JPH07259749A - Solution pump for absorption type heat pump - Google Patents

Abstract

PURPOSE:To provide a highly efficient and compact solution pump to ensure sealing ability against liquid having high corrosion properties, in a pump type and a drive type used for conveyance of the working solution of an absorption type heat pump. CONSTITUTION:1 is taken as a DC brushless motor and a stator is separated in an airtight state from a rotor 4 by a liner 3 inserted in a stator 2. A volume type pump part 5 is integrally constituted in front of a body 6. The volume type pump part 5 is a trochoid type pump driven by a main shaft 7 pressed in the rotor 4 and formed in such a manner that boosting is effected in two stages. The main member of the volume type pump part 5 is pressed in a cavity 6a formed in front of the body 6 and the volume type pump part 5 is formed in lamination structure. Since the pump part 5 is driven by a DC motor, the number of revolutions is controlled with sharply high controllability, whereby a circulation amount of a pump is reliably controlled.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pump system and a drive system of a solution pump used for transporting a working solution of an absorption heat pump.

[0002]

2. Description of the Related Art As a conventional absorption pump, particularly a solution pump used in a heat pump using an aqueous ammonia solution as a working medium, a hydraulic pump driven diaphragm pump has been generally used. The structure of this type of pump is a piston type hydraulic pump that can ensure high pump efficiency by using high-viscosity hydraulic oil, and a diaphragm type low viscosity fluid pump that is entirely driven by the hydraulic pressure generated by this hydraulic pump. Consists of. This is a method in which the medium such as ammonia and the pump mechanism are separated from each other by the diaphragm because the refrigerant such as ammonia has low viscosity and is highly corrosive, and the pump efficiency and the pump reliability are secured.

There is also a displacement type pump driven by a can seal type motor which does not have a fear of fluid leakage to the outside without adopting the indirect pump driving system. This method aims at downsizing of the pump section and uses a general AC motor as a drive source.

[0004]

However, in the above-mentioned conventional structure, when a hydraulic pump drive type diaphragm pump is used, two types of pumps are required, which is a drawback in terms of downsizing of equipment and cost. . Further, the absorption type system in which this type of pump is used is a pump having a diaphragm and hydraulic oil, which is required to be regularly maintained for commercial use, and which requires regular maintenance.

Instead of this conventional diaphragm pump,
Among rotary rotary pumps that are direct drive pumps, there is a canned motor pump type in which the positive displacement pump is driven by an ordinary AC motor and there is no fear of fluid leakage to the outside. Since the canned motor pump type has a cylindrical liner inserted inside the motor stator, the magnetic gap is widened by that amount, and since the AC motor is used, the motor efficiency is low and therefore the motor shape is large. However, there are many problems such as poor controllability due to the AC motor.

Further, heat generation of the motor has been a serious problem in reducing the size of the motor section. When natural heat is radiated without cooling the normal motor part, the shape of the motor is determined by the heat resistant temperature of the motor winding, which is a major obstacle to downsizing.

Further, in the absorption type solution pump, the degree of supercooling of the solution on the suction side of the pump may not be sufficient depending on the operating conditions, and in an extreme case, a "gas leak" state in two phases may occur. At this time, the displacement type pump has a drawback that its pumping capacity is significantly lowered and vibration and noise are increased.

The present invention solves the above-mentioned drawbacks, and an object thereof is to provide a highly efficient and compact solution pump for an absorption heat pump, which secures a sealing property against a highly corrosive liquid. Is.

[0009]

In order to achieve the above object, the technical means of the present invention comprises, as a first means, a DC brushless motor and a rotary positive displacement pump section driven by the DC brushless motor. The DC brushless motor and the positive displacement pump are integrated into a canned motor pump.

As a second means, a canned motor pump having a direct current brushless motor and an overcurrent type pump unit driven by the direct current brushless motor, wherein the direct current brushless motor and the overcurrent type pump unit are integrated, is provided. It was done.

As a third means, a direct current brushless motor, an overcurrent type pump unit driven by the direct current brushless motor, and a positive displacement pump unit connected in series with the overcurrent type pump unit are provided. The overflow type pump unit is provided in the preceding stage of the positive displacement pump unit, and the DC brushless motor, the overflow type pump unit driven by the DC brushless motor, and the overflow type pump unit, This is a configuration of a canned motor pump in which positive displacement pump units connected in series are integrated.

