TW201502451A - Heat pump unit and operating method of heat pump unit - Google Patents

Abstract

The heat pump unit (200) includes a circulation flow passageway (210) through which a heating medium is circulated; a compressor (230) which includes a containing space (R) containing a lubricating oil to be supplied to a compression mechanism (232, 234) and which adiabatically compress the heating medium so as to increase a temperature of the heating medium; a condenser (240) which condenses the heating medium; an expansion valve (260) which decompresses and expands the heating medium; an evaporator (220) which evaporates the heating medium; a controller (280) which controls drive of the compressor and an opening degree of the expansion valve. The controller is configured, when receiving instructions that compression operation of the compressor is stopped, to decrease the opening degree of the expansion valve so that a level of a liquid surface of the lubricating oil contained in the containing space is maintained to be greater than or equal to a predetermined threshold value, and to stop operation of the compressor after completely closing the expansion valve.

Description

Heat pump unit and heat pump unit operation method

The invention relates to a method for operating a heat pump unit and a heat pump unit.

The present application claims priority based on Japanese Patent Application No. 2013-082117, filed on Jan.

Conventionally, there is known a heat pump unit comprising: a compressor that adiabatically compresses a heat medium circulating in a circulation path for heating; and a condenser that cools a heat medium heated by a compressor to condense the heat medium; The valve causes the heat medium condensed by the condenser to expand under reduced pressure for cooling; and the evaporator heats the heat medium cooled by the expansion valve to vaporize the heat medium. Such a heat pump unit is applied to various fields such as a refrigerator, a freezer, an air conditioner, a hot water supply, and the like.

In the case where the operation of the heat pump unit is to be stopped, for example, if the driving of the compressor is stopped without closing the expansion valve, the liquid medium in the liquid state remains in the evaporator. In this case, when the operation of the heat pump unit is started next time, the heat medium remaining in the liquid state of the evaporator is introduced into the compressor in this state, which may cause the compressor to malfunction.

Therefore, a technique has been disclosed in which the expansion valve is completely closed at a time before stopping the operation of the heat pump unit including the expansion valve having the switch control (for example, refer to Patent Document 1).

[Previous Technical Literature]

[Patent Literature]

Patent Document 1: Japanese Patent Laid-Open Publication No. 2001-165511

Lubricating oil is supplied to the compression mechanism constituting the compressor, and in the heat pump unit, when the compressor adiabatically compresses the heat medium, the heat medium may be dissolved in the lubricating oil. In this case, according to the technique of Patent Document 1, when the expansion valve is completely closed at the time of driving the compressor, the pressure in the compressor is rapidly lowered, and the heat medium dissolved in the lubricating oil may be foamed. .

When the heat medium is foamed, the viscosity of the lubricating oil is lowered, and the oil film of the lubricating oil is not sufficiently formed in the compression mechanism, so that the wear of the compression mechanism is accelerated, and the compressor is damaged.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for operating a heat pump unit and a heat pump unit, which can prevent foaming of a heat medium contained in a lubricating oil when the compressor is to be stopped, thereby preventing damage of the compressor.

In order to solve the above problems, in a first aspect of the present invention, a heat pump unit includes: a circulation path for circulating a heat medium; and a compressor having a compression mechanism and a lubricating oil for accommodating the supply to the compression mechanism a space, and the heat medium circulating in the circulation path is adiabatically compressed to increase the temperature; the condenser is disposed downstream of the compressor in the circulation path, and the heat medium heated by the compressor is cooled to condense the heat medium; An expansion valve is disposed downstream of the condenser in the circulation path, and decompresses and expands the heat medium condensed by the condenser for cooling; the evaporator is disposed downstream of the expansion valve in the circulation path and is cooled by the expansion valve The heat medium is heated to vaporize the heat medium; and the control unit controls the driving of the compressor and the opening of the expansion valve to control the circulation amount of the heat medium in the circulation path. Further, the control unit is configured to reduce the opening degree of the expansion valve so as to reduce the liquid level of the lubricating oil accommodated in the accommodating space when receiving an instruction to stop the content of the compression operation of the heat medium by the compressor The height is maintained at a value set in advance above the threshold of the compressor, and after the expansion valve is completely closed to block the flow of the heat medium into the compressor through the expansion valve, the compression of the heat medium by the compressor is stopped. action.

According to a second aspect of the present invention, in the heat pump unit of the first aspect, the control unit is configured to maintain the rate of change of the opening degree of the expansion valve by reducing the opening degree of the expansion valve. At a predetermined first value, the height of the liquid surface of the lubricating oil accommodated in the accommodating space is maintained at a value equal to or greater than a threshold value.

According to a third aspect of the present invention, in the heat pump unit of the first aspect, the control unit is configured to maintain a decrease in the pressure of the accommodating space by reducing the opening degree of the expansion valve. The predetermined second value maintains the height of the liquid surface of the lubricating oil accommodated in the accommodating space at a value equal to or greater than a threshold value.

