JPH0659748A - Temperature control method of heat storage tank in cogeneration system - Google Patents

Abstract

PURPOSE:To perform the backup of heat reservoir equipment groups by a simple control and to eliminate temperature irregularity in a heat storage tank for also an arbitrary heat reservoir equipment, in a system including a cogeneration system, a heat pump, a boiler and the heat storage tank. CONSTITUTION:The heat load QL side and the heat reservoir equipment groups output side are composed via a heat storage tank ST, a cogeneration system CGS, a heat pump H an a boiler B as heat reservoir equipments are connected with the heat storage tank ST equally and in parallel, feeding water is performed by constant flow rate pumps PH, PB, PC from the tanks of the both ends of a high temperature tank and a low temperature tank, via three way valves VH, VB, VC, on all of the load side and the heat reservoir equipment side, the mixture ratio by the three way valves VH, VB, VC is controlled so that the same return hot water temperature may be on the heat reservoir equipment groups side and the mixture ratio by a three way valve VL can be controlled so that arbitrary supply water temperature may be obtained on the load side.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cogeneration system and a combined heat and power supply system in which a plurality of heat source units of a heat pump and a boiler are combined with a heat storage tank, and more particularly to a temperature control method for the heat storage tank in the cogeneration system. .

[0002]

2. Description of the Related Art FIG. 3 shows, for example, "cogeneration".
(Vol. 4, No. 2, 1989, P25 to P30) is a system diagram showing the optimum operation of the heat storage tank in the conventional cogeneration system shown in the figure, in which DG is a diesel engine generator and RE is an electric turbo. Refrigerator, RW is hot water absorption refrigerator, BA is hot water boiler, R
A is an oil-fired air conditioner, PC, PD, PH, PT, PW are various pumps, CT is a cooling tower, and ST is a heat storage tank.

Next, the operation will be described. In FIG. 3, the chain double-dashed line indicates the flow of fuel, and the heavy fuel oil A is input to the diesel engine generator DG, the hot water boiler BA, and the oil-fired air conditioner RA. Electric power is generated by the diesel engine generator DG,
Exhaust heat is recovered and stored in the heat storage tank ST. The hot water in the heat storage tank is used to obtain cold water by the hot water absorption refrigerator RW to meet the cooling demand. Furthermore, the hot water in the heat storage tank is used for heating and hot water supply. If there is still excess, excess heat is discarded in the cooling tower CT. When the demand for heating and the demand for hot water supply cannot be met, the oil-fired air conditioner RA and hot water are supplied from the boiler BA.
Further, the cooling demand is covered by the oil-fired air conditioner RA and the electric turbo refrigerator RE.

[0004]

Since the conventional method of operating the heat storage tank in the cogeneration system is configured as described above, it does not function as a joint between the load side and the heat source side, There is a drawback that it can only have a buffer function of the cogeneration system and does not contribute to the selection and control of the heat source machine group including other heat source machines, and since the backup system at the time of failure is not considered, There was a problem that the control was complicated and the reliability was poor, and the combination of control with the heat storage tank was not clear.

The present invention has been made in order to solve the above problems, and a heat storage tank is arranged between the load side and the heat source side to serve as a joint between the two, and the entire heat source unit group is provided. Cogeneration system that can control the capacity of the heat storage tank, can easily meet the demand on the load side by simple control such as heat source model selection and backup at the time of failure, and can easily control the temperature in the heat storage tank. An object of the present invention is to provide a method for controlling the temperature of a heat storage tank.

[0006]

A method for controlling the temperature of a heat storage tank in a cogeneration system according to the present invention is a cogeneration system, a heat pump, and a combined heat and power system including a plurality of heat sources of a boiler, via a heat storage tank, The heat source side sucks cold water from the low temperature tank and hot water from the high temperature tank through the three-way valve, and connects the heat source devices in parallel so that all the heat source devices have the same output hot water temperature, and the load side. Is to supply hot water from the high temperature tank side and cold water from the low temperature tank side through a three-way valve, respectively, and supply them at an arbitrary temperature.

[0007]

According to the present invention, in a heat source supply system including a cogeneration system and a plurality of heat sources of a heat pump and a boiler, a heat storage tank separates a load side and a heat source machine side, and the load side also has a plurality of heat source machine sides. All of the high temperature tank and the low temperature tank are supplied with water from the tanks at both ends via a three-way valve with a constant flow pump, the heat source machine group side controls the mixing ratio by the three-way valve so that the return hot water temperature is the same, and the load side The mixing ratio by the three-way valve is changed so that an arbitrary supply water temperature can be obtained.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. In Figure 1, CGS cogeneration system, B is the boiler, H is the heat pump, Q _L is the thermal load,
ST is the heat storage tank, θ _ST is the temperature level inside the heat storage tank, and P _C and P
_H, P _L, respectively P _{B pump, V C, V H, V} L,
Each V _B is a three-way valve.

