanism <NUM>. To be noted, a check valve that prevents a backward flow of the refrigerant is provided in the inlet port.

A discharge port 32a communicating with the compression chamber Sc of the scroll compression mechanism <NUM> is formed at a center portion of the fixed-side mirror plate <NUM> to penetrate the fixed-side mirror plate <NUM> in a thickness direction. The refrigerant compressed in the compression chamber Sc is discharged through the discharge port 32a, and flows into a high-pressure space S1 through a first refrigerant channel R1 formed in the fixed scroll <NUM> and the housing <NUM>.

As illustrated in <FIG> and <FIG>, the movable scroll <NUM> includes a movable-side mirror plate <NUM> having a flat plate shape, a movable-side lap <NUM> having a spiral shape and projecting from a front surface of the movable-side mirror plate <NUM>, and a boss portion <NUM> having a cylindrical shape and projecting from a back surface of the movable-side mirror plate <NUM>.

Here, the fixed-side lap <NUM> of the fixed scroll <NUM> and the movable-side lap <NUM> of the movable scroll <NUM> are combined such that a lower surface of the fixed-side mirror plate <NUM> and an upper surface of the movable-side mirror plate <NUM> oppose each other. As a result of this, the compression chamber Sc is formed between the fixed-side lap <NUM> and the movable-side lap <NUM> that are adjacent to each other. Then, as a result of the movable scroll <NUM> revolving around the fixed scroll <NUM>, the volume of the compression chamber Sc periodically changes. As a result of this, the refrigerant sucked in through the inlet tube <NUM> is compressed in the compression chamber Sc.

The boss portion <NUM> has a cylindrical shape whose upper end is closed. An eccentric portion <NUM> of the crank shaft <NUM> is inserted in a hollow portion of the boss portion <NUM>. As a result of this, the movable scroll <NUM> and the crank shaft <NUM> are coupled to each other. The boss portion <NUM> is disposed in an eccentric portion space Sn defined between the movable scroll <NUM> and the housing <NUM>. The eccentric portion space Sn communicates with the high-pressure space S1 through an oil supply path in the crank shaft <NUM> or the like, and a high pressure is applied to the eccentric portion space Sn. As a result of this pressure, a lower surface of the movable-side mirror plate <NUM> in the eccentric portion space Sn is pushed upward toward the fixed scroll <NUM>. As a result of this, the movable scroll <NUM> comes into firm contact with the fixed scroll <NUM>.

To be noted, the movable scroll <NUM> is supported by the housing <NUM> via an oldham ring. An oldham ring is a member that prevents rotation of the movable scroll <NUM> and causes the movable scroll <NUM> to revolve.

The housing <NUM> is press-fitted in the body portion <NUM>, and an outer peripheral surface thereof is entirely fixed to the body portion <NUM> in the peripheral direction. In addition, the housing <NUM> and the fixed scroll <NUM> are fixed to each other with bolts or the like such that an upper end surface of the housing <NUM> is in firm contact with a lower surface of the outer edge portion <NUM> of the fixed scroll <NUM>.

In the housing <NUM>, a concave portion <NUM> recessed in a center portion of the upper surface and a bearing portion <NUM> disposed below the concave portion <NUM> are formed.

The concave portion <NUM> surrounds the side surface of the eccentric portion space Sn where the boss portion <NUM> of the movable scroll <NUM> is disposed.

In the bearing portion <NUM>, a bearing 62r that rotatably supports a main shaft <NUM> of the crank shaft <NUM> is disposed. The bearing 62r rotatably supports the main shaft <NUM> inserted in the bearing 62r.

The driving motor <NUM> includes a ring-shaped stator <NUM> fixed to an inner wall surface of the body portion <NUM>, and a rotor <NUM> rotatably accommodated inside the stator <NUM> with a gap (air gap path) therebetween.

The rotor <NUM> is coupled to the movable scroll <NUM> via the crank shaft <NUM> disposed to extend in the up-down direction along the axial center of the body portion <NUM>. The rotor <NUM> rotates, and thus the movable scroll <NUM> revolves around the fixed scroll <NUM>.

In addition, the driving motor <NUM> is disposed to form a refrigerant channel R3 in part of a space between the outer periphery of the driving motor <NUM> and the inner wall of the casing <NUM>. Details of the refrigerant channel R3 will be described later.

The crank shaft <NUM> (drive shaft) is disposed inside the body portion <NUM>, and drives the scroll compression mechanism <NUM>. Specifically, the crank shaft <NUM> transmits a driving force of the driving motor <NUM> to the movable scroll <NUM>. The crank shaft <NUM> is disposed to extend in the up-down direction along the axial center of the body portion <NUM>, and couples the rotor <NUM> of the driving motor <NUM> and the movable scroll <NUM> of the scroll compression mechanism <NUM> to each other.