In the fourth aspect of the present invention, the first to In the heat pump unit of any of the third aspects, the control unit is configured such that after the expansion valve is completely closed, the pressure in the accommodating space becomes a pressure that does not reach a predetermined concentration of the heat medium contained in the lubricating oil. Previously, the compression operation of the heat medium by the compressor is continued, and when the pressure in the accommodating space becomes a pressure corresponding to a predetermined concentration of the heat medium contained in the lubricating oil, the compressor is stopped. The compression action of the heat medium.

In order to solve the above problems, in the fifth aspect of the present invention, the operation method of the heat pump unit is used in a heat pump unit having a circulation path for circulating heat supply, a compressor having a compression mechanism, and the like. The heat storage medium that is supplied to the compression mechanism is housed, and the heat medium circulating in the circulation path is adiabatically compressed to increase the temperature; the condenser is disposed downstream of the compressor in the circulation path and is heated by the compressor. The heat medium is cooled to condense the heat medium; the expansion valve is disposed downstream of the condenser in the circulation path, and the heat medium condensed by the condenser is decompressed and expanded for cooling; and the evaporator is disposed in the circulation path. Downstream of the expansion valve, the heat medium cooled by the expansion valve is heated to vaporize the heat medium. In this operation method, when receiving an instruction to stop the content of the compression operation of the heat medium by the compressor, the opening degree of the expansion valve is reduced to increase the level of the liquid level of the lubricating oil accommodated in the accommodating space. The value is set to a value equal to or higher than the threshold value of the compressor, and after the expansion valve is completely closed and the heat medium is blocked from flowing into the compressor through the expansion valve, the compression operation of the heat medium by the compressor is stopped.

According to the present invention, when the compressor is to be stopped, The foaming of the heat medium contained in the lubricating oil prevents damage to the compressor.

100‧‧‧Vacuum cleaning device

102‧‧‧cleaning room

104‧‧‧Vacuum container

108‧‧‧Loading Department

110‧‧‧ rinse department

114‧‧‧Vapor supply pipe

120‧‧Condensing room

122‧‧‧Condensation cleaning agent supply pipe

124‧‧‧Cleans Storage Department

126‧‧‧Condensation cleaning agent supply pipe

128‧‧‧Use end cleaning agent introduction tube

130‧‧‧Vapor Supply Department

150‧‧ ‧ vapor room

152‧‧‧heater

200‧‧‧ heat pump unit

210‧‧‧Circular path

210a to 210f‧‧‧ cycle path

220‧‧‧Evaporator

230‧‧‧Compressor

232‧‧‧Piston (compression mechanism)

234‧‧‧Drive shaft (compression mechanism)

236‧‧‧Compression room

238a‧‧ Entrance

238b‧‧‧Export

240‧‧‧Condenser

250‧‧‧Intermediate heat exchanger

260‧‧‧Expansion valve

270‧‧‧ Pressure Measurement Department

280‧‧‧Control Department

310‧‧‧Lubricating oil pump

312‧‧‧ oil passage

320‧‧‧Distribution Department

LH‧‧‧ liquid level

R‧‧‧ containment space

W‧‧‧Workpiece

Figure 1 is a conceptual diagram for explaining a vacuum cleaning device.

Fig. 2 is a view for explaining the constitution of a compressor.

Figure 3 is a flow chart for explaining the processing flow of the operation method of the heat pump unit.

Preferred embodiments of the present invention will be described in detail below with reference to the drawings. The dimensions, materials, and other specific numerical values of the embodiments are merely illustrative of the invention, and are not intended to limit the invention unless otherwise stated. In the present specification and the drawings, elements that have substantially the same functions and configurations are denoted by the same reference numerals, and the description thereof will not be repeated, and the elements that are not directly related to the present invention are not shown.

Conventionally, heat pump units have been installed in various electrical equipment such as refrigerators, freezers, air conditioners, and hot water heaters. Further, in recent years, a vacuum cleaning device that uses a vapor of a hydrocarbon-based cleaning agent to clean a work (object to be treated) under reduced pressure has been developed, and a heat pump unit is also used in the vacuum cleaning device. The workpiece refers to, for example, an industrial product, and the vacuum cleaning device cleans the workpiece to remove contaminants attached to the workpiece. In the present embodiment, a vacuum cleaning device will be described as an example of a device including a heat pump unit.

(Vacuum cleaning device 100)

Fig. 1 is a conceptual diagram (block diagram) for explaining the vacuum cleaning device 100. In the first drawing, the flow of the hydrocarbon cleaning agent is indicated by a solid arrow symbol, and the flow of the heat medium is indicated by a broken arrow symbol, and the direction of the signal is indicated by an arrow symbol of a dotted line. As shown in Fig. 1, the vacuum cleaning device 100 includes a vacuum container 104 in which a cleaning chamber 102 is provided. In the vacuum container 104, an opening (not shown) is formed, and the opening can be opened and closed by an opening and closing door (not shown). Therefore, when the workpiece W is cleaned, the opening and closing door is opened and the workpiece W is carried into the cleaning chamber 102 from the opening, the workpiece W is placed on the placing portion 108, and the opening and closing door is closed to clean the workpiece W. After that, the opening and closing door is opened again, and the workpiece W is carried out from the opening.

In the above-described cleaning chamber 102, a shower portion 110 is provided. Further, the vapor chamber 150 is sequentially connected to the rinsing unit 110 via the steam supply pipe 114, the condensing chamber 120, the condensing detergent supply pipe 122, the cleaning agent storage portion 124, and the condensing cleaning agent supply pipe 126.

