JP2003207225A - Heat pump device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To properly switch a load-corresponded operation by two heat sources, the load-corresponded operation only by a first heat source, and the load- corresponded operation only by a second heat source to secure high efficiency of the device. <P>SOLUTION: The load-corresponded operation by two heat sources are executed only under a condition that the difference Δt between a temperature t1 of the first heat source heat medium A and a temperature t2 of a second heat source heat medium L is less than a set temperature difference Z1 (or Z2), under a condition that the temperature t1 of the first heat source heating medium A is more than a first set threshold temperature X, and the temperature t2 of the second heat source heat medium L is more than a second threshold temperature Y, and the load-corresponded operation only by the first heat source, or the load-corresponded operation only by the second heat source is executed when the difference Δt is more than the set temperature difference Z1 (or Z2). <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat pump device, and more specifically, a load heat exchanger for exchanging heat between a refrigerant and a load heat medium, and a first heat source heat exchanger for exchanging heat between a refrigerant and a first heat source heat medium. , A second heat source heat exchanger for exchanging heat between the refrigerant and the second heat source heat medium is provided, and the first and second heat source heat exchangers are connected to the first and second heat source heat exchangers in a state of passing the refrigerant in series. A load-compatible operation in which two heat sources are used in combination, where the load heat exchanger functions as a condenser to heat the load heat medium while functioning as an evaporator and collecting heat from both the first and second heat source heat media, and a second heat source With the heat exchanger stopped, the first heat source heat exchanger functions as an evaporator to collect heat from the first heat source heat medium, while the load heat exchanger functions as a condenser to heat the load heat medium. Load-only operation of the first heat source and the first heat source heat exchanger In the stopped state, the second heat source heat exchanger alone functions as an evaporator to collect heat from the second heat source heat medium, while the load heat exchanger functions as a condenser to heat the load heat medium alone. Of the first heat source and the second heat source, and the load corresponding operation of the first heat source alone and the load compatible operation of the second heat source alone are switched. The present invention relates to a heat pump device provided with a control means that automatically performs the heating medium in accordance with the temperature of each heat medium.

[0002]

2. Description of the Related Art Conventionally, in this type of heat pump device,
The temperature of the first heat source heat medium when a predetermined lower limit amount of heat can be extracted from the first heat source heat medium in the first heat source heat exchanger in the situation where the first heat source heat exchanger is independently functioning as an evaporator The first set threshold temperature is set, and similarly, in the second heat source heat exchanger, a predetermined lower limit amount of heat is extracted from the second heat source heat medium in the situation where the second heat source heat exchanger is independently functioning as an evaporator. The temperature of the second heat source heat medium when possible is set to the second set threshold temperature, and the control means is simply set to the following (A) to (C).
For each condition of t1 ≧ X and t2 ≧ Y (A) t1 ≧ X and t2 <Y (B) t1 <X and t2 ≧ Y (C) where t1: First heat source heat medium temperature t2: Second heat source heat medium temperature X: First set threshold temperature Y: Second set threshold temperature When the first and second heat source heat mediums are in the condition (A), both heat sources are used together When the first and second heat source heat mediums are in the condition (B), the load corresponding operation of the first heat source alone is performed, and the first and second heat source heat mediums are (C). When the conditions are met, the load corresponding operation of the second heat source alone is performed.

[0003]

However, in the above-described conventional heat pump device, the temperature t1 of the first heat source heat medium is equal to or higher than the first set threshold temperature X and the temperature t2 of the second heat source heat medium.
Even under the condition of (A) above that the second set threshold temperature Y or more, the device efficiency (the amount of heat taken for the required power of the entire device in the load-corresponding operation in which two heat sources are used is performed under the condition). Ratio value of) may be lower than that when the load-corresponding operation of the first heat source alone or the load-corresponding operation of the second heat source alone is carried out under the same heat source condition. There was a problem that the energy saving effect was reduced by that much because it was limited to a low level.

In view of this situation, the main problem of the present invention is to
The above problem is effectively solved by adopting a rational switching control mode based on the research results.