The crank shaft <NUM> includes the main shaft <NUM> whose center axis coincides with the axial center of the body portion <NUM>, and the eccentric portion <NUM> eccentric with respect to the axial center of the body portion <NUM>. The main shaft <NUM> is rotatably supported by the bearing 62r of the bearing portion <NUM> of the housing <NUM> and a bearing 90r of the lower bearing portion <NUM>. The eccentric portion <NUM> is inserted in the boss portion <NUM> of the movable scroll <NUM> as described above.

Inside the crank shaft <NUM>, an oil supply path is formed for supplying the refrigerating machine oil O to the scroll compression mechanism <NUM> and the like. The lower end of the main shaft <NUM> is positioned in the oil reservoir space So formed in a lower portion of the casing <NUM>, and the refrigerating machine oil O in the oil reservoir space So is supplied to the scroll compression mechanism <NUM> and the like through the oil supply path.

The lower bearing portion <NUM> is provided in a lower portion of the body portion <NUM>, and rotatably supports the crank shaft <NUM>. Specifically, the lower bearing portion <NUM> includes the bearing 90r on the lower end side of the crank shaft <NUM>. As a result of this, the main shaft <NUM> of the crank shaft <NUM> is rotatably supported. To be noted, an oil pickup communicating with the oil supply path of the crank shaft <NUM> is fixed to the lower bearing portion <NUM>. (<NUM>) Operation of Scroll Compressor.

Next, the operation of the scroll compressor <NUM> described above will be described.

First, the driving motor <NUM> is activated. As a result of this, the rotor <NUM> rotates with respect to the stator <NUM>, and the crank shaft <NUM> fixed to the rotor <NUM> rotates. When the crank shaft <NUM> rotates, the movable scroll <NUM> coupled to the crank shaft <NUM> revolves around the fixed scroll <NUM>. Then, the low-pressure gas refrigerant of the refrigeration cycle is sucked into the compression chamber Sc through the inlet tube <NUM> from the peripheral side of the compression chamber Sc. As the movable scroll <NUM> revolves, the inlet tube <NUM> and the compression chamber Sc cease to communicate with each other. Then, as the capacity of the compression chamber Sc decreases, the pressure in the compression chamber Sc starts increasing.

The refrigerant in the compression chamber Sc is compressed as the capacity of the compression chamber Sc decreases, and eventually becomes a high-pressure gas refrigerant. The high-pressure gas refrigerant is discharged through the discharge port 32a positioned near the center of the fixed-side mirror plate <NUM>. Then, the high-pressure gas refrigerant flows into the high-pressure space S1 through the refrigerant channel R1 formed in the fixed scroll <NUM> and the housing <NUM>, and is discharged through the discharge tube <NUM>.

Next, a configuration for measuring the temperature of the refrigerant in the scroll compressor <NUM> described above will be described.

The scroll compressor <NUM> includes a first temperature sensor <NUM> and a second temperature sensor <NUM> for measuring the temperature of the refrigerant compressed by the scroll compression mechanism <NUM>.

As illustrated in <FIG>, the first temperature sensor <NUM> includes a temperature sensing portion 15a and a screw-shaped portion 15n. The temperature sensing portion 15a includes a thermistor that measures the temperature, and a metal cover that protects the thermistor. The metal is, for example, copper. As illustrated in <FIG>, the metal cover of the temperature sensing portion 15a is disposed to be in contact with the refrigerant flowing in the second refrigerant channel R2. In other words, the temperature sensing portion 15a is disposed so as to directly measure the temperature of the refrigerant. Here, the second refrigerant channel R2 is a space continuous from the first refrigerant channel R1 formed in the housing <NUM>. In addition, "directly measure" means directly measuring the temperature of the refrigerant instead of measuring the temperature of a pipe in which the refrigerant flows or a part that receives heat transmission from the refrigerant.

The first temperature sensor <NUM> is disposed to penetrate the casing <NUM>. The first temperature sensor <NUM> can be fixed and disposed by being screwed to a screw-in joint 21f provided to the body portion <NUM> of the casing <NUM> and by being sealed. In addition, since the first temperature sensor <NUM> is screwed at the screw-shaped portion 15n, the first temperature sensor <NUM> can be easily attached from the outside of the casing <NUM>. In addition, the temperature sensing portion 15a of the first temperature sensor <NUM> is thermally insulated from the casing <NUM>. The first temperature sensor <NUM> is disposed at a position near an outlet port of the refrigerant channel R1 of the housing <NUM>. To be noted, the temperature sensing portion 15a is formed from copper or the like having high thermal conductivity. In addition, the joint 21f is formed from iron or the like having low thermal conductivity.