Further, a steam supply unit 130 is provided in the cleaning chamber 102. The steam supply unit 130 communicates with the steam chamber 150 via the steam supply pipe 114.

The steam chamber 150 includes a heater 152 and a condenser 240 for heating the hydrocarbon cleaning agent (solvent) to, for example, about 80 to 140 ° C, preferably about 120 ° C, to produce a hydrocarbon cleaning agent. Vapor (hereinafter referred to as "steam"). The vapor generated in the vapor chamber 150 is introduced into the condensation chamber 120 via the vapor supply pipe 114 or is supplied to the cleaning chamber 102 through the vapor supply unit 130. The vapor supplied to the cleaning chamber 102 by the steam supply unit 130 is cooled by adhering to the workpiece W. Condensed. The heating mechanism operated by the condenser 240 will be described in detail later.

Further, the type of the hydrocarbon-based cleaning agent is not particularly limited, but from the viewpoint of safety, it is preferred to use a third petroleum-based cleaning agent. For example, a normal paraffin type, an isoparaffin type, a naphthene type, and an aromatic hydrocarbon-based cleaning agent can be mentioned. Specifically, the third petroleum-based cleaning agent is preferably a Teclean N20, a Cleansol G, a Daphne (registered trademark) solvent or the like called a cleaning solvent.

The condensation chamber 120 is provided with an evaporator 220. The vapor introduced into the condensation chamber 120 is a hydrocarbon-based cleaning agent (hereinafter referred to as "condensation cleaning agent") which is cooled by the evaporator 220 and condensed into a liquid. The condensing cleaning agent is stored in the cleaning agent storage unit 124 via the condensing cleaning agent supply pipe 122, and is supplied to the cleaning chamber 102 via the condensing cleaning agent supply pipe 126 and the rinsing unit 110. The cooling mechanism that operates by the evaporator 220 will be described in detail later.

The condensed cleaning agent that is supplied from the rinsing unit 110 to clean the workpiece W and the condensed cleaning agent that is supplied from the steam supply unit 130 and condensed on the workpiece W are again introduced to the cleaning agent introduction pipe 128 by using the cleaning agent. Steam chamber 150. The used cleaning agent introduction pipe 128 that has been introduced into the steam chamber 150 is heated again by the above-described heater 152 and condenser 240 to become steam. In this manner, the cleaning agent is circulated in the vapor chamber 150, the vapor supply tube 114, the condensation chamber 120, the condensing cleaning agent supply tube 122, the cleaning agent storage portion 124, the condensing cleaning agent supply tube 126, the rinsing portion 110, the cleaning chamber 102, and the use thereof. The cleaning agent introduction pipe 128 is finished.

Further, a vacuum pump (not shown) is connected to the cleaning chamber 102 and the steam chamber 150. This vacuum pump is depressurized to a predetermined pressure (for example, 6 kPa) by evacuating the vacuum vessel 104 (cleaning chamber 102) by a vacuum (initial vacuum) before starting the cleaning of the workpiece W. Further, in the cleaning chamber 102, a pipe (not shown) for opening the cleaning chamber 102 to the atmosphere is connected. In the piping, an atmosphere opening valve that can block the atmosphere and the cleaning chamber 102 is provided, and in the step of carrying out the cleaning step and the drying step of the workpiece W, the cleaning chamber 102 is opened to the atmosphere and returned to the atmosphere. Atmospheric pressure.

(heat pump unit 200)

The heat pump unit 200 is configured to include a circulation path 210 (indicated by 210a to 210f in Fig. 1), an evaporator 220, a compressor 230, a condenser 240, an intermediate heat exchanger 250, an expansion valve 260, and pressure measurement. The unit 270 and the control unit 280. In the heat pump unit 200, the heat medium is circulated to the circulation path 210 as indicated by the arrow symbol in broken line in Fig. 1, and passes through the evaporator 220, the intermediate heat exchanger 250, the compressor 230, and the condenser provided in the circulation path 210. 240, the intermediate heat exchanger 250, and the expansion valve 260 are again introduced to the evaporator 220. Further, the type of the heat medium is not particularly limited, but a fluorine-based heat medium (for example, R-245fa (1, 1) which uses a latent heat of the heat medium in the evaporator 220 is used as a liquid at normal temperature and atmospheric pressure. Preferably, 1,3,3-pentafluoropropane is used, and the room temperature system is, for example, 25 °C.

The evaporator 220 is configured to expand in the circulation path 210 Downstream of valve 260. The evaporator 220 is in the condensation chamber 120, and heat exchanges with the vapor of the hydrocarbon cleaning agent introduced from the vapor chamber 150 to condense (cool) the vapor into a condensing cleaning agent, and heat the heating medium. And make it vaporized. That is, heating is performed via the evaporator 220, whereby the heat medium becomes a gas (indicated by G in the first drawing). The heat medium heated by the evaporator 220 is further heated by the intermediate heat exchanger 250. The heating mechanism operated by the intermediate heat exchanger 250 will be described in detail later.