As a fourth means, the structure is such that the total amount of the pump discharge flow rate passes through the gap between the rotor of the DC brushless motor and the liner of the stator.

As a fifth means, the drive circuit of the DC brushless motor has a circuit for directly switching the power supply voltage and supplying it to the motor winding of the DC brushless motor.

[0014]

According to the present invention, according to the above-described structure, the direct current brushless motor and the positive displacement pump portion driven by the direct current brushless motor are provided, and these are constituted by the canned motor pump type. Even if electromagnetic loss is included, the motor efficiency of the DC motor can be secured sufficiently higher than that of the AC motor, and the pump efficiency can be set to a sufficiently high value because it is a positive displacement pump. is there. Further, in the absorption heat pump, accurately controlling the circulation amount of the binary fluid according to the heat load is an essential requirement for stabilizing the system operation, and the solution pump according to the present invention is driven by a DC motor. Therefore, the controllability is very good, and the circulation amount control of the pump can be surely performed by controlling the rotation speed.

Further, the eddy-current type pump section has a "gas trap" which may occur during actual load operation of the absorption heat pump.
It is effective for operating conditions, and can reduce pump performance and pump noise during "gas spill" operation.

By arranging the vortex type pump in the first stage and the positive displacement type pump in the second stage, pressurization is generated in the first stage vortex type pump and It is also possible to secure the degree of supercooling on the suction side and maintain the pump efficiency.

Further, since the total circulating flow rate of the pump is passed through the gap between the rotor of the DC brushless motor and the liner inserted in the stator, the heat transfer coefficient of the surface of the liner inserted in the stator is extremely high. Therefore, the temperature of the motor winding can be suppressed to almost the same as the temperature of the fluid passing through. Furthermore, the drive circuit of the DC brushless motor is configured to convert the power supply voltage to DC as it is, and switch this with the motor drive circuit to supply it to the motor winding. A switching power supply for converting to a low voltage for voltage adjustment is not required, and the drive circuit of the DC brushless motor can be configured compactly and at low cost.

[0018]

Embodiments of the present invention will be described with reference to the drawings. 1 to 7, reference numeral 1 denotes a DC brushless motor, which is a liner 3 inserted inside a stator 2 and a rotor 4
And hermetically separated. The positive displacement pump unit 5 is integrally formed in front of the body 6. The positive displacement pump unit 5 is a trochoid type pump driven by a main shaft 7 press-fitted into the rotor 4, and has a structure for boosting pressure in two stages. The main members of the positive displacement pump unit 5 are press-fitted into a cavity 6a provided in front of the body 6, and the positive displacement pump unit 5 has a laminated structure.
Make up. The side plate A8 is located at the bottom of the main components of the stacked pumps, and the bearing 8a is located at the center.
Has a bearing function of the main shaft 7 of the DC brushless motor 1. The eccentric ring A is stacked on the side plate A8.
It is 9. The eccentric ring A9 rotatably holds the trochoidal outer gear A10 while maintaining an appropriate eccentricity with the inner gear A11. Further, the eccentric ring A9 has a function of holding the clearance in the thickness direction of the outer gear A10 and the inner gear A11 at an appropriate value.
The main shaft 7 and the inner gear A11 are fixed by a D cut 7a. On the side plate A8 side of the intermediate spacer 12, there is a notch 14 which communicates with the suction port 13 of the pump, which also communicates with the suction groove 15 provided in the intermediate spacer 12, and the discharge groove 16 has a discharge hole 17. There is. The eccentric ring B18 is further stacked on the intermediate spacer 12, and the eccentric direction of the eccentric ring B18 is eccentric rings A9 and 1
It is set in the direction reversed by 80 degrees. Intermediate spacer 12
The surface of the intermediate spacer 12 on the side of the eccentric ring B18 is also provided with the suction groove 19 and the discharge groove 20 similar to those on the side of the eccentric ring A9 of the intermediate spacer 12, but the angles are set at positions shifted by 180 degrees.
Discharge groove 1 provided on the eccentric ring A9 side of the intermediate spacer 12
The discharge hole 17 of No. 6 communicates with the suction groove 19 provided on the surface on the eccentric ring B18 side. The eccentric ring B21 rotatably holds the trochoidal outer gear B22 and the inner gear B23 while maintaining an appropriate eccentric amount, and the eccentric ring B18 holds the outer gear B22 and the inner gear B23.
It has a function of keeping the clearance in the thickness direction of 23 at an appropriate value. The main shaft 7 and the inner gear B23 are fixed by a D cut 7a. Further, side plates B24 are stacked on the eccentric ring B18. The side plate B24 is provided with a discharge port 2 at a position corresponding to the discharge groove 20 of the intermediate spacer 12.
5 are provided. The main members of the pump are laminated in this way to form the main part of the pump. A cavity 6 a provided in front of the body 6 is closed by a pump lid 26.
The body 6 is provided with a flow path A27, and the side plate B2
The solution discharged from the discharge port 25 of No. 4 has a flow path A27.
Through a gap between the liner 3 inserted inside the stator 2 and the rotor 4, and further, a flow passage B30 provided in a bearing sleeve 29 for fixing a bearing 28 rotatably supporting the rotor 4 is provided. After passing, it reaches the discharge port 31 and flows out to the system system. The DC brushless motor 1 is driven by directly rectifying a single-phase AC 100V, which is a commercial power source, with a rectifier 32 and performing a switching operation with the transistors 33 to 38.