[0005]

[1] The invention according to claim 1 relates to a heat pump device, which is characterized by a load heat exchanger for exchanging heat between a refrigerant and a load heat medium, and a refrigerant as a first heat source heat medium. A first heat source heat exchanger for exchanging heat with the second heat source heat exchanger for exchanging heat with the second heat source heat medium, and a refrigerant passing through the first and second heat source heat exchangers in series. While making the first and second heat source heat exchangers function as an evaporator and collecting heat from both the first and second heat source heat medium, the load heat exchanger functions as a condenser to heat the load heat medium 2
With the load-compatible operation using a heat source and the second heat source heat exchanger stopped functioning, the first heat source heat exchanger is caused to function as an evaporator and heat is taken from the first heat source heat medium while the load heat exchanger is operated. The load-corresponding operation of the first heat source alone, which functions as a condenser to heat the load heat medium, and the second heat source heat exchanger, which functions as an evaporator, with the first heat source heat exchanger stopped 2 Heat source While collecting heat from the heat medium, the load heat exchanger functions as a condenser to heat the load heat medium. In a configuration in which a control means is provided for automatically switching between the corresponding operation and the load-compatible operation of the first heat source alone and the load-compatible operation of the second heat source alone according to the temperature of each of the first and second heat source heat mediums, The control means is
For each condition of (f): t1 ≧ X and t2 ≧ Y and t1 ≧ t2 and Δt <Z1 ... (A) t1 ≧ X and t2 ≧ Y and t1 ≦ t2 and Δt <Z2 ... (B) t1 ≧ X and t2 ≧ Y and t1> t2 and Δt ≧ Z1 ... (C) t1 ≧ X and t2 ≧ Y and t1 <t2 and Δt ≧ Z2 ... (D) t1 ≧ X and t2 <Y ... (E) t1 <X and t2 ≧ Y ... (F) where, t1: temperature of first heat source heat medium t2: temperature of second heat source heat medium Δt: first heat source heat medium and first 2 Temperature difference from heat source heat medium X: First set threshold temperature Y: Second set threshold temperature Z1: First set temperature difference Z2: Second set temperature difference The first and second heat source heat mediums are (a) or ( When the condition of (b) is met, the load-corresponding operation using two heat sources together is carried out, and the first and second
When the heat source heat medium is in the condition of (c) or (e), the load corresponding operation of the first heat source alone is performed, and when the first and second heat source heat medium is in the condition of (d) or (f), The point is that the configuration is such that load-only operation of the two heat sources is performed.

That is, in the above-mentioned structure, the first set threshold temperature X is the same as in the conventional apparatus, and in the situation where the first heat source heat exchanger alone functions as an evaporator, the first heat source heat exchanger has the first heat source. The temperature of the first heat source heat medium when a predetermined lower limit amount of heat can be collected from the heat medium, and the second set threshold temperature Y
Similarly to the conventional device, in the second heat source heat exchanger in the situation where the second heat source heat exchanger is independently functioning as the evaporator, the second lower limit amount of heat can be extracted from the second heat source heat medium. Although the temperature of the heat source heat medium is used, as a result of various experiments, the first
In the case where the refrigerant is allowed to pass through the first and second heat source heat exchangers in series to cause the first and second heat source heat exchangers to function as an evaporator (that is, load compatible operation using two heat sources together),
The temperature t1 of the heat source heat medium is equal to or higher than the first set threshold temperature X (t1 ≧
X), and even if the temperature t2 of the second heat source heat medium is equal to or higher than the second set threshold temperature Y (t2 ≧ Y), the temperature t1 of the first heat source heat medium and the temperature t2 of the second heat source heat medium. When the difference Δt between the heat source heat medium and the heat source heat medium is larger than a certain value, the refrigerant evaporates only in the heat source heat exchanger having the higher temperature, and the influence of the temperature of the heat source heat medium is lower. It has been found that the heat source heat exchanger hardly vaporizes the refrigerant (in other words, takes heat from the heat source heat medium).

Due to this, the temperature t1 of the first heat source heat medium is equal to or higher than the first set threshold temperature X, and the temperature t2 of the second heat source heat medium is also equal to or higher than the second set threshold temperature Y. Despite the above, if the first heat source heat medium is higher in temperature than the second heat source heat medium, it is better to carry out the load-corresponding operation of the first heat source alone, or the second heat source heat medium is the first heat source. When the temperature is higher than that of the heating medium, performing the load-corresponding operation of the second heat source alone is more effective than performing the load-corresponding operation of the two heat sources under the same heat source condition. There is a problem that the efficiency of the device is increased by the reduction of the required power due to the stop (that is, the above-mentioned problem in the conventional device).