The second temperature sensor <NUM> is disposed at a different position from the first temperature sensor <NUM>. Here, as illustrated in <FIG>, the second temperature sensor <NUM> is disposed on the surface of the discharge tube <NUM>, and measures the temperature of the surface of the discharge tube <NUM>. In addition, the second temperature sensor <NUM> is disposed within a range where the length of a channel from the casing <NUM> is <NUM> or less. Therefore, the second temperature sensor <NUM> is disposed on the surface of the discharge tube <NUM> within a range of <NUM> from the body of the compressor <NUM>.

The scroll compressor <NUM> includes a guide plate <NUM> as illustrated in <FIG> and <FIG>. The first temperature sensor <NUM> described above measures the temperature in a space (second refrigerant channel R2) defined by the guide plate <NUM>.

The guide plate <NUM> is disposed inside the casing <NUM>, and reduces the channel cross-sectional area of the second refrigerant channel R2. Specifically, the guide plate <NUM> is disposed to guide the refrigerant to the third refrigerant channel R3, which is a space defined below the housing <NUM> and defined in part of the space between the outer periphery of the driving motor <NUM> and the inner wall of the casing <NUM>. In other words, the second refrigerant channel R2 and the third refrigerant channel R3 are continuous from each other via the guide plate <NUM>.

To be noted, the guide plate <NUM> has a shape as illustrated in <FIG>, and defines the second refrigerant channel R2 such that the second refrigerant channel R2 is concentrated in a part (core cut portion of one pole part of the stator <NUM>) of the space between the outer periphery of the driving motor <NUM> and the inner wall of the casing <NUM>. Therefore, other core cut portions can be used for oil return or the like.

The scroll compressor <NUM> is connected to the control apparatus <NUM> that will be described later. The control apparatus <NUM> functions as a calculation unit 5a that calculates a temperature estimation value HTp of the refrigerant at the discharge port 32a on the basis of a measurement value Tp of the first temperature sensor <NUM> and a measurement value Td of the second temperature sensor <NUM>. Specifically, the control apparatus <NUM> (calculation unit 5a) estimates the temperature of the refrigerant on the basis of the following formula (<NUM>). To be noted, K represents a correction coefficient, and is set on the basis of a measured value of the refrigerant temperature at the discharge port 32a measured in an experimental environment. In addition, n is a natural number. <NUM>]<MAT>.

The scroll compressor <NUM> according to the present embodiment includes the first temperature sensor <NUM> and the second temperature sensor <NUM> described above and estimates the refrigerant temperature at the discharge port 32a, and this is based on the following findings by the present inventors. In other words, as a result of intensive effort, the present inventors found that the refrigerant temperature at the discharge port 32a can be estimated with high accuracy by using the formula (<NUM>) described above.

For example, a result illustrated in <FIG> was obtained for the measurement values of the temperature sensors when the scroll compressor <NUM> was controlled. Here, the measured value of the refrigerant temperature at the discharge port 32a, the measurement value of the first temperature sensor <NUM>, and the measurement value of the second temperature sensor <NUM> are respectively indicated by lines T, Tp, and Td in <FIG>. In addition, the temperature estimation value calculated by using the formula (<NUM>) described above is indicated by a line HTp. To be noted, in <FIG>, the horizontal axis represents the time, and the vertical axis represents the temperature.

Focusing on dotted parts A1 and A2 in <FIG>, it can be recognized that the line HTp follows well the line T indicating the measured value, even when sudden temperature change is caused by change in the performance or the like. To be noted, the safety can be improved by configuring such that the error has a positive value when the temperature of the discharge port 32a, which needs to be protected, increases.

In addition, a result illustrated in <FIG> was obtained when the horizontal axis was set to represent the measured value T of the refrigerant temperature at the discharge port 32a and the vertical axis was set to represent the temperature estimation value HTp calculated by using the formula (<NUM>) described above. Here, it can be recognized that the estimation accuracy is approximately within ±<NUM>.

As described above, it was confirmed that the refrigerant temperature at the discharge port 32a can be estimated with high accuracy by using the scroll compressor <NUM> including the first temperature sensor <NUM> and the second temperature sensor <NUM> described above.

<FIG> is a diagram for describing an example of a configuration of the refrigeration cycle apparatus <NUM> including the compressor <NUM> according to the present embodiment.

Here, the refrigeration cycle apparatus <NUM> is a water heating apparatus and/or cooling apparatus using a heat pump. Specifically, the refrigeration cycle apparatus <NUM> as a water heater or a water cooler supplies heated or cooled water. In addition, the refrigeration cycle apparatus <NUM> heats or cools a room by using the heated or cooled water as a medium.