The operation of the above configuration will be described. When the rotor 4 of the DC brushless motor 1 rotates, the main shaft 7 press-fitted into the rotor 4 rotates. When the main shaft 7 rotates, the inner gear A11 and the inner gear B fixed to the main shaft 7
23 rotates, and the outer gear A10 and the outer gear B22 which mesh with these gears respectively rotate as driven gears and perform pumping operation as a trochoid pump. The pump operation is performed in two stages in series, and the boosting action is divided into the first stage in which the inner gear A11 and the outer gear A10 perform the pump action and the second stage in which the inner gear B23 and the outer gear B22 perform the pump action. To be done. Also, the side plate B
The fluid discharged from the discharge port 25 of the channel 24 has a flow path A2.
7, a passage B30 provided in a bearing sleeve 29 for fixing a bearing 28 that rotatably supports the rotor 4, passing through a gap between the liner 3 inserted inside the stator 2 and the rotor 4. Liner 3 inserted into the inside of the stator 2 through the discharge port 31 and outflow to the system system.
In the gap between the rotor 4 and the rotor 4, the flow passage area is narrow and the flow becomes faster, and the flow passing through the gap between the liner 3 and the rotor 4 due to the swirling flow due to the rotation of the rotor 4 is a flow of good heat transfer. Become. Further, the DC brushless motor 1 is driven by directly rectifying a single-phase AC100V, which is a commercial power source, with a rectifier 32 and applying a signal to the bases of the transistors 33 to 38 with a microcomputer (not shown) to perform a switching operation. Is going on.

According to the above-described structure, first, the DC brushless motor 1 and the positive displacement pump section driven by the DC brushless motor 1 are provided. Since these are of the canned motor pump type, the electromagnetic waves generated in the canned section are generated. The motor efficiency of the DC motor can be ensured to be sufficiently higher than that of the AC motor even if the power loss is included. Further, since the pump efficiency is a positive displacement pump, it can be set to a sufficiently high value. In addition, the gap between the rotor of the DC brushless motor and the liner inserted in the stator is usually set to a very small value of about 0.5 mm in order to secure motor efficiency. Since the pressure loss at the time of passage is too large, a fluid is not made to flow through this portion, or measures such as bypassing are taken, and the cooling effect is not so great. Since the solution pump used for the absorption heat pump has a low pump pressure difference of 20 kg / cm ² and a high flow rate of about 1 l / min, the total flow rate of the pump should be inserted into the rotor and stator of the motor. There is no problem even if it passes through the gap of a certain liner, but rather the heat transfer coefficient of the surface of the liner inserted in the stator becomes very high because the fluid passes at a high speed, and the fluid that almost passes the motor winding temperature. It can be suppressed to about the same temperature.
Further, in the absorption heat pump, accurately controlling the circulation amount of the binary fluid according to the heat load is an essential requirement for stabilizing the system operation, and the solution pump according to the present invention is a DC brushless motor. Since it is driven by, the controllability is very good, and it is possible to reliably control the circulation amount of the pump by controlling the rotation speed. In addition, the DC motor has higher motor efficiency in a state where the output is reduced compared to the AC motor controlled by an inverter, which reduces the power consumption when the room temperature shifts to a steady state, which is often used as a heat pump. Is effective on.