On the other hand, according to the above configuration, the first
The temperature t1 of the heat source heat medium is equal to or higher than the first set threshold temperature X, and
Even under the condition that the temperature t2 of the second heat source heat medium is equal to or higher than the second threshold temperature Y, the difference Δt between the temperature t1 of the first heat source heat medium and the temperature t2 of the second heat source heat medium is smaller than the set temperature differences Z1 and Z2. The load-corresponding operation using the two heat sources together is carried out only under the condition of (a) or (b), and the difference Δt is (c) or (d) above the set temperature difference Z1, Z2. As in the case of (e) or (f), the load-corresponding operation of the first heat source alone and the load-corresponding operation of the second heat source alone are carried out. It is possible to make the switching between the load-supporting operation of the first heat source alone and the load-supporting operation of the second heat source more accurate in order to ensure the device efficiency as high as possible. It is possible to effectively increase the energy saving effect. You can

In the practice of the invention according to claim 1, in the sense of correction in consideration of the difference between the refrigerant evaporation temperature in the first heat source heat exchanger and the refrigerant evaporation temperature in the second heat source heat exchanger,
The following correction values may be adopted for t1 and t2 under the above conditions (a) to (f). Correction value t1: Difference between temperature of first heat source heat medium and refrigerant evaporation temperature in first heat source heat exchanger Correction value t2: Difference between temperature of second heat source heat medium and refrigerant evaporation temperature in second heat source heat exchanger (In this case also, Δt is equal to the first heat source heat medium and the second heat source heat medium.
Temperature difference with heat source heat medium)

[2] The invention according to claim 2 specifies the preferred embodiment for carrying out the invention according to claim 1, and is characterized in that the first heat source heat medium is atmospheric air. On the other hand, in addition to the switching operation of each load corresponding operation described above, while the load heat exchanger is stopped, the second heat source heat exchanger functions as an evaporator to collect heat from the second heat source heat medium, The second heat source defrosting operation in which the first heat source heat exchanger functions as a condenser to radiate heat, and the load heat exchanger functions as an evaporator in a state in which the second heat source heat exchanger is deactivated. While taking heat from the medium, the first heat source heat exchanger is configured to be switchable to a load heat source defrosting operation in which the first heat source heat exchanger functions as a condenser to radiate heat, and the control means is configured to defrost the first heat source heat exchanger. Perform defrosting operation prior to each load operation when necessary When the temperature t2 of the second heat source heat medium is equal to or higher than the set threshold temperature Y'for defrosting, the second heat source defrosting operation is performed, and the temperature t2 of the second heat source heat medium is the set threshold temperature Y'for defrosting. When it is less than the above, the configuration is such that the load heat source defrosting operation is performed.

In other words, in this configuration, the first heat source is used in the load handling operation in which two heat sources are used in combination or the first heat source is used in the load handling operation.
The second heat source defrosting operation and the load heat source defrosting operation as the defrosting operation for removing the adhered frost generated in the heat source heat exchanger (adhered frost generated by the moisture contained in the atmospheric air as the first heat source heat medium) In the second heat source defrosting operation, the heat of the load heat medium is not collected, and only the heat of the second heat source heat medium is collected to defrost the first heat source heat exchanger. On the contrary, in the heat source defrosting operation, the first heat source heat exchanger is defrosted only by the heat collected from the second heat source heat medium.

In order to selectively carry out these two defrosting operations, as in the case of the second set threshold temperature Y, the second heat source heat exchanger is operated independently as an evaporator. The temperature of the second heat source heat medium when the predetermined lower limit amount of heat for defrosting can be collected from the second heat source heat medium in the second heat source heat exchanger is set to the defrosting set threshold temperature Y ′ (typically, 2 set threshold temperature Y) and the second as described above.
When the temperature t2 of the heat source heat medium is equal to or higher than the set threshold temperature Y'for defrosting, the second heat source defrosting operation is selectively executed, and the second heat source defrosting operation is prioritized over the load heat source defrosting operation. By adopting the selected form to be implemented, it is possible to avoid a decrease in load adaptability due to heat collection from the load heat medium as much as possible, and it is possible to obtain high load adaptability.

Further, the load heat source defrosting operation is performed when the temperature t2 of the second heat source heat medium is lower than the set threshold temperature Y'for defrosting, so that the second heat source heat medium serves as a heat collecting source. It is possible to perform defrosting of the first heat source heat exchanger even in an insufficient condition, and after the defrosting, it is possible to return to load compatible operation using both two heat sources or load compatible operation of the first heat source alone,
From this point as well, the device has excellent load adaptability.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a snow melting device using a two-source heat pump device, where Ng is a U-shaped underground heat exchanger buried vertically in the ground G, and Ny is a snow melting target such as a road surface. A heat exchanger for snow melting, HP, which is installed at a location, is a package-type two-heat-source heat pump device in which main components of the refrigerant circuit side and the heat medium side are housed in a casing.