As illustrated in <FIG>, the refrigeration cycle apparatus <NUM> includes the scroll compressor <NUM>, an accumulator <NUM> a four-way switching valve <NUM>, an air heat exchanger <NUM>, a check valve bridge <NUM>, a first expansion mechanism <NUM>, a second expansion mechanism (flow rate adjustment mechanism) <NUM>, an economizer heat exchanger <NUM>, and a water heat exchanger <NUM>. Further, the refrigeration cycle apparatus <NUM> includes a fan <NUM> for passing air through the air heat exchanger <NUM>, and a motor <NUM> that drives the fan <NUM>. To be noted, the devices and a branching portion <NUM> are interconnected by pipes <NUM> to <NUM>.

In addition, each apparatus is controlled by the control apparatus <NUM>.

To be noted, in the present embodiment, an "expansion mechanism" refers to one that can reduce the pressure of the refrigerant, and for example, an electronic expansion valve and a capillary tube correspond thereto. In addition, the opening degree of the expansion mechanism can be appropriately adjusted.

In the refrigeration cycle apparatus <NUM>, the control apparatus <NUM> performs the following control on each constituent device. To be noted, the control apparatus <NUM> is constituted by a microcomputer, a memory storing a program, and so forth.

The control apparatus <NUM> includes a circulation control unit <NUM> as illustrated in <FIG>, and controls each constituent device of the refrigeration cycle apparatus <NUM> to perform control to circulate the refrigerant. Specifically, the refrigeration cycle apparatus <NUM> performs control to circulate the refrigerant when heating or cooling water.

For example, when water is heated, the gas refrigerant is delivered to the scroll compressor <NUM> under the control of the control apparatus <NUM>. Then, the gas refrigerant is compressed by the scroll compressor <NUM>. The compressed gas refrigerant is delivered to the water heat exchanger <NUM> that functions as a condenser. In the water heat exchanger <NUM>, heat is exchanged between the gas refrigerant and water, and thus the refrigerant is liquified. Subsequently, the refrigerant is delivered to the first expansion mechanism <NUM>. The first expansion mechanism <NUM> reduces the pressure of the refrigerant. Next, the refrigerant is delivered to the air heat exchanger <NUM> that functions as an evaporator. In the air heat exchanger <NUM>, heat is exchanged between the refrigerant and air, and thus the refrigerant is evaporated. Then, the evaporated refrigerant is delivered to the scroll compressor <NUM> again. Thereafter, the refrigerant circulates among the constituent devices of the refrigeration cycle in a similar manner.

Then, at or after the timing when the circulation of the refrigerant is started, water is delivered from a water inlet pipe <NUM> to the water heat exchanger <NUM>. At this time, a high-temperature refrigerant is flowing in the water heat exchanger <NUM>. Therefore, in the water heat exchanger <NUM>, water is heated by the refrigerant. The heated water is discharged through a water outlet pipe <NUM>. The heated water is supplied in this manner.

To be noted, the water can be cooled by changing the flow of the refrigerant by switching the four-way switching valve <NUM>. In this case, the water heat exchanger <NUM> functions as an evaporator of the refrigerant.

The control apparatus <NUM> includes an injection control unit 5i as illustrated in <FIG>, and performs injection control when performing the circulation control described above. In the refrigeration cycle apparatus <NUM> according to the present embodiment, the second expansion mechanism <NUM>, the economizer heat exchanger <NUM>, the branching portion <NUM>, and the pipes <NUM> to <NUM> constitute a so-called injection circuit.

For example, in the case of heating water, the gas refrigerant compressed by the scroll compressor <NUM> is delivered under the control of the control apparatus <NUM> to the water heat exchanger <NUM> functioning as a condenser. In the water heat exchanger <NUM>, heat is exchanged between the gas refrigerant and water, and thus the refrigerant is liquified. The liquified refrigerant is branched at the branching portion <NUM> and delivered to the second expansion mechanism <NUM>.

Here, the second expansion mechanism <NUM> functions as a flow rate adjustment mechanism. Specifically, under the control of the control apparatus <NUM>, the opening degree and the like of the second expansion mechanism <NUM> is adjusted. As a result of this, the flow rate of the branched refrigerant is adjusted. At this time, the pressure and temperature of the refrigerant is reduced as a result of a throttling-expansion effect of the second expansion mechanism <NUM>. Then, the refrigerant is delivered from the second expansion mechanism <NUM> to the economizer heat exchanger <NUM>.