The compressor 230 is constituted, for example, by a reciprocating compressor (reciproc compressor), and has a compression mechanism and a housing space for accommodating the lubricating oil supplied to the compression mechanism for heating the intermediate heat exchanger 250. The heat medium is adiabatically compressed and further heated. That is, the compressor 230 adiabatically compresses the heat medium to raise the temperature. The specific configuration of the compressor 230 will be described in detail later.

The condenser 240 is disposed downstream of the compressor 230 in the circulation path 210. The condenser 240 is heat-exchanged with the liquid hydrocarbon cleaning agent by the (heating) heat medium heated by the compressor 230 in the vapor chamber 150, whereby the hydrocarbon-based cleaning agent is heated to generate a hydrocarbon-based cleaning. The vapor of the agent, and the heat medium is cooled to condense. The heat is cooled by the condenser 240, whereby the heat medium is in a gas-liquid mixed state (in the first drawing, it is represented by G and L).

The intermediate heat exchanger 250 is passed through the circulation paths 210a and 210b (between the evaporator 220 and the compressor 230) and flows through the circulation paths 210d and 210e (between the condenser 240 and the expansion valve 260). The heat medium exchanges heat. The heat medium which is heated by the evaporator 220 and flows through the circulation path 210a may be incompletely vaporized to become a gas-liquid mixed fluid. In this case, when the liquid state heat medium is introduced to the compressor 230, the compressor 230 may be malfunctioning.

Therefore, by providing the intermediate heat exchanger 250, the heat medium flowing through the circulation path 210a is heated to a higher temperature than the saturation temperature, whereby the heat medium introduced into the compressor 230 can be circulated in the circulation. The heat medium of path 210b is indeed only gas. Thereby, it is possible to avoid a situation in which the compressor 230 is malfunctioning.

The expansion valve 260 is a valve that causes a decrease in fluid pressure, and is provided downstream of the condenser 240 for decompressing and expanding the heat medium condensed (cooled) by the condenser 240 to further cool. Cooling is performed via the expansion valve 260, whereby the heat medium becomes a liquid (indicated by L in Fig. 1). The heat medium cooled in the expansion valve 260 is reintroduced into the evaporator 220 through the circulation path 210f.

The pressure measuring unit 270 is for measuring the pressure of the gas portion in the accommodating space described later in the compressor 230.

The control unit 280 is constituted by a semiconductor integrated circuit including a CPU (Central Processing Unit), and reads a program or a parameter for operating the CPU from the ROM (read only memory), and serves as a work area. The RAM (Random Access Memory) or other electronic circuits cooperate to manage and control the heat pump unit 200 as a whole. In the present embodiment, the control unit 280 controls the driving amount (driving) of the compressor 230 and the opening degree of the expansion valve 260 based on the pressure measured by the pressure measuring unit 270 to control the cycle. The amount of circulation of the heat medium in the loop path 210.

As described above, in the lubricating oil accommodated in the compressor 230, the heat medium may be dissolved. Hereinafter, the action of dissolving the heat medium in the lubricating oil accommodated in the compressor 230 will be described using FIG.

Fig. 2 is a view for explaining the configuration of the compressor 230. In Fig. 2, the flow of the heat medium is indicated by a solid arrow symbol, and the flow of the lubricating oil is indicated by a white arrow symbol, and the lubricating oil is represented by a gray color. As shown in Fig. 2, a piston (compression mechanism) 232 of the compressor 230 is connected to a drive shaft (compression mechanism) 234, and when the drive shaft 234 is rotationally driven by a motor (not shown), the piston 232 That is, the reciprocating motion is performed with respect to the compression chamber 236 (cylinder). Further, in order to rotationally drive the drive shaft 234, a drive device other than the motor may be used. When the piston 232 is located near its bottom dead center, the heat medium is introduced into the compression chamber 236 from the circulation path 210b via the inlet 238a of the compressor 230. The heat medium introduced into the compression chamber 236 is compressed by the compression operation of the piston 232, and is then sent out from the outlet 238b to the circulation path 210c when the piston 232 is near the top dead center.

Further, as shown in FIG. 2, inside the compressor 230, a lubricating space for accommodating a lubricating oil (for example, POE (polyol ester)) and a lubricating oil accommodated in the accommodating space R are formed. It is supplied to the oil passage 312 of the drive shaft 234 by the lubricating oil pump 310. The lubricating oil supplied to the oil passage 312 is supplied to the outer peripheral surface of the piston 232 through an oil passage (not shown) of the piston 232. Further, the lubricating oil accommodated in the accommodating space R is supplied to the piston 232 by the scatter unit 320. The connection portion with the drive shaft 234, or the outer circumferential surface of the piston 232, and the inner circumferential surface of the compression chamber 236 (cylinder). In this manner, by supplying the lubricating oil to the outer circumferential surface of the piston 232 and the inner circumferential surface of the compression chamber 236, the friction coefficient between the piston 232 and the compression chamber 236 is lowered, and the wear of the piston 232 and the compression chamber 236 is reduced.