The two heat source heat pump device HP is a main component on the refrigerant circuit side. The compressor 1 is a first heat source heat exchange 2 for exchanging heat between the refrigerant R and the outside air A (atmosphere air) as the first heat source heat medium. The second heat source heat exchanger 3 for exchanging heat between the refrigerant R and the heat source side heat medium liquid L as the second heat source heat medium, and the load heat exchanger for exchanging heat between the refrigerant R and the load side heat medium liquid M as the load heat medium. 4, a receiver 5, a refrigerant guide circuit 6 in which four check valves 6a to 6d are combined in a bridge circuit shape, an expansion valve mechanism 7, and a four-way valve Vx.

Also, this two-source heat pump device HP
Between the second heat source heat exchanger 3 and the underground heat exchanger Ng through the heat source side circulation passage 8 as a fan 2a that ventilates the outside air A to the first heat source heat exchanger 2 as main components on the heat medium side. The heat source side heat medium pump P1 for circulating the heat source side heat medium liquid L, and the load side for circulating the load side heat medium liquid M between the load heat exchanger 4 and the snow melting heat exchanger Ny through the load side circulation path 9 Heat medium pump P
Equipped with 2.

The first heat source heat exchanger 2 is a fin tube coil type dry heat exchanger that allows the refrigerant R to pass through the heat transfer tube while allowing the outside air A to pass outside the heat transfer tube.
The load heat exchanger 4 also uses a dry heat exchanger that allows the refrigerant R to pass through the heat transfer tube while allowing the load-side heat transfer medium M to pass outside the heat transfer tube, while the second heat source heat exchanger is used. 3 is a liquid-filled heat exchanger that allows the heat source side heat transfer liquid L to pass through inside the heat transfer tube while allowing the refrigerant R to pass outside the heat transfer tube.
Brine and water are used for the heat source side heat transfer medium L and the load side heat transfer medium M, respectively.

The refrigerant circuit of the two-heat-source heat pump device HP has a circuit structure in which the four-way valve Vx switches the refrigerant circulation mode between the refrigerant circulation mode for load-corresponding operation and the refrigerant circulation mode for defrosting operation. In the refrigerant circulation mode for operation, as shown in FIG. 2, the refrigerant R is supplied to the compressor 1-the four-way valve Vx-the load heat exchanger 4-the refrigerant guide circuit 6-the receiver 5-.
Expansion valve mechanism 7-Refrigerant guide circuit 6-First heat source heat exchanger 2-
The four-way valve Vx, the second heat source heat exchanger 3, and the compressor 1 are circulated in this order.

Further, in the refrigerant circulation mode for the defrosting operation, as shown in FIG. 5, the refrigerant R is supplied to the compressor 1-four-way valve Vx-first heat source heat exchanger 2-refrigerant guide circuit 6-receiver 5-expansion valve. Mechanism 7-Refrigerant guide circuit 6-Load heat exchanger 4-Four way valve Vx-
The second heat source heat exchanger 3 and the compressor 1 are circulated in this order.

S1 is an outside air temperature sensor for detecting the temperature t1 of the outside air A, S2 is a liquid temperature sensor for detecting the temperature t2 of the heat source side heat transfer medium L, and S3 is a frosted state of the first heat source heat exchanger 2. The frost sensor 10 is a controller that controls the operation of the two-source heat pump device HP. The controller 10 switches the four-way valve Vx based on the detection information of the sensors S1 to S3, and the fan 2a. , The heat source side heat medium pump P1,
Each of the following five operations is selectively switched by starting / stopping each of the load-side heat medium pumps P2.

(Load Corresponding Operation Using Two Heat Sources Together) As shown in FIG. 2, the four-way valve Vx is switched to the side in which the refrigerant circulation mode for load-corresponding operation is set, and the refrigerant R is compressed by the compressor 1-four-way valve Vx-load heat. Exchanger 4-Refrigerant guide circuit 6-Receiver 5-Expansion valve mechanism 7-Refrigerant guide circuit 6-First heat source heat exchanger 2-Four-way valve V
The x-second heat source heat exchanger 3-compressor 1 is circulated in this order, while the fan 2a, the heat source side heat medium pump P1, and the load side heat medium pump P2 are operated.