The economizer heat exchanger <NUM> functions as a gasification mechanism. Specifically, in the economizer heat exchanger <NUM>, heat is exchanged between the refrigerant flowing from the pipe <NUM> to the pipe <NUM> (refrigerant flowing in the injection circuit) and the refrigerant flowing from the pipe <NUM> to pipe <NUM> (refrigerant flowing in the main refrigeration cycle), and thus the refrigerant flowing from the pipe <NUM> to the pipe <NUM> (refrigerant flowing in the injection circuit) is gasified. Then, the gasified refrigerant is injected during compression by the scroll compressor <NUM>. As a result of this, the discharge temperature of the gas refrigerant compressed by the scroll compressor <NUM> is adjusted so as not to be excessively high. To be noted, the "gasification" in the injection circuit used herein is satisfied as long as at least part of the liquid refrigerant is gasified (gas-rich state), and does not necessarily mean gasifying all of the liquid refrigerant.

The control apparatus <NUM> includes a rotation number control unit 5b as illustrated in <FIG>, and controls the number of rotations of the driving motor <NUM>. Specifically, the rotation number control unit 5b controls the number of rotations of the driving motor <NUM> such that the temperature estimation value HTp of the refrigerant calculated by the calculation unit 5a described above reaches a discharge target temperature.

For example, in the case of supplying water of high temperature, the control apparatus <NUM> performs control such that the number of rotations of the driving motor <NUM> of the scroll compressor <NUM> increases. As a result of this, the amount of circulation of the refrigerant in the refrigeration cycle increases, and the amount of heat dissipation from the refrigerant in the water heat exchanger <NUM> per unit time increases. As a result of this, the temperature of the water with which heat is exchanged increases, and water of high temperature can be supplied. To be noted, the control apparatus <NUM> stops the rotation of the driving motor <NUM> when the temperature of the water is higher than a set temperature.

The control apparatus <NUM> includes a first opening degree control unit 5c as illustrated in <FIG>, and controls the opening degree of the first expansion mechanism <NUM>. Specifically, the first opening degree control unit 5c controls the opening degree of the first expansion mechanism <NUM> on the basis of the temperature estimation value HTp of the refrigerant calculated by the calculation unit 5a described above.

For example, the control apparatus <NUM> performs control such that the opening degree of the first expansion mechanism <NUM> increases in the case where the estimation value of the discharge temperature of the refrigerant discharged from the scroll compressor <NUM> is higher than a target discharge temperature. As a result of this, the flow rate of the refrigerant passing through the air heat exchanger <NUM> increases, and the degree of superheating of the refrigerant sucked into the scroll compressor <NUM> decreases. Therefore, the discharge temperature of the refrigerant becomes closer to the target discharge temperature.

In addition, the control apparatus <NUM> may control the opening degree of the first expansion mechanism <NUM> such that the degree of subcooling of the refrigerant at an outlet portion of the water heat exchanger <NUM> or the degree of subcooling of the refrigerant at an outlet portion of the economizer heat exchanger <NUM> reaches a target degree of subcooling.

The control apparatus <NUM> includes a second opening degree control unit 5d as illustrated in <FIG>, and controls the opening degree of the second expansion mechanism <NUM>.

Specifically, the opening degree of the second expansion mechanism <NUM> is controlled by a procedure illustrated in <FIG>. First, the calculation unit 5a of the control apparatus <NUM> obtains the measurement value Tp of the first temperature sensor <NUM> (S1). In addition, the calculation unit 5a obtains the measurement value Td of the second temperature sensor <NUM> (S2). Here, the timings of the step S1 and the step S2 may be revered or the same. Then, the calculation unit 5a calculates the temperature estimation value HTp of the refrigerant at the discharge port 32a of the scroll compression mechanism <NUM> from the measurement value Tp of the first temperature sensor <NUM> and the measurement value Td of the second temperature sensor <NUM> (S3). Next, the second opening degree control unit 5d of the control apparatus <NUM> controls the opening degree of the second expansion mechanism <NUM> on the basis of the temperature estimation value HTp of the refrigerant calculated by the calculation unit 5a described above (S4).

For example, the control apparatus <NUM> performs control such that the opening degree of the second expansion mechanism <NUM> increases in the case where the estimation value of the discharge temperature of the refrigerant discharged from the scroll compressor <NUM> is higher than the target discharge temperature. As a result of this, the flow rate of the refrigerant flowing into the injection circuit increases, and the temperature of the refrigerant sucked into the scroll compressor <NUM> is reduced. Therefore, the discharge temperature of the refrigerant becomes closer to the target discharge temperature.

(<NUM>-<NUM>)
As described above, the scroll compressor <NUM> of the present embodiment includes the casing <NUM>, the scroll compression mechanism <NUM>, the discharge tube <NUM>, the first temperature sensor <NUM>, and the second temperature sensor <NUM>.