Next, another embodiment of the present invention will be described with reference to FIGS.
Will be explained. In this embodiment, the pump portion of the previous embodiment is a vortex type pump instead of the positive displacement pump, the same components are designated by the same reference numerals, and the description of the same components will be omitted. The vortex type pump unit 40 includes the rotor 4
It is a vortex flow type pump driven by a main shaft 7 press-fitted in, and has a structure for boosting pressure in two stages. The main member of the vortex type pump unit 40 is the cavity 6 provided in front of the body 6.
It is press-fitted into a to form the vortex type pump unit 40 having a laminated structure. Reference numeral 41 denotes an eccentric cam A, which has a function of forming a pressurizing flow path A43 while maintaining a constant distance from the outer circumference of the blade A42. Reference numeral 44 denotes an eccentric cam B, which has a function of maintaining a constant distance from the outer circumference of the blade B45 and forming a pressurizing flow path B46.

The operation of the above configuration will be described. When the rotor 4 of the DC brushless motor 1 rotates, the main shaft 7 press-fitted into the rotor 4 rotates. When the main shaft 7 rotates, the blade A42 fixed to the main shaft 7 rotates, and the pressurizing flow path A43
The first-stage pressure increase is performed, and the blade B45 also rotates at the same time, and the second-stage pressure increase is performed in the pressurizing flow path B46.

With the above-described structure, since the vortex type pump unit 40, which is strong against gas entrapment operation, is used in the pump unit, a two-phase flow is generated near the suction port of the pump which is generated in the absorption type system operation. It is possible to continue stable pump operation.

Next, another embodiment of the present invention will be described with reference to FIGS.
Will be explained. In this embodiment, the pump portion of the previous embodiment is a vortex type pump in the first stage and a positive displacement type pump in the second stage, and the same components are designated by the same numbers.
Description of the same components will be omitted.

The composite type pump unit 50 is a composite type pump driven by the main shaft 7 press-fitted into the rotor 4, and has a structure for boosting pressure in two stages. The main members of the composite pump unit 50 are press-fitted into the cavity 6a provided in front of the body 6 to form the composite pump unit 50 with a laminated structure. 1
The stage pump is a vortex type pump, and 51 is an eccentric cam A, which has a function of maintaining a constant distance from the outer circumference of the blade A52 and forming a pressurizing flow path A53. The second-stage pump is a positive displacement pump, and the eccentric ring B54 rotatably holds the trochoidal outer gear B55 with the inner gear B56 while maintaining an appropriate amount of eccentricity, and the eccentric ring B54 is the outer gear B55. And a function of holding the clearance in the thickness direction of the inner gear B56 at an appropriate value. The main shaft 7 and the inner gear B56 are fixed by a D cut 7a.

The operation of the above configuration will be described. When the rotor 4 of the DC brushless motor 1 rotates, the main shaft 7 press-fitted into the rotor 4 rotates. When the main shaft 7 rotates, the blade A52 fixed to the main shaft 7 rotates, and the pressurizing flow path A53
, The first step-up pressure is applied, and then the inner gear B56 also rotates and the outer gear B55 on the driven side rotates.
The boosting of the step is performed.

With the above-mentioned structure, the first stage of the pump section employs the vortex type pump which is strong against gas entrainment, and the vortex type pump pressurizes the vortex type pump to flow into the second stage positive displacement type pump. Even if a two-phase flow is generated near the suction port of the pump, which occurs during system operation, stable pump operation can be continued, and pump efficiency can be ensured with the positive displacement pump section, so highly efficient and stable pump operation Is possible.

[0028]

As described above, according to the solution pump for absorption heat pump of the present invention, the following effects can be obtained.

(1) A DC brushless motor and a positive displacement pump section driven by the DC brushless motor,
Because these are canned motor pump type,
The sealing performance and pump efficiency can be realized at a high level. Further, since it is driven by a DC brushless motor, the controllability is very good, and by controlling the number of revolutions, it is possible to reliably control the circulation amount of the pump.