That is, in the load-corresponding operation using the two heat sources in combination, the refrigerant R is passed through the first heat source heat exchanger 2 and the second heat source heat exchanger 3 in series, and the first and second heat source heat exchangers are exchanged. The load heat exchanger 4 is caused to function as a condenser C while the load side heat transfer medium M is heated while the devices 2 and 3 function as the evaporator E to collect heat from both the outside air A and the heat source side heat transfer liquid L. (The heat is dissipated to the heating medium liquid M on the load side).

By the load-corresponding operation using both of the two heat sources, the snow melting device can collect heat from the underground G by the underground heat exchanger Ng and heat from the outside air A by the first heat source heat exchanger 3. And heat the collected heat by the heat pump device HP and then dissipate the heat from the snow-melting heat exchanger Ny to melt the snow-melting target portion.

(Load-only operation of the first heat source alone) As shown in FIG. 3, the four-way valve Vx is switched to the side in which the refrigerant circulation mode for the load-compatible operation is set, so that the refrigerant R is compressed by the compressor 1-four-way valve Vx-.
The load heat exchanger 4-refrigerant guide circuit 6-receiver 5-expansion valve mechanism 7-refrigerant guide circuit 6-first heat source heat exchanger 2-four-way valve Vx-second heat source heat exchanger 3-compressor 1 Let
On the other hand, the fan 2a and the load side heat medium pump P2 are operated in a state where the heat source side heat medium pump P1 is stopped.

That is, in the load-only operation of the first heat source alone, the second heat source heat exchanger 3 is substantially stopped by stopping the supply of the heat source side heat medium liquid L by stopping the heat source side heat medium pump P1. In this state, while allowing the first heat source heat exchanger 2 to function as the evaporator E and collecting heat from the outside air A, the load heat exchanger 4
To function as a condenser C to heat the load-side heat transfer medium M.

By the load-corresponding operation of the first heat source alone, the snow melting device only collects heat from the outside air A by the first heat source heat exchanger 2, and the collected heat is raised by the heat pump device HP. Heat exchanger for snow melting Ny
The heat is radiated from and the snow is melted in the target area.

(Load Corresponding Operation of Second Heat Source Alone) As shown in FIG. 4, the four-way valve Vx is switched to the side in which the refrigerant circulation mode for load-corresponding operation is established, so that the refrigerant R is compressed by the compressor 1-four-way valve Vx-.
The load heat exchanger 4-refrigerant guide circuit 6-receiver 5-expansion valve mechanism 7-refrigerant guide circuit 6-first heat source heat exchanger 2-four-way valve Vx-second heat source heat exchanger 3-compressor 1 Let
On the other hand, the heat source side heat medium pump P1 and the load side heat medium pump P2 are operated in a state where the operation of the fan 2a is stopped.

That is, in the load-corresponding operation of the second heat source alone, the second heat source heat exchanger 2 is substantially stopped by stopping the ventilation of the outside air by stopping the fan 2a. The load heat exchanger 4 is made to function as the condenser C and the load side heat medium M is heated while the heat exchanger 3 is made to collect heat from the heat source side heat medium liquid L while functioning as the evaporator E.

By the load-corresponding operation of the second heat source alone, the snow melting device only collects heat from the underground G by the underground heat exchanger Ng, and the collected heat is raised by the heat pump device HP. Heat is radiated from the snow-melting heat exchanger Ny to melt the snow-melting target portion.

(Second heat source defrosting operation) As shown in FIG. 5, the four-way valve Vx is switched to the side of the refrigerant circulation mode for the defrosting operation, and the refrigerant R is compressed by the compressor 1-four-way valve Vx-first heat source. The heat exchanger 2-refrigerant guide circuit 6-receiver 5-expansion valve mechanism 7-refrigerant guide circuit 6-load heat exchanger 4-four-way valve Vx-second heat source heat exchanger 3-compressor 1 are circulated in this order, and On the other hand, the heat source side heat medium pump P1 is operated while the load side heat medium pump P2 and the fan 2a are stopped.

In other words, in the second heat source defrosting operation, the load heat exchanger 4 is substantially stopped by stopping the supply of the load side heat transfer medium liquid M by stopping the load side heat transfer medium pump P2. While allowing the second heat source heat exchanger 3 to function as the evaporator E and collecting heat from the heat source side heat transfer medium L, the first heat source heat exchanger 2 functions as the condenser C to radiate heat.