Here, the first temperature sensor <NUM> includes the temperature sensing portion 15a. The temperature sensing portion 15a is disposed in the second refrigerant channel R2. The temperature sensing portion 15a is capable of directly measuring the temperature of the refrigerant (measurement value Tp). "Directly measure" means directly measuring the temperature of the refrigerant instead of measuring the temperature of a pipe in which the refrigerant flows or a part that receives heat transmission from the refrigerant. Therefore, temperature quickly following the change of the discharge temperature immediately after the discharge port 32a of the scroll compression mechanism <NUM> can be measured by using the first temperature sensor <NUM>.

In addition, the second temperature sensor <NUM> measures the temperature of the surface of the discharge tube <NUM> (measurement value Td). Therefore, temperature reflecting an influence of the heat capacity of constituent members of the scroll compressor <NUM> can be measured by using the second temperature sensor <NUM>.

Therefore, in the scroll compressor <NUM> of the present embodiment, by using the two temperature values measured by the first temperature sensor <NUM> and the second temperature sensor <NUM>, the temperature of the refrigerant immediately after the discharge port 32a of the scroll compression mechanism <NUM> (temperature estimation value HTp) can be estimated with high accuracy. As a result, the scroll compressor <NUM> of high reliability can be disposed.

Here, additional description will be given on the effect of the scroll compressor <NUM> of the present embodiment. In the scroll compressor <NUM>, constituent members therein may be damaged when the discharge temperature of the refrigerant becomes excessively high, and therefore control is performed such that the discharge temperature of the refrigerant does not exceed a predetermined value. Further, as a first method for performing the control described above, there is a method of measuring the temperature of the discharge tube <NUM> extending from the casing <NUM> of the scroll compressor <NUM> and estimating a value corrected in consideration of heat loss or the like as the discharge temperature. In addition, as a second method, there is a method of disposing a temperature sensor at the position of the discharge port 32a of the scroll compressor <NUM> where the temperature becomes the highest, and estimating the measurement value thereof as the discharge temperature.

In the case of the first method, delay or retardation of response to temperature change derived from the heat capacity of the casing <NUM> or the like of the scroll compressor <NUM>, or temperature reduction derived from heat dissipation to the surroundings occurs. Here, the amount of temperature change greatly differs depending on the operation conditions. Therefore, in some cases, the temperature at the discharge port 32a of the scroll compressor <NUM> cannot be accurately estimated. As a result, in some cases, the discharge temperature exceeds an acceptable upper limit, and the scroll compressor <NUM> may be damaged. Alternatively, in some cases, an excessively large error is taken into consideration for ensuring reliability, thus the compressor is overdesigned, and the cost may increase. In addition, as a result of setting the upper limit of the discharge temperature to be low, in some cases, an operation allowable area of the compressor may become small, or the operation of the scroll compressor <NUM> may be inefficient. Further, in some cases, cooling is performed by liquid injection or the like such that the temperature at the discharge port 32a does not exceed the upper limit. However, in some cases, the timing of the cooling is delayed due to the delay in the response of temperature measurement, and superheating occurs or discharge wetting occurs due to subcooling. As a result, the reliability of the scroll compressor <NUM> may be degraded in some cases.

Meanwhile, using the second method to resolve the problems of the first method can be also considered. However, in the second method, a temperature sensor needs to be disposed inside the casing <NUM> of the scroll compressor <NUM>. Therefore, attaching the temperature sensor is complicated, and the cost increases. In addition, due to a structure for attaching the temperature sensor near the discharge port 32a, leakage of refrigerant, loss of pressure, and the like sometimes occur inside the compressor. In addition, since the temperature sensor is exposed to a high-temperature high-pressure atmosphere, malfunction is likely to occur. Further, once malfunction occurs, a problem arises that, for example, the temperature sensor cannot be easily replaced.

The scroll compressor <NUM> according to the present embodiment includes the two temperature sensors, that is, the first temperature sensor <NUM> that is disposed in a refrigerant channel in the casing <NUM> and directly measures the temperature of the refrigerant and the second temperature sensor <NUM> that measures the surface temperature of the discharge tube <NUM>, and therefore can calculate the discharge temperature of the refrigerant with high accuracy. As a result, the problems that arise in the first method and the second method described above can be avoided, and the scroll compressor <NUM> of high reliability can be disposed.

(<NUM>-<NUM>)
In addition, in the scroll compressor <NUM> according to the present embodiment, the first temperature sensor <NUM> is disposed to penetrate the casing, and is detachably attached to the casing <NUM> from the outside. Therefore, maintenance can be easily performed even if the first temperature sensor <NUM> is out of order. In addition, since a structure in which the first temperature sensor <NUM> can be easily replaced is employed, the durability does not need to be considered more than necessary. As a result, the production cost can be suppressed.

(<NUM>-<NUM>)
In addition, in the scroll compressor <NUM> according to the present embodiment, the temperature sensing portion 15a of the first temperature sensor <NUM> is thermally insulated from the casing <NUM>. Therefore, the temperature of the refrigerant can be measured with high accuracy.