As described above, since the heat medium is introduced into the compression chamber 236 in the heat pump unit 200, and the lubricating oil is supplied to the inner peripheral surface of the compression chamber 236, the heat medium may be dissolved in the lubricating oil in the compression chamber 236. In this case, the lubricating oil circulates in the circulation path 210 in a state where the heat medium is dissolved, that is, the compression operation of the compressor 230 is continued in a state where the heat medium is dissolved in the lubricating oil.

As described above, when the operation of the heat pump unit 200 is to be stopped, if the driving of the compressor 230 is stopped without closing the expansion valve 260, the liquid medium may remain in the evaporator 220. In this state, when the operation of the heat pump unit 200 is started next time, the heat medium remaining in the liquid state of the evaporator 220 is introduced into the compressor 230 in this state, and the compressor 230 may be caused to malfunction. On the other hand, when the heat pump unit 200 is to be stopped, in order to avoid the residual of the heat medium in the liquid state in the evaporator 220, when the compressor 230 is driven, if the expansion valve 260 is all closed at one time, the compressor 230 The pressure in the accommodating space R is rapidly lowered, and the heat medium dissolved in the lubricating oil of the compressor 230 is foamed to damage the compressor 230. For example, there may even be cases where bubbles of the heat medium reach the compression chamber 236.

Especially in the heat pump unit 200 of the vacuum cleaning device 100 The heat medium used in the heat medium is more soluble in the lubricating oil than the heat medium used in the heat pump unit such as a refrigerator, a freezer, an air conditioner, or a hot water supply device (hereinafter referred to as "home appliance"). More specifically, in the vacuum cleaning apparatus 100, in order to generate the vapor of the hydrocarbon-based cleaning agent, it is necessary to heat the hydrocarbon-based cleaning agent to a high temperature of, for example, about 80 ° C to 140 ° C. Therefore, the boiling point of the heat medium used in the heat pump unit 200 of the vacuum cleaning apparatus 100 is higher than that of the heat medium used in the household electrical appliance or the general industrial heat pump unit. For example, the heat medium used in the heat pump unit of the household electrical appliance has a temperature of about 30 ° C at the inlet of the compressor and a temperature of about 60 ° C at the outlet temperature of the compressor, and is used for the heat medium of the general industrial heat pump unit at the compressor inlet. The temperature is about 90 ° C, and the compressor outlet temperature is about 110 ° C. On the other hand, the temperature of the heat medium used in the heat pump unit 200 of the vacuum cleaning apparatus 100 is about 100 ° C to 110 ° C at the inlet 238 a of the compressor 230 (the heat medium passing through the circulation path 210 b ), and is in the compressor 230. The temperature of the outlet 238b (the heat medium passing through the circulation path 210c) is about 140 °C.

The solubility of such a relatively high boiling heat medium to the lubricating oil constituting the compressor 230 of the heat pump unit 200 is generally larger than that of the relatively low boiling point heat medium. More specifically, the heat medium used in the heat pump unit of the household appliance device only dissolves about a few percent of the lubricating oil of the compressor, but the heat medium used in the heat pump unit 200 of the vacuum cleaning device 100 dissolves 20%. The case of lubricating oil to the compressor 230. Therefore, in the compressor 230 of the heat pump unit 200 of the vacuum cleaning apparatus 100, the foaming of the heat medium is more remarkable than that of the heat pump unit of the household appliance unit, and the compressor 230 is caused by the lowering of the liquid level LH of the lubricating oil. Damaged High energy. Further, since the foaming of the heat medium is caused by vaporization of the heat medium of the liquid material, the liquid surface LH of the lubricating oil is lowered as long as the heat medium in the lubricating oil is vaporized. When the liquid level LH is lowered to ensure the amount of lubricating oil necessary for lubrication between the piston 232 and the drive shaft 234, or the outer circumferential surface of the piston 232 and the inner circumferential surface of the compression chamber 236, etc., the constituent members are accelerated. The wear and tear may cause damage to the compressor 230.

Therefore, when the compressor 230 is to be stopped, the control unit 280 adjusts the opening degree of the expansion valve 260 to suppress the foaming of the heat medium in the housing space R of the compressor 230. The stop control of the compressor 230 by the control unit 280 will be described below.

(Stop control of compressor 230)

The control unit 280 receives an instruction to stop the content of the heat pump unit 200, that is, when receiving an instruction to stop the compression operation of the heat medium by the compressor 230, that is, gradually reducing the opening degree of the expansion valve 260 so that The height of the liquid surface LH of the lubricating oil accommodated in the accommodating space R of the compressor 230 does not become a threshold value that is not set in advance in the compressor 230. In other words, the control unit 280 gradually reduces the opening degree of the expansion valve 260 so that the height of the liquid surface LH of the lubricating oil accommodated in the accommodating space R is maintained at a value set in advance of the threshold value of the compressor 230 or more. The threshold value preset to the compressor 230 is the height of the liquid level of the lubricating oil required for lubrication between the connection portion of the piston 232 and the drive shaft 234, or the outer circumferential surface of the piston 232 and the inner circumferential surface of the compression chamber 236, and the like. Lower limit. Therefore, by maintaining the height of the liquid surface LH of the lubricating oil at a value equal to or higher than the above threshold value, the compressor can be maintained. Appropriate lubrication of the constituent members of 230. Further, the instruction to stop the content of the heat pump unit 200 may be input to the control unit 280 via an input device or the like, or may be received from another control device or the like.