By this second heat source defrosting operation, the snow melting device only collects heat from the underground G by the underground heat exchanger Ng in a state where the heat radiation from the snow melting heat exchanger Ny is stopped. The collected heat is heated by the heat pump device HP and then radiated from the first heat source heat exchanger 2 to defrost the first heat source heat exchanger 2.

(Load heat source defrosting operation) As shown in FIG. 6, the four-way valve Vx is switched to the side of the refrigerant circulation mode for the defrosting operation, and the refrigerant R is transferred to the compressor 1-four-way valve Vx-first heat source heat source. The exchanger 2 -refrigerant guide circuit 6 -receiver 5 -expansion valve mechanism 7 -refrigerant guide circuit 6 -load heat exchanger 4-four-way valve Vx -second heat source heat exchanger 3 -compressor 1 is circulated in this order, and On the other hand, the load side heat medium pump P2 is operated in a state where the heat source side heat medium pump P1 and the fan 2a are stopped.

That is, in the load heat source defrosting operation, the second heat source heat exchanger 3 is substantially stopped by stopping the supply of the heat source side heat medium liquid L by stopping the heat source side heat medium pump P1. While making the load heat exchanger 4 function as the evaporator E and collecting heat from the load side heat transfer medium M, the first heat source heat exchanger 2 functions as the condenser C to radiate heat.

By this load heat source defrosting operation, the snow melting device performs only heat extraction from the load side heat transfer medium M in a state where heat radiation from the snow melting heat exchanger Ny is stopped, and the collected heat is collected. Is heated by the heat pump device HP and then radiated from the first heat source heat exchanger 2 to defrost the first heat source heat exchanger 2.

The above five operations are switched by each sensor S.
Although automatically performed based on the detection information of 1 to S3, the controller 10 sets t1 ≧ X and t2 ≧ Y and t1 ≧ t2 and Δt for each of the following conditions (a) to (f). <Z1 ... (A) t1 ≧ X and t2 ≧ Y and t1 ≦ t2 and Δt <Z2 ... (B) t1 ≧ X and t2 ≧ Y and t1> t2 and Δt ≧ Z1 ... (C) t1 ≧ X and t2 ≧ Y and t1 <t2 and Δt ≧ Z2 ... (D) t1 ≧ X and t2 <Y ... (E) t1 <X and t2 ≧ Y ... (F) However, t1 : Outside air A detected by outside air temperature sensor S1
Temperature t2: heat source side heat transfer liquid L detected by the liquid temperature sensor S2
Temperature difference Δt: difference between t1 and t2: first set threshold temperature Y: second set threshold temperature Z1: first set temperature difference Z2: second set temperature difference outside air A and heat source side heat transfer liquid L ) Or (b) under the condition, perform load compatible operation using two heat sources together,
When the condition (c) or (e) is satisfied, the load-corresponding operation of the first heat source alone is executed, and when the condition (d) or (f) is satisfied, the load-corresponding operation of the second heat source alone is executed. is there.

Further, whether or not the defrosting operation is necessary is determined based on the detection information of the frost sensor S3, and when the defrosting operation is required, the defrosting operation is given priority over each load corresponding operation for a predetermined time ( Or until the completion of defrosting is detected by the frost sensor S3), and at that time, the temperature t2 of the heat source side heat transfer medium L detected by the liquid temperature sensor S2 is the set threshold temperature Y'for defrosting.
In the above case, the second heat source defrosting operation is performed, while the temperature t2 of the heat source side heat transfer medium L detected by the liquid temperature sensor S2.
Is less than the set threshold temperature Y'for defrosting, the load heat source defrosting operation is performed.

Under each of the above conditions (a) to (f), the first set threshold temperature X is the first heat source when the first heat source heat exchanger 2 is solely functioning as the evaporator E. The temperature of the outside air A when the heat exchanger 2 can extract a predetermined lower limit amount of heat from the ventilation outside air A (for example, the first heat source heat exchanger 2
The temperature is about 1 ° C. higher than the refrigerant evaporation temperature in the second heat source, and the second set threshold temperature Y is similarly set to the second heat source in the situation where the second heat source heat exchanger 3 is independently functioning as the evaporator E. The temperature of the heat-source-side heat-transfer liquid L when the heat of the heat-source-side heat-transfer liquid L can be extracted from the heat-source-side heat-transfer liquid L (for example, about 1 ° C. higher than the refrigerant evaporation temperature in the second heat-source heat exchanger 3). High temperature).