(<NUM>-<NUM>)
In addition, the scroll compressor <NUM> according to the present embodiment further includes the guide plate <NUM> that is disposed inside the casing <NUM> and reduces the channel cross-sectional area of the refrigerant channel. Here, since the guide plate <NUM> is disposed such that the channel cross-sectional area is reduced, the flow rate of the refrigerant in that space increases. Then, the first temperature sensor <NUM> measures the temperature in the space (second refrigerant channel R2) defined by the guide plate <NUM>. Therefore, according to such a configuration, the temperature of the refrigerant of high flow rate is measured, and therefore the responsiveness can be improved.

(<NUM>-<NUM>)
In addition, in the scroll compressor <NUM> according to the present embodiment, the driving motor <NUM> is disposed to form the third refrigerant channel R3 in part of the space between the outer periphery of the driving motor <NUM> and the inner wall of the casing <NUM>. In addition, the guide plate <NUM> is disposed so as to guide the refrigerant to the third refrigerant channel R3 between the outer periphery of the driving motor <NUM> and the inner wall of the casing <NUM>. Therefore, the scroll compressor <NUM> can be manufactured in a small size. Specifically, according to the configuration described above, a core cut portion of the outer periphery of the driving motor <NUM> can be used as a channel. Therefore, no additional space needs to be provided, and thus reduction of the size and cost of the scroll compressor <NUM> can be realized.

To be noted, here, the guide plate <NUM> is disposed such that the refrigerant is concentrated in part (core cut portion of one pole portion) of the space between the outer periphery of the driving motor <NUM> and the inner wall of the casing <NUM>. Therefore, other core cut portions can be used for oil return or the like.

In addition, in the scroll compressor <NUM> according to the present embodiment, among a region near the inner wall of the casing <NUM>, the discharge tube <NUM> is disposed approximately on the opposite side to the region defined by the guide plate <NUM> in plan view. According to such a configuration, the second temperature sensor <NUM> can measure a temperature reflecting an influence that is not reflected in the first temperature sensor <NUM>. In addition, the first temperature sensor <NUM> can measure a temperature not greatly reflecting an influence of the heat capacity of constituent members of the scroll compressor <NUM>. Meanwhile, the second temperature sensor <NUM> can measure a temperature greatly reflecting the influence of the heat capacity of constituent members of the scroll compressor <NUM>. Therefore, the temperature measurement value of the second temperature sensor <NUM> reflects an influence not reflected in the first temperature sensor <NUM>.

(<NUM>-<NUM>)
In addition, in the scroll compressor <NUM> according to the present embodiment, the second temperature sensor <NUM> is disposed within the range where the length of a channel from the casing <NUM> is <NUM> or less. According to such a configuration, influence of heat loss and heat capacity can be suppressed.

(<NUM>-<NUM>)
As described above, in the refrigeration cycle apparatus <NUM> according to the present embodiment, the water heat exchanger <NUM> and the air heat exchanger <NUM> can be respectively used as a condenser and an evaporator. In this case, the refrigeration cycle apparatus <NUM> has a refrigeration cycle in which the refrigerant flows in the order of the scroll compressor <NUM>, the condenser (water heat exchanger <NUM>), the first expansion mechanism <NUM>, and the evaporator (air heat exchanger <NUM>).

Here, the refrigeration cycle apparatus <NUM> further includes the calculation unit 5a that calculates the temperature of the refrigerant discharged from the scroll compression mechanism <NUM>, by using the first temperature sensor <NUM> and the second temperature sensor <NUM>.

Therefore, the refrigeration cycle apparatus <NUM> can estimate the refrigerant temperature immediately after the discharge port 32a of the scroll compression mechanism <NUM> with high accuracy.

(<NUM>-<NUM>)
In addition, the refrigeration cycle apparatus <NUM> according to the present embodiment further includes the rotation number control unit 5b that controls the number of rotations of the driving motor <NUM> on the basis of the temperature of the refrigerant calculated by the calculation unit 5a. According to such a configuration, the refrigeration cycle apparatus <NUM> of high reliability can be disposed.

For example, the pressure in a high-pressure state can be reduced by reducing the number of rotations of the driving motor <NUM> under the control of the rotation number control unit 5b. As a result of this, the discharge temperature can be lowered, and problems such as deterioration of oil and damage to mechanical parts can be avoided.