FIG. 2 is a thermoelectric generation diagram of the CGS of the engine-driven cogeneration system. The horizontal axis Q _h is the heat generation amount, the vertical axis W is the power generation amount, a is the thermoelectric generation line, and X is
₁ and X ₂ are thermoelectric load demand points, and Y ₁ and Y ₂ 'are operating points of the cogeneration system. Q _ST1 indicates that excess heat is generated, and Q _ST2 indicates the amount of heat collected from the heat storage tank.

As shown in FIG. 1, through the heat storage tank ST,
It is configured by being separated into a load side and a heat source machine group side. In the heat storage tank ST, the left end is a high temperature tank and the right end is a low temperature tank. The heat load Q _L side so make any hot water through the three-way valve V _L to the constant flow rate pump P _L.
On the heat source side, a cogeneration system CGS, a heat pump H, and a boiler B are connected in parallel, and constant flow pumps P _C , P _H , and P _B are three-way valves V _C and V, respectively.
It is connected via _H and V _B , and the outlet water temperature is controlled to be a constant high temperature.

Therefore, in response to the demand for X ₁ having a small thermoelectric load ratio in FIG. 2, the cogeneration system CGS operates at Y ₁ following the power load W _L , and the surplus heat Q _ST1 is stored in the heat storage tank ST. . On the other hand, X _{2 with} a large thermoelectric load ratio
= Q _L / W _L , part of the heat load Q _ST2 is stored in the heat storage tank ST
Since the heat is radiated from the heat source, the deemed heat demand required for the cogeneration system is Q _h 'and the necessary thermoelectric demand point is X ₂ '. An intersection Y between a thermoelectric generation line a and a straight line 1 passing through the thermoelectric demand point X ₂ 'and having a slope of 1 / COP
₂ 'is the operating point of the cogeneration system. The cogeneration system in FIG. 1 is the same for a diesel engine, a gas engine drive, and a gas turbine drive system, and the fuel cell cogeneration system is also the same.

Therefore, according to the above embodiment, regardless of the type of the heat source machine, a constant high temperature tank is caught, and a sudden load change is caused by an arbitrary mixing ratio of the high temperature and the cold water in the low temperature tank. It is possible to provide a reliable temperature control method that can cope with the above problem and can predict the amount of stored heat with little temperature variation in the heat storage tank.

[0013]

As described above, according to the present invention, the load side and the heat source machine group side are constituted by the heat storage tanks, and both the load side and the heat source machine side are tanks at both ends of the high temperature tank and the low temperature tank. From the three-way valve through a constant flow pump, and the heat source machine group side controls the mixing ratio by the three-way valve so that the same return hot water temperature is obtained.
Regardless of the type of heat source crisis side, a constant high temperature tank can be obtained, the temperature inside the heat storage tank is less uneven, and the amount of heat storage can be predicted with good controllability and high reliability.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a cogeneration system, a heat pump, a boiler, and a heat storage tank according to an embodiment of the present invention.

FIG. 2 is a thermoelectric generation diagram of an engine-driven cogeneration system.

FIG. 3 is a configuration diagram of a system including a heat storage tank in a conventional cogeneration system.

[Explanation of symbols]

CGS engine driven cogeneration system ST heat storage tank H heat pump COP coefficient of performance B boiler θ heat load X ₁ , X ₂ thermoelectric (load) demand point Y ₁ , Y ₂ 'cogeneration operation point Q _ST1 surplus heat Q _{ST2 from} heat storage tank use heat a thermoelectric generator linear _{P H, P B, P C} , P L pump _{V H, V B, V C} , V L three-way valve

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location H02J 11/00

Claims (1)

[Claims] 1. A cogeneration system comprising a cogeneration system and a plurality of heat sources of a heat pump and a boiler, wherein a heat source side has a three-way valve for supplying cold water from a low temperature tank and hot water from a high temperature tank through a heat storage tank. The heat source units are connected in parallel so that all the heat source units have the same output hot water temperature.On the load side, hot water is supplied from the high temperature tank side and cold water is supplied from the low temperature tank side via three-way valves. A method for controlling the temperature of a heat storage tank in a cogeneration system, which comprises mixing and supplying the mixture at an arbitrary temperature.