The control unit 280 reduces the opening degree of the expansion valve 260 so that the height of the liquid surface LH of the lubricating oil accommodated in the accommodating space R of the compressor 230 does not become a threshold value set in advance to the compressor 230. Hereinafter, for example, the following four means can be mentioned.

(Adjustment of opening degree of expansion valve 260 by control unit 280 1)

The control unit 280 maintains the opening degree of the expansion valve 260 so that the rate of change of the opening degree of the expansion valve 260 is maintained at a predetermined first value, so that the height of the liquid surface LH of the lubricating oil accommodated in the accommodating space R is not Will become the threshold. In the case where the opening degree when the expansion valve 260 is fully opened is set to 100%, the first value is, for example, 3%/min.

(Adjustment of opening degree of expansion valve 260 by control unit 280 2)

The control unit 280 reduces the opening degree of the expansion valve 260 so that the pressure reduction rate of the accommodating space R measured by the pressure measuring unit 270 is maintained at a predetermined second value, so that the lubrication accommodated in the accommodating space R is maintained. The height of the oil level LH does not become a threshold. The second value is, for example, a slow speed of 10% or less of the pressure of the compressor 230 during normal operation. Therefore, when the pressure during normal operation of the compressor 230 is, for example, 500 kPa, the second value becomes 50 kPa/min.

(Adjustment of opening degree of expansion valve 260 by control unit 280 3)

The compressor 230 is provided with a liquid level gauge, and the control unit 280 reduces the opening degree of the expansion valve 260 so that the height of the liquid surface LH of the lubricating oil accommodated in the housing space R of the compressor 230 does not reach the predetermined level. Set to the threshold of the compressor 230. For the liquid level meter, for example, an existing technique such as an optical sensor or an image processing device can be used.

(Adjustment of opening degree of expansion valve 260 by control unit 280 4)

The compressor 230 is provided with means for measuring the amount of bubbles (the amount of bubbles caused by the foaming of the heat medium), and the control unit 280 reduces the opening degree of the expansion valve 260 so as to be generated in the housing space R of the compressor 230. The bubbles do not become more than a predetermined amount. The predetermined amount is an upper limit value of the amount of bubbles of lubrication (lubrication using lubricating oil) between the connection portion between the piston 232 and the drive shaft 234, or the outer circumferential surface of the piston 232 and the inner circumferential surface of the compression chamber 236. The apparatus for measuring the amount of bubbles is, for example, an existing technique such as a void rate meter, an optical sensor, an image processing apparatus, or the like.

According to the values explained in the opening degree adjustments 1 to 4 described above, by reducing the opening degree of the expansion valve 260, the liquid level LH of the lubricating oil accommodated in the housing space R of the compressor 230 can be made. The height does not become a threshold that is not set in advance to the compressor 230. Further, as described above, as long as the amount of foaming (gasification amount) of the heat medium increases, the liquid level LH of the lubricating oil decreases, so there is a correlation between the two. Therefore, the amount of foaming of the heat medium can be maintained by maintaining the height of the liquid surface LH of the lubricating oil accommodated in the accommodating space R at a value equal to or greater than a predetermined threshold value. The amount of foaming per unit time is suppressed to a certain value or less, so that rapid foaming of the heat medium can be prevented.

Therefore, before the driving of the compressor 230 is stopped, the pressure can be gradually lowered in the accommodating space R, and the foaming of the heat medium dissolved in the lubricating oil can be suppressed. Therefore, it is possible to avoid a situation in which the viscosity of the lubricating oil is lowered, and the oil film of the lubricating oil can be sufficiently formed in the sliding member such as the piston 232, the drive shaft 234, and the compression chamber 236. Thereby, it is possible to avoid the wear of the sliding member and cause damage to the compressor 230.

The control unit 280 closes the expansion valve 260 and blocks the flow of the heat medium into the compressor 230 through the expansion valve 260. The pressure of the accommodating space R measured by the pressure measuring unit 270 becomes the heat medium contained in the lubricating oil. The compression operation of the heat medium by the compressor 230 is maintained before the pressure corresponding to the predetermined concentration (hereinafter referred to as "corresponding pressure"). Further, the corresponding pressure system is, for example, 40 kPa (Abs).

In this manner, since the control unit 280 stops the driving of the compressor 230 after the expansion valve 260 is completely closed, it is possible to prevent the state in which the heat medium in the liquid state remains in the evaporator 220. As a result, when the control unit 280 starts the operation of the heat pump unit 200 next time, the liquid medium in the liquid state is not introduced into the compressor 230, so that the damage of the compressor 230 can be prevented.

Further, after the expansion valve 260 is completely closed, the control unit 280 maintains (continues) the heat medium by the compressor 230 before the pressure of the housing space R measured by the pressure measuring unit 270 becomes the corresponding pressure. The compression action allows the heat medium dissolved in the lubricating oil to be vaporized. Therefore, the heat medium can be removed from the lubricating oil and started next time. When the heat pump unit 200 is operated, foaming of the heat medium in the lubricating oil can be suppressed, and the lowering of the liquid surface LH of the lubricating oil can be suppressed.