Further, the first and second set temperature differences Z1, Z2
As an example, a temperature difference of 5 ° C to 10 ° C can be mentioned.

Further, the set threshold temperature Y'for defrosting is
Similar to the second set threshold temperature Y, in the second heat source heat exchanger 3 in the situation where the second heat source heat exchanger 3 is independently functioning as the evaporator E, a predetermined defrosting is performed from the heat source side heat transfer liquid L. Is the temperature of the heat source side heat transfer liquid L when the lower limit amount of heat can be collected,
A typical example is a temperature equal to the second set threshold temperature Y.

In order to switch the operation between the above-mentioned three load-corresponding operations, strictly speaking, the above conditions (a) to (f) are strictly transmitted between the two load-corresponding operations. Hysteresis is provided to prevent repeated switching.

Further, the above two heat source heat pump device HP
Then, although the heat source side heat transfer medium pump P1 and the load side heat transfer medium pump P2 are stopped, a pump interlock for stopping the operation of the compressor 1 and stopping the refrigerant circulation operation is provided. When the heat source side heat medium pump P1 or the load side heat medium pump P2 is stopped in each of the operation, the second heat source defrosting operation, and the load heat source defrosting operation, the pump interlock for the stopped pump is released. is there.

The temperature of the heat medium L on the heat source side is detected for a predetermined time at regular intervals during the load-corresponding operation of the first heat source alone for stopping the operation of the heat medium pump P1 on the heat source side and the defrosting operation of the load heat source. A detection method such as operating the side heat medium pump P1 is used.

The expansion valve mechanism 7 has a first diameter different from the first diameter.
-Third series connection circuits 7a-7c formed by connecting the first to third electromagnetic on-off valves va-vc separately in series to the third needle valves ea-ec are connected in parallel,
By selectively opening the first to third electromagnetic on-off valves va to vc in a state where the opening degrees of the needle valves ea to ec functioning as expansion valves are fixedly adjusted in advance, the expansion valve mechanism 7 can be operated. The expansion valve opening as a whole is changed.

On the other hand, in any of the refrigerant circulation modes for the load-corresponding operation and the defrosting operation in the refrigerant circuit, the low pressure side of the three heat exchangers 2, 3 and 4 is always located at the most downstream position of the refrigerant path. The liquid-filled second heat source heat exchanger 3 is equipped with a liquid level sensor 11 that detects the liquid level of the liquid-phase refrigerant R that has not evaporated and remains in the container, whereas the controller 10 The expansion valve control means is configured to automatically change one of the first to third electromagnetic on-off valves va to vc in the expansion valve mechanism 7 that is in an open state, based on the liquid level detected by the liquid level sensor 11. I am doing it.

That is, by automatically adjusting the expansion valve opening of the expansion valve mechanism 7 as a whole based on the detected liquid level of the liquid-phase refrigerant R in the full-heat type second heat source heat exchanger 3 as described above,
The opening degree of the expansion valve is adjusted appropriately to an opening degree suitable for the heat-collecting source situation at that time, thereby reliably avoiding troubles such as low pressure abnormality and liquid backing, and
It enables stable equipment operation while maintaining high operation efficiency.

[Other Embodiments] Next, other embodiments will be listed.

In the implementation of the invention according to claim 1, the first
The first heat source heat medium A for exchanging heat with the refrigerant R in the heat source heat exchanger 2, the second heat source heat medium L for exchanging heat with the refrigerant R in the second heat source heat exchanger 3, and the refrigerant R and heat in the load heat exchanger 4. The load heat mediums M to be exchanged are not limited to atmospheric air and heat medium liquids, and may be any heat mediums regardless of gas, liquid or solid.

In the load corresponding operation of the first heat source alone, the load compatible operation of the second heat source alone, the second heat source defrosting operation, and the load heat source defrosting operation, the first heat source heat exchanger 2 and the second heat source heat exchanger In order to bring the heat exchanger 3 or the load heat exchanger 4 into the function-disabled state, the above-described embodiment shows the method of bringing the heat exchanger into the function-disabled state by stopping the supply of the heat medium to the heat exchanger to be stopped. However, instead of this, a method may be adopted in which the heat supply of the heat exchanger to be stopped is stopped so that the heat exchanger is stopped.

The two-source heat pump device according to the present invention is
Not limited to snow melting, it can be applied to various fields that require heat.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing a device configuration of a snow melting device.