(2) The vortex type pump section is effective against the gas squeezing operation state which may occur during the actual load operation of the absorption heat pump, and the pumping capacity is deteriorated during the gas squeezing operation. The generation of pump noise can be suppressed.

(3) Since the first stage of the pump section employs a vortex flow type pump that is strong against gas entrainment operation, and the vortex flow type pump is used to pressurize the vortex flow type pump to flow into the second stage positive displacement type pump, an absorption type system Even if a two-phase flow occurs near the suction port of the pump that occurs during operation, stable pump operation can be continued, and pump efficiency can be secured with the positive displacement pump section, so highly efficient and stable pump operation is possible. Is.

(4) Since the entire circulating flow rate of the pump is passed through the gap between the rotor of the DC brushless motor and the liner inserted in the stator, the heat transfer coefficient of the surface of the liner inserted in the stator Is very high, the motor winding can be effectively cooled, and it is effective in downsizing the motor section.

(5) The drive circuit of the DC brushless motor has a structure in which the power supply voltage is directly converted to DC, which is switched by the motor drive circuit and supplied to the motor winding. It is used in a normal DC brushless motor. The switching power supply for converting the power supply voltage into a low voltage is not required, and the drive circuit of the DC brushless motor can be made compact and low cost.

[Brief description of drawings]

FIG. 1 is a schematic sectional view of a solution pump for an absorption heat pump according to a first embodiment of the present invention.

FIG. 2 is a sectional view of an essential part of the first stage of the solution pump.

FIG. 3 is a sectional view of the intermediate spacer.

FIG. 4 is a plan view of a side plate A side end surface of the intermediate spacer.

FIG. 5 is a plan view of an end surface of the intermediate spacer on the side plate B side.

FIG. 6 is a sectional view of a main part of a second stage of the solution pump.

FIG. 7 is a plan view of a partial main part of the solution pump with the pump lid removed.

FIG. 8 is a plan view of a coaxial receiver and a sleeve.

FIG. 9 is a drive circuit diagram of the same DC brushless motor.

FIG. 10 is a schematic sectional view of a solution pump for an absorption heat pump according to a second embodiment of the present invention.

FIG. 11 is a sectional view of the main part of the first stage of the solution pump.

FIG. 12 is a sectional view of a main part of a second stage of the solution pump.

FIG. 13 is a schematic sectional view of a solution pump for an absorption heat pump according to a third embodiment of the present invention.

FIG. 14 is a sectional view of the main part of the first stage of the solution pump.

FIG. 15 is a sectional view of an essential part of a second stage of the solution pump.

[Explanation of symbols]

 1 DC brushless motor 2 Stator 3 Runner 4 Rotor 5 Positive displacement pump unit 40 Eddy current type pump unit

Front page continued (72) Inventor Masaru Ito 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Takahito Ishii 1006 Kadoma, Kadoma City, Osaka Matsushita Electric Industrial Co., Ltd. Person Yasuhiro Kawamoto 1006 Kadoma, Kadoma-shi, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (5)

[Claims] 1. A direct current brushless motor and a rotary positive displacement pump section driven by the direct current brushless motor,
A solution pump for an absorption heat pump, wherein the DC brushless motor and the positive displacement pump section are integrated into a canned motor pump. 2. An absorption heat pump having a direct current brushless motor and an eddy current type pump portion driven by the direct current brushless motor, wherein the direct current brushless motor and the eddy current type pump portion are integrated into a canned motor pump. Solution pump. 3. A vortex type pump having a DC brushless motor, a vortex type pump section driven by the dc brushless motor, and a positive displacement type pump section connected in series with the vortex type pump section. A part is provided in the preceding stage of the positive displacement pump part, and the direct current brushless motor, the swirl type pump part driven by the direct current brushless motor, and a positive displacement type pump part connected in series with the swirl type pump part. Solution pump for absorption heat pumps, which has a structure of a canned motor pump with an integrated pump part. 4. The solution pump for an absorption heat pump according to claim 1, 2 or 3, wherein the entire amount of the pump discharge flow rate passes through the gap between the rotor of the DC brushless motor and the liner of the stator. 5. The absorption heat pump solution according to claim 1, 2 or 3, wherein the drive circuit of the DC brushless motor has a circuit for directly switching the power supply voltage and supplying it to the motor winding of the DC brushless motor. pump.