(How to operate the heat pump unit 200)

Next, the operation method of the heat pump unit 200, particularly the stopping method, will be described. Fig. 3 is a flow chart for explaining the processing flow of the operation method of the heat pump unit 200. In addition, the stop control of the heat pump unit 200 is performed when the heat pump unit 200 is in operation.

The control unit 280 receives an instruction to stop the content of the compression operation of the heat medium by the compressor 230 in accordance with the operation input of the operator (YES in step S410), that is, gradually reduces the expansion valve 260. The opening degree is such that the height of the liquid surface LH of the lubricating oil accommodated in the accommodating space R of the compressor 230 does not reach the threshold value A set in advance in the compressor 230 (step S412).

Next, the control unit 280 determines whether or not the expansion valve 260 has all been closed (step S414), and if not all of them are closed (NO in step S414), the processing of step S412 is continued. Further, step S414 is performed again.

On the other hand, when the expansion valve 260 is all closed (YES in step S414), the control unit 280 determines whether the pressure of the housing space R of the compressor 230 measured by the pressure measuring unit 270 has not reached the corresponding pressure (steps). S416). When the pressure of the accommodating space R has not reached the corresponding pressure (NO in step S416), the control unit 280 maintains the driving of the compressor 230 and executes step S416 again. control When the pressure of the accommodating space R becomes the corresponding pressure (YES in step S416), the portion 280 stops the driving of the compressor 230 (step S418).

As described above, according to the operation method of the heat pump unit 200 and the heat pump unit 200 of the present embodiment, when the compressor 230 is to be stopped, the foaming of the heat medium contained in the lubricating oil can be suppressed, and the compressor 230 can be prevented. damage.

Although the preferred embodiments of the present invention have been described above with reference to the drawings, the present invention is not limited to the embodiments. As long as the company is within the scope of the patent application, various modifications and modifications can be made without departing from the scope of the invention, and such modifications and modifications are of course also within the technical scope of the invention.

For example, in the above-described embodiment, the heat pump unit 200 constituting the vacuum cleaning device 100 has been described as an example, but the device in which the heat pump unit 200 is mounted is not limited. For example, even in a heat pump unit mounted in various electric appliances such as a refrigerator, a freezer, an air conditioner, or a hot water supply device, there is a case where the heat medium is dissolved in the lubricating oil of the compressor. Therefore, the operation method of the heat pump unit 200 and the heat pump unit 200 of the present invention can be applied to the above-described electric equipment and the like.

Further, in the above-described embodiment, the control unit 280 has been described as being configured to maintain the pressure of the accommodating space R measured by the pressure measuring unit 270 before the corresponding pressure is reached after the expansion valve 260 is completely closed. The compression operation of the heat medium by the compressor 230. However, it is also possible to maintain the heat by the compressor 230 after the expansion valve 260 is fully closed until the expected time that the corresponding pressure is not reached. Media compression action. This time can also be set in advance by experiments or the like.

Further, in the above-described embodiment, the configuration in which the heat pump unit 200 includes the intermediate heat exchanger 250 has been described. However, the intermediate heat exchanger 250 may not be provided. Even when the intermediate heat exchanger 250 is not provided, when the compressor 230 is to be stopped, the foaming of the heat medium contained in the lubricating oil can be suppressed, and the damage of the compressor 230 can be prevented.

Further, in the above-described embodiment, the vacuum cleaning device that performs the cleaning by the condensing cleaning agent supplied from the rinsing unit 110 and the cleaning by the steam supplied from the steam supply unit 130 is performed in the cleaning chamber 102. 100 has been explained. However, for example, an impregnation chamber may be provided in advance under the cleaning chamber 102 in the vacuum vessel 104, and the workpiece W may be immersed in the impregnation chamber to clean the workpiece W.

Specifically, in the impregnation chamber, a hydrocarbon-based cleaning agent (liquid) in an amount sufficient for the workpiece W to be completely impregnated is stored, and a heater for heating the hydrocarbon-based cleaning agent is provided. Further, an intermediate door is provided between the cleaning chamber 102 and the impregnation chamber, and the cleaning chamber 102 is connected to the impregnation chamber by the intermediate door, or is configured to be disconnected. Further, the hydrocarbon cleaning agent stored in the impregnation chamber is either a condensing cleaning agent supplied from the rinsing unit 110 or a condensing cleaning agent supplied from the cleaning agent storage unit 124 via the condensing cleaning agent supply pipe 126 or Both. Further, in this case, the lifting device is provided in advance on the placing portion 108, and the placing portion 108 is configured to be movable in the vertical direction. Therefore, the lifting device is driven in a state where the intermediate door is opened to communicate the cleaning chamber 102 with the impregnation chamber, whereby the workpiece W is moved from the cleaning chamber 102 to the impregnation chamber, or the workpiece W is moved from the impregnation chamber. The cleaning to the cleaning chamber 102 is performed to clean the workpiece W.

Further, the respective steps of the operation method of the heat pump unit of the present specification are not necessarily processed in time series in accordance with the order of the flowchart, and may include processing by a parallel or subroutine.

[Industrial availability]

The invention can be utilized in the operation of a heat pump unit and a heat pump unit.