(<NUM>-<NUM>)
In addition, the refrigeration cycle apparatus <NUM> according to the present embodiment further includes the pipes <NUM> to <NUM> (injection pipes), the second expansion mechanism <NUM> (flow rate adjustment mechanism), and the second opening degree control unit 5d. Here, the pipes <NUM> to <NUM> are branched from a pipe extending from the water heat exchanger <NUM> (condenser) to the first expansion mechanism <NUM>, and are connected to the scroll compressor <NUM>. The second expansion mechanism <NUM> adjusts the flow rate of the refrigerant in the pipes <NUM> to <NUM>. The second opening degree control unit 5d controls the opening degree of the second expansion mechanism <NUM> on the basis of the temperature of the refrigerant calculated by the calculation unit 5a. According to such a configuration, the refrigeration cycle apparatus <NUM> of high reliability can be disposed.

For example, by estimating the discharge temperature with high accuracy, occurrence of superheating, discharge wetting, or the like derived from response delay of temperature measurement can be avoided.

(<NUM>-<NUM>)
In addition, the refrigeration cycle apparatus <NUM> according to the present embodiment further includes the economizer heat exchanger <NUM> (gasification mechanism) that gasifies the liquid refrigerant flowing in the pipes <NUM> to <NUM>. According to such a configuration, control can be performed with higher accuracy such that the discharge temperature of the refrigerant reaches a target value.

(<NUM>-<NUM>)
To be noted, the refrigeration cycle apparatus <NUM> according to the present embodiment is suitable for a use in which the temperature of the refrigerant discharged from the scroll compressor <NUM> needs to be high. Particularly, in the case of using R32 as the refrigerant, since the discharge temperature is high, the refrigeration cycle apparatus <NUM> according to the present embodiment is suitably used. For example, the refrigeration cycle apparatus <NUM> according to the present embodiment is suitably applied to a water-heating air-heating machine using a heat pump, as a substitute for a combustion heater.

(<NUM>-<NUM>)
In the description above, the scroll compressor <NUM> and the control apparatus <NUM> have been described as separate apparatuses, but part or all of the functions of the control apparatus <NUM> may be incorporated in the scroll compressor <NUM>. In other words, the scroll compressor <NUM> may have the function of estimating the temperature of the refrigerant at the discharge port 32a.

(<NUM>-<NUM>)
Although the second temperature sensor <NUM> has been described as the temperature sensor measuring the temperature of the surface of the discharge tube <NUM> in the description above, the second temperature sensor <NUM> is not limited thereto. Specifically, the second temperature sensor <NUM> may be disposed at a different position from the first temperature sensor <NUM> and measure the temperature of one of the surface of the discharge tube <NUM>, an inner space of the discharge tube <NUM>, and the surface of the casing <NUM>. Even if the second temperature sensor <NUM> is disposed in these positions, the temperature of the refrigerant at the discharge port 32a can be estimated with high accuracy by using the measurement value of the first temperature sensor <NUM> in combination.

(<NUM>-<NUM>)
Although the refrigeration cycle apparatus <NUM> has been described as heating or cooling water in the description above, the refrigeration cycle apparatus <NUM> is not limited thereto. For example, the refrigeration cycle apparatus <NUM> may heat and cool a brine as a fluid different from water, or heat and cool a room as a direct-expansion air conditioner by using an indoor unit in which the water heat exchanger is replaced by an air heat exchanger.

(<NUM>-<NUM>)
Although the description above has been given by describing the scroll compressor <NUM>, the compressor is not limited thereto. The compressor according to the present embodiment may be a different compressor such as a rotary compressor.

Embodiments have been described above, and it should be understood that the embodiments and details can be modified in various ways without departing from the scope of claims.

In other words, the present disclosure is not limited to the original embodiments described above.

Claim 1:
A refrigeration cycle apparatus (<NUM>) comprising a refrigeration cycle in which a refrigerant flows in an order of a compressor (<NUM>), a condenser (<NUM>), an expansion mechanism (<NUM>), and an evaporator (<NUM>),
the compressor (<NUM>) comprising:
a casing (<NUM>);
a compression mechanism (<NUM>) that is disposed inside the casing, compresses a sucked refrigerant, and discharges the compressed refrigerant to a refrigerant channel (R1, R2, or R3) formed in an inner space of the casing;
a discharge tube (<NUM>) through which the compressed refrigerant flows from the inner space of the casing to an outside; and characterised by comprising
a first temperature sensor (<NUM>) including a temperature sensing portion (15a), the temperature sensing portion being disposed in the refrigerant channel and directly measuring a temperature of the refrigerant; and
a second temperature sensor (<NUM>) that is disposed at a different position from the first temperature sensor and measures a temperature of one of a surface of the discharge tube, an inner space of the discharge tube, and a surface of the casing,
wherein the refrigeration cycle apparatus further comprises a calculation unit (5a) configured to calculate a temperature of a refrigerant discharged from the compression mechanism, by using the first temperature sensor and the second temperature sensor.