FIG. 2 is a circuit diagram showing the flow of refrigerant in a load-compatible operation using two heat sources together.

FIG. 3 is a circuit diagram showing the flow of refrigerant in a load-only operation of the first heat source alone.

FIG. 4 is a circuit diagram showing the flow of refrigerant in a load-only operation of the second heat source alone.

FIG. 5 is a circuit diagram showing a refrigerant flow in a second heat source defrosting operation.

FIG. 6 is a circuit diagram showing a refrigerant flow in a load heat source defrosting operation.

[Explanation of symbols]

2 First heat source heat exchanger 3 Second heat source heat exchanger 4 load heat exchanger 10 Control means A first heat source heat medium, atmospheric air C condenser E evaporator L second heat source heat medium M load heat medium R refrigerant

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) F25B 47/02 570 F25B 47/02 570A

Claims (2)

[Claims] 1. A load heat exchanger for exchanging heat between a refrigerant and a load heat medium, a first heat source heat exchanger for exchanging heat for a refrigerant with a first heat source heat medium, and a heat exchange for a refrigerant with a second heat source heat medium. A second heat source heat exchanger is provided, and the first and second heat source heat exchangers are caused to function as an evaporator in a state in which the refrigerant is allowed to pass through the first and second heat source heat exchangers in series. In the load compatible operation of using two heat sources in combination, in which the load heat exchanger functions as a condenser to heat the load heat medium while collecting heat from both of the heat medium, and the second heat source heat exchanger is deactivated. A load-corresponding operation of the first heat source alone that causes the first heat source heat exchanger to function as an evaporator and collects heat from the first heat source heat medium, while causing the load heat exchanger to function as a condenser to heat the load heat medium; With the first heat source heat exchanger stopped functioning, the second heat source heat exchanger functions as an evaporator. The load heat exchanger functions as a condenser to heat the load heat medium while collecting heat from the second heat source heat medium, and the second heat source alone can be switched to a load-corresponding operation. A control means is provided for automatically switching between load compatible operation using the heat source together, load compatible operation of the first heat source alone, and load compatible operation of the second heat source alone according to the temperature of each of the first and second heat source heat mediums. The heat pump device according to any one of the following conditions (a) to (f): t1 ≧ X and t2 ≧ Y and t1 ≧ t2 and Δt <Z1 (A) t1 ≧ X and t2 ≧ Y and t1 ≦ t2 and Δt <Z2 ... (B) t1 ≧ X and t2 ≧ Y and t1> t2 and Δt ≧ Z1 ... (C) t1 ≧ X and t2 ≧ Y and t1 <t2 and Δt ≧ Z2 ... (D) t1 ≧ X and t2 <Y (E) t1 <X and t2 ≧ Y (f) where t1: temperature of the first heat source heat medium t2: temperature of the second heat source heat medium Δt: first heat source heat medium and second heat source heat Temperature difference with medium X: First set threshold temperature Y: Second set threshold temperature Z1: First set temperature difference Z2: Second set temperature difference First and second heat source heat medium is (a) or (b) When the condition is met, a load-corresponding operation using two heat sources is performed, and when the first and second heat source heat mediums are in the condition (c) or (e), the load-corresponding operation of the first heat source alone is performed, And a heat pump device configured to perform a load-corresponding operation of the second heat source alone when the second heat source heat medium is in the condition (d) or (f). 2. The second heat source heat exchanger with the load heat exchanger stopped in addition to the above-described switching operation for each load operation, while the first heat source heat medium is atmospheric air. Second heat source defrosting operation in which the first heat source heat exchanger functions as a condenser to radiate heat while the heat is taken from the second heat source heat medium by causing the second heat source heat exchanger to function as an evaporator, and the second heat source heat exchanger to stop functioning. In this state, it is possible to perform switching from load heat source defrosting operation in which the load heat exchanger functions as an evaporator and heat is taken from the load heat medium while the first heat source heat exchanger functions as a condenser to radiate heat. When the defrosting operation is performed by prioritizing the operation corresponding to each load when defrosting the first heat source heat exchanger is required, the control means sets the temperature t2 of the second heat source heat medium to a set threshold for defrosting. When the temperature is equal to or higher than Y ', the second heat source defrosting operation is performed to The heat pump apparatus according to claim 1, wherein you have to configure to implement load heat source defrosting operation when the temperature t2 is set threshold temperature less than Y 'for defrosting the medium.