100‧‧‧Vacuum cleaning device

102‧‧‧cleaning room

104‧‧‧Vacuum container

108‧‧‧Loading Department

110‧‧‧ rinse department

114‧‧‧Vapor supply pipe

120‧‧Condensing room

122‧‧‧Condensation cleaning agent supply pipe

124‧‧‧Cleans Storage Department

126‧‧‧Condensation cleaning agent supply pipe

128‧‧‧Use end cleaning agent introduction tube

130‧‧‧Vapor Supply Department

150‧‧ ‧ vapor room

152‧‧‧heater

200‧‧‧ heat pump unit

210‧‧‧Circular path

210a to 210f‧‧‧ cycle path

220‧‧‧Evaporator

230‧‧‧Compressor

240‧‧‧Condenser

250‧‧‧Intermediate heat exchanger

260‧‧‧Expansion valve

270‧‧‧ Pressure Measurement Department

280‧‧‧Control Department

W‧‧‧Workpiece

Claims (7)

A heat pump unit includes: a circulation path for circulating a heat medium; and a compressor having a compression mechanism and a receiving space for accommodating the lubricating oil supplied to the compression mechanism, and the heat medium circulating in the circulation path is Adiabatic compression to increase the temperature; a condenser disposed downstream of the compressor in the circulation path, cooling the heat medium heated by the compressor to condense the heat medium; and an expansion valve disposed in the circulation path Downstream of the condenser, the heat medium condensed by the condenser is decompressed and expanded for cooling; the evaporator is disposed downstream of the expansion valve in the circulation path, and the heat medium cooled by the expansion valve is used. The heating medium vaporizes the heat medium; and the control unit controls the driving of the compressor and the opening degree of the expansion valve to control the circulation amount of the heat medium in the circulation path; the control unit is configured to receive When the instruction of the content of the compression operation of the heat medium by the compressor is stopped, the opening degree of the expansion valve is reduced to be accommodated in the receiving The height of the liquid surface of the lubricating oil in the space is maintained at a value set in advance of the threshold value of the compressor, and is stopped after all the expansion valves are closed to block the flow of the heat medium into the compressor through the expansion valve. By the aforementioned compressor The compression action of the aforementioned heat medium. The heat pump unit according to claim 1, wherein the control unit is configured to maintain a speed of change of an opening degree of the expansion valve at a predetermined level by reducing an opening degree of the expansion valve The value of 1 is such that the height of the liquid surface of the lubricating oil accommodated in the accommodating space is maintained at a value equal to or higher than the above threshold value. The heat pump unit according to claim 1, wherein the control unit is configured to maintain a decrease rate of a pressure of the accommodating space by a predetermined second by reducing an opening degree of the expansion valve The value is such that the height of the liquid surface of the lubricating oil accommodated in the accommodating space is maintained at a value equal to or higher than the threshold value. The heat pump unit according to claim 1, wherein the control unit is configured to continue the compression operation of the heat medium by the compressor until the expansion valve is completely closed. The pressure in the space is less than a predetermined pressure of the predetermined concentration of the heat medium contained in the lubricating oil, and the pressure in the accommodating space becomes lower than a predetermined pressure of the predetermined concentration of the heat medium contained in the lubricating oil. At this time, the compression operation of the heat medium by the compressor is stopped. The heat pump unit according to claim 2, wherein the control unit is configured to continue the compression operation of the heat medium by the compressor until the expansion valve is completely closed. The pressure of the space becomes less than the pressure corresponding to the predetermined concentration of the heat medium contained in the lubricating oil, and the accommodating space When the pressure is less than a predetermined pressure corresponding to the predetermined concentration of the heat medium contained in the lubricating oil, the compression operation of the heat medium by the compressor is stopped. The heat pump unit according to claim 3, wherein the control unit is configured to continue the compression operation of the heat medium by the compressor until the expansion valve is completely closed. The pressure in the space is less than a predetermined pressure of the predetermined concentration of the heat medium contained in the lubricating oil, and the pressure in the accommodating space becomes lower than a predetermined pressure of the predetermined concentration of the heat medium contained in the lubricating oil. At this time, the compression operation of the heat medium by the compressor is stopped. A method for operating a heat pump unit, comprising: a circulation path for circulating a heat medium; and a compressor having a compression mechanism and a receiving space for accommodating the lubricating oil supplied to the compression mechanism, and circulating in the cycle The heat medium of the path is adiabatically compressed to raise the temperature; the condenser is disposed downstream of the compressor in the circulation path, and the heat medium heated by the compressor is cooled to condense the heat medium; the expansion valve is Downstream of the condenser in the circulation path, a heat medium condensed through the condenser is decompressed and expanded for cooling; and an evaporator is disposed downstream of the expansion valve in the circulation path. The heat medium cooled by the expansion valve is heated to make the heat medium In the operation method, when an instruction to stop the compression operation of the heat medium by the compressor is received, the opening degree of the expansion valve is reduced to allow the lubricating oil accommodated in the accommodating space The height of the liquid surface is maintained at a value set in advance of the threshold value of the compressor, and after the expansion valve is completely closed to block the flow of the heat medium into the compressor through the expansion valve, the compression is stopped. The compression operation of the aforementioned heat medium by